120-Volt Electric Heaters for Garages

Types of 120-Volt Heaters

• There are two basic types of 120-volt garage heaters. The first is infrared or radiant. You will only feel the heat from this type if you are near the heater. It's the best option if you only want to provide heat for yourself or an object (such as a car) but not the whole room. The second type is a convection or fan-forced heater. Convection heaters can heat a whole room by moving the heated air throughout the space. Convection heaters make sense if the model you choose can efficiently heat the space.

Choosing Convection Heaters

• In order to select a convection heater for the space you are heating, you must first know the square footage of the floor and the ceiling height. Start by using a 10 watt per square foot multiplier. If your ceilings are higher than the average 8 feet, increase your wattage requirement by 9 percent per foot of ceiling height. A watt is equal to 3.41 BTUs (British Thermal Unit, a traditional measure of heating energy). Most 120-volt heaters are rated at no more than 5,000 BTUs, which roughly translates into the capacity to heat a 10-foot by 15-foot space, if the garage has average insulation and leakage. Efficient use of a 120-volt convection heater requires a pretty small garage. See the resources section for an online garage heater size calculator.

Insulation

• If you are trying to heat the whole garage with a 120-volt garage heater, consider whether the garage is insulated. An uninsulated garage, especially in a northern climate, will be very difficult to keep warm. All of your heating power will be lost and the unit will work constantly to heat the space, driving up your utility costs. Using a radiant space heater may be the better choice in this case.

Other Heater Considerations

• Heaters can have additional features that may be attractive. If you need consistent heat for a longer period of time, a thermostat is important. For heating a larger space, the heater should definitely have a fan. In addition to a fan, oscillation can offer additional benefits for heating larger areas. Any heater you choose should have safety features such as tip-over cutoff switches and cool-touch housing.

Choosing a 120-Volt Heater Over a 240-Volt Model

• A 240-volt heater can deliver more heat efficiently and heat larger spaces, so why would you buy a 120-volt heater? Perhaps 240-volt power is unavailable in your garage and the cost of rewiring would be prohibitive. Or perhaps you really only want to heat a small portion of the garage, for example where a workbench is located, so a small space heater makes sense. Maybe you are willing to trade heating the whole space for lower cost of operation.