Heating an outdoor pool
deano
pool.
It came as a pre-fabbed product that was hoisted into position over his
house,
using a large crane (the video of this happening was pretty
impressive).
Now it's in situ and the pipes and manifold have been run to a shed
next to his house,
he's asked me about fitting a gas boiler into his shed to heat the
pool's water.
The pool company have suggested a combi boiler of 80,000btu output (to
heat the
20,000 litre capacity pool). This would mean using only the CH side of
the boiler and
dismissing the water-on-demand, HW functions of the boiler. (not too
sure what repercussions
this might have or even how to facilitate such use).
I'd be interested in your opinions, advice, recommendations as to a
sensible solution, even
if involving alternative heating methods, as long as they were
comparable to installing an additional gas
(combi boiler), in terms of cost, timescale and feasability. i.e.
realistic and not "in an ideal world" type solution. He is interested
in cost, time, ease of maintenance and future servicing.
I've read a bit about solar heating (even if combined with part fuel
supply for the winter months) but I don't want to overcomplicate
something he wants to embark upon in the very near future.
In a nutshell, his pool supplier suggested a combi and I need a very
good reason to suggest otherwise to him.
Look forward to your replies.
rgds,
deano.
meow...@care2.com
> In a nutshell, his pool supplier suggested a combi and I need a very
> good reason to suggest otherwise to him.
thats easy. Full solar pool heat has much lower install cost, simpler
so easy to diy, and much lower run cost.
NT
Andy Hall
>
> The pool company have suggested a combi boiler of 80,000btu output (to
> heat the
> 20,000 litre capacity pool). This would mean using only the CH side of
> the boiler and
> dismissing the water-on-demand, HW functions of the boiler. (not too
> sure what repercussions
> this might have or even how to facilitate such use).
It's always a little concerning when suppliers make recommendations and
mix the units of measurement. 80,000BTU is 23.5kW in proper units....
Anyway... the question is then the ability of the boiler to heat
20,000 kg of water.
It takes 4200 Joules to raise the temperature of 1kg of water by one
degree centigrade, so for this lot, so 84 million Joules.
A Watt is defined as one Joule/sec, so it means that a 23.5kW boiler
will take 3574 seconds or about an hour per degree of temperature rise.
Of course, this assumes no heat loss at all....
The timescale may be reasonable, but is he ready for the cost?
deano
But how big are such panels? How many are needed? and what sort of
siting do they need?
The garden is to be landscaped and the pool is not covered, except for
a temporary plastic tent type thing that can be opened over the top of
it, like a section of a tyre (with side walls).
DH.
Codswallop
Several options available
(http://www.poolboy.co.uk/swimming_pool_heating.htm), lots of info here:
http://tinyurl.com/yxvrlg . Do you feel competent to advise him on this?
The Wanderer
> A friend has asked my advice on heating his newly installed outdoor
> pool.
<snip>
> The pool company have suggested a combi boiler of 80,000btu output (to
> heat the
> 20,000 litre capacity pool).
Just for comparison, take a look at the Thermalec site
http://www.thermalec.co.uk/en/index.htm
I've used Thermalec heaters with pools at 2 properties now, and I see
little point in changing. I reckon to get something like 20 weeks or so
with the pool around 28 - 30 C for about £500 per annum - it used to be
much less, but energy prices creep up relentlessly!
The most important thing for your friend is to buy a solar blanket for the
pool if it wasn't supplied with one. It reduces heat loss when the pool
isn't in use, and there's actually a quite significant passive solar gain
using a blanket - the top 6" or so of water is usually noticeably warmer
when the cover comes off. To maximise the solar gain, he needs to pump
whenever the sun is out, to circulate any heat gain through the pool. My
pool will peak at about 33 C at the height of summer.
You'll see plenty who'll advocate solar panels, but remember there are
other considerations. I had solar panels at my present place, installed by
a previous owner. I removed them, as they covered a significant corner of
the poolside area and the area underneath was gloomy and dank.
If there's a corner of the garden where they could be installed without a
problem, then solar is worth considering if you can pump the pool water
directly through them, but forget it if space is a problem. Solar panels
any height above the pool will almost certainly require a change in pump
size to lift the water. Commercial systems will probably use a separate
heating circuit with heat exchanger for the pool water.
--
the dot wanderer at tesco dot net
Christian McArdle
> good reason to suggest otherwise to him.
Here's several good reasons.
1. Same price to install.
2. MUCH lower cost to run.
3. Isn't a needless and profligate waste of the planet's resources.
4. Won't cause global warming.
Christian.
Peter Parry
wrote:
>meow...@care2.com wrote:
>> thats easy. Full solar pool heat has much lower install cost, simpler
>> so easy to diy, and much lower run cost.
>But how big are such panels? How many are needed? and what sort of
>siting do they need?
Solar pool heating is somewhat of a no-brainer as the low temperature
rise needed makes solar very effective. Partly the pool can be
heated and insulated by getting a suitable cover which maximises
insulation and solar gain - something like those described in
<http://www.eere.energy.gov/consumer/your_home/water_heating/index.cfm/mytopic=13140>
(That site has a lot more information on heating pools)
The greatest loss of heat from a pool occurs from its surface because
of evaporation, the cover eliminates this loss when the pool is not
in use.
Swimming pool take huge amounts of energy to heat them and solar
alone will usually not be sufficient to heat the pool in the UK
unless the collectors are of very large size. However it makes a
useful contribution and is the only solar heating energy system with
a payback time significantly less than its lifetime.
For solar heating you don't even need solar panels - a black pipe
collection system works well as the low temperature means low heat
losses. A matt black pipe (or pipes) (hosepipe really) placed around
the landscaping can be both unobtrusive and effective. More
efficient in that it gathers more heat for a smaller area is the
black polypropylene plastic collector - basically a semi flexible
plastic sheet. Front glazing as used on conventional hot water
panels is not essential as the temperature is so low so they go well
on the roof of sheds, garages etc. Using higher performance panels
such as the Navitron makes the installation smaller. Two panels each
of 2.25m2 would make a very significant contribution to the pool
heating needs (Navitron say it would suffice on its own for an 11m2
pool)
http://www.navitron.org.uk/solar_collector_panel.htm
Using gas as suggested as the other source of heating makes sense. I
presume some sort of stainless steel heat exchanger is included in
the proposal?
Electric heating is the worst possible way to go. Although it may be
the cheapest to install the running costs are by far the highest and
quickly wipe out the savings on installation.
http://www.builditsolar.com/Projects/PoolHeating/pool_heating.htm
has links to a lot of information on solar pool heating.
http://www.pacificgunite.com/solar%20pool%20heating.htm is one way of
integrating the heating with the structure.
http://www.powermat.com/pools/index.html
http://www.fsec.ucf.edu/solar/APPS/POOLHTG/en6.htm#Collectortypes
--
Peter Parry.
http://www.wpp.ltd.uk/
The Wanderer
<snip>
> Electric heating is the worst possible way to go. Although it may be
> the cheapest to install the running costs are by far the highest and
> quickly wipe out the savings on installation.
It would have been much better, and would lend some credence to your
argument, if you supplied references (applicable to the UK, for instance
using E7 night-time units, and not nice warm sunny, southern US states) to
substantiate your claim. As it stands, it appears to be no more than
prejudice.
Peter Parry
wrote:
>On Fri, 13 Oct 2006 11:16:22 +0100, Peter Parry wrote:
>
><snip>
>
>> Electric heating is the worst possible way to go. Although it may be
>> the cheapest to install the running costs are by far the highest and
>> quickly wipe out the savings on installation.
>
>It would have been much better, and would lend some credence to your
>argument, if you supplied references (applicable to the UK, for instance
>using E7 night-time units, and not nice warm sunny, southern US states) to
>substantiate your claim.
OK - depending upon where you are in the UK electricity (off peak) is
somewhere between 3.5 - 7p a unit. Using your figure of a cost of
about GBP500 per annum that comes out at roughly 16,600 kWh at the
lower price or 8,300kWh at the higher one.
Using the expensive option of 4 Navitron panels (costing GBP1,600)
plus a few bits and pieces the solar installation would cost about
GBP2,000 (with DIY fitting). That would provide about 5,000 kWh per
season (probably somewhat more as the only information I have to hand
is for hot water systems and the solar panel efficiency is better at
the much lower pool temperatures) or just under one third of the
requirement and save you about GBP150 per year at the lower boundary
of the current electricity price or GBP300 at the higher one. Taking
a very simplistic calculation and assuming that interest rates and
fuel price rises will broadly cancel each other out that gives a
payback of 13 years at the lower price or half that at the higher.
meow...@care2.com
> On Fri, 13 Oct 2006 12:47:48 +0100, The Wanderer <m...@privacy.net>
> wrote:
> >On Fri, 13 Oct 2006 11:16:22 +0100, Peter Parry wrote:
> Using the expensive option of 4 Navitron panels (costing GBP1,600)
> plus a few bits and pieces the solar installation would cost about
> GBP2,000 (with DIY fitting).
But why would anyone spend that on pool panels. Pool heating uses very
low temp rise, so the simplest of panels will work nicely. Dark
coloured hosepipe and polythene film work just fine, anything better is
mainly for cosmetic reasons. Simple black panels with neat glass covers
dont cost anywhere near 2k.
Pool heating can be set up for £200 if electricity is already
available for the pump. That gives ROI in the region of 50-100% pa,
depending on other heating method options. Glass covered panels will
add to the cost, but its still very cheap compared to gas or oil..
Re calculations, I'd suggest asking advice in alt.solar.thermal. Or
crossposting this thread to there. How much of the year solar will heat
for you depends on your panel area and design, whether youve got
electronic pump control or something basic, whether you have a pool
cover and so on. I woudl suggest doing all you can to make good use of
solar before adding fuel heating on, as its a much better option and if
designed ok can heat the pool for as long as people are likely to want
to use it outdoors.
Panels can go at ground level, on rooftops, under glass roofing, pipes
can be embedded in dark coloured hard surfacing, fencing can be made
from or covered with solar panelling, and so on. And at its simplest
you can even run a dark hosepipe along the front of your flower
borders, where it wll see the sun. In most properties big enough to
have a pool, that gives quite a lot of heating area.
You can have a pump on a plug in timer initially, just to see some
result. Adding a thermostat set to 30C onto the panels and a 2nd pool
stat set to your desired temp limit will get max result from min
pumping cost. A differential stat will give you a bit more output
still.
NT
Peter Parry
>Peter Parry wrote:
>> On Fri, 13 Oct 2006 12:47:48 +0100, The Wanderer <m...@privacy.net>
>> wrote:
>> >On Fri, 13 Oct 2006 11:16:22 +0100, Peter Parry wrote:
>
>> Using the expensive option of 4 Navitron panels (costing GBP1,600)
>> plus a few bits and pieces the solar installation would cost about
>> GBP2,000 (with DIY fitting).
>
>But why would anyone spend that on pool panels. Pool heating uses very
>low temp rise, so the simplest of panels will work nicely. Dark
>coloured hosepipe and polythene film work just fine, anything better is
>mainly for cosmetic reasons. Simple black panels with neat glass covers
>dont cost anywhere near 2k.
I agree, I was simply using the most expensive option to show that
even then there are obvious advantages. As you say effective systems
can be made for far less.
