It's cold outside, and you want to use your garage workshop. First, you must determine what kind of heater to get for the garage. Do you want something warming the entire garage or just a small area?
You need 7,500 to 30,000 BTU minimum to heat a garage in the winter. The heater's burner type (radiant, forced air, convection) determines whether the heater warms you or warms the air around you. The power (gas, electric, or propane) determines how much you'll spend to heat the garage.
The most economical choice is to insulate the garage before heating it.
Learn more in my articles: Is Batt or Rigid Foam a Better Choice for Garage Insulation?, and Should You Insulate the Garage Door? Read This Before You Do (they open in new browser windows)
We go over each choice below.
Key Takeaways
Decide if you want to warm the air or your body:
- convection and radiant heat warm the body
- forced air warms the room
You need a minimum BTU for the garage size and climate. Here are some heater examples for a one-car and a two-car garage in warm and cold climates.
Minimum heater BTUs to warm the garage:
- 1-car garage in a warm climate: 7,500 BTU
- 1-car garage in a cold climate: 15,000 BTU
- 2-car garage in a warm climate: 15,000 BTU
- 2-car garage in a cold climate: 30,000 BTU
Choose your garage heater's fuel:
- electric is expensive but clean
- propane is relatively clean and cheaper than electric
- natural gas is great if you have a line to your home
- kerosene is middle-priced and needs ventilation
The Heater's Burner Warms the Air or You
Do you know how standing beside a fireplace warms your clothes and body?
But you don't get that same warmth from a baseboard heater?
This is because infrared heat from the fire warms your skin.
When you think about your garage heater, you must decide if you are warming the air or your body.
- Radiant heat feels warm because it warms the person rather than the air.
- Forced air feels good but wastes energy on heating air that quickly gets cold again.
- Convection heat feels good so long as it's close to your body.
The Garage Heater's Energy Type Determines Your Costs
You can choose to heat your garage from electric, natural gas, propane, and kerosene energy.
Electric Garage Heaters
You need a garage power outlet for an electric heater.
Electric is usually the most expensive option, but that changes with the market.
Electric is cleaner than liquid fuels and doesn't need ventilation
Natural Gas Garage Heaters
Natural gas can be a cost-effective fuel for a garage heater.
However, if you don't have natural gas, it's not a good choice for the garage heater.
Propane Garage Heaters
Propane is usually the cheapest choice for garage heat.
You can buy a portable propane tank from a hardware store.
Some hardware stores and gas stations refill these tanks or allow you to exchange empty tanks plus cash for full ones.
Kerosene Garage Heaters
Kerosene is usually in the middle range for costs.
It can be dirty if the heater runs out of fuel.
You do want good ventilation if you heat it with kerosene.
You can buy kerosene at hardware stores.
Table: Garage Heaters for Warm and Cold Climates
| Garage Heater | BTU | Power | Burner |
|---|---|---|---|
| DuraHeat EWH9615 | 34,120 | Electric | Forced Air |
| COSTWAY Tank Top Heater | 15,000 | Propane | Radiant |
| Mr. Heater Requires portable propane tank | 60,000 | Propane | Convection |
| Dura Heat Tank Top Heater | 40,000 | Propane | Radiant |
| Dyna-Glo KFA50DGD | 50,000 | Kerosene | Forced Air |
| Hot Dawg Garage Ceiling Heater – Stainless Steel Heat Exchanger | 75,000 | Natural Gas | Radiant |
| Dyna-Glo Dyna-Glo IR30NMDG-1 Wall Heater | 30,000 | Natural Gas | Radiant Infrared |
The Pros and Cons of Radiant Heat
Radiant heaters create infrared heat, the nicest and warmest type of heating.
Infrared warms objects rather than air. That's how infrared headers use less energy than other types.
However, radiant heaters are expensive to run.
They can also overheat you to the point of strong burning sensations where your heated clothing touches your skin.
The Pros and Cons of Convection Heat
Convection heat warms the air near the heater.
The larger the heater's BTUs, the larger the heated area around the heater.
Convection heat warms more of the room than radiant heat.
The Pros and Cons of Forced-Air Heat
Forced-air heaters use blowers to warm the garage air.
They warm you, too, if you're in the line of fire or the warmed air.
Forced-air heat gets more of the room warm than convection or radiant heat. This type of heat also dissipates quickly.
Radiant heat is better for very cold climates. Forced air heat is good at heating larger areas for short periods.
The Pros and Cons of Electric Garage Heat
Electric heaters do not output fumes and do not require ventilation.
