Garage Heater Installation and Repair in Oakland County

Forced air or infrared, gas or electric?

A forced-air unit heater heats the air. It is quick, it is the simpler job in most garages and it takes the chill off the whole space. Its weaknesses: warm air collects at the ceiling and leaves when the door goes up, and the fan stirs dust, which matters if you paint or finish wood.

An infrared tube heater heats surfaces. The slab, the tools and the car soak up the heat and give it back, so the garage recovers quickly after the door closes and your feet stay warm. It is quiet and moves no air, but it needs clear space beneath it and enough ceiling height.

On fuel: a gas heater typically delivers more heat than an electric one of similar size and is the usual pick for a two- or three-car garage used through the winter, if a gas line can reach it. An electric heater needs no vent, but a large one draws heavy current and may need more capacity than your panel has to spare. Running cost depends on your rates and the hours it runs.

What size garage heater do you need?

Garage heaters are rated in BTU per hour. The rules of thumb you find online, a set number of BTU per square foot, disagree with each other because each assumes a climate and a level of insulation that may not be yours. Use one as a rough starting point. The real answer comes from the garage itself.

Too small, and the heater runs all night without catching up. Too large, and it short cycles, runs loud and wears out sooner. We size from a heat-loss calculation of your garage, then choose the heater.

• Floor area and ceiling height, since you are heating a volume, not a floor
• Insulation in the walls and ceiling, or the lack of it
• The overhead doors: how many, how big, insulated or not
• Attached or detached, and how many walls face the weather
• How warm you want it: just above freezing, or shirt-sleeve working temperature

Insulate first, then heat

Insulation is what makes any garage heater work. Bare stud walls, an open ceiling and an uninsulated steel door let heat out about as fast as a small heater can make it. Insulating the walls and ceiling, fitting an insulated door and renewing its weather seals can mean a smaller heater that runs less. If insulation is not in the plan, an infrared tube heater often copes better than forced air, because it warms you and the floor directly.

Venting, clearances and why not to use the house furnace

A gas garage heater burns fuel indoors, so its exhaust has to go outside through a vent in the wall or roof, and the heater needs air to burn. It also has to hang at the clearances its manufacturer lists: away from the ceiling, the walls, the door tracks, shelving and anything parked or stored below. Gasoline, solvents and paint belong well away from it, because their vapors can reach a flame. We install every heater to the manufacturer's instructions.

People ask whether we can run a duct from the house furnace into the garage. We will not. The wall between an attached garage and the house is there to keep exhaust, fumes and fire out of the living space, and a duct through it opens a path for all three. A separate heater on its own thermostat is the right way, and it gets the same care as any home heating job.