Radiant Floor heating - nonliquid?
vjp...@at.biostrategist.dot.dot.com
I see a lot of "Radiant Floor Heating" with a rubbery tubing stapled under
the floor. SInce I tend to be in horror of any kind of leaks, I wonder why
they don't use some compresses gas instead?
Mind you, I have even had experience with central venting "leaking": I
haven't used a/c since my folks died but my uncle's a/c duct sweats onto my
ceiling. That's the price for freeloading (hot air rises) off his a/c.
Edwin Pawlowski
<vjp...@at.BioStrategist.dot.dot.com> wrote in message
news:gb61u0$4vh$1...@reader1.panix.com...
Gas does not transmit heat very well. Gas is often used as an insulator to
prevent thermal transfer, not to enhance it.
Rod Speed
> I see a lot of "Radiant Floor Heating" with a rubbery tubing stapled
> under the floor. SInce I tend to be in horror of any kind of leaks, I
> wonder why they don't use some compresses gas instead?
Some do, including the Romans. Not so much compressed gas as just gas/air.
Plenty of solar air heaters use air as the transfer medium.
The 'tubing' required is substantially bigger tho.
> Mind you, I have even had experience with central venting "leaking": I haven't
> used a/c since my folks died but my uncle's a/c duct sweats onto my ceiling.
Thats a different effect, inadequately insulated ducts.
John Weiss
>
>> I see a lot of "Radiant Floor Heating" with a rubbery tubing stapled under
>> the floor. SInce I tend to be in horror of any kind of leaks, I wonder why
>> they don't use some compresses gas instead?
>>
>> Mind you, I have even had experience with central venting "leaking": I
>> haven't used a/c since my folks died but my uncle's a/c duct sweats onto my
>> ceiling. That's the price for freeloading (hot air rises) off his a/c.
>
> Gas does not transmit heat very well. Gas is often used as an insulator to
> prevent thermal transfer, not to enhance it.
Also, gas can leak just as easily as liquid -- in some cases (e.g., monatomic
molecules and/or high pressure).
However, you can also get under-floor heating that is simply electric resistance
heat. Not necessarily cheap or efficient, but you don't have to worry as much
about leaks...
Rod Speed
But you can still get failures in that which while not damaging anything
that matters, still need to be fixed if you want the heating to continue.
John Weiss
>>>
>>>> I see a lot of "Radiant Floor Heating" with a rubbery tubing
>>>> stapled under the floor. SInce I tend to be in horror of any kind
>>>> of leaks, I wonder why they don't use some compresses gas instead?
>> However, you can also get under-floor heating that is simply electric
>> resistance heat. Not necessarily cheap or efficient, but you don't
>> have to worry as much about leaks...
>
> But you can still get failures in that which while not damaging anything
> that matters, still need to be fixed if you want the heating to continue.
So what?!? ANYTHING is subject to failure! The OP SPECIFICALLY said he doesn't
want LEAKS!
Rod Speed
> Rod Speed <rod.sp...@gmail.com> wrote
>>>>> I see a lot of "Radiant Floor Heating" with a rubbery tubing
>>>>> stapled under the floor. SInce I tend to be in horror of any kind
>>>>> of leaks, I wonder why they don't use some compresses gas instead?
>>> However, you can also get under-floor heating that is simply
>>> electric resistance heat. Not necessarily cheap or efficient, but
>>> you don't have to worry as much about leaks...
>> But you can still get failures in that which while not damaging anything that matters, still need to be fixed if you
>> want the heating to continue.
> So what?!?
So that approach has some real downsides in addition to the ones you listed.
> ANYTHING is subject to failure!
SOME approaches are a hell of a lot easier to fix when they do fail.
> The OP SPECIFICALLY said he doesn't want LEAKS!
The OP is completely irrelevant to the advantages and disadvantages of various approaches to radiant floor heating.
ransley
Non liqued, yes its called forced air with ducts.
John Weiss
>
> The OP is completely irrelevant to the advantages and disadvantages of various
> approaches to radiant floor heating.
Gotcha. Now you're on record as saying the OP is irrelevant.
We'll see how long it takes to contradict yourself on this one...
Rod Speed
> Rod Speed <rod.sp...@gmail.com> wrote
>> The OP is completely irrelevant to the advantages and disadvantages of various approaches to radiant floor heating.
> Gotcha.
Just another of your pathetic little drug crazed fantasys.
> Now you're on record as saying the OP is irrelevant.
Never said anything even remotely resembling anything like that, liar.
> We'll see how long it takes to contradict yourself on this one...
Just how many of you are there between those ears, fuckwit ?
Pat
They make electric radiant heating systems but they experience the
same problems. The electricity sometimes leaks. That's why they put
those covers on electrical outlets in houses that have kids.