Owain
> Using the expensive option of 4 Navitron panels (costing GBP1,600)
> plus a few bits and pieces the solar installation would cost about
> GBP2,000 (with DIY fitting). That would provide about 5,000 kWh per
> requirement and save you about GBP150 per year at the lower boundary
> of the current electricity price or GBP300 at the higher one.
Probably rather more savings, because solar power will be greatest
during the day when the pool is most likely to be in use and when the
ambient temp is higher.
Off-peak electricity will be heating the pool at night, when the ambient
temperature is at its lowest, and the pool is (working on the storage
heater principle) likely to be at its hottest at 7 am. It's most likely
to be used in the afternoons and evenings, by which time a lot of the
stored heat will have been lost.
Owain
meow...@care2.com
> On 13 Oct 2006 10:00:33 -0700, meow...@care2.com wrote:
> >Peter Parry wrote:
> >> On Fri, 13 Oct 2006 12:47:48 +0100, The Wanderer <m...@privacy.net>
> >> wrote:
> >> >On Fri, 13 Oct 2006 11:16:22 +0100, Peter Parry wrote:
> >> Using the expensive option of 4 Navitron panels (costing GBP1,600)
> >> plus a few bits and pieces the solar installation would cost about
> >> GBP2,000 (with DIY fitting).
> >
> >But why would anyone spend that on pool panels.
> I agree, I was simply using the most expensive option to show that
> even then there are obvious advantages.
Ah, I see.
NT
David Sims
degree celsius in that time
Low rate electricity has a further benefit in that running the pump for
the filter is mandatory and this can use the low rate as well
We pay 2.6p (+5% vat) per unit off peak
deano
me, I love a challange and with access to the amassed knowledge and
experience, and the kind help, of the many who frequent this ng, I'm
completely confident I can deliver on this project. If you have the
time, please read on...
Peter Parry wrote:
> Solar pool heating is somewhat of a no-brainer as the low temperature
> rise needed makes solar very effective. Partly the pool can be
> heated and insulated by getting a suitable cover which maximises
> insulation and solar gain - something like those described in
> <http://www.eere.energy.gov/consumer/your_home/water_heating/index.cfm/mytopic=13140>
Thanks Peter, some great and very concise info there, and with links
for me to do some further reading.
> Using gas as suggested as the other source of heating makes sense. I
> presume some sort of stainless steel heat exchanger is included in
> the proposal?
My friend tells me that everything 'for the pool' was supplied and
installed by the pool company and, when asked what else was needed,
their response was "you only need a boiler, to connect up to the system
we have installed. This can be either a combi boiler or a standard
boiler (with a pump) and it needs to be able to have an output of
80,000btu to cope with the 20,000 litre capacity of the pool".
I assume that they don't get too involved in that side of the
installation and stick to just supplying the pool and directly
associated components. Their advice to him about heating the pool was
probably just relaying what most of their existing clients had done to
heat pools they've supplied.
Knowing my pal, this was very much a leap before you look purchase (he
has the resources to be able to do that, bless him) and his reason for
getting me involved was because he knew I'd do the homework before
spending his money. I've been tasked with installing the necessary for
him (not for free I might add, but it'll still be at mate's rates)
because he knows I'll do a thorough job and won't rip him off.
Straight off the bat, I have called for some time out before turning up
in the van, with tools on board, in order for me to do some research on
a suitable solution for both the short and long term usage of the pool.
The pool being currently in situ and full of water, he is under some
pressure from his 9 and 5 year old (and therefore his wife) to get it
useable ASAP. However, the garden landscaping will not be completed for
quite some time and all is still at the groundworks stage, as his
garden was quite high up from the house and a lot of muck has been, and
is being, removed.
So, his thinking is to cordon off the pool area so that the kids can
use it, and I was wondering what I could do temporarily to get some
heat into the pool. I've had a quote for a combi boiler and also for a
system boiler... the combi is a lot cheaper than the system boiler,
they sell more I suppose, hence the lower price. Both are about
24-25kw, which will give the 80kbtu. Obviously the combi is the cheaper
option, but I'm not sure what, if anything, needs to be done to
decommission the HW side of the unit. Do I just leave it unconnected or
install capped feed and return pipes?
Also, would it be reasonable to assume that I could run the boiler by
tapping into the nearest source of gas and electricity for now with the
intent to reconfigure at a later date? To explain, the shed which will
house the boiler, consumer unit and pool systems is at the side of the
house. I can get gas from a 15mm copper pipe that supplies a gas fire
on the other side of the wall, and for the electricity, I can run a
spur from the outside security lights, as they are on their own circuit
straight from the main domestic consumer unit, although this is likely
a radial circuit rather than ring main. Would there be enough gas
pressure and electrical power from these sources to run the boiler for
a few weeks without causing problems?
Eventually, my pal wants to run all sorts of lighting, power outlets,
internet access points and speaker setups in the completed garden, he's
also considering mains supplied patio heaters, barbeque and (get this)
'fire features' as well as water features. I am unable to devise a
system for this right now, as his designers have not yet put forward
their proposal for these installations, so I don't know what products
will be used nor how many and what are their requirements.
To cope with this final load, I have suggested that, when the time
comes for the patio, adjacent to the back of the house, to be uprooted,
we take the opportunity to put in a yellow plastic gas pipe and a
suitably sized armoured cable. These will run from the shed to the
other side of the house where the main gas supply is located and there
is easy access to the domestic consumer unit, meter and tails. When the
garden is finished and the various systems have been designed and
installed, the boiler and consumer unit connections can then be moved
over to the higher capacity gas and power feeds, to cope with the
additional loads from the whole garden.
Does this sound like a plan? Is it likely that the temporary gas and
electricity supply will be able to cope with the demands from the
boiler? Obviously, the greatest draw on the gas and power supplies will
be during the initial heating period, up from the ambient temperature
to a comfortable bathing level. Some 25hrs or so as indicated by Andy
Hall's earlier post to this thread, therefore, during this period, I
can ensure that no other gas appliances are used within the house,
keeping pressure as high as possible (through routed 15mm copper) for
the boiler. As I said above, I'm a bit dubious about the electrical
supply, spurred from the exterior security lights, being up to the
task. But that's easy enough to find out from the boiler manufacturers.
Appreciative of my efforts and receptive to my advice, my friend will
go along with whatever I suggest. However, I'd really like to be able
to give him a short-tern fix and get the pool useable, via a temporary
connection ASAP, followed by a permanent installation. If this is a bit
hair-brained, or fly-by-nightish then I'll tell him to be patient and
put it straight to his kids... you know what they're like... pool's
coming, pool's coming, pool's here, pool's in, it's in... whoopeee...
can't use it!
Many thanks for all the useful replies.
deano.
Andy Wade
> OK - depending upon where you are in the UK electricity (off peak) is
> somewhere between 3.5 - 7p a unit.
At least one supplier has much better prices than that on the E7 night
rate. Look at the British Gas (YIK) 'Click Energy' tariff: 2.062 -
2.689 p/kWh (inc. VAT) depending on region. The day rate price is high
of course, but the tariff could still be a good choice if a substantial
fraction of your consumption is at the night rate.
--
Andy
fred
>, deano <de...@yesits.freeserve.co.uk> writes
central heating (hopefully gas). One zone valve, one stat, one plate heat
exchanger, a loop of insulated MDPE pipe to the pool and a pump
(possibly the pool's existing circulation pump) and you're laughing. That'll
give you more time to play with clever solar or mixed systems and
certainly less dodgy than the shared 15mm gas connection and locking
appliances off ;-). It might even work as a permanent solution if there is the
spare capacity in the boiler and in the colder months or after the pool is up
to temp the heat exchanger feed could be throttled down to ease the load
on the boiler.
--
fred
Plusnet - I hope you like vanilla
John Rumm
> So, his thinking is to cordon off the pool area so that the kids can
> use it, and I was wondering what I could do temporarily to get some
> heat into the pool. I've had a quote for a combi boiler and also for a
> system boiler... the combi is a lot cheaper than the system boiler,
> they sell more I suppose, hence the lower price. Both are about
> 24-25kw, which will give the 80kbtu. Obviously the combi is the cheaper
> option, but I'm not sure what, if anything, needs to be done to
> decommission the HW side of the unit. Do I just leave it unconnected or
> install capped feed and return pipes?
Depends a bit on the boiler. Some may have an inhibit on mains water
failure.
Assuming you have a supply of mains pressure water available[1] then I
would hook it up to the inlet side anyway, and just connect a short pipe
to the outlet with a service valve on the end.
[1] Would be handy for filling the sealed system!
> Also, would it be reasonable to assume that I could run the boiler by
> tapping into the nearest source of gas and electricity for now with the
> intent to reconfigure at a later date? To explain, the shed which will
> house the boiler, consumer unit and pool systems is at the side of the
> house. I can get gas from a 15mm copper pipe that supplies a gas fire
> on the other side of the wall, and for the electricity, I can run a
> spur from the outside security lights, as they are on their own circuit
> straight from the main domestic consumer unit, although this is likely
> a radial circuit rather than ring main. Would there be enough gas
> pressure and electrical power from these sources to run the boiler for
> a few weeks without causing problems?
Gas would be a concern... lets do some sums:
Lets assume the boilers input energy is 24kW (as opposed to its output,
so we can ignore its efficency), 24kW is 24,000 joules / sec or 86.4MJ/hour.
Calorific value for natural gas is about 39 MJ / m^3, so you would need
a gas flow rate of say 0.615 l/sec or 0.22 m^3/hour
So if we look at:
http://www.cda.org.uk/megab2/build/pub124/sec3.htm#4.3%20Copper%20Tube%20Sizing
The discharge rate for 15mm pipe at a 1mbar pressure drop is listed as
2.9m^3 for a 3m effective pipe length or 1.9m^3 for a 6m one.
That would suggest a maximum effective pipe length from the meter to the
boiler of no more than about 4m (counting each bend as 0.3m or an elbow
at 0.5m equivilent)
The electrical load presented by the boiler will be low (under 3A) so is
less difficult. However all the normal precautions about running a power
supply to outbuildings would apply.
> To cope with this final load, I have suggested that, when the time
> comes for the patio, adjacent to the back of the house, to be uprooted,
> we take the opportunity to put in a yellow plastic gas pipe and a
> suitably sized armoured cable. These will run from the shed to the
> other side of the house where the main gas supply is located and there
> is easy access to the domestic consumer unit, meter and tails. When the
The gas supplier may appreciate it if you draw the gas from your mates
side of the meter rather than theirs... (although that would make the
pool heating much cheaper!)
> Appreciative of my efforts and receptive to my advice, my friend will
> go along with whatever I suggest. However, I'd really like to be able
> to give him a short-tern fix and get the pool useable, via a temporary
> connection ASAP, followed by a permanent installation. If this is a bit
> hair-brained, or fly-by-nightish then I'll tell him to be patient and
> put it straight to his kids... you know what they're like... pool's
> coming, pool's coming, pool's here, pool's in, it's in... whoopeee...
> can't use it!
I take it he has a gas boiler in the house for the CH etc? If so why not
use that as a temporary source of heating?
Have a look at the design that Andy implemented for supplying heat to a
outbuilding:
That way you could implement solar for the pool, with gas boiler for
backup / topup. The pool however would remain isolated from the house CH
circuit so no chance of compromising that, and also no need to take gas
or electrcity out to the shed for a temporary lash up.
you may find this thread interesting: http://tinyurl.com/y7hmls
--
Cheers,
John.
