Floor heat – whether it is electric cable or hydronic tubing – offers efficient heat when installed properly and designed for the cooperative’s off-peak electric heating rate. Electric cable is resistance heat commonly placed in sheetrock panels spread throughout the area needed to be heated. Hydronic heating systems use resistance coils in an electric boiler to heat a liquid (water or an environmentally friendly antifreeze solution), which is then circulated to transfer heat.
While there are many ways to install these systems and be comfortable, creating a heat storage base to utilize the cooperative’s cycled off-peak program is an excellent way to maximize comfort and affordable operating costs. Being on off-peak requires an automatic backup heating source during times when the electric heat is being controlled (off).
Having a recommended heat storage base of 12 inches for electric cable and 6 to 8 inches of sand for hydronic tubing will create such a back-up heat storage base to comfortably heat the space during the cooperative’s cycled control periods. During a control period, the heat that is stored in the earth and sand below the concrete slab radiates upward to evenly heat the floor and objects, and keep the air at a consistent temperature.
With our current cycled off-peak program, floor heat is cycled from Nov. 1 to April 30 on a timed schedule. In a 24-hour period, the electric floor heat would be cycled (off) for a total of 11 hours and on a total of 13 hours per day, and could be controlled up to 16 hours per day if regional energy use was high.
Red River’s current off-peak electric heating rate is about half the cost of the regular electric rate and competitive versus propane and fuel oil. Remember, having a professional install the floor heat electric cable or hydronic tubing for the cycled off-peak program is extremely important. The key to comfortable and affordable operating costs with cycled floor heat is having a proper heat storage base with enough reserves to keep the building comfortable on cold days. The floor heat storage system must be built before the slab is poured. Perimeter insulation is extremely important to prevent heat loss (click on diagrams below).
Red River Valley Co-op Power has a pamphlet detailing the steps a trained installer should take to design a total electric cable floor heat off-peak system. Copies will be sent out upon request. We also have a diagram of a hydronic installation, courtesy of Electro Industries.
Tips for hydronic on off-peak
For a hydronic underfloor storage system, please keep the following recommendations in mind when discussing cycled off-peak floor heat with your contractor:
- Insulate around the whole perimeter of the foundation down at least 2
feet, being sure not to stop at the driveway apron.
- Make sure that a floor sensing thermostat is installed instead of an
air thermostat to regulate the temperature.
- Make sure you check the water table if you are building in an area with
possible water problems.
- Install 2-inch rigid board insulation to go below the sand and hydronic
tubing for increased efficiency and to stop moisture.
An important note: floor heat without the heat storage bases listed above can be on off-peak with another automatic backup fuel source like a gas furnace or boiler. For more information on our off-peak program, please call member services.