Electric garage heaters are safe to use, but gas-powered heaters can be dangerous. Even with newer safety features, gas heaters can potentially cause dangerous chemicals to build in a garage.
Most homeowners prefer to use space heaters in garages. Electrical units provide safe heating, but they cost more to run, which makes natural gas the preferred option for people who spend a considerable amount of time in their garages. However, the cost of installing ventilation leads many to consider unvented gas heaters.
Newer, more efficient combustion techniques allow heaters to burn natural gas while producing only trace amounts of dangerous chemicals. As a result, some units claim to be safe for indoor use. However, problems with the heater can make the combustion process less efficient, which can lead to carbon monoxide buildup. Installing a carbon monoxide detector can provide a warning if the unit is not functioning properly.
Newer, unvented heaters typically have a safeguard that detects if carbon monoxide is being generated. While these heaters are safer than older heaters, they only detect carbon monoxide formation due to inefficient combustion. Burning particulate matter in the air can also create carbon monoxide, and people working in dusty garages or in garages with sawdust floating around should exercise caution.
Certain types of garage heaters have built-in safety features, such as an auto power shut-off when knocked over or an overheating warning light. During daily use, it is important to keep a garage heater running only when there is someone using the room. A portable garage heater should be placed on a stable surface to reduce the chances of it being knocked over. Flammable materials, such as paper and paint, should also be placed away from a garage heater to avoid accidental fires.