/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/
meow...@care2.com
> I was wondering what I could do temporarily to get some
> heat into the pool
A large length of dark flexible hose, preferably large diameter, 1"-2",
100ft or so. Lay it out in a spiral, with very roughly a pipes width of
space between each turn. Put sheet polythene on top, weighing it down
round the edges. Hook up a 100w pump and run during daylight hours.
Cheap basic setups like these will give plenty of heat. Something under
it would help a bit more too, even just sheet poly.
Be aware though that whatever the source, 20,000 litres is a huge
thermal store, and it will take many days to reach target temp if you
only install enough to keep it at target temp. Getting it there fast
would require another big spiral of pipe.
If you have a CH pump lying about, that would do to get it running.
People tend to install overly large pumps, wasting electricity. CH pump
is a bit low power, but the system will still run, still capture the
same heat, just lose a little more of it.
> Also, would it be reasonable to assume that I could run the boiler by
> tapping into the nearest source of gas and electricity for now with the
> intent to reconfigure at a later date?
no way Jose. 25kW is a serious load. To get it into perspective, a
lighting circuit is fused at 1.2kW or thereabouts.
Instead of putting a yellow gas pipe in from the house, you'd be better
to put 2 pipes in for warm water. That way if you want more heat,
you've got the options of adding panels to the house roof or gas.
You can make fire effects with solar tech too... :)
NT
Adrian
they were saying :
> So, his thinking is to cordon off the pool area so that the kids can
> use it, and I was wondering what I could do temporarily to get some
> heat into the pool. I've had a quote for a combi boiler and also for a
> system boiler... the combi is a lot cheaper than the system boiler,
> they sell more I suppose, hence the lower price. Both are about
> 24-25kw, which will give the 80kbtu. Obviously the combi is the
> cheaper option, but I'm not sure what, if anything, needs to be done
> to decommission the HW side of the unit. Do I just leave it
> unconnected or install capped feed and return pipes?
Wouldn't he (the missus/kids) like a nice hot shower at the poolside?
deano
options.
My leaning is currently towards gas combi in the shed with solar top-up
using
a suitable pool cover.
I liked the idea of a zone off the main house CH but this means more
disruption to the house, drawing from the house heating and possibly
overloading the boiler. Plus I still have to get the new zone out into
the garden and thru a heat exchanger with another circuit for the pool
to linkup with the HE. This is as involved as piping the gas main from
the meter [whichever side ;-)] to the shed. And would also provide for
the gas fired patio heaters and barbeque he's considering.
The black hosing is also a beautifully simple idea but he just doesn't
have the space.
Thermalac electric heater would be the simplest to install and if
£500pa to run it is less than the cost of a gas boiler/solar cover
combi and as instant then I'd certainly consider suggesting the use of
one to him... any numbers (£'s) on how the two systems compare?
On the route of gas fired boiler in the shed and thermal cover on the
pool, my main questions would be... how redundant would the boiler
become, once the pool was up to temp in the 'swimming season'? and
could the thermal/solar cover then be relied upon to the keep the water
at the desired temp? Do I have this right or will the gas fired heating
always be in demand throughout the period?
If the boiler is just to perform the role of starter motor, then it
follows that the use of one may be uneconomical, however I do believe
that my pal is looking for performance and results over economy and
environmental factors... sorry, not my criteria but his.
Still in favour of the gas to shed, firing combi boiler, route is the
desire for gas in the garden AND, in addition, using the HW side of the
combi boiler to facilitate a shower by the pool makes me feel better
that the combi is being fully utilised... and he gets another benefit,
albeit at additional cost :)
If we're talking hundreds of pounds difference between the options then
I need to make him aware, otherwise, he won't be that bothered and I'll
be making my own job harder for little return. Another caveat is that a
good friend of his already has a pool which he heats using a gas boiler
and performance comparisons are always gonna be made between the two of
them, before costs come into the equation. Plus his pool supplier
suggested a gas combi and so has another friend of mine.
You can see where I'm going with this... I don't want to end up giving
him a solution that meets my requirements and expectations but not his,
and I don't want to give myself unnecessary or unappreciated work!
Thanks for sharing your knowledge(s)
deano.
meow...@care2.com
> My leaning is currently towards gas combi in the shed with solar top-up
> using
> a suitable pool cover.
> The black hosing is also a beautifully simple idea but he just doesn't
> have the space.
Whats round the pool? Has it been surfaced yet? If not, you can use the
hard surfacing as a basic solar panel by putting pipes down before the
coccrete / tarmac / etc. This method has been used to provide full
heating before. Driveway, path etc can also be used if any is due to be
surfaced.
> On the route of gas fired boiler in the shed and thermal cover on the
> pool, my main questions would be... how redundant would the boiler
> become, once the pool was up to temp in the 'swimming season'? and
> could the thermal/solar cover then be relied upon to the keep the water
> at the desired temp?
a pool cover doesnt heat the water, it stops evaporation and provides a
little insulation. The sunlight that goes in through a cover was going
into the pool already.
> Do I have this right or will the gas fired heating
> always be in demand throughout the period?
If you want the water above average ambient temp, and theres no other
heating, then naturally yes.
> If we're talking hundreds of pounds difference between the options then
> I need to make him aware, otherwise, he won't be that bothered and I'll
> be making my own job harder for little return.
The difference is thousands, not hundreds. I get the feeling you've not
done the figures.
> You can see where I'm going with this... I don't want to end up giving
> him a solution that meets my requirements and expectations but not his,
> and I don't want to give myself unnecessary or unappreciated work!
why not do better and ask him what run cost he thinks would be
reasonable, then say if you can design and implement something
superefficient he gives you n% of what he saves over the next 3 years.
NT
The Wanderer
<snip>
>
> Thermalac electric heater would be the simplest to install and if
> £500pa to run it is less than the cost of a gas boiler/solar cover
> combi
Thermalec recommend using a solar cover with their heater. As others have
also said, the prime loss of heat occurs at the surface, the pool surface
size - x ft x y ft is far more relevant than the nominal capacity of the
pool. Ambient temperature and hours of sunlight will also have a bearing on
comfort levels.
> and as instant then I'd certainly consider suggesting the use of
> one to him... any numbers (£'s) on how the two systems compare?
I was actually quite late in opening my pool this year. It wasn't until
early June, coincidentally immediately after after I'd had my meter read. I
had another reading mid September, and I closed the pool down just three of
four days after that for winter.
I've used a little over 7,500 units on the E7 night rate between the June
and September readings. E7 night rate varies according to supplier, but is
somewhere between 3p and 4.5p per unit. In my case it worked out to
something around £340 for three months, using an 18kw heater, surface size
14ft x 28ft.
That was strictly pool use only, heating and night time pumping. I have a
three phase supply just for the garage and pool, so I can be qite certain
about that. I also pump for three hours from midday when the sun is at it's
strongest to get the benefit of solar gain from the bubble cover. Pool
temperature averaged 90F+ for a capacity of about 9,500 gallons (about
42,000 litres) from June to Mid september when I closed down for winter.
Allowing that I was about 6 weeks late in opening the pool this year, my
estimate of £500 for a full season ain't too far out. Bear in mind also
that I run my pool quite warm. If your mate can settle at about 80F then
his costs would be lower. He will, however, find that he'll have some
difficulty getting anything like that temperature through winter without
putting a lot more heat into the pool.
Oh, and those are actual, not hypothetical figures. :-)
There are a few websites out there that will have comparison info - google
is your friend. Remember though that manufacturers have a vested interest
in presenting any 'statistics' to their advantage.
deano
meow...@care2.com wrote:
> Whats round the pool? Has it been surfaced yet? If not, you can use the
> hard surfacing as a basic solar panel by putting pipes down before the
> coccrete / tarmac / etc. This method has been used to provide full
> heating before. Driveway, path etc can also be used if any is due to be
> surfaced.
The whole garden is currently a building site... the plans are on paper
and the pool area will be paved all around. So, by laying pipes
underneath the slabs, would that make for an ideal secondary heating
system? Anywhere I can look this up as to how to set up? Wouldn't a lot
of heat be lost into the surrounding ground, rather than cycled back
through the pool?
> a pool cover doesnt heat the water, it stops evaporation and provides a
> little insulation. The sunlight that goes in through a cover was going
> into the pool already.
Ah! got that wrong then, I thought there was a cover that did both,
using solar panels on the cover to heat the water via either an
electric heater or cycled somehow through the cover using the pool's
pump, as well as keeping heat in the pool.
> If you want the water above average ambient temp, and theres no other
> heating, then naturally yes.
Ok, so constant use of the boiler if no other system then.
> The difference is thousands, not hundreds. I get the feeling you've not
> done the figures.
You're right, I haven't. Anywhere I can study the formulas and
equations used to do the sums and compare the results?
> why not do better and ask him what run cost he thinks would be
> reasonable, then say if you can design and implement something
> superefficient he gives you n% of what he saves over the next 3 years.
Not a bad idea, although my guess is that he has no idea whatsoever on
the cost of running this, I'll give him a buzz to find out.
deano.
Christian McArdle
> than cycled back through the pool?
Insulate underneath to prevent this. It will only provide large amounts of
usable heat in good weather, though. To get that all important April and
October warmth, proper solar panels are a better bet. Still, if you're
thinking of dino fuelled heating as your main source, it will signicantly
reduce environmental impact as supplementary heat.
> Ah! got that wrong then, I thought there was a cover that did both,
> using solar panels on the cover to heat the water via either an
> electric heater or cycled somehow through the cover using the pool's
> pump, as well as keeping heat in the pool.
Certainly running the pump is a good idea around midday. This is because it
circulates the warm water to the bottom and the cold to the top, getting
more efficient heat transfer.
Christian.
meow...@care2.com
> meow...@care2.com wrote:
> > Whats round the pool? Has it been surfaced yet? If not, you can use the
> > hard surfacing as a basic solar panel by putting pipes down before the
> > coccrete / tarmac / etc. This method has been used to provide full
> > heating before. Driveway, path etc can also be used if any is due to be
> > surfaced.
> The whole garden is currently a building site... the plans are on paper
> and the pool area will be paved all around.
well, any place you've got hard surfacing you can run a pipe under. The
more the better.
> So, by laying pipes
> underneath the slabs, would that make for an ideal secondary heating
> system? Anywhere I can look this up as to how to set up? Wouldn't a lot
> of heat be lost into the surrounding ground, rather than cycled back
> through the pool?
This type of collector is far from ideal from a thermal point of view,
but solar is all about payback, which depends on install cost and
return figures. Pipes under hard surfacing has the advantage that its
very cheap to set up. All thats needed is some pipe, a low power pump
and a thermostat. The nearer the top the pipes are, the more of the
heat they'll harvest.
Look how hot tarmac gets in summer. It can melt. Despite its thermal
inefficiencies as a solar collector, it does work. These type of
collectors dont provide full heating unless you've got a largish area
in use. However even a smallish area contributes and reduces both
installed heating capacity requirement and run cost of gas or oil
heating. What area of hard surface are you likely to have available?
> > a pool cover doesnt heat the water, it stops evaporation and provides a
> > little insulation. The sunlight that goes in through a cover was going
> > into the pool already.
> Ah! got that wrong then, I thought there was a cover that did both,
> using solar panels on the cover to heat the water via either an
> electric heater or cycled somehow through the cover using the pool's
> pump, as well as keeping heat in the pool.
