Editor's note:The Energy Services Bulletin features real answers to real questions posed to our staff at the Energy Services Power Line. We hope you find it useful.

Question:

An auto body repair shop wants to add heaters for worker comfort in their 32' x 48' open-space building. They don't want a forced-air system so they are considering radiant (infrared) heaters. Can you recommend any specific radiant heating systems, and advise us on sizing and positioning the heaters?

Answer:

Most radiant heating system manufacturers will provide information about distributors in your area. Online directories, such as infraredheaters.info and infraredheaters.net, are a good place to begin your search for manufacturers. These companies often provide the layout support your customer will need. Heating contractors can also provide assistance.  Call four to five contractors and ask them about their experience and the number of radiant heater jobs they have done. Try to visit the sites where they installed systems.

Radiant heaters work particularly well in applications such as garages because they warm people and objects in a space without heating the volumes of air in between. Infrared heaters can also be used for freeze protection by focusing the heaters on areas where freezing could cause damage. This direct heating saves a considerable amount of energy, too.

Designing an infrared heating system for comfort control is subjective—it depends on the degree of comfort that you want and the size and layout of the garage. Infrared heaters can be cycled to run only when cars are being repaired, and be locked out through thermostats to turn off when outside temperatures are high enough to maintain comfort. A heating contractor might be able to give you more specific recommendations for locations and sizes of heaters.

If energy conservation is one of the reasons for installing a radiant system, it is important to be aware of control strategies.  Various reports suggest using conventional setback thermostats to reduce the temperature by 5 to 10 degrees during unoccupied hours. Also, using ceiling fans to control thermal stratification enhances comfort and saves energy. Make sure that thermostats are not located within the "radiant zone," so as to provide a true measure of air temperature.

Related articles and fact sheets

• Radiant Floors Create More Comfort, Use Less Energy
  Energy Source Builder article: radiant floor heating

• Research Supports Benefits of Radiant Ceiling Panels
  Article describes the research and benefits of radiant ceiling panels.

• Thermal Energy Storage for Small Commercial Buildings (.pdf)
  A fact sheet on thermal energy storage from the Energy Center of Wisconsin.

Organizations and programs

• Radiant Panel Association
  A trade organization for the radiant panel industry – contractors, wholesalers, manufacturers, and designers. Offers tech notes, publications, design guidelines, membership information and an education program.

• Energy Star-labeled heating and cooling products
  Official Energy Star Web site from the U.S. Environmental Protection Agency.