It's cold outside and you want to use your garage workshop. First, you need to figure out what kind of heater to get for the garage. Do you want something that will keep the entire garage warm or just a small area? Here's how to choose the power and features of your new garage heater.
Radiant heat feels the warmest 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. Electric heat is expensive to run but requires no ventilation. Natural gas is only slightly cheaper than electricity. Propane is competitively priced. Electric heat does not require ventilation, while propane and natural gas do require ventilation.
The most economical choice is to insulate the garage before heating it. Learn more in our 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)
Takeaway
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 in cold climates.
| 1-Car Garage, Warm Climate, Minimum 7500 BTU | 1-Car Garage, Cold Climate, Minimum
15000 BTU |
2-Car Garage, Warm Climate, Minimum 15000 BTU | 2-Car Garage, Cold Climate,
30000 BTU |
|
| ELECTRIC HEATERS | ||||
| Newair NGH170GA00 Electric Convection 5120 BTU, $109.99, I just put this here to show you that a heater can be too weak even for a small garage in a warm climate | NO | NO | NO | NO |
| DuraHeat Electric Forced Air 34120 BTU, $223.99 | YES | YES | YES | YES |
| PROPANE HEATERS, REQUIRES PORTABLE TANK | ||||
| Dyna-Glo Thermoheat Propane Radiant 15000 BTU Requires portable propane tank, $59.95 | YES | YES | YES | NO |
| Mr. Heater Propane Convection 38000 BTU Requires portable propane tank, $149.99 | YES | YES | YES | YES |
| Dyna-Glo Thermoheat Propane Radiant 40000 BTTU Requires portable propane tank, $106.46 | YES | YES | YES | YES |
| Mr. Heater Propane Forced Air 60000 BTU Requires portable propane tank, 519.99 | YES | YES | YES | YES |
| KEROSENE | ||||
| Dyna-Glo Delux KFA80DGD Kerosene Forced Air 80000 BTU, $199 | YES | YES | YES | YES |
| NATURAL GAS, REQUIRES NATURAL GAS LINE | ||||
| Hot Dawg Garage Ceiling Heater Natural Gas Convection 30000 BTU, $958.14 | YES | YES | YES | YES |
| Dyna-Glo Natural Gas Radiant 30000 BTU, $232.14 | YES | YES | YES | YES |
| Hot Dawg Garage Ceiling Heater Natural Gas Convection 45000 BTU, $952.26 | YES | YES | YES | YES |
The Pros and Cons of Radiant Heat
Radiant heaters create infrared heat, which is by far 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 in 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 amount of time you can use the heater before needing to change 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. If you are too far from a radiant heater, you will not benefit from its warmth. 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 can find some above 25,000 BTU.