Solar covers are basically long lived versions of bubblewrap. They let
the sun straight in - there would be no advantage in capturing the
radiant heat and pumping it in instead.
> > The difference is thousands, not hundreds. I get the feeling you've not
> > done the figures.
> You're right, I haven't. Anywhere I can study the formulas and
> equations used to do the sums and compare the results?
I suggested crossposting this thread to alt.solar.thermal.
> > why not do better and ask him what run cost he thinks would be
> > reasonable, then say if you can design and implement something
> > superefficient he gives you n% of what he saves over the next 3 years.
> Not a bad idea, although my guess is that he has no idea whatsoever on
> the cost of running this, I'll give him a buzz to find out.
I'd just say theres more than one option, and a superefficient system
will cost a bit more either upfront or downline, but cost him less
overall.
NT
Peter Parry
wrote:
>The whole garden is currently a building site... the plans are on paper
>and the pool area will be paved all around. So, by laying pipes
>underneath the slabs, would that make for an ideal secondary heating
>system? Anywhere I can look this up as to how to set up? Wouldn't a lot
>of heat be lost into the surrounding ground, rather than cycled back
>through the pool?
If its all dug up you might have a once only opportunity to install a
ground source heat pump
http://portal.est.org.uk/myhome/generating/types/groundsource/
and use it to help heat the house in the winter as well as the pool
in summer.
http://www.geothermalheatpump.com/how.htm
meow...@care2.com
> If its all dug up you might have a once only opportunity to install a
> ground source heat pump
> http://portal.est.org.uk/myhome/generating/types/groundsource/
> and use it to help heat the house in the winter as well as the pool
> in summer.
>
> http://www.geothermalheatpump.com/how.htm
yes, if you want to spend all his money. :)
NT
Peter Parry
>yes, if you want to spend all his money. :)
Possibly :-) Don't know a great deal about them but even an air one
might be worth looking at.
Andy Hall
> On 16 Oct 2006 11:26:17 -0700, meow...@care2.com wrote:
>
>
>> yes, if you want to spend all his money. :)
>
> Possibly :-) Don't know a great deal about them but even an air one
> might be worth looking at.
I've seen one used to heat a pool in Sweden. Pretty effective in fact.
meow...@care2.com
Theyre good where you cant get gas or oil to the pool heater. Use
electrickery but at 300% efficient, loosely speaking. Install cost high
though.
NT
David Hansen
<pe...@wpp.ltd.uk> wrote this:-
>Possibly :-) Don't know a great deal about them but even an air one
>might be worth looking at.
If they are run overnight on an Economy 7 tariff ground source heat
pumps can work well and economically. A swimming pool, like
underfloor heating, is ideally suited to one due to the low
temperature output. Combined with a solar system to maintain
temperature during the day it would be a good combination.
--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54
deano
Having mentioned the Thermalac system to my friend and the BPF of £500
per annum, it would now appear that this is the route he wants to go.
His main concern is getting some heat into the pool pronto so that he
can get the circulation going and avoid the water becoming stagnant,
resulting in the need to get it shocked and back to ph... very
expensive.
As previously mentioned, his pool is 20,000L it also has a jaccuzi
built into it and he wants to use it all year round. The jacuzzi can be
set up to get hotter than the pool and there are controls that allow
the water from this to trickle over into the pool (providing some top
up heat there).
So, I'm going to study the Thermalec site now and see what system
requirements are needed.
cheers
Dean.
deano
deano wrote:
> As previously mentioned, his pool is 20,000L it also has a jaccuzi
> built into it and he wants to use it all year round. The jacuzzi can be
> set up to get hotter than the pool and there are controls that allow
> the water from this to trickle over into the pool (providing some top
> up heat there).
This is the actual pool he has had put in...
http://www.swimtek.co.uk/pools/buccaneer.htm
d.
The Wanderer
<snip>
> Having mentioned the Thermalac system to my friend and the BPF of £500
> per annum, it would now appear that this is the route he wants to go.
Yeah, fine, just make sure he realises that his pool ain't the same as my
pool, and my costs are for about 5 months use not 12 months use.
> His main concern is getting some heat into the pool pronto so that he
> can get the circulation going and avoid the water becoming stagnant,
> resulting in the need to get it shocked and back to ph... very
> expensive.
Having a pool *is* expensive, full stop.
Has the pool been plumbed up except for the heater? Looking at the website
for the pool, it makes no mention of a filter or circulation pump included
as part of the package. They're both essential for the pool. If they're not
included, you can add, at a guess, another £500 - £600 for those before
anything else! The inlets to the pump from the skimmers and drains should
probably have ball valves or similar fitted, to assist when it comes to
vacuuming.
It does, however, say a pool heater is included, also a solar cover, so I'm
a bit puzzled now by your query about pool heating.
A Thermalec heater goes into the return pipe from the multiport valve on
the filter to the pool. As long as there's space for that pipe to be cut
and a Thermalec heater to be installed, there's no reason the pump and
filter shouldn't be operated.
If the plumbing isn't complete, at least tell him to get some long-life
algicide into the pool, it's available from any pool supplier. That'll help
to keep algae under control, and at this time of year algae growth is quite
slow anyway with relatively low ambient temperatures.
> As previously mentioned, his pool is 20,000L it also has a jaccuzi
> built into it and he wants to use it all year round. The jacuzzi can be
> set up to get hotter than the pool and there are controls that allow
> the water from this to trickle over into the pool (providing some top
> up heat there).
Err, this is getting more and more complicated. Dunno what sort of deal
he's made with the suppliers, but in his shoes, I'd be pressing them for
some more info. ISTM the pool suppliers have a lot to answer for.
As it happens I also have a separate hot tub, but that is much smaller,
only about 800L. That uses a 3kw heater and runs at about 40C - anything
less in mid winter will feel quite cool. It also has plenty of insulation
within the body of the tub, and a very robust and well-insulated cover. I
very much doubt he will get more than 2 or 3 degrees temprature difference
between the pool and the jacuzzi.
> So, I'm going to study the Thermalec site now and see what system
> requirements are needed.
I'm no expert on pools, but I've a horrible feeling you're getting out of
your depth, and *you'll* finish up getting the blame if the pool doesn't
live up to your mate's expectations.
Peter Parry
wrote:
>Having mentioned the Thermalac system to my friend and the BPF of £500
>per annum, it would now appear that this is the route he wants to go.
If he is going to use it all the year around he is not looking at
GBP500 to heat it but more like GBP2,500 to GBP5,000 per annum,
especially if his "Jacuzzi" is the open spa shown in the picture.
deano
> Yeah, fine, just make sure he realises that his pool ain't the same as my
> pool, and my costs are for about 5 months use not 12 months use.
>
> Having a pool *is* expensive, full stop.
Having spoken to Thermalec, specialist off ill at the moment, so info
not from the company guru, it would appear that the size of the pool,
combined wiith a built-in spa and my friend's desire to use the pool
all year round, demands the employment of a 21kw unit, used on a 24hr
basis, so no real advantage from using E7 power. A Thermalec heater of
this rating, is £1200 retail + carriage + VAT. On top of that, the
cost of running the thing is going to be way more than £500pa. More
like £2000 (at least). Plus, I've just learned that the pool is
actually 3,500L not 2,000L which changes things dramatically as you
would expect.
> Has the pool been plumbed up except for the heater? Looking at the website
> for the pool, it makes no mention of a filter or circulation pump included
> as part of the package. They're both essential for the pool. If they're not
> included, you can add, at a guess, another £500 - £600 for those before
> anything else! The inlets to the pump from the skimmers and drains should
> probably have ball valves or similar fitted, to assist when it comes to
> vacuuming.
AFAIK, the package he bought includes everything up to the Wall Plate
(Heat Exchanger I presume) and only the heat source is required to get
it all going.
> It does, however, say a pool heater is included, also a solar cover, so I'm
> a bit puzzled now by your query about pool heating.
He got a 'bubble wrap' cover and a winter cover in the deal, but I
think the 'pool heater' must be a misprint, unless it means something
completely different... will check that out with the supplier.
> A Thermalec heater goes into the return pipe from the multiport valve on
> the filter to the pool. As long as there's space for that pipe to be cut
> and a Thermalec heater to be installed, there's no reason the pump and
> filter shouldn't be operated.
After speaking with Thermalec, I then called SwimTek (my pal's pool
supplier) and had a good chat with the heating expert there. He was
also on-site during delivery and installation, of the pool in question,
and is therefore familiar with the site logistics and client's
expectations. His opinion of the Thermalec heaters was that they
represent the "Rolls-Royce" of electric heaters, a great product which
delivers well on performance, reliability, low-maintenance and ease of
installation, with a price tag to match, added to an already 'high
cost', electric power source. With a 21kw heater, I'll be able to watch
the meter spin, is what he said!
Therefore, I've decided to go back to my original route of using a gas
boiler (either system or combi. Combi cheaper so far and with facility
to heat pool-side shower, as suggested by Adrian). I can pick up a
condensing combi with 80,000btu output for about £400, plus a pressure
vessel system for about £60. Groundworks to get the trenches dug for
the mains water, gas and electric, from the far side of the house, to
the shed is not an issue. He runs a demo company and has a JCB and
groundworker on site, at his disposal, indefinitely. I have already
asked that two trenches be dug for this span, to keep gas main separate
from electrical cable. Also in the shed, a Consumer unit will be
required, with fused way for boiler, say £50.
A future project will require garden circuits to be hooked up to this
with added ways to support, as yet, unkown loads; so I'll overspec the
amroured cable going in the ground, from the meter to the shed...
overspec cable is cheaper than digging up underspec cable.
To get mains water to the shed is a doddle and therefore negligible.
Other than that, to meet corgi regs, the shed will also probably need
to be lined with a suitable fire-rated insulating material (need to get
advice on this) as well as adequate airflow so the boiler can get fresh
air and dispel exhaust fumes.
I also expect that there are rules governing the installation of both a
gas boiler and a consumer unit, and their proximity to each other in a
confined location, such as a garden shed. Will do some research on
this.
> If the plumbing isn't complete, at least tell him to get some long-life
> algicide into the pool, it's available from any pool supplier. That'll help
> to keep algae under control, and at this time of year algae growth is quite
> slow anyway with relatively low ambient temperatures.
Thanks, that might take the heat off somewhat (scuze the pun!)
>
> Err, this is getting more and more complicated. Dunno what sort of deal
> he's made with the suppliers, but in his shoes, I'd be pressing them for
> some more info. ISTM the pool suppliers have a lot to answer for.
Done that on his behalf and taking him out of the info loop has made
things
much clearer :)
> As it happens I also have a separate hot tub, but that is much smaller,
> only about 800L. That uses a 3kw heater and runs at about 40C - anything
> less in mid winter will feel quite cool. It also has plenty of insulation
> within the body of the tub, and a very robust and well-insulated cover. I
> very much doubt he will get more than 2 or 3 degrees temprature difference
> between the pool and the jacuzzi.
Heating the spa separate from the pool is AIHBT controlled via the
incorporated
system, so that's an issue between him and SwimTek. They've installed
everything
up to the HE, leaving just the heat source to be installed! Even the
electrical systems
coming from the pool leave 3 cables that just need hooking up to a
fused supply.
When speaking to them today, no mention was made of a separate source
for the spa,
and I believe that would have been pointed out to me, but nothing's
ever certain, so I'll
raise this with them.