The only real solution is a hat made of aluminum foil. It works great
for electricity and all of those people listening to your thoughts.
Sometimes it even keeps the voices in your head quiet.
Jeff
> I see a lot of "Radiant Floor Heating" with a rubbery tubing stapled under
> the floor. SInce I tend to be in horror of any kind of leaks, I wonder why
> they don't use some compresses gas instead?
Nothing has a greater heat capacity than water (per pound). You would
need to run a *lot* of air through the system, that's why forced air
systems have large ducts and run hotter.
Even mini duct systems need to run the same *volume* of air as their
larger brethren. Now think of running several hundred cfm through even a
1" tube. Daunting and a lot of loss both in pumping and line loss.
Completely impractical.
Leaks really aren't a problem in underfloor staple up systems. The
runs tend to be in one piece for each room.
I believe the better underfloor systems use not "rubber" hoses but
PEX (cross linked polyethelene with oxygen barriers) with heat spreaders.
The only problem I've heard of with that (PEX) has been rodents.
Jeff
David Lesher
> Leaks really aren't a problem in underfloor staple up systems. The
>runs tend to be in one piece for each room.
> I believe the better underfloor systems use not "rubber" hoses but
>PEX (cross linked polyethelene with oxygen barriers) with heat spreaders.
Actually, the better installations I've seen have 2 interleaved runs
for a room. The idea is: if in fact one leaks, the other still handles
the room...
--
A host is a host from coast to coast.................wb8foz@nrk.com
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433
Eeyore
ransley wrote:
A miserable form of heating IMHO.
Graham
Eeyore
John Weiss wrote:
A few lies and contradictions will do it with no trouble.
Graham
Eeyore
Pat wrote:
> The electricity sometimes leaks. That's why they put
> those covers on electrical outlets in houses that have kids.
Tell me more about how this electricity 'leaks' please.
Are you 'trailer trash' by any chance ?
Graham
Rob Dekker
"David Lesher" <wb8...@panix.com> wrote in message news:gb937c$qm4$3...@reader1.panix.com...
> Jeff <jeff@spam_me_not.com> writes:
>
>
>> Leaks really aren't a problem in underfloor staple up systems. The
>>runs tend to be in one piece for each room.
>
>> I believe the better underfloor systems use not "rubber" hoses but
>>PEX (cross linked polyethelene with oxygen barriers) with heat spreaders.
Leaks in hydronic (water-based) floor heating systems used to be a big problem :
In the 60's, many hydronic floorheating systems were installed using copper pipes inside concrete slabs.
It took 30 years but most of these systems eventually start leaking at the pipe joints inside the concrete causing very tricky
leaks.
Leaks in piping in concrete is hard to locate (use helium gas detection method), you need to rip up your flooring, and jackhammer
into the concrete and fix the broken joint.
Very expensive leaks indeed.
Luckily, life got a lot easier with PEX (cross-linked Poly Ethylene).
Apart from being probably the future for all residential plumbing in general (replacing expensive copper plumbing), PEX is almost
ideal for hydronic floor heating systems.
PEX is very, very stable (corrosion free; lasts longer than your home), can handle high pressure if that may occur has flexibility
but is not 'floppy', so it is easy to install and it is much cheaper than copper too. Typically hydronic systems have a continuous
PEX loops, so that there are NO joints in the tubing that is under the floor. This again reduces chances of leaks, since leaks
typically occur at joints.
Basically the only way to get a leak in a correctly installed PEX hydronic system is if you drill into the floor (and into the PEX
tubing) or jam a nail through it. PEX is sturdy, but it cannot handle nails and drillbits.
Once you have a leak, it really depends on how accessible the tubing is if it is costly to fix or not.
If the tubing is inside a poured concrete slab, then fixing it is difficult and expensive.
If the tubing is 'staple-up' underneith an existing wood sub floor, then there is access to the tubing, and fix is easy.
If the tubing is in a 'sandwitch' on top of a sub floor, then of course you need to remove flooring to fix it, so it is difficult.
I have installed a hydronic floor heating system (with PEX tubing) in a sandwich on top of an existing concrete slab sub floor.
Installed 2 years ago.
It's working great, and the PEX tubing was not a problem at all to install.
Risk of leaks is only there when people start drilling into the flooring.
Pictures below
>
> Actually, the better installations I've seen have 2 interleaved runs
> for a room. The idea is: if in fact one leaks, the other still handles
> the room...
Actually, the interleaved runs are called 'counterflow' loops.
Counterflow loops minimize temperature differences on the floor, by placing inlet and outlet of a loop next to each other.
Multiple loops in a room are needed for pretty much any reasonable sized room, since the temperature drop limits the length of the
loops to about 250 feet.
