Solar assisted radiant floor heating system

 Hi guys,

I am planning on building a radiant floor heating system, which will run off a
(the) water heater.

I want the floor heater to have maximum efficiency. Obviously for energy
conservation, but also because I want to make a serious
attempt to get to energy-zero at least for heating, using DHW solar panels.

The house has a concrete slab, and I plan to first put a layer of insulation
material down, then a snake pattern of PEX tubing, and
then the actual floor (hardwood or laminate) on top.
I would like to know if somebody has experience with (building yourself, or
using a commercial) floor system like that.
And then, obviously, which important issues I will be facing. Like :

- How to make the system strong enough so it can hold up the wood floor ?
- What type of insulation material is best to use ? How thick should it be to
avoid more that 10 or 20% of the heat to disappear
down into the concrete slab ?
- How to thermally attach the PEX tubing to the floor above ? Aluminum strips ?
submerge in a hard thermally conductive compound ?
- Any links to / experience with commercial systems ?
- How good (efficiency, strength, thickness) are various solutions ?
- Any other tips and things to keep in mind ?

Any advice wouold be greatly appreciated..

Thanks !

Rob

  First stop:
http://builditsolar.com/SiteMap.htm
Then maybe:
http://www.radiantcompany.com/details/
http://www.trendsetterindustries.com/radfloorheating.html
http://www.thermo-dynamics.com/solar_radiant_heat.html


(the) water heater.

conservation, but also because I want to make a serious

material down, then a snake pattern of PEX tubing,

using a commercial) floor system like that.

avoid more that 10 or 20% of the heat to disappear

? submerge in a hard thermally conductive compound ?

 
Rob Dekker wrote:

(the) water

Does it have to be a water heater, or can you support the needs of a
boiler? Temperature rules in radiant fluid heating systems.


conservation, but also because I want to make a serious

Consider the vacuum tubes instead of the flat plates. They give higher
performance in the off-peak seasons, when you need the heating. Bur
remember you'd need a dump load in the peak seasons, then.


material down, then a snake pattern of PEX tubing, and

Usually a cement layer contains the PEX, but alternatively, there is a
plywood sheeting available with the proper cut-ins to take the tubing.
Then you lay the flooring on top of that.

Wood isn't the best conductor of heating, though. Tile would be better,
especially if the house design is passive solar.


using a commercial) floor system like that.

Cutouts, cement, spacers... there's a variety of ways.


avoid more that 10 or 20% of the heat to disappear

Thicker is better. Most often I see a few inches of blue syrofoam under
the slab, then that "foil stuff" under the PEX.


? submerge in a hard thermally conductive compound ?

The floor below, actually. Often, folks use screening traditionally
used for reinforcing concrete, and tie it off to that.


Zone it definitively and intelligently. Pump it as fast as you can.
Keep the fluid as hot as possible.

DJ

 

Even with an overhang for summer shading? Bummer.


Warmboard.

Nick

 
nicksans...@ece.villanova.edu wrote:

Vacuum tubes can make a huge amount of heat, which, when for space
heating, is exactly what you want. However, you bring up a very
interesting idea. If only a few tubes (10-30) were mounted in a
location that was year-round solar exposed, dedicated for SDHW use, and
the rest of the array was wall mounted with an overhang that shadowed
it during peak summer, exposing it during late fall to early spring,
that might well solve that problem. Interesting idea. Increased
installation costs, but might potentially save on the dump load...


Thanks Nick. I forgot the brand!

DJ