> I'm no expert on pools, but I've a horrible feeling you're getting out of
> your depth, and *you'll* finish up getting the blame if the pool doesn't
> live up to your mate's expectations.
I appreciate your honesty and your concern. Yes, this is all new to me,
however,
there are two issues here: speccing a system and installing a system. I
am up to the
challenge of installing any of the suggested systems, but 'choosing' a
system is where
I had a weakness, which is why I began this thread. I hadn't even
considered some of the alternatives that were suggested and having
assessed each of them, even if to find them unsuitable, I have learned
a great deal and am now much better positioned to advise my friend than
I was to begin with. He knows I'm thorough, in whatever I do, and
that's why he got me involved. I spoke to him today and, even though
we've come full circle, he knows why.
I can also relax in the knowledge that my work will be inspected and
approved by friends who are Corgi and IEE certified, before the
system(s) are comissioned and connected to the supply(ies).
Thanks for your help.
d.
deano
in the shed, as mentioned in my previous posts?
There are some requirements as to fireproofing and I need to establish
whether this implies just the local of the boiler itself, i.e. behind
and above the boiler, or if I need to line the whole shed with a
suitable fireproof material, such as supalux or Gyproc Fire.
I have my own reservations about putting a boiler in a timber shed, but
AFAICT it seems that this has been done many times before and I just
want to ensure that by so doing, regs are not just met, rather, the
installation surpases the minimum requirements for the locale. I'm even
thinking of reccommending that my friend installs a fire/smoke detector
with an alarm in the house to help protect the installation.
I've tried searching for info relavant to this but have so far not
found anything specific.
Cheers,
deano.
Andrew Gabriel
"deano" <de...@yesits.freeserve.co.uk> writes:
> Can anyone help me with the what regs apply to installing a gas boiler
> in the shed, as mentioned in my previous posts?
There are requirements for combustable sheds being a minimum
distance from a house and from the property boundary. This is
usually ignored, but if you're actually putting a boiler in it,
then you should certainly bare this in mind.
Also, a wall mounted boiler will be far too heavy for the wall
of your typical garden shed kit.
You can get boilers which are intended to be installed outdoors.
--
Andrew Gabriel
deano
> A friend has asked my advice on heating his newly installed outdoor pool.
For those interested, here's an update...
After exploring the various options kindly suggested here and
elsewhere, and after meeting with a Corgi engineer/inspector/trainer on
site, the following solution was adopted for this project.
I worked under the supervision of the CORGI man and will be undertaking
full training with him, so that I can get qualified myself. After
inspecting the existing gas meter, it became apparent that this would
not be sufficient to supply an additional shed boiler as well as the
current domestic system boiler, for the house.
The decision was made to remove the current boiler and replace it with
a Keston C55. The old boiler (Ideal brand) was rated at 25kw and the
pool needed a heating source in the region of 23.5kw (80,000btu), thus
a boiler with a total output power of about 48.5-50kw was the ideal,
while 40kw would probably suffice. Concerned that my client's
expectations should be met (preferably exceeded), and with a good price
quoted for the C55, I chose that model as a suitable replacement for
the 10 year old 'Ideal' model.
The C55 has a variable output, ranging from 14-55kw, depending on
demand, and could easily cope with the additional requirements of the
pool's Heat Exchanger, as well as the current domestic HW and CH, with
output power to spare. There are also the obvious economy benefits to
be gained from the variable output when the demand is less, plus the
energy savings that come with a condensing boiler such as the C55.
To incorporate the pool zone onto the primary system, I branched off
from the flow and return ports of the C55, to serve the new loop, as
well as reconnecting to the existing primaries of the domestic system.
To allow isolation of either the house primary or the pool primary,
avoiding unnecessary water circulation, I fitted actuating 2-port MVs
on both branches of the flow primaries, one on the house side and one
on the pool side. Likewise, I fitted gate valves on the returns.
Other changes made to the existing domestic system included: removal of
the, now-redundant, circulation pump, located in the airing cupboard...
the C55 has an integral pump that has the oomph to push water round the
house and pool loop combined. To avoid the C55's pump discharging water
into the CH expansion tank, via the vent pipe, in the loft, the system
has been converted over to a pressurised one, incorporating a suitably
sized pressure vessel.
I had a great time measuring the volume of water in the system, by
draining it into a 3 gallon bucket and counting the number of times I
had to empty it! Adding to this the volume of water held within 50m of
22mm barrier pipe and contained within the C55 (when full) gave me the
total volume of the new system (in gallons), and enabled me to select a
vessel of the appropriate size, with a bit extra for good measure... in
this case, an 8 gallon vessel was required and a 12 gallon was
selected.
The new loop for supplying heated water to the pool's heat exchanger,
in the shed, and back, was run using 22mm HEP barrier pipe. This was
sheathed in consecutive lengths of foam insulation and then wrapped
with 4" Denso tape along the full extent of the run. The 2 pipes were
then buried in an 18" deep trench, backfilled with pea shingle and will
eventually be patio'd over.
With most of the project now completed, I do have some uncertainty on
the configuration of the electrical wiring of the additional system.
The pool's thermostat will need to call for heat via the MV on the pool
branch of the flow primaries. If the pool's programmer (which I have
purchased but have yet to install) confirms that this call occurs
within an "on" period, the boiler will fire and heating commences.
Exactly as would happen if a call for HW and/or CH came through to the
domestic programmer, during an "on" period. However, the domestic MV
needs to be closed if pool-only heating is called and the pool MV has
to be closed if domestic-only heat is called. If calls are made to both
zones, during coinciding "on" periods, they both need to be open! As
these valves are "normally closed", it follows that either will only be
'open' during an 'on' period, as allowed by their respective
programmers. That's all fine, but what about the need for an "open
system" to facilitate pump-overrun of the boiler's integrated pump? If
both circuits have switched off, following a heating period, then both
MVs will close and water cannot be pumped around the primary to cool
down! How can I get round this? I am wondering if this is accounted for
within the boiler itself, as the C55's manual states that all system
wiring is external to the boiler, with only L,N,E and switched L needed
internally.
Cheers
deano.
meow...@care2.com
> I wrote:
> > A friend has asked my advice on heating his newly installed outdoor pool.
> For those interested, here's an update...
> The decision was made to remove the current boiler and replace it with
> a Keston C55. The old boiler (Ideal brand) was rated at 25kw and the
> pool needed a heating source in the region of 23.5kw (80,000btu), thus
> a boiler with a total output power of about 48.5-50kw was the ideal,
> while 40kw would probably suffice. Concerned that my client's
> expectations should be met (preferably exceeded), and with a good price
> quoted for the C55, I chose that model as a suitable replacement for
> the 10 year old 'Ideal' model.
>
> The C55 has a variable output, ranging from 14-55kw, depending on
> demand, and could easily cope with the additional requirements of the
> pool's Heat Exchanger, as well as the current domestic HW and CH, with
> output power to spare. There are also the obvious economy benefits to
> be gained from the variable output when the demand is less, plus the
> energy savings that come with a condensing boiler such as the C55.
Increase in efficiency is your only gain afaics. It might be worth it,
I dont know, but it appears your old boiler would have done the job
quite satisfactrily.
House heating requirement varies, but a few kW averaged through the
heating time is normal enough. IOW a 23.5kW boiler would normally only
need to feed the house a very small percentage of the time to heat it.
So all you needed do was give the house priority over the pool, the
boiler gives you the required output for the pool then, and house heat
is not sacrificed at all. However you friend will be guzzling so much
gas the change to a higher efficiency model might be worthwhile. But
according to your figs above there was no need for a 50kW unit.
NT
John Rumm
> For those interested, here's an update...
Thanks for that.
> The decision was made to remove the current boiler and replace it with
> a Keston C55. The old boiler (Ideal brand) was rated at 25kw and the
> pool needed a heating source in the region of 23.5kw (80,000btu), thus
> a boiler with a total output power of about 48.5-50kw was the ideal,
> while 40kw would probably suffice. Concerned that my client's
> expectations should be met (preferably exceeded), and with a good price
> quoted for the C55, I chose that model as a suitable replacement for
> the 10 year old 'Ideal' model.
You could have probably got away with less power - since you won't be
sinking the full output into the house for long durations. Still it
should give nice snappy heating times for the house and HW.
> The C55 has a variable output, ranging from 14-55kw, depending on
> demand, and could easily cope with the additional requirements of the
> pool's Heat Exchanger, as well as the current domestic HW and CH, with
> output power to spare. There are also the obvious economy benefits to
> be gained from the variable output when the demand is less, plus the
> energy savings that come with a condensing boiler such as the C55.
The variable output in this case is not modulating that low - so you can
still expect cycling in all but the very coldest of weather (unless the
house is very poorly insulated).
> avoiding unnecessary water circulation, I fitted actuating 2-port MVs
> on both branches of the flow primaries, one on the house side and one
> on the pool side. Likewise, I fitted gate valves on the returns.
> With most of the project now completed, I do have some uncertainty on
> the configuration of the electrical wiring of the additional system.
> The pool's thermostat will need to call for heat via the MV on the pool
> branch of the flow primaries. If the pool's programmer (which I have
> purchased but have yet to install) confirms that this call occurs
> within an "on" period, the boiler will fire and heating commences.
yup
> Exactly as would happen if a call for HW and/or CH came through to the
> domestic programmer, during an "on" period.
yup
> However, the domestic MV
> needs to be closed if pool-only heating is called and the pool MV has
> to be closed if domestic-only heat is called.
Not really - given the power of the boiler there is no need to make them
exclusive, it should eb able to feed both zones at once if required.
> If calls are made to both
> zones, during coinciding "on" periods, they both need to be open!
yup
> As
> these valves are "normally closed", it follows that either will only be
> 'open' during an 'on' period, as allowed by their respective
> programmers. That's all fine, but what about the need for an "open
> system" to facilitate pump-overrun of the boiler's integrated pump? If
> both circuits have switched off, following a heating period, then both
> MVs will close and water cannot be pumped around the primary to cool
> down! How can I get round this?
You need some form of bypass[1]... This can take the form of a pipe
connecting flow to return via a automatic bypass valve. This pipe needs
ot be connected before the zone valves obviously. During normal
operation the valve will stay shut and the bypass does nothing. However
when the pump is pumping against an otherwise closed system during
overrun, the auto valve should open with the pressure (most can be
tweaked to see the pressure) and allow some flow. The other option would
be to provide some other form of bypass like a small radiator or towel
rail that you want heated any time the boiler runs.
> I am wondering if this is accounted for
> within the boiler itself, as the C55's manual states that all system
> wiring is external to the boiler, with only L,N,E and switched L needed
> internally.
Some boilers do include an automatic bypass, however if the manual does
not specify it as a feature, the chances are you don't have it.
[1] Previously the bypass would normally have been provided by a rad
without a TRV - usually situated in the same room and the main room
stat. Now you have added the two port valve, you can no longer rely on
this since the path through the whole domestic loop could be blocked by
the new valve.
Andy Hall
> I wrote:
>> A friend has asked my advice on heating his newly installed outdoor pool.
>
> For those interested, here's an update...
<<SNIP>>
Essentially, you have implemented something quite close to my workshop
heating project.
The difference is that you presumably have the pool water on the
secondary side of the heat exchanger whereas I have a second heating
circuit, sealed and pressurised running to radiators in the workshop.