I've never heard about installing loops so that one still works if the other is leaking. If anything leaks in the system, you want
to fix that before continuing. Unless you want to risk wrecking your hardwood (or whatever else you have installed on top of the
floor heating).
Here are pictures of my (PEX in a sandwich configuration) system under construction.
Some pictures also show counterflow loops with
http://viper.verific.com/WebSites/RadiantFloor
Regards
Rob
Jeff
>
>> On Sep 21, 12:57 pm, vjp2...@at.BioStrategist.dot.dot.com wrote:
>> > I see a lot of "Radiant Floor Heating" with a rubbery tubing stapled
>> > under
>> > the floor. SInce I tend to be in horror of any kind of leaks, I wonder
>> > why
>> > they don't use some compresses gas instead?
You can get electric radiant heating mats.
David Lesher
>PEX is very, very stable (corrosion free; lasts longer than your home),
....
>Basically the only way to get a leak in a correctly installed PEX
>hydronic system is if you drill into the floor (and into the PEX tubing)
>or jam a nail through it. PEX is sturdy, but it cannot handle nails and
>drillbits.
Or if it does not last as long as the venders claim it will. Obviously,
we don't have 50 years of experience with it.
I know it has temperature limits. If using a boiler, better have a
hi-temp monitor/safety.
>> Actually, the better installations I've seen have 2 interleaved runs
>> for a room. The idea is: if in fact one leaks, the other still handles
>> the room...
>Actually, the interleaved runs are called 'counterflow' loops.
>Counterflow loops minimize temperature differences on the floor, by
>placing inlet and outlet of a loop next to each other. Multiple loops
>in a room are needed for pretty much any reasonable sized room, since
>the temperature drop limits the length of the loops to about 250 feet.
Interesting; I thought they always started at the outside wall side
of the room, and returned from the inside. But I didn't lay the floor,
just designed the GSHP controls and installed them.
>I've never heard about installing loops so that one still works if the
>other is leaking. If anything leaks in the system, you want to fix that
>before continuing. Unless you want to risk wrecking your hardwood (or
>whatever else you have installed on top of the floor heating).
The idea was you can disconnect that one loop and use the other{s}.
>http://viper.verific.com/WebSites/RadiantFloor
The house I refer to had them cast in ?3-6"? of Gunite, with random slate
as the surface.
Rob Dekker
"David Lesher" <wb8...@panix.com> wrote in message news:gbbqsg$sjd$1...@reader1.panix.com...
> "Rob Dekker" <r...@verific.com> writes:
>
>
>
>>PEX is very, very stable (corrosion free; lasts longer than your home),
> ....
>>Basically the only way to get a leak in a correctly installed PEX
>>hydronic system is if you drill into the floor (and into the PEX tubing)
>>or jam a nail through it. PEX is sturdy, but it cannot handle nails and
>>drillbits.
>
> Or if it does not last as long as the venders claim it will. Obviously,
> we don't have 50 years of experience with it.
>
True. But there is 30+ years experience with it in Europe.
Also extensive durability and very stringent tests show that it is extremely stable in even very harsh environments (like inside
concrete) and/or using brutally hot water.
> I know it has temperature limits. If using a boiler, better have a
> hi-temp monitor/safety.
PEX comes in various ratings, but typically can handle close-to-boiling water under pressure easily.
My system is a closed-loop system driven from the water heater, and can't get any hotter than 130 F and low pressure (12 psi PT
relief valve on the loop).
But even if all safety measures would fail, the my (cheap) PEX can handle 100 psi at 180 F, so I feel pretty secure that something
else will blow out first.
>
>>> Actually, the better installations I've seen have 2 interleaved runs
>>> for a room. The idea is: if in fact one leaks, the other still handles
>>> the room...
>
>>Actually, the interleaved runs are called 'counterflow' loops.
>>Counterflow loops minimize temperature differences on the floor, by
>>placing inlet and outlet of a loop next to each other. Multiple loops
>>in a room are needed for pretty much any reasonable sized room, since
>>the temperature drop limits the length of the loops to about 250 feet.
>
> Interesting; I thought they always started at the outside wall side
> of the room, and returned from the inside.
That's often used for in-slab or slab-on-slab floor heating, where you have total freedom of putting the PEX wherever you want.
The idea is that the outside of the room (where the windows are) should get the warmest, since they experience the most heat loss.
With that you can even use put the PEX lines closer to each other at the windows, and further away in the center.
Using a panel sandwich system, I had more restrictions because of the pre-set groves in the panels.
Also, the panels are less good at distributing heat between the PEX tubes than a slab-on-slab, so I was concerned about local heat
distribution also.
So to avoid local hot spots and cold spots, I used counter-flow loops.
I just made sure that the loop that serves the window sides is a bit shorter than the other loops, which results in average higher
temperature and higher heat throughput than the loops that serve more of the center of the room.
