Hot Topic: Your comfort on the shop floor

Feb. 1, 2004

By Emily Refermat

Ever wonder about the heat at your job? You're probably more concerned about what you're doing on the job. Heat is an invisible amenity until the day you come to work and it's as cold inside as out. Maintenance buildings are especially difficult to heat because of the high ceilings and large doors opening and closing daily.

If you suddenly find yourself distracted by the cold and in need of a new heating system here are some heating technologies worth looking at.

Going beyond forced air
Most people are familar with forced air heat. A furnace heats air and sends it into ducts and out through vents. In a hangar the warm air rushes out and hangs in the upper reaches of the ceiling, as hot air rises. More hot air is pushed out until the temperature on the shop floor reaches the desired temperature, say 70 F. Temperatures near the ceiling might be closer to 80 F or 90 F.

Thomas D. Lester, vice president of sales and marketing at Solaronics Inc., says, "That's the problem with these forced air unit heaters. Because in order for the air on the ground to be warm, [the heaters need] to blow out air to heat the whole building from the ceiling down." Instead Lester recommends infrared heaters, which use technology similar to the sun, to warm surfaces and not air.

For large buildings, like a hangar, an infrared system will be much more efficient and comfortable for the mechanics on the floor, Lester begins. Infrared heaters start with a burner and transfer the heat down a tube or through ceramics The exterior reflector "beams" the infrared waves from the heat down to surfaces below. "There's no air involved in the transfer of heat," which means there are no drafts. The temperature is controlled by thermostat, which tells the system when to cycle on and off.

When the infrared rays touch anything solid, a person, the floor, a bench, etc., they warm that surface. The heat then radiates from that surface back up to warm the air around you, not the air near the ceiling. The biggest benefit of infrared heating systems is your recovery time, says Bob Genisol, vice president of sales and marketing for Space-Ray Infrared Gas Heaters. In a Space-Ray case study the hangar door was open for 30 minutes. Once the door was closed again the concrete slab that had absorbed the heat before and during the door being open, radiated heat so fast that after only 22 minutes the temperature was the same as before the door was opened.

Infrared heaters are made maintenance-free, mostly because they are suspended from the ceiling per NFPA code 88. "You're not going to maintain these heaters when they are mounted [so] high," says Genisol, "so we provide them with motors that do not require any lubricant for the life of the heater," as well as, "ignition systems and gas systems that are good up to 1 million cycles."

When you look at installation costs, Genisol says, you might pay 10 to 30 percent more for an infrared system, but according to the payback analysis, one year of your savings will pay for the project. Infrared heaters can deliver 50 to 70 percent fuel savings.

Infrared systems heat the floor and allow radiant heat to rise, but what if your heat came from the floor enabling you to use the principle of hot air rising, to your advantage. That's what Infloor Radiant Heating Inc.'s in-the-floor heating systems are based on. Infloor® offers tubing, much like a heavy-duty garden hose, which runs through the floor of a building. Hot water is then run through these tubes, radiating heat. Chris Wasley, general manager for Infloor, says, "Concrete is an excellent thermal mass for distributing the heat generated by the hot water and tubing, giving an even heat across the floor and throughout the hangar building." Radiant floor systems are quiet, comfortable, and unseen. They are even used in approaches and ramps to melt snow and ice.

The application of an Infloor system does have a drawback; it's not really feasible to use as a part of a heating retrofit. Wasley says, "It would be very difficult to convert an existing hangar to a radiant floor application because of the labor involved in replacing the existing concrete floor with tubing and new concrete."

The water used in these systems is heated by a boiler in some central location.

The boiler and the furnace
A company called Clean Burn has an interesting product available either as a boiler or a furnace, a unit that burns used motor and engine oil for heat recovery. Commonly seen in auto repair and truck maintenance facilities, used oil furnaces and boilers are also used in aircraft maintenance facilities, and other locations where significant amounts of used crankcase oil, transmission fluid, and hydraulic fluids are collected.

Mark Nicholas, spokesperson for Clean Burn, says if a facility produces 1,000 gallons or more of petroleum based products a year, (and yes, Thom Elmire, service manager at Clean Burn says there is "no problem burning aviation specific oils"), a clean burn used oil furnace or boiler will pay for itself.

If you work in a climate where winter is not just a winter wonderland, but a concern for your comfort, then look over these options and see if any of them would make your working conditions more comfortable.

Additional ReSources

Solaronics Inc.
(800) 223-5335

Space-Ray Infrared Gas Heaters
(800) 438-4936

Infloor® Radiant Heating Inc.
(800) 588-4470

Clean Burn
(877) 216-0359

(800) 222-1100

Research Inc.
(952) 941-3300

About the Author

Emily Refermat