What makes auto body shops so difficult to heat during the cold season? To shop owners, the answer is obvious. Auto body shops are characteristically dusty, breezy, high heat-loss environments. To make the indoor air more breathable and safe for workers, fresh air must be introduced through use of exhaust fans and/or raising overhead doors to help dissipate and eliminate contaminants. The problem is, as contaminants are pulled out, so is the heated air. Seemingly a “no win” scenario right? Maybe not.
So what’s the most effective and efficient way to heat body shops?
Answer: Infrared radiant tube heaters.
To help answer that question, let’s review what “infrared” is and how it works.
Infrared (IR) is electromagnetic wave energy that travels at the speed of light until it strikes an object. Upon striking an object, the IR energy converts to heat and is either reflected or absorbed. Dark and opaque objects (i.e. asphalt, concrete, etc.) readily absorb radiant IR heat energy, whereas highly reflective objects such as chrome and polished aluminum are poor absorbers and tend to reflect that energy away.
The most familiar IR emitter (heater) is our own sun. The sun radiates its IR energy through our atmosphere to the earth’s surface, uninhibited by wind. As the earth’s surface absorbs that energy, our air becomes warm.
During our North American winters the sun’s rays are less dense due to the angle of the sun in the sky and our air temperatures are much cooler. But by summer solstice the sun’s rays are at their peak angle and absorption is at its highest, resulting in warmer air temperatures.
Why use infrared tube heaters for your body shop?
Ceiling suspended infrared tube heaters mimic the warmth of the sun by warming up tools, machinery, floors and people directly, thereby warming the air indirectly.
Unlike forced air heaters, infrared tube heaters do not blow air throughout the space. That’s a big plus in body shops where dust in painting areas is a problem.
Quicker heat recovery. As infrared energy absorbs into floors, tools, vehicles, etc., heat is recovered much more quickly when overhead doors are opened and closed again or when exhaust fans are cycled on and off periodically. That’s because surfaces in the direct path of the infrared rays become a “heat sink”. In other words, stored heat in objects re-radiates to warm the surrounding air.
Energy efficiency – an infrared tube heating system can save as much as 50% or more in fuel savings compared to conventional forced air. This is especially true in body shops where air exchanges are very high.
Infrared heaters can increase production. A carefully designed infrared tube heating system can be used to decrease drying times and enhance paint job quality. Placing vehicles in the path of infrared radiation warms cold metal surfaces. Paint applied to warm metal surfaces is less likely to run or drip than when applied to cold surfaces. And because infrared heaters don’t move air around, there is less opportunity for dust particles to mix with newly applied paint.
We should note that gas infrared tube heaters are NOT to be used inside paint booths or paint mixing rooms. Tube heater emitters can reach 900 to 1100 Degrees F, well above the flash point of solvent-based primers and sprays. Spraying should be contained in a designated paint room with a filter bank and exhaust system to carry away potentially explosive fumes. Once spraying is done and the booth is ventilated with fresh air, vehicles and components can then be moved out of the spray booth to an isolated drying area where the infrared heaters are located.
Are some infrared tube heaters better than others for heating body shops?
That’s where you need to do a bit of homework. A thorough review of the various infrared tube heater manufacturers can turn up some surprising differences between brands and product offerings. In your search, ask about burner design (are controls isolated from the air stream? They should be.), emitter tubing (heat-treated aluminized or cheaper hot-rolled steel?), reflector efficiency (50% efficient or 100%), and warranty (10 years is better than 5 years).
Scott Workman is president of Infra-Red Products Supply, Inc, a leading distributor of gas infrared radiant heaters and an expert in energy saving heating systems.