What height must a gas unit heater be above the floor in a commercial garage?

What height must a gas unit heater be above the floor in a commercial garage?

• A. Six feet
• B. Seven feet
• C. Eight feet
• D. Nine feet

Answer: (C)

In garages where gasoline vapors may collect near the floor, the ignition source of a gas-fired unit heater must be kept above the vapor layer. Mounting the heater not less than eight feet above the floor places the burner and ignition components out of the low-lying vapor zone, reducing the risk of igniting flammable vapors. This eight-foot minimum is the requirement for commercial garages, so eight feet is the correct height. The other heights do not meet this code protection and therefore are not acceptable.

In garages where gasoline vapors may collect near the floor, the ignition source of a gas-fired unit heater must be kept above the vapor layer. Mounting the heater not less than eight feet above the floor places the burner and ignition components out of the low-lying vapor zone, reducing the risk of igniting flammable vapors. This eight-foot minimum is the requirement for commercial garages, so eight feet is the correct height. The other heights do not meet this code protection and therefore are not acceptable.