Anyone here experience fitting air source heating?

[Michael Kilpatrick]

Curious to know of anyone - but not a new build, something pre 1980s -
who has fitted air source heating to their house? And perhaps installed
compact fan-assisted radiators such as the Dimplex SmartRad and
such-like, where space was at a premium and to use lower flow temperatures?

I'm keen to have recommendations of professionals to discuss the
possibilities.


Michael

[The Natural Philosopher]

I have fan assisted rads but they need 50 C water to switch on.

Really they haven't been very successful. They are noisy, and whilst
they do put out a decent amount of warmth, its fairly localised.

In a low temp retrofit of UFH is not possible, I'd be inclined to lay a
new wall surface on an outside wall with water pipes coiled behind it.

The issue boils down to simple physics - at lower temps you need more
radiative/convective surface. If you cant use the best option - the
floor - then a wall is next best.

Radiators are not great - ugly and huge. And trap dust

I'll pass on heatpumps. Looked at them and at the time not cost
effective, and now with gas prices pushing electric prices through the
roof, not very useful today either.

Once the grid is all nuclear, probably worth looking at simple resistive
electric heating.

Air source is really not that useful as when you need the most power -
very low outside temperatures - it is at its least efficient.

Ecobollox™ is the order of the day with anything that's being promoted
as anything other than a cost effective way to heat a house. And if you
think legislation is there to ensure that technology no one would touch
otherwise, is *mandatory*, you are Green and wet behind the ears...


> Michael


--
"Socialist governments traditionally do make a financial mess. They
always run out of other people's money. It's quite a characteristic of them"

Margaret Thatcher

[Theo]

Michael Kilpatrick <ne...@mkilpatrick.co.uk> wrote:
> Curious to know of anyone - but not a new build, something pre 1980s -
> who has fitted air source heating to their house?

We fitted a Grant ASHP in December. So far it's holding up OK - 1960s
chalet bungalow, somewhat draughty. About 25-30kWh per day on the coldest
days. I suspect this could be improved quite a bit - see below.

> I'm keen to have recommendations of professionals to discuss the
> possibilities.

Installer was Shelford Heating, but I wouldn't recommend them. They've
basically installed it like a boiler, and heat pumps really shouldn't be
installed that way (they should keep running while modulating their flow
temp down, rather than using an on/off thermostat like a boiler). There
were some egregious faults (they left site with the radiators unbalanced and
the system full of air) and they're still due to come back and sort things
out.

Some posts about about my experience:
https://renewableheatinghub.co.uk/forums/renewable-heating-air-source-heap-pumps-ashps/share-your-electricity-bills
https://renewableheatinghub.co.uk/forums/renewable-heating-air-source-heap-pumps-ashps/install-a-grant-aerona-13kw-instead-of-mitsubishi-ecodan-11-2kw#post-6532
https://renewableheatinghub.co.uk/forums/renewable-heating-air-source-heap-pumps-ashps/whilst-regs-allow-on-off-simple-thermostats-nest-hive-heatmiser-honeywell-etc-installers-should-never-be-responsible-for-failing-heat-pumps#post-6483

> And perhaps installed compact fan-assisted radiators such as the Dimplex
> SmartRad and such-like, where space was at a premium and to use lower flow
> temperatures?

I'm looking at ordering some fan coil units from Italy or China to do
cooling, which the Dimplex SmartRads won't do (the same idea, but you need
condensate collection):
https://renewableheatinghub.co.uk/forums/renewable-heating-air-source-heap-pumps-ashps/chilled-water-ac-system#post-5949

My Grant doesn't officially admit to offering cooling, but it's a rebadge
of a Chofu unit that does. The cooling function has enabled in settings - I
await a warm day to test it before I'll go ahead with FCUs. Shelford don't
know anything about cooling, so that bit is down to me.


