Radiant Heat Thermostats, Radiant Floor Heating Thermostat
Thermostats (Air and Slab)
Our radiant heat thermostats are easy to read, electronic, very sensitive, and use no mercury.
Radiant floor heating thermostats should have a +/- 1 degree differential.
All thermostats have a differential - that is the difference between the temperature at which the thermostat is satisfied and the temperature at which it calls for heat. The temperature you set on the thermostat sets the temperature at which the thermostat is satisfied. However, if it has a four degree differential and you set it for seventy degrees; that means it will be sixty-six degrees before the heating system will begin to respond. Most radiant heat systems will drop another couple of degrees before they start catching up. That means the air temperature could drop to as low as sixty-four degrees. Because the room is too cool you might then set the thermostat higher in an attempt to catch up. Of course that will result in a room that is too warm once the system does catch up. A low differential eliminates this problem.
Number of radiant floor heating thermostats needed
It isn't practical to put a radiant heat thermostat in every room. At best the system becomes expensive and complicated, and it may not work or work very effectively. As a general rule, areas that are open to each other are on one thermostat. If you have a small basement, one thermostat will probably work. If the basement is very large or has separate spaces used for different proposes, you may need two thermostats. If the garage is heated it will require its own thermostat. As for the main floor, smaller homes will typically need one for the living area and one for the sleeping area. Large homes may use three or four radiant heat thermostats for the main floor area. Small upper floors with a couple of bedrooms and a bath typically use only one thermostat. Larger upstairs areas may require two thermostats or more.
Often people will want to put a bathroom on its own thermostat because they want to "bump" the temperature up while they are in the shower. Setting aside the control/mechanical problems of small, isolated zones, many hydronic radiant systems are not responsive/fast enough to provide the instant on/off heat they are looking for. We recommend installing the infloor radiant heat system as the primary heat source tied into adjacent rooms for installation and control simplicity. That will provide the basic heating needs for the space. Installing either an electric cable/mat system under tile or a wall mounted electric heater can then be used to provide the instant on/off heat when you want it.
Slab Thermostats vs. Air Thermostats
Some hydronic radiant heating systems with tubing installed in a concrete slab can benefit from the installation of a "slab thermostat". These devices have a probe or sensor that is inserted into a conduit pipe (capped) embedded in the slab. They measure and control the temperature of the slab directly and the room temperature "falls out" as an indirect result of the slab heating and cooling. They are typically more expensive than standard air thermostats and don't result in better system performance except in some specific situations.
One such situation is where there is the potential for significant solar gain. If you have a slab in a room where there are lots of windows that allows the sun to beat down on the slab you run the risk of overshooting the setting of an air temperature thermostat. In other situations, it may be difficult to find a location for a room thermostat where it will not be suject to drafts or other spurious temperature fluctuations. Finally, it may be as or more important in some cases to insure a constant slab temperature as it is a room temperature.
Inquire with one of our sales folks if you think you might have one of these situations. One or more of our slab thermostats might be best for you.