I dealt with most of the issues you mention, so a few comments:
> To incorporate the pool zone onto the primary system, I branched off
> from the flow and return ports of the C55, to serve the new loop, as
> well as reconnecting to the existing primaries of the domestic system.
> To allow isolation of either the house primary or the pool primary,
> avoiding unnecessary water circulation, I fitted actuating 2-port MVs
> on both branches of the flow primaries, one on the house side and one
> on the pool side. Likewise, I fitted gate valves on the returns.
I felt that it was important to protect the integrity of the house
primary circuit in the event that the secondary circuit isn't used for
a period of time. I wanted to avoid the case of freezing of the water
in the underground pipes or the workshop causing loss of the primary
heating water and hence the loss of CH and HW in the house. To that
end, I fitted the heat exchanger inside the house, where there is no
need to protect it from freezing - just insulate to avoid unwanted heat
loss. The secondary circuit runs between the house and the workshop
and the water is dosed with an inhibitor with antifreeze (Fernox Alphi
11). Obviously you wouldn't do this with the secondary being pool
water, but I just wonder whether it might not be better to site the
heat exchanger inside the house so that at least the integrity of the
main CH/HW primary circuit is protected.
Alternatively, it would be a very good idea to implement a frost
protection thermostat so that water could be circulated for short
periods in the external heating pipework when it gets really cold.
>
> The new loop for supplying heated water to the pool's heat exchanger,
> in the shed, and back, was run using 22mm HEP barrier pipe. This was
> sheathed in consecutive lengths of foam insulation and then wrapped
> with 4" Denso tape along the full extent of the run. The 2 pipes were
> then buried in an 18" deep trench, backfilled with pea shingle and will
> eventually be patio'd over.
For this aspect, I wrapped the pipes in foam insulation and ran them in
some 150mm underground soil pipe for protection. This was a
recommendation in a document that I found, originating from the
Building Research Establishment in connection with how to connect a
boiler in a remote boiler room to the house. It included how to run
the pipes into the house and so on. I suppose that buryoing the pipes
in pea shingle affords some protection...
>
> With most of the project now completed, I do have some uncertainty on
> the configuration of the electrical wiring of the additional system.
> The pool's thermostat will need to call for heat via the MV on the pool
> branch of the flow primaries. If the pool's programmer (which I have
> purchased but have yet to install) confirms that this call occurs
> within an "on" period, the boiler will fire and heating commences.
> Exactly as would happen if a call for HW and/or CH came through to the
> domestic programmer, during an "on" period. However, the domestic MV
> needs to be closed if pool-only heating is called and the pool MV has
> to be closed if domestic-only heat is called. If calls are made to both
> zones, during coinciding "on" periods, they both need to be open! As
> these valves are "normally closed", it follows that either will only be
> 'open' during an 'on' period, as allowed by their respective
> programmers. That's all fine, but what about the need for an "open
> system" to facilitate pump-overrun of the boiler's integrated pump? If
> both circuits have switched off, following a heating period, then both
> MVs will close and water cannot be pumped around the primary to cool
> down! How can I get round this? I am wondering if this is accounted for
> within the boiler itself, as the C55's manual states that all system
> wiring is external to the boiler, with only L,N,E and switched L needed
> internally.
This is the other challenge to deal with - how to do the signalling and
control.
I decided that I didn't want to run control signalling by cable between
the house and the workshop. The workshop is wired with its own circuit
directly from the CU and with local earthing and is hence a TT system
for electrical purposes. This is deemed safer than exporting the house
earth to the external building.
I'd strongly recommend that you read through the relevant sections of
BS7671, because a pool is considered to be a special installation
(meaning some specific potential hazards) and there are some particular
wiring requirements. In order to avoid possible future liability, I
think that this is one case where it would also make good sense to
involve a qualified (and insured) electrician with appropriate
experience in this area and to make sure that there is a paper trail
that the installation has been inspected and signed off properly.
That said.... In order to do the controls at the far end and
signalling to the boiler, I did the following arrangement:
- At the workshop end, there is an optimising CH controller with
thermostat, time control etc because I want different heating profiles
on different days, temperature set back etc. This operates a pump
in the workshop which is in the secondary circuit, so water flows when
there is a heat requirement.
- At the house end, there is a flow switch in the secondary circuit and
the contacts for that close when said water flows. This switch is
treated as a zone thermostat for the purposes of the boiler and
controls in the house. So there is a motorised valve controlled by the
flow switch, opening for heat demand and allowing system primary water
to flow through the heat exchanger.
- The auxilliary contacts of the motorised valve are connected in
parallel with those of the valves of the CH and HW valves and
effectively form 'OR' logic to turn on the boiler - i.e. if any of the
contacts close, boiler fires. If you look at the Honeywell web site
and search for S-plan plus, you will find the needed wiring diagram.
For the arrangement that you have at the moment, you can't do exactly
what I did, but you could if the heat exchanger were in the house.
The pump in the outbuilding would be controlled by thermostat and you
could have a flow switch in the house.
As it is now, you will need to run control wiring between the
outbuilding and the house or implement some other method of signalling.
It would be a good idea (may be a requirement) to isolate the house
and outbuilding electrical earthing at least. One way to achieve that
would be to put a small isolating transformer to effectively separate
them. The controls in the outbuilding would power the transformer
when heat is required and then the motorised valve at the house end
would be run from the secondary side. Even better would be to run the
wiring between the two in 24v (i.e. step down transformer at the
outbuilding end) and then a relay in the house controlling the MV.
>
deano
> Increase in efficiency is your only gain afaics. It might be worth it,
> I dont know, but it appears your old boiler would have done the job
> quite satisfactrily.
>
> House heating requirement varies, but a few kW averaged through the
> heating time is normal enough. IOW a 23.5kW boiler would normally only
> need to feed the house a very small percentage of the time to heat it.
> So all you needed do was give the house priority over the pool, the
> boiler gives you the required output for the pool then, and house heat
> is not sacrificed at all. However you friend will be guzzling so much
> gas the change to a higher efficiency model might be worthwhile. But
> according to your figs above there was no need for a 50kW unit.
Efficiency AND 'performance'!
The old boiler was an "ideal" model, rated at 27kw. The house (value:
£0.9-1.0m)) is only about 10-12 years old and is part of an estate of
executive mansions, all built at the same time... nice houses, but
still built to developer specs on previous agricultural land.
Developer's Time and budget constraints would have meant tight control
over all aspects of initial build, including boiler spec. There are 18
radiators in the house and the HW is stored in a constant pressure
water cylinder (not a Mega-flow, but a Watermill product with a
pressurised supply off the mains).
On the basis that the developers had fitted a 27kw boiler for good
reason, without going overboard (perhaps allowing for the addition of
an extra rad or two); plus the fact that the homeowners are mid
thirties, have three kids, regularly entertain both personal and
business acquaintances, and both drive Range Rover Sports'... I thought
it best to avoid risking a lag in the performance of the domestic
heating system, to which they are accustomed.
>From a client/supplier POV, it was also very easy to convey to my mate
that adding 23.5kw (for the pool) to the 27kw (output of the old
domestic boiler) equaled 50.5kw. In his mind, choosing a boiler with a
max output of 55kw, gave a 4.5kw comfort zone (akin to how we feel
about a 200mph(+) performance car, while knowing we can never (legally)
drive it at that speed).
I've no doubt that there are numerous other solutions to this project,
far more economical and efficient than the one I have installed.
However, having done a fair amount of research, on this, my most
challenging project to date, I am confident that the system will give
the performance that is expected of it (and more) and that's more
important than overall cost when my relationship with my friend is at
stake... after all, he was aware of my lack of experience in this area,
before asking me to get involved, and yet, still gave me the go-ahead
when I put forward my proposal.
There's more to a job than just tools and parts don't you think?
cheers,
deano.
deano
John Rumm wrote:
> deano wrote:
>
> > For those interested, here's an update...
>
> Thanks for that.
~ Welcome... share the knowledge and all that.
> You could have probably got away with less power - since you won't be
> sinking the full output into the house for long durations. Still it
> should give nice snappy heating times for the house and HW.
~ How much less power? I can't see how the existing unit would have
been up
to the task, so a replacement was always on the cards. With the
likelihood that,
at some point in the future, there will be an instance when the CH, HW
and pool
will all demand maximum output from the boiler, at the same time,
doesn't it follow
that a replacement boiler should have a max output equal to the sum of
the output
from the current domestic boiler, plus the extra 23.5kw required by the
pool?
As for giving snappy heating times, I think that is important to the
homeowner...
we all like to hand check the rads on a cold day, shortly after firing
up the heating,
and I would certainly have got some negative comments from the lady of
the house
if the rads took longer to get warm than before before hooking up to
the HE for the pool.
> The variable output in this case is not modulating that low - so you can
> still expect cycling in all but the very coldest of weather (unless the
> house is very poorly insulated).
~ Not sure I follow! Will the boiler always give a burn at the same
output rate?
I know it adjusts itself automatically and heat is controlled by the
speed of the fan,
but does this mean that the boiler sets itself to the system just once,
to calibrate
itself, and then remains at that setting until there is a significant
change in the system
demands?
> > However, the domestic MV
> > needs to be closed if pool-only heating is called and the pool MV has
> > to be closed if domestic-only heat is called.
>
> Not really - given the power of the boiler there is no need to make them
> exclusive, it should eb able to feed both zones at once if required.
~ So, should I then remove the MV and gate valve that I have installed
in the
flow and return pipes that go off to the domestic system? Is there no
benefit to
having these as part of the system? I suppose that water to heat the
pool during
an 'off period' for the domestic heating would only have to travel a
short loop round
the house primary, so no real heat loss incurred there. Then again,
having this zone
isolated during pool/jaccuzzi heating would prevent the slight heating
that the primary
loop would give off in that part of the house, which may be a good
thing during a hot
period in the summer?
> You need some form of bypass[1]... This can take the form of a pipe
> connecting flow to return via a automatic bypass valve. This pipe needs
> ot be connected before the zone valves obviously. During normal
> operation the valve will stay shut and the bypass does nothing. However
> when the pump is pumping against an otherwise closed system during
> overrun, the auto valve should open with the pressure (most can be
> tweaked to see the pressure) and allow some flow. The other option would
> be to provide some other form of bypass like a small radiator or towel
> rail that you want heated any time the boiler runs.
~ The length of system pipework between these two MV (with the boiler
half way
along) is quite short... only about 8' of flow and 8' of return. Would
a by-pass valve
still be able to cope with this and allow the short-circuited water to
cool sufficiently?
> > I am wondering if this is accounted for
> > within the boiler itself, as the C55's manual states that all system
> > wiring is external to the boiler, with only L,N,E and switched L needed
> > internally.
>
> Some boilers do include an automatic bypass, however if the manual does
> not specify it as a feature, the chances are you don't have it.
~ Agreed, I had a good read through the vey thick manual and don't
recall a reference
to such a device being fitted. There is an air-pressure release valve
mounted on the
flow pipe, just before it enters the HE on the boiler, but this is
obviously not the same
as a by-pass valve to allow bridging of the closed-off primary circuit.
>
> [1] Previously the bypass would normally have been provided by a rad
> without a TRV - usually situated in the same room and the main room
> stat. Now you have added the two port valve, you can no longer rely on
> this since the path through the whole domestic loop could be blocked by
> the new valve.