A brief roundup of things I found useful:

A book on the basics, worth reading for the background:
https://www.amazon.co.uk/Heat-Pumps-Home-John-Cantor/dp/1785007793

https://renewableheatinghub.co.uk/
particularly the forums and videos, also:
https://forum.buildhub.org.uk/forum/119-air-source-heat-pumps-ashp/

This YT channel is good - they focus on the idea of system design to
maximise efficiency, rather than the boiler installer slap in the biggest
and hope for the best. They have training courses which are one of the main
heatpump installer courses - I'd look for installers who have done the
course (there's a list on their site), rather people slapping them in like
boilers:
https://www.youtube.com/c/HeatGeek
https://www.heatgeek.com/find-a-heat-geek/

(the MCS is another certification scheme, but seems a lot of MCS certified
people don't really know what they're doing as far as heat pump efficiency
goes)

Another YT training channel, useful in understand how all the parts fit
together:
https://www.youtube.com/c/FreedomHeatpumps

Happy to answer any questions that I can...

Theo

[Michael Kilpatrick]

On 24/02/2022 13:53, Theo wrote:
> Michael Kilpatrick <ne...@mkilpatrick.co.uk> wrote:
>> Curious to know of anyone - but not a new build, something pre 1980s -
>> who has fitted air source heating to their house?
>
> We fitted a Grant ASHP in December. So far it's holding up OK - 1960s
> chalet bungalow, somewhat draughty. About 25-30kWh per day on the coldest
> days. I suspect this could be improved quite a bit - see below.
>
>> I'm keen to have recommendations of professionals to discuss the
>> possibilities.
>
> Installer was Shelford Heating, but I wouldn't recommend them. They've
> basically installed it like a boiler, and heat pumps really shouldn't be
> installed that way (they should keep running while modulating their flow
> temp down, rather than using an on/off thermostat like a boiler). There
> were some egregious faults (they left site with the radiators unbalanced and
> the system full of air) and they're still due to come back and sort things
> out.

Thanks Theo, I shall try and look at all of those links tomorrow.

But I didn't know the above. You're saying the water in the CH radiator
circuits will be flowing all the time, day and night, in a sensible
set-up? That's curious.



Michael

[Theo]

Michael Kilpatrick <ne...@mkilpatrick.co.uk> wrote:
> Thanks Theo, I shall try and look at all of those links tomorrow.
>
> But I didn't know the above. You're saying the water in the CH radiator
> circuits will be flowing all the time, day and night, in a sensible
> set-up? That's curious.

Basically, the heatpump works more efficiently the lower the flow (output)
temperature. That means a lower output for longer is better than a high
output for a shorter period.

In the optimal state, the HP will be balancing the losses from your house -
eg if your house has say 5kW of losses on a freezing day, then the HP only
needs to put in 5kW. It is more efficient to have the HP outputting a
constant 5kW than to have it outputting 10kW for half the time and cycling
50/50 like a boiler. A 5kW HP is also smaller and more efficient than
modulating down a 10kW HP.

However if you turn off the 5kW HP and the house gets cold, it'll take a
long time to bring it up to temperature again. 5kW losses might be at 20C
inside, if it's 10C inside the losses might be 3kW - the 5kW can still make
progress in raising the temperature (net input 2kW), but it'll struggle to
reach target where the losses are balancing. A bigger HP can swing the
temperature faster.

This is in the depths of winter. I think in spring and autumn when you
don't need a lot of heat then it will still modulate.

That said, we have a quite large (13kW) unit and it's being modulated every
20 mins thanks to the incorrect controls they're installed, and we turn it
off at night for noise reasons. It works fine (a bit slow to warm up in the
morning compared with the previous boiler), but probably efficiency is
taking a hit.

Theo

[Mark Carroll]

On 24 Feb 2022, Theo wrote:

> However if you turn off the 5kW HP and the house gets cold, it'll take a
> long time to bring it up to temperature again.

Mmmm, in that kind of case, my house's HP adds in resistive heat too,
obviously killing efficiency rather. It doesn't if I've not turned it
off or down far though, it's more like, I got back from holidays or
whatever, and now I've asked it to raise by many degrees.

-- Mark

[Theo]

Mine can do that - there's an immersion in the buffer tank and an output to
control it - but it's not wired up. Generally HP installers don't like
doing that because it's an easy way to get unexpected bills if the HP is
incorrectly configured.

It's safer not to have it - although perhaps might be useful if we ever got
a -20C winter. And I agree there are rare occasions where you want the
'just make it hot asap dammit' and it would be useful for that. Perhaps I
could wire it on a manual switch or something, for emergency purposes
only...

