Heat From Under Our Feet
One of our goals with the TREE House is to implement a variety of green technologies, materials, and strategies in order to be able to share information with visitors about how (and how well) they work. With the guidance of our Construction Manager Jim Zella, we recently installed a radiant floor heat system in our basement and future classroom.
Through a network of wires or tubing set beneath the floor level, radiant floor systems circulate hot air, electricity, or hot water to warm the thermal mass of the floor (they can be installed in walls too). This transforms floors into surfaces that provide even, steady heat, supplementing the warmth we try to generate in our homes when it’s cold outside. Radiant floor systems have a number of clear advantages, they are:
- efficient, putting the heat where you live, and not up above your head (our system is water-fed, i.e., hydronic, the most efficient of the three styles).
- quiet, virtually silent, with none of the engine-like sounds of furnaces blasting on or off.
- cost-effective, saving you money on monthly heating bills.
- hypoallergenic, with no dust mites being distributed through ductwork or hot dry air to irritate asthmatics.
- easy to install, as you can see from the pictures below.
Getting wire mesh panels down and connected. (Pictured here, students Zach Baker, Caitlin Joseph, and Devlin Geroski.)
Rolling out the tubing in looping patterns in our three “zones” and tying it to the wire mesh. Each zone contains 300’ of tubing and its own return and supply connection to the manifold. (Pictured here, me wrestling with what feels like a giant slinky, Jim Zella in the background, Zach Baker in foreground.)
Voila! Now that the tubing is installed, we’ll add a layer of concrete and, over that, our floor.
Our system includes a dual purpose water tank that will heat water for the radiant system and for general use in the house. This may not be a good option for a more typical home with higher hot water demand. Our costs break down as follows:
- wire mesh: $200
- manifold and tubing: $758
- dual purpose water heater: $2,000
A recent "Scientific American" article explains that efficiency gains from a radiant floor system "can be magnified significantly with good insulation and a well-designed system," saving households hundreds of dollars a year. In a nutshell, "while tearing out old heating systems and/or replacing decent existing flooring might be overkill for the sake of moving to radiant heat, those embarking on new building projects or contemplating major renovations should certainly consider it." Some states offer financial incentives to upgrade the energy efficiency of home heating systems. To learn more about tax rebates or other incentives available here, check out the Database of State Incentives for Renewable Energy (DSIRE).