~ It has been and all the new system components have been installed
around the
boiler, in the utility room at the back of the house. The roomstat is
located in the
entrance hall. If, however, (as mentioned above) there is no real need
for the MV
and gate valve I have installed on the house primary, these can be
removed and
the pump-overrun can use the full length of the domestic primary,
uninterrupted.
Many thanks,
deano.
meow...@care2.com
> meow...@care2.com wrote:
Youre not understanding something here. Briefly, the addition of the
pool heating loop to the old boiler would have made _no_ difference
whatever to the house heating performance - assuming it was wired up
competently of course.
NT
John Rumm
>>You could have probably got away with less power - since you won't be
>>sinking the full output into the house for long durations. Still it
>>should give nice snappy heating times for the house and HW.
>
>
> ~ How much less power? I can't see how the existing unit would have
> been up
> to the task,
I agree that the existing boiler was certainly on the small size.
Certainly if you had used it then you would have to have given the house
heating priority over the pool to maintain short heat up times in the
house. However once the house was up to temperature there probably would
be a fair amount of spare capacity to heat the pool - but perhaps not
enough to heat it at the maximum rate supported by its heat exchanger.
With boilers in the 30 - 35kW range you would have had a bit more choice
of models and would probably also be able to find a boiler with a wider
modulation range, which will offer better comfort and economy for the
house heating. The house is unlikely to require more than say 8kW
continous demand for space heating once up to temperature, so there
would then been adequate power to drive the pool at full rate and the
house.
> so a replacement was always on the cards. With the
> likelihood that,
> at some point in the future, there will be an instance when the CH, HW
> and pool
> will all demand maximum output from the boiler, at the same time,
> doesn't it follow
> that a replacement boiler should have a max output equal to the sum of
> the output
> from the current domestic boiler, plus the extra 23.5kw required by the
> pool?
Well given that the heat up time of the pool is going to be many hours
regardless of how much boiler power you have available to throw at it,
delaying the pool from reaching its target temperature for an hour or so
in unlikely to be a problem.
>>The variable output in this case is not modulating that low - so you can
>>still expect cycling in all but the very coldest of weather (unless the
>>house is very poorly insulated).
>
>
> ~ Not sure I follow! Will the boiler always give a burn at the same
> output rate?
No the boiler will change its rate based on the temperature of the
return water. As this gets hotter it ought to reduce its burn rate. This
has the effect of matching the boilers output to the actual load, and
also in the case of a condensing boiler, helping to increase the
efficency of the boiler.
Ideally (for house heating) it is better to have a continous burn
matching the heat loss of the house, rather than intermittent burns that
overshoot the set point of the house and then require the boiler to
cycle on an off too often. So a boiler with a wide modulation range
(i.e. can go down to 5kW or lower) is good in this respect. If the
minimum burn rate on the boiler is significantly higher than the heat
loos rate of the house then you are back to situation similar to using a
smaller fixed rate boiler.
> I know it adjusts itself automatically and heat is controlled by the
> speed of the fan,
> but does this mean that the boiler sets itself to the system just once,
> to calibrate
> itself, and then remains at that setting until there is a significant
> change in the system
> demands?
No, it should be a continous closed loop control system.
>> > However, the domestic MV
>>
>>>needs to be closed if pool-only heating is called and the pool MV has
>>>to be closed if domestic-only heat is called.
>>
>>Not really - given the power of the boiler there is no need to make them
>>exclusive, it should eb able to feed both zones at once if required.
>
>
> ~ So, should I then remove the MV and gate valve that I have installed
> in the
> flow and return pipes that go off to the domestic system? Is there no
> benefit to
> having these as part of the system? I suppose that water to heat the
> pool during
> an 'off period' for the domestic heating would only have to travel a
> short loop round
> the house primary, so no real heat loss incurred there. Then again,
> having this zone
> isolated during pool/jaccuzzi heating would prevent the slight heating
> that the primary
> loop would give off in that part of the house, which may be a good
> thing during a hot
> period in the summer?
Ideally you need a S Plan system where the boiler and the house are each
on independaent zone. So the pool or the house or the domestic hot water
can call for heat, and the zone valves enable or disable the zone as
appropriate. Since you have the power available with the big boiler you
also have the option of running the heating and fast recovery domestic
hot water concurrently (you could divert the pool heating zone to the
DHW and have no impact on the house).
Since you have to allow for the possibility that none of the zones will
be open, you would still need the bypass.
(I presume the pools heating circuit is designed to limit its maximum
rate of absorption to something reasonable (say 25kW))
> ~ The length of system pipework between these two MV (with the boiler
> half way
> along) is quite short... only about 8' of flow and 8' of return. Would
> a by-pass valve
> still be able to cope with this and allow the short-circuited water to
> cool sufficiently?
The main requirement for the bypass it to avoid obstructing the pump. A
small amount of heat loss is handy to dissapate heat out of the primary
heat exchanger, but since this is probably a lightweight construction on
a modern boiler this won't be that great.
>>[1] Previously the bypass would normally have been provided by a rad
>>without a TRV - usually situated in the same room and the main room
>>stat. Now you have added the two port valve, you can no longer rely on
>>this since the path through the whole domestic loop could be blocked by
>>the new valve.
>
>
> ~ It has been and all the new system components have been installed
> around the
> boiler, in the utility room at the back of the house. The roomstat is
> located in the
> entrance hall. If, however, (as mentioned above) there is no real need
> for the MV
> and gate valve I have installed on the house primary, these can be
> removed and
> the pump-overrun can use the full length of the domestic primary,
> uninterrupted.
Since you have plenty of power to play with I suppose the ideal zoning
would something like house heating split into however many are required
to adequately partition the house, with pool heating and domestic hot
water sharing another. You could then have the water heating zone itself
partitioned as a W plan setup with priority given to the DHW using a
fast recover cylinder. That way when someone runs a bath, the hot water
can be given 20kW of heat input to recover, and unlike a typical
domestic setup there would be no need to prioritise this over the house
heating. (it would be prioritised over the pool, however that is not
going to notice the 15 min interruption to restore the cylinder).
deano
Thanks for your reply. I did read it soon after you posted, but have
been so busy, I just haven't had the time to give a concise response,
until now.
Andy Hall wrote:
> Essentially, you have implemented something quite close to my workshop
> heating project.
You're right there and, as it happens, I have studied all the posts on
the thread you initiated, regarding your workshop... somebody here
referred me to it, only for me to discover that I had read it before,
as part of the research I did, some months ago, when constructing my
own garden workshop, and looking at various ways to heat it.
Furthermore, as a result of replacing the boiler on this pool project,
I am in possession of the old boiler that I removed, and I'm
considering re-installing this into my workshop, to provide the heat
source needed there!
>
> The difference is that you presumably have the pool water on the
> secondary side of the heat exchanger whereas I have a second heating
> circuit, sealed and pressurised running to radiators in the workshop.
YES! The additional zone that I have installed, branches off the
primary flow and return, from the boiler. It runs externally, to the
shed, and is connected up to a heat exchanger. On the other 'side' of
the HE is the pool loop which is an 'in-direct' secondary circuit,
getting its heat from the transfer provided by the HE.
> I dealt with most of the issues you mention, so a few comments:
>
> I felt that it was important to protect the integrity of the house
> primary circuit in the event that the secondary circuit isn't used for
> a period of time. I wanted to avoid the case of freezing of the water
> in the underground pipes or the workshop causing loss of the primary
> heating water and hence the loss of CH and HW in the house. To that
> end, I fitted the heat exchanger inside the house, where there is no
> need to protect it from freezing - just insulate to avoid unwanted heat
> loss. The secondary circuit runs between the house and the workshop
> and the water is dosed with an inhibitor with antifreeze (Fernox Alphi
> 11). Obviously you wouldn't do this with the secondary being pool
> water, but I just wonder whether it might not be better to site the
> heat exchanger inside the house so that at least the integrity of the
> main CH/HW primary circuit is protected.
I understand your point completely and keeping all of the main system
components in the house makes a lot of sense. However, certain parts of
the installation were the responsibility of the pool supplier and they
did their bit long before I came on to the job. On the behest of the
client (and no doubt, with a bit of persuasion from themselves... to
make the installation easier) all of the pool's plant components,
including the pump, filter, blower and Heat Exchanger, were located in
the shed, down the side of the house, nearest to the pool, as was all
pipework connecting the above, to the pool, in 1.5 and 2" plastic with
solvent fittings. This had then also been buried underground, as part
of the ongoing groundworks. This is where the original brief of putting
a boiler in the shed initially came from and, as you know, things have
since digressed from that in many ways, due to feasibility issues.
Hence, I'm stuck with the HE in the shed.
> Alternatively, it would be a very good idea to implement a frost
> protection thermostat so that water could be circulated for short
> periods in the external heating pipework when it gets really cold.
Affirmative... having put the two tubes in the ground, freezing of the
pipes during a non-use period, occurred to me and I have been thinking
about fitting a pipe-stat, to monitor the temp in the sub-terranian
pipes.
> For this aspect, I wrapped the pipes in foam insulation and ran them in
> some 150mm underground soil pipe for protection. This was a
> recommendation in a document that I found, originating from the
> Building Research Establishment in connection with how to connect a
> boiler in a remote boiler room to the house. It included how to run
> the pipes into the house and so on. I suppose that buryoing the pipes
> in pea shingle affords some protection...
They have also been topped off with soft sand and will have a patio
re-instated above them, so I'm not really worried about that aspect of
the installation. Point taken for future ref though, about using the 4"
pipe... although drainage fittings are very expensive.
> This is the other challenge to deal with - how to do the signalling and
> control.
>
> I decided that I didn't want to run control signalling by cable between
> the house and the workshop. The workshop is wired with its own circuit
> directly from the CU and with local earthing and is hence a TT system
> for electrical purposes. This is deemed safer than exporting the house
> earth to the external building.
I have also installed a CU into the shed, where the pool components are
located. This is fed by a 16mm armoured cable, run in the same trench
as the heating pipes. However, I have connected this up to a spare
"way" on the domestic consumer unit, using a 45a MCB, which is on the
"RCD-protected" side of the DIN rail. Contrary to what you learned, I
was advised that using the house earth was suitable... but that doesn't
mean I disagree with what you did. I also bonded the metal sheathing,
of the armoured cable, and the metal components of the pool's plant
equipment, to earth, in the shed CU, via suitable banjos, bolts and
crimp fittings, using 6mm earth cable.
> I'd strongly recommend that you read through the relevant sections of
> BS7671, because a pool is considered to be a special installation
> (meaning some specific potential hazards) and there are some particular
> wiring requirements. In order to avoid possible future liability, I
> think that this is one case where it would also make good sense to
> involve a qualified (and insured) electrician with appropriate
> experience in this area and to make sure that there is a paper trail
> that the installation has been inspected and signed off properly.
I have a man that can... my mate's dad does just that! He certifies
installations, during the morning, at various commercial properties, in
central London. In the afternoons, he looks after his private
customers, such as me. I always get him to come and check what I've
done, it makes sense to have a fresh pair of eyes check your work,
regardless of what is required by law. I'm happy to say that he has yet
to find fault with my work, yet he always has useful suggestions on
alternatives to certain things I have done, which would have been
quicker to implement, while remaining within the guidelines.
My intention is to run a cable from the pool/shed area, to the utility
room, in the house... as you have mentioned above. I was going to take
power for the circuit from the shed's CU and just use the armoured
cable as a control wire, to operate the MV for the pool zone, in the
utility room.