Theo

[The Natural Philosopher]

On 24/02/2022 15:56, Theo wrote:
> Mark Carroll <mt...@kings.cantab.net> wrote:
>> On 24 Feb 2022, Theo wrote:
>>
>>> However if you turn off the 5kW HP and the house gets cold, it'll take a
>>> long time to bring it up to temperature again.
>>
>> Mmmm, in that kind of case, my house's HP adds in resistive heat too,
>> obviously killing efficiency rather. It doesn't if I've not turned it
>> off or down far though, it's more like, I got back from holidays or
>> whatever, and now I've asked it to raise by many degrees.
>
> Mine can do that - there's an immersion in the buffer tank and an output to
> control it - but it's not wired up. Generally HP installers don't like
> doing that because it's an easy way to get unexpected bills if the HP is
> incorrectly configured.
>
> It's safer not to have it - although perhaps might be useful if we ever got
> a -20C winter.

Do you really think a bunch of mediaeval windmills and solar panels are
going to allow any access to electricity in a -20°C winter?

And I agree there are rare occasions where you want the
> 'just make it hot asap dammit' and it would be useful for that. Perhaps I
> could wire it on a manual switch or something, for emergency purposes
> only...
>
> Theo

--
"And if the blind lead the blind, both shall fall into the ditch".

Gospel of St. Mathew 15:14

[Tim Ward]

On 24/02/2022 15:56, Theo wrote:
>

> Perhaps I
> could wire it on a manual switch or something, for emergency purposes
> only...

In this household such devices are called "fan heaters". Which you have
to have anyway for when the central heating breaks down.

--
Tim Ward - 07801 703 600
www.brettward.co.uk

[Tim Ward]

On 24/02/2022 15:26, Theo wrote:
>
> we turn it off at night for noise reasons

Yes, I've read that the things are noisy. Not encouraging. Our existing
gas central heating is almost silent. (Well, it is after I had the
system desludged and the pump replaced.)

[Theo]

Tim Ward <t...@brettward.co.uk> wrote:
> On 24/02/2022 15:26, Theo wrote:
> >
> > we turn it off at night for noise reasons
>
> Yes, I've read that the things are noisy. Not encouraging. Our existing
> gas central heating is almost silent. (Well, it is after I had the
> system desludged and the pump replaced.)

Noise-wise it's a lot quieter than our oil boiler (no 'click <pause>
whoomf') - there's a bit of buzzing ourside, but inside it's no more than a
fridge or regular central heating pump. I'm fine with it, but a family
member is however ultra noise sensitive, which means we're paranoid about
noise.

The main issue for me is the dozy installer decided to mount the pipework
and relay boxes on a solid wall adjoining the bedroom, with regular screws.
So all the contactor clunking and the pump running transmits through the
wall. It's a bit like trying to sleep in the airing cupboard.

Theo

[tony sayer]

In article <oLf*b8...@news.chiark.greenend.org.uk>, Theo <theom+news@chi
ark.greenend.org.uk> scribeth thus

Where else might he have put them I'd not expect an installer to think
of that aspect;!...

--
Tony Sayer


Man is least himself when he talks in his own person.

Give him a keyboard, and he will reveal himself.

[Theo]

tony sayer <to...@bancom.co.uk> wrote:
> In article <oLf*b8...@news.chiark.greenend.org.uk>, Theo <theom+news@chi
> ark.greenend.org.uk> scribeth thus

> >The main issue for me is the dozy installer decided to mount the pipework
> >and relay boxes on a solid wall adjoining the bedroom, with regular screws.
> >So all the contactor clunking and the pump running transmits through the
> >wall. It's a bit like trying to sleep in the airing cupboard.
>

> Where else might he have put them I'd not expect an installer to think
> of that aspect;!...

There was a perfect good wall at 90 degrees to the bedroom, which is where
the existing pipework was and where I told them to put things...

Meanwhile, rubber lined pipe clips are 36p+VAT...

Theo

[tony sayer]

In article <nLf*TE...@news.chiark.greenend.org.uk>, Theo <theom+news@chi

Right i see! Mind you every bloody drawing I've ever done i always put;

"IF IN DOUBT ASK" complete with a 24 hour phone number.

Do they ever ask?, do they feck!....