DIY Hydronic Floor Heating

[Geo NR Gee]

Has any of you used the foil backed foam board for the staple up plates on the radiant floor heating? Sitting here in my living room with cold feet and thinking how nice it would be to have that warm feeling.

[pachai]

Originally Posted by Geo NR Gee

Has any of you used the foil backed foam board for the staple up plates on the radiant floor heating?

I don't know how well that would work, as the plates serve two purposes....conducting the heat and holding the pipes in place.

It *does* make sense to me to use the foiled insulation in addition to the plates, to cut heat "loss." That would make heat circulation more real time. But I put the loss in quotes,
because (except perhaps in the basement), the tubes are in the heating envelope. If they "lose" the heat, where is it likely to go? ...Into the thermal mass of the structure...
(my opinion).

BTW, I don't have the thremostat wired up yet,
so based on the day's performance, I set the pump up for a 50% duty cycle. My pump is plugged into a widget that delivers 110V only when it gets 1vdc-12vdc....so I can use a thermostat in the future, but for now, I shorted the wires, and plugged the transformer for the relay widget into a 24-hour timer so every other on/off setting is on - approx 50% duty cycle.
It's too much, it was hot in the affected area this morning. (Thermostat:tonite? :-)

[AC_Hacker]

Originally Posted by Geo NR Gee

Has any of you used the foil backed foam board for the staple up plates on the radiant floor heating? Sitting here in my living room with cold feet and thinking how nice it would be to have that warm feeling.

If you do not have a basement, and the area you want to heat is on the ground floor, you will have heat loss. The foil faced insulation board is a very good idea for your situation. In fact, if you want radiant floors, you would want the maximum insulation between your heated floor and the unheated space below, if that is the case.

And staple up with spreader plates will work for your house, but the feed temperatures required to drive the heat into the living area will be fairly high, in the order of 160F and up. You will not be able to get this temp with a heat pump... the current technology goes to about 120F to 130F... your feet will still be cold.

There are above floor solutions that will do it however. There is a company named WarmBoard that makes a product that should work well. Their first product was a hydronic subfloor system that would get put in before the floor went down. They just started making a top of floor product that can go over the sub floor.

What makes WarmBoard good is that the entire panel is covered with relatively thick (twice as thick as other similar systems) aluminum which conducts the heat evenly over the entire surface. This product will work with heat pump hydronic feed temps. Robust insulation is still required.

There are other manufacturers of similar aluminum-surfaced systems that will likely need gas or oil or electric boilers.

There is another option, which is electric floor heating mats that you could put on the floor in the areas of your house where you spend "down time". Again, robust insulation should go under the heated area.

-AC_Hacker

[Geo NR Gee]

Originally Posted by AC_Hacker

There are above floor solutions that will do it however. There is a company named WarmBoard that makes a product that should work well. Their first product was a hydronic subfloor system that would get put in before the floor went down. They just started making a top of floor product that can go over the sub floor.

What makes WarmBoard good is that the entire panel is covered with relatively thick (twice as thick as other similar systems) aluminum which conducts the heat evenly over the entire surface. This product will work with heat pump hydronic feed temps. Robust insulation is still required.
-AC_Hacker

Thank you for the suggestions. After reading about WarmBoard, I see some contractors are saying that it is a very expensive product at over $200 per 4x8 sheet, but the product is the cadillac of heated flooring products. They did suggest another product that was less expensive and it looks pretty good. Its Quik Trak or from the mfg. Uponor

Originally Posted by AC_Hacker

There is another option, which is electric floor heating mats that you could put on the floor in the areas of your house where you spend "down time". Again, robust insulation should go under the heated area.

-AC_Hacker

That is another option, thank you.

Geo

[pachai]

Now that I am circulating hot water, I am able to contemplate how to heat it. Right now, I am using
an electric HW heater, because it cost a fraction of the cost of a "solar" tank, and it has built-in backup heat.
Electric is not an ideal way to heat water, but the fact is, half of my electricity is from solar PV, and it should improve next year.

I'd like to bounce ideas for how to heat off
anyone who has done such....

1. The best part of my roof is occupied by PV panels,
but a) There is about 80 square feet available on a
SSW roof and b) There could be room for one parabolic trough 30' long on this same roof
b) There are 375 square feet available on the WNW roof, with a very shallow angle. I was thinking I could put up a few parabolic troughs, and tilt them ESE or even S. - I don't think I can put up panels of any sort at an angle.

2. I have a hugely oversized gas boiler for heating the parts of the house that don't have Hydronic Radiant (YET). The boiler does not have an opening to add a heat exchanger inside it, but I may be able to take hot water OUT and run it through a heat exchanger and bring it back. (the best would be to get a bushing so I can route it through my Hot Water Tank and out, while keeping it isolated.) I am thinking of putting a few lengths of 1/2" copper on either side of one return pipe and see how much heat I can recover. This could be done with another pump or perhaps just a valve that enables that loop when safe. I could also add a pipe with a vent to be a "radiator" just for this.

3. In the summer, I want to put pipes in the ground (I mentioned that hope once before). They could be water pipes to any depth, but if I DIY, it will be 5'
Or, they could be copper (ie.,for refrigerant) down to 10' - I need to discuss with the City. OR, a friend who is a plumber said he knows a driller. For cooling, pump and dump, a heat pump might not even be needed.

I appreciate any suggestions.

[ThomSjay]

Originally Posted by pachai

1. The best part of my roof is occupied by PV panels,
but a) There is about 80 square feet available on a
SSW roof and b) There could be room for one parabolic trough 30' long on this same roof

My limited knowledge says that a reasonably high flow rate would be needed for that length.

Originally Posted by pachai

3. In the summer, I want to put pipes in the ground (I mentioned that hope once before). They could be water pipes to any depth, but if I DIY, it will be 5'
Or, they could be copper (ie.,for refrigerant) down to 10' - I need to discuss with the City. OR, a friend who is a plumber said he knows a driller. For cooling, pump and dump, a heat pump might not even be needed.

I appreciate any suggestions.

Isn't copper a no-no for in the ground due to electrolysis? Any other metal would rust out after a time. I may be wrong, but I think plastic would be better.

[lt190b]

have there been any new developments on this <wonderboard>? lt190b

[randen]

Geo NR Gee

The staple up from beneth the floor dosen't work. I had tried that in a bedroom over a heated garage with sprayed insulation between and the room was cold. Even with the tubes 8" apart and hot water (160 deg F) running 24/7 "no heat". Best having the tubes running on top of the 3/4 ply in the warm board or quik trak with a ceramic tile over that. If your good with a router I can see why you can't make your own with 1/2 ply and aluminum sheet stock. The warm tile in the morning when you feet touch it is almost therapeutic.

Randen

[Geo NR Gee]

Randen,
Good to know, thanks

[AC_Hacker]

Hey Vlad,

When you were putting in these floors:

...did you use stamped transfer plates like this:

...or did you use an extruded transfer plate like this:

The reason I'm asking is that in my investigations of high performance radiant floors, the thickness of the aluminum seems to have a very large impact. For instance, Warmboard has higher specs than any similar product, and the only difference I can see is that it has a thicker aluminum layer... like .025" instead of .008" or .012" or .018" as the other products had.

The extruded aluminum spreader plates are an amazing .062" thick, compared to the typical .018" that is usually seen in stamped spreader plates. Their price is higher by almost exactly the same ratio of thickness, too.

Also I am wondering if your floors make the popping noise I have read about?

Did you use oxygen barrier coated PEX or PEX-Al-PEX?

-AC