However, this would result in a circuit remaining live, even when the
main fused switch for the system is switched off, which is not ideal,
nor good practise. So, I intend to run a 5-core+earth, armoured cable
from the shed, into the utility room. The pool's thermostat will send a
'demand' signal, via this cable, to a separate programmer, located in
the utility room. If the programmer is currently in an "on" period, the
signal will be passed on to the MV for the pool zone, and this will
open, thus allowing flow to begin and the boiler to fire.
I still need to work out whether I need the MV on the house side of the
primary circuit, so that this can be closed if no demand is currently
coming from the house HW and CH. Or, should I just allow flow around
the house primary, when only pool heating is called for? If I am to
completely isolate the house primary when 'pool only' heating is
called,I need to start thinking about pressure relief and by-pass
valves, and also, an additional pressure vessel, located in the shed,
to protect the pool circuit, as the house circuit, and its pressure
vessel will be cut off from this circuit!
The saga continues....
cheers
deano.
meow...@care2.com
> > Alternatively, it would be a very good idea to implement a frost
> > protection thermostat so that water could be circulated for short
> > periods in the external heating pipework when it gets really cold.
> Affirmative... having put the two tubes in the ground, freezing of the
> pipes during a non-use period, occurred to me and I have been thinking
> about fitting a pipe-stat, to monitor the temp in the sub-terranian
> pipes.
I think in practice you're unlikely to be bathing outdoors when the
temp is sub zero, hence no pool heating would be needed at such times.
NT
raden
meow...@care2.com writes
under a flap to the outside - strange experience swimming in the snow
--
geoff
deano
I disagree, on two counts...
Firstly: Having recently spent thousands of pounds on this project, my
mate is desperate to take a dip in his new pool (as are his kids)
regardless of the time of year and the outside temperature. He has also
described to me his vision of sitting in the spa / jacuzzi section of
the pool, with his wife, sipping champagne, whilst surrounded by
snow-covered ground and steam coming off the water's surface... I'd be
exactly the same if it was my pool.
Come this time next year, following extensive use throughout the
summer, the novelty may have worn off, amongst the resident family, and
there will be less demand for regular 'winter' use of the pool.
However, being the party-throwers, for which they are renowned, they
will want to keep the pool on standby, so it can be used, at short
notice. and as such, are likely to maintain it at a status sufficient
for constant use.
Secondly: Should it be necessary for the pool to be shut down for any
period of time, water would still remain in the flow and return pipes
of the zone loop from the boiler to the shed. This water would be prone
to freezing during a cold spell, regardless of being buried in the
ground and sheathed with insulation. A pipe stat, connected to the MV,
for this zone, would provide protection against freezing by initiating
flow and firing the boiler, thus warming and circulating the water in
this loop. The water in the pipes on the secondary side of the HE, to
and from the pool, is protected from freezing by devices fitted to the
pool pump and/or filter.
So, as you can see, there is a need for some form of frost protection
for this additional zone.
cheerz,
deano.
meow...@care2.com
> > > > Alternatively, it would be a very good idea to implement a frost
> > > > protection thermostat so that water could be circulated for short
> > > > periods in the external heating pipework when it gets really cold.
> > > Affirmative... having put the two tubes in the ground, freezing of the
> > > pipes during a non-use period, occurred to me and I have been thinking
> > > about fitting a pipe-stat, to monitor the temp in the sub-terranian
> > > pipes.
> > I think in practice you're unlikely to be bathing outdoors when the
> > temp is sub zero, hence no pool heating would be needed at such times.
> I disagree, on two counts...
Well, its in interesting definition of 'need' :)
NT
The Wanderer
<snip>
> Firstly: Having recently spent thousands of pounds on this project, my
> mate is desperate to take a dip in his new pool (as are his kids)
> regardless of the time of year and the outside temperature. He has also
> described to me his vision of sitting in the spa / jacuzzi section of
> the pool, with his wife, sipping champagne, whilst surrounded by
> snow-covered ground and steam coming off the water's surface... I'd be
> exactly the same if it was my pool.
Oh, being *in* a nice warm pool is fine, it's the bit between the pool and
a nice warm indoors that's the problem......
> Come this time next year, following extensive use throughout the
> summer, the novelty may have worn off, amongst the resident family, and
> there will be less demand for regular 'winter' use of the pool.
My spa is in my conservatory and it don't get used that often in winter!
> However, being the party-throwers, for which they are renowned, they
> will want to keep the pool on standby, so it can be used, at short
> notice. and as such, are likely to maintain it at a status sufficient
> for constant use.
Unless they have unlimited funds, I suspect the novelty will soon wear off.
> Secondly: Should it be necessary for the pool to be shut down for any
> period of time, water would still remain in the flow and return pipes
> of the zone loop from the boiler to the shed.
I had a heat exchanger from the c/h system to the pool in my last house
(oil-fired boiler). It was installed by a previous owner. I hardly ever
used it - probably two or three times at most. I found the Thermalec heater
was much better for the purpose. The pipes from the boiler (28mm copper)
had two gate valves in the pump chamber. These were left more or less
permanently shut. The pipes were only just below g/l where they came out of
the house, although they did then drop to perhaps 12 to 15 inches below
g/l. I never had any problems with the pipes freezing in 13 years. The
original pump did, and cracked. It was an elderly cast iron body, so was in
need of replacing anyway.
deano
Yeah, I'll give you that.
Every time my mate moans about how much this project is costing him and
how he has to keep chasing suppliers and tradesmen for delivery dates
and install dates, I have had to bite my tongue on a number of
occassions and refrain from saying things like "Oh, I really feel for
you mate, having all this aggravation, just so you can have the luxury
of a heated swimming pool. All those folk who'll be freezing this
winter because they can't afford to heat their homes, really have no
idea, do they!" [removes tongue from cheek].
d.
meow...@care2.com
> On 23 Nov 2006 15:49:41 -0800, deano wrote:
> > Firstly: Having recently spent thousands of pounds on this project, my
> > mate is desperate to take a dip in his new pool (as are his kids)
> > regardless of the time of year and the outside temperature. He has also
> > described to me his vision of sitting in the spa / jacuzzi section of
> > the pool, with his wife, sipping champagne, whilst surrounded by
> > snow-covered ground and steam coming off the water's surface... I'd be
> > exactly the same if it was my pool.
> Oh, being *in* a nice warm pool is fine, it's the bit between the pool and
> a nice warm indoors that's the problem......
Some actions are only ever carried out the once :)
NT
Andy Hall
I do see his point in a way. He is probably also very busy and in
general he probably delivers on what he says he will do or puts in the
extra effort when needed to meet a commitment.
I have a similar approach
It's very irritating when dealing with people who make commitments and
don'r keep them, have no sense of urgency in terms of meeting a
customer's requirements and have to be constantly pushed in order that
they do so.
Paradoxically, if suppliers did have a better customer service ethic
and made things happen more quickly, they would have the time to do
more business or to have more personal time.
Unfortunately, that requires a change of mindset for most people.
deano
Andy Hall wrote:
> I do see his point in a way. He is probably also very busy and in
> general he probably delivers on what he says he will do or puts in the
> extra effort when needed to meet a commitment.
> I have a similar approach
As do I. I take pride in my work, am as thorough as I can be (when
compiling my estimates and during the actual works), am concerned for
my clients' convenience, their faith in me to deliver, and I try to
keep my prices as keen as possible even though I know I am usually
competing with other tradesmen, who's standards are below my own. I'm
always busy, so I must be doing something right!
My mate is not short of a bob or two and the cost of the high powered
boiler has already been forgotten... my labour costs were the same as
they would have been for any replacement boiler and I passed all my
trade discounts on to him. On the other hand, if I had walked the line
when speccing the replacement boiler, and gone for a lower power,
cheaper model, I would have risked getting it slightly wrong and if the
performance was on the disappointing side... I would have never heard
the end of it and putting it right would cost a fortune and mean
starting from scratch.
>
> It's very irritating when dealing with people who make commitments and
> don'r keep them, have no sense of urgency in terms of meeting a
> customer's requirements and have to be constantly pushed in order that
> they do so.
>
> Paradoxically, if suppliers did have a better customer service ethic
> and made things happen more quickly, they would have the time to do
> more business or to have more personal time.
>
> Unfortunately, that requires a change of mindset for most people.
Agreed... it seems to be the general behaviour of most of the big names
out there, and its only getting worse. I often spend ages in my local
plumbers' merchant chatting and learning no end of new tips from the
staff and regulars who are often there. Go to one of the sheds and
you're lucky to find someone who even knows where they are!
d.
Andy Hall
>
> Andy Hall wrote:
>> I do see his point in a way. He is probably also very busy and in
>> general he probably delivers on what he says he will do or puts in the
>> extra effort when needed to meet a commitment.
>> I have a similar approach
>
> As do I. I take pride in my work, am as thorough as I can be (when
> compiling my estimates and during the actual works), am concerned for
> my clients' convenience, their faith in me to deliver, and I try to
> keep my prices as keen as possible even though I know I am usually
> competing with other tradesmen, who's standards are below my own. I'm
> always busy, so I must be doing something right!
>
> My mate is not short of a bob or two and the cost of the high powered
> boiler has already been forgotten... my labour costs were the same as
> they would have been for any replacement boiler and I passed all my
> trade discounts on to him. On the other hand, if I had walked the line
> when speccing the replacement boiler, and gone for a lower power,
> cheaper model, I would have risked getting it slightly wrong and if the
> performance was on the disappointing side... I would have never heard
> the end of it and putting it right would cost a fortune and mean
> starting from scratch.
Exactly. It is important to know the customer's expectations. To
him, the difference in cost is not a big deal. A disappointing result
is.
>
>>
>> It's very irritating when dealing with people who make commitments and
>> don'r keep them, have no sense of urgency in terms of meeting a
>> customer's requirements and have to be constantly pushed in order that
>> they do so.
>>
>> Paradoxically, if suppliers did have a better customer service ethic
>> and made things happen more quickly, they would have the time to do
>> more business or to have more personal time.
>>
>> Unfortunately, that requires a change of mindset for most people.
>
> Agreed... it seems to be the general behaviour of most of the big names
> out there, and its only getting worse. I often spend ages in my local
> plumbers' merchant chatting and learning no end of new tips from the
> staff and regulars who are often there. Go to one of the sheds and
> you're lucky to find someone who even knows where they are!
>
>
That's expectation again. I don't really expect a lot of any of
these places other than a good price and delivery plus replacement
without titting around if something is wrong. It shouldn't be difficult
tony sayer
A LOT of people. I spend sometimes a whole morning or two a week chasing
up other firms to get things done. Some of these like telecommunications
suppliers have effective monopolies still, so no real chance of going
elsewhere either:(
--
Tony Sayer
Andy Hall
>
> A LOT of people. I spend sometimes a whole morning or two a week chasing
> up other firms to get things done. Some of these like telecommunications
> suppliers have effective monopolies still, so no real chance of going
> elsewhere either:(
Sad isn't it.
I have real difficulty with people and organisations who promise
something and then don't deliver, don't bother to let me know in
reasonable time so that I have the opportunity to rearrange other
things or make other arrangements and then don't seem to appreciate
that it's unacceptable.
I suppose that if we have to have monopolies or as you say, effective
monopolies, nobody in them would think of the concept of having
individual performance targets with money attached to them. It's
amazing how that focuses attention.