Most Efficient Garage Heater

A ductless mini split heat pump. It moves heat in from outdoors instead of making it, so it delivers more heat than the electricity it uses. At a winter COP of 2.2 that is 220%. Electric resistance heaters, including infrared ones, turn 100% of their electricity into heat. Vented gas and propane heaters deliver about 80% of the fuel's heat; the rest goes out the vent.

Usually a vented natural gas heater, even though it is less efficient, because gas costs less per unit of heat. At 2025 U.S. average prices, a million BTU of heat costs about $18.50 from natural gas, $23.05 from a mini split at COP 2.2, $34.90 from propane and $50.70 from an electric heater. Enter your own prices above: cheap electricity or expensive gas can change the order.

Not per kWh. An electric infrared heater turns its electricity into heat at the same 100% as a fan heater. It can feel warmer sooner because it heats you and the surfaces in front of it rather than all the air, so it can save energy when you only need one work area warm. Size an infrared heater for one work area.

They release nearly all of the fuel's heat into the garage because nothing goes up a vent, but that includes the exhaust, carbon monoxide and a lot of water vapor. This site leaves them out of every ranking for that reason. Read the ventless heater safety guide.

It costs the most to install, often about $2,400 to $5,500 for a single zone, but it is the cheapest electric heat to run and it cools the garage in summer. It pays off best in a garage you use most days, in a climate where it rarely drops far below 5°F, and where there is no gas line. Size a mini split for your garage.