> But I didn't lay the floor,
> just designed the GSHP controls and installed them.
>
Cool. I did not go that far. How much piping went into the ground ? How deep did you have to go ?
What were the economics calculations of such a ground-heat system versus other heat sources ?
What was the water temperature requirement for the floor heating system ? How did that affect your GSHP specs ?
I wonder how that system looks like. Have any pics ?
I currently use my water heater as a heat source, but are now planning to hook that up to DHW solar panels to get some heat from the
sun.
>>I've never heard about installing loops so that one still works if the
>>other is leaking. If anything leaks in the system, you want to fix that
>>before continuing. Unless you want to risk wrecking your hardwood (or
>>whatever else you have installed on top of the floor heating).
>
> The idea was you can disconnect that one loop and use the other{s}.
>
OK. Makes sense, especially in emergency situations.
But often a leak did already do water damage to the flooring before we find it out, so I would think that it requires fixing either
way.
>>http://viper.verific.com/WebSites/RadiantFloor
>
> The house I refer to had them cast in ?3-6"? of Gunite, with random slate
> as the surface.
I think that's called a insulated sandwich slab-on-slab. Great system !
Over existing slab, put 1 inch (or more) insulation, lay out rebar and PEX tubes, and poor a couple of inches of concrete over it
for the new floor.
Cheap and fast to build, and excellent floor heating : relatively fast response (as opposed to putting PEX in the slab itself),
energy efficient (due to the insulation) and great heat distribution (no risks of hot spots). Slate (or any tile) finish is also
close to perfect for floor heating : high heat conductance, so the floor feels very comfortable.
Downsides are that the system is pretty thick (4 inch minimum) and that water temps need to be relatively high (140 F and up).
I had only 1 inch space for the floor heater plus finished flooring, or else would get in trouble with all doors and some windows.
That's why I chose this panel system. It's insulated (3/4 inch thick enforced polystyrene) and topped with alu strip for heat
distribution.
Finished flooring is hardwood and backerboard+tile. The tiled part is most comfortable.
Apart from the ultra-thin design, another advantage the panel system (with alu fins) like mine (as opposed to a slab-on-slab) is
that the water temp is low. Rarely higher than 110 F, or else the floor gets uncomfortably hot. Disadvantages are that the panel
system is more expensive, less 'solid', and risks of hot spots (if loop layout is not carefully designed).
David Lesher
>PEX comes in various ratings, but typically can handle close-to-boiling
>water under pressure easily.
>My system is a closed-loop system driven from the water heater, and
>can't get any hotter than 130 F and low pressure (12 psi PT relief
>valve on the loop). But even if all safety measures would fail, the my
>(cheap) PEX can handle 100 psi at 180 F, so I feel pretty secure that
>something else will blow out first.
I'm talking degradation, not sudden pressure failures...I'll let you find
out if it's true...your tubing is easy to replace.
>> But I didn't lay the floor, just designed the GSHP controls and
>> installed them.
>Cool. I did not go that far. How much piping went into the ground ? ?
>How deep did you have to go What were the economics calculations of ?
>such a ground-heat system versus other heat sources What was the water ?
>temperature requirement for the floor heating system ? How did that ?
>affect your GSHP specs I wonder how that system looks like. Have any ?
>pics ?
Well, it was that or propane; and the 10 years since have proven
the wells a wise choice.. but it was lots of capital. [3 wells,
~250 ft deep.]
I don't have any pictures. I think there are 12 floor zones and
6 FCU's used for AC as well.
>I currently use my water heater as a heat source, but are now planning
>to hook that up to DHW solar panels to get some heat from the sun.
We installed a spare 40 gal in case of a GSHP failure or lengthy power
outage. My SWAG showed it would keep the house about freezing. It's never
been used; when occupied & fed, the 2 wood stoves can drive you out onto the
porch in a blizzard, if fueled with pine.
The desuperheater feeds the domestic HW tempering tank.
>> The idea was you can disconnect that one loop and use the other{s}.
>OK. Makes sense, especially in emergency situations. But often a leak
>did already do water damage to the flooring before we find it out, so I
>would think that it requires fixing either way.
Hard to damage concrete with a little water.
>I think that's called a insulated sandwich slab-on-slab. Great system !
>Over existing slab, put 1 inch (or more) insulation, lay out rebar and
>PEX tubes, and poor a couple of inches of concrete over it for the
>new floor.
This IS slab; installed at construction. Yes, it is slow response.
>Downsides are that the system is pretty thick (4 inch minimum) and that
>water temps need to be relatively high (140 F and up).
No way. I have to think but I recall our upper limit is 30C. With
a GSHP, it costs exponentially more to raise the loop temp.