Return to the Remodeling Forum | Post a Follow-Up

 o
Radiant heat inside holow composite decking

Posted by uniberp (My Page) on
Fri, Nov 26, 10 at 22:09

I want to put a raised floor in my sunroom, 2" above the concrete deck. I think the easiest thing to do would be to put decking on 2x joists. If I use hollow core composite deck mmaterial, has anyone put radiant electric wires through them to provide floor heat? I'd also put down a layer of foiled styrofoam to reflect up.

I think I might make the floor sections removable, because it is used as a garden room and would collect a bit of dirt under the floor.

Doing both would require some special connections, I'm sure.

thanks for helpful opinions


Follow-Up Postings:

 o
RE: Radiant heat inside holow composite decking

Composite materials might not be able to accept the heat or conduct it well enough to radiate it to the room effectively. Find out what the conductivity and emissivity of the decking is and ask what materials the wiring can be placed directly against. Being able to disconnect the cables may not be allowed by the electrical code.

Heat of this nature is first conducted through the decking material and then radiated by the face of that material through the air of the room to objects in the room. Of course, the flooring also heats the room by convection.

Insulation added below the decking will help to reduce heat loss downward and increase heat movement upward but if you want to also use a radiant barrier to help with that effect (I doubt that it does much at that temperature) at least a 3/4" air space is necessary since otherwise the energy transferred will be by conduction through the foil and the other materials in contact with it instead of by radiation and there will be no benefit. In a house, radiant heat can only exist in air. Therefore, it is not the heating cables that provide "radiant" energy, it is the warm surface of the flooring/decking where it is in contact with air.

I suspect increasing the thickness of the extruded polystyrene foam board (Styrofoam) would be just as effective if not better.

Don't burn the house down to save energy.


 o
RE: Radiant heat inside holow composite decking

If your room is enclosed you may want to consider heat panels as a way to heat it.
We installed the panels in rooms that are in DS's horse barn 2 years ago. The tack room is 14x28' and 2 of the panels supply more heat than is needed. They can be connected to thermostats or timers, but I recommend you use thermostat to keep the room at a set temp.

I know this isn't an answer to your question, but I thought it may work for what you're needing.

I have no affiliation with this company............

Here is a link that might be useful: e-heat


 o
RE: Radiant heat inside holow composite decking

Thanks.

How would I find out what the "conductivity and emissivity of the decking is" without conducting my own lab tests?

They put (certain kinds of) heating wires under carpet and laminate, so I think they would work. The composite has exterior quality durabilty.

At any rate, I'm starting with hollow core decking. Maybe I can even put PEX tubing through them for hydro-radiant. It would probably work much better than wires anyhow.

It's all glass 4 sides to the floor (Mounted to house at picture windows) and roof, so no room for vertical panels.


 o
RE: Radiant heat inside holow composite decking

The emissivity of the composite material is probably similar to wood and/or plastics which is probably good enough; the larger issue is how well it conducts heat if it is hollow since it would radiate infra-red energy from all surfaces.

The best commonly available radiator of infrared energy is a thick conductive metal with a large surface that has a dull finish, like cast iron which works well even with (non-reflective) paint on it. The worst would be polished aluminum.


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Remodeling Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here