Environmental Leadership Center
Warren Wilson College
Campus Box 6323
P.O. Box 9000
Asheville, NC 28815-9000
Please refer comments or questions about this website to Ellen Querin.
What It Is:
Radiant floor heating is a method of heating that applies heat from underneath or within the floor. There are three types of radiant heating: hydronic, electric, and air.
Hydronic radiant floor heating is a system of plastic or metal tubes/pipes laid within a floor that carries hot water into specific rooms or “zones”, dispersing the heat through the floor surface. The cooler water returns to the heat source where it is reheated and sent out again in what is known as a “closed-loop system”. The pipes can be encased in a concrete slab, a concrete or gypsum cement overpour, laid into thin grooved panels that nail on top of a subfloor, or suspended below a wooden subfloor using metal fins fastened under the floor surface.
Why We Do It:
Energy Efficiency –
Energy is conserved as heat comes from the floor where it is desired as opposed to being pushed toward the ceiling as in forced air heating systems. In addition, radiant floor heating systems provide the same heat benefits as forced-air systems when set 3 to 4 degrees lower than these traditional systems. A third benefit of the radiant floor heating system in conserving energy is the break up of the building into zones, which allows for different temperatures suited to various needs.
Air Quality –
Hydronic floor heating does not stir up allergens, dust, or dirt. Studies show a significant reduction in dust mite populations
The hydronic systems can be heated with a wide variety of energy sources, including standard gas- or oil-fired boilers, wood-fired boilers, solar water heaters, or some combination of these heat sources. This allows one to choose the option that is best for them.
How We Do It:
The Warren Wilson College EcoDorm is heated with hydronic radiant floor heating and is divided into many zones to allow for optimum adaptability to varying needs and energy consumption. The photovoltaic solar panels (link) behind EcoDorm are used to heat the hot water that flows through the pipes. This system is backed up by natural gas.
How You Can Do It:
There are three types of radiant floor heating: air, electric, and hydronic. Of these three types hydronic is thought to be the most cost-effective and most popular of the options and involves the closed loop system discussed above.
Types of installations include “wet” installations and “dry” installations. Wet installations involve tubing embedded directly into a floor that is constructed of concrete, gypsum, or other material that will retain and disseminate heat. The benefit of this type of installation is the ability of the material to store heat however slow response time may make daily setbacks difficult to achieve. Dry installations involve tubing which runs through an air space beneath the floor surface. These systems are faster and less expensive to build but require the heating to be maintained at a higher temperature.
Costs associated with radiant floor heating are estimated at $600 - $800 per hundred square feet. It is important to consider the costs of this system with regards to the energy and associated costs that are saved with the ensuing increase in efficiency.