Electricity tends to be the most expensive of the fuel types, coming in at about three times the price of propane.
Electric heaters using radiant infrared are the most comfortable because they warm the person rather than the air.
This makes radiant infrared the most efficient type of electric heater.
The Pros and Cons of Propane Garage Heat
Propane is slightly less expensive than electrical energy.
Your garage does not require a natural gas type of hookup for propane.
This type of heater uses portable propane fuel purchased in 20 lb. tanks.
The tank method limits the time you can use the heater before changing propane tanks.
Assume a propane gas heater requires ventilation unless the instructions indicate otherwise.
The Pros and Cons of Natural Gas Garage Heat
Natural gas prices are less than half of electricity.
Natural gas heaters are cheaper to run than propane and electric heaters.
The only catch is you need a gas hookup line to your home.
Natural gas heaters are not portable because they require this gas connection.
Assume a natural gas heater requires ventilation unless the instructions indicate otherwise.
The Pros and Cons of Oil-Filled Garage Heaters
Oil-filled heaters are closed systems.
You don't add oil or any other fuel to them.
Oil heaters take quite a while to warm up.
They are convection heaters that warm the air around them.
They do not warm the air any farther than their limited reach.
The Pros and Cons of Wood-Burning Garage Heaters
Wood stoves output infrared heat, which is pleasant and warm. However, wood-burning stoves are strictly regulated because they are dangerous.
Speak to a dealer about the regulations for your municipality before buying a wood stove for the garage.
Wood stoves must be ventilated, and they must be installed on non-flammable surfaces.
The municipality bases stove clearances on fire codes.
Calculating Garage BTUs
One way to calculate the BTUs required is by climate zone.
- Zone 1 is the warmest and requires about 30 BTU per sf.
- Zone 7 is the coolest and requires 60 BTU per/sf.
You can also estimate your BTUs by garage size and approximate climate.
A one-car garage needs:
- 7500 BTU in a warm climate
- 15000 BTU in a cold climate
A two-car garage needs:
- 15000 BTU in a warm climate
- 30000 BTU in a cold climate
LearnMetrics did a good job breaking this down. If you need more help, visit their site.
How Much Do Garage Heaters Cost to Buy?
To help you compare heater prices, I research red 80,000 BTU heaters in the categories mentioned in this article. The table tells the story of what works and what does not work in a cold garage.
Whether radiant, convection, or forced air, propane heaters output the 30,000 to 60,000 BTU needed to heat a garage.
Electric radiant and convection heaters are underpowered for that space.
Forced air uses more BTUs, and much of that energy is lost to the cold air. Only radiant heat sticks to you.
Natural gas convection and forced air heaters are about four times more expensive than propane and electric heaters.
Natural gas radiant heaters hit the sweet spot for garage heating.
The fuel and heat type combinations that make sense for a garage are, in order:
- Propane convection 80,000 BTU
- Propane convection 25,000 BTU
- Propane-forced air 40,000 BTU
- Propane-forced air 60,000 BTU
- Propane radiant 40,000 BTU
- Propane radiant 15,000 BTU
- Natural gas radiant 30,00 BTU
- Electric forced air 34,120 BTU
- Electric radiant 5,000 BTU
Possibly unacceptable combinations:
- Natural gas convection 30,000 BTU (expensive)
- Natural gas convection 45,000 BTU (expensive)
- Electric convection 5120 BTU (underpowered)
- Natural gas-forced air (couldn't find any for garages)
Decision Maker Rundown: The Best Type of Heater for Your Garage
- Do you have a natural gas line? Are you going to get one? Natural gas heaters are expensive to buy but cheap to run.
- Are you outside for a few minutes or all day? Natural gas and electric heaters run for hours. Propane heaters have shorter run times before the need to swap out the tank.
- Are you staying in one spot or moving throughout the garage? Radiant heaters warm you up, so you need to stay close to stay warm. Convection heaters heat the area near them, so you need to stay within their reach. Forced air heaters heat the garage, so you can move about in a warm space.
Summary
Radiant infrared heat is the most comfortable. If the heater is too close, it will warm your clothes and cause burning.
You will not benefit from its warmth if you are too far from a radiant heater.
Convection and forced air heaters warm the air, so their energy is quickly lost on very cold days. They work better in insulated garages.
Natural gas convection heaters are more expensive than any other combination.
Electric convection heaters are too weak to work in a garage but are fine if you find some above 25,000 BTU.
