Garage and Workshop Heaters: Gas, Electric and Ductless Options

It depends on the building, how you use it and what is available. Gas unit heaters suit larger or leakier spaces with gas nearby, electric heaters suit smaller jobs with spare panel capacity, and ductless suits well-insulated shops.

Usually not. Codes generally restrict it for fume and carbon monoxide reasons, and a house furnace is sized for the house. A separate heater is the normal solution.

It depends on the heater type and housekeeping. Fine dust near an open flame or glowing element is a fire risk, so we look at heater type, location, enclosure and dust control. Some shops are better served by sealed-combustion or ductless equipment.

For a gas unit heater, yes. The line has to be sized for the added load and installed by licensed gas-fitting professionals, with permits and inspections where required. See gas lines for how that works.

Yes. Heat loss through walls, the door and air leaks sets the heater size, so a better-sealed garage can use smaller equipment that costs less to run. We include notes on the building shell in the site review.

It depends on insulation, ceiling height, door leakage and the temperature you want to hold. Two garages that look the same can need very different heaters. We base the size on a heat loss estimate, not a square-foot rule. Keeping the space just above zero needs far less than holding a comfortable workshop temperature.

We do not recommend it. Unvented fuel-burning heaters use up oxygen, produce carbon monoxide and moisture, and many are not meant for enclosed garages. Fuel and vapours stored nearby add a fire risk. A heater designed and approved for the space, with proper venting where required, is the safer route.

Electric heaters are simple to install but draw high current, so they usually need a dedicated circuit. Older panels may lack spare capacity. Electrical work is done by licensed electrical professionals or trade partners, with permits and ESA notification where required. See electrical panel and circuits. Running cost depends on your electricity rates and how often you use the space.

Some cold-climate models can in an insulated, air-sealed garage, but output drops as outdoor temperature falls. Check the low-temperature data for the model. A leaky, uninsulated garage with a door that opens often is a poor fit. See ductless mini split installation.

Gas appliances and gas piping are regulated work in Ontario, and permit requirements depend on the municipality. A detached garage can add underground piping rules. Rules differ by municipality and change, so we confirm what applies before work, and arrange permits and inspections where required.

Clearances come from the manufacturer's instructions and the gas code, and they depend on the heater type and mounting. Heaters in garages with vehicles generally need to be listed for the use and mounted to keep ignition sources away from vapours. We confirm clearances to vehicles, shelving, doors and combustible items on site.

Often yes, but a detached building adds work. Gas needs a protected, buried line sized for the load, and electric heat needs adequate supply to the building. Frost depth and local bylaws matter in Ontario's climate. We review the route and supply during the site review.