Most garages weren’t built to stay warm in frigid weather. They lack insulation and have chilly concrete floors year-round. Even with a small heater, indoor temperatures likely rise only a few degrees. Source: bobvila.com.
When the garage air is bitterly cold, it affects more than just your comfort. Tools become icy. Paints and glues fail to bond. Automotive and woodworking tasks become hard. To work year-round, combine these tips to heat your garage to a comfortable level. You’ll have a productive space, no matter the season.
Choose a portable space heater (or two) sized for your garage.
Visit a home improvement store in late fall. You’ll find many portable, energy-efficient space heaters. Most aren’t powerful enough to heat an entire garage. For serious heating, install a ceiling-mounted forced-air unit like the Dr. Infrared 7,500-Watt or Comfort Zone Garage Heater. Confirm the model matches your garage’s square footage. Place it in a corner, angled downward at 45 degrees for best warmth. Most come with a remote and thermostat so you can set your preferred temperature. For more options, see our tested guide to the best garage heaters.
The main drawback? The floor near the heater stays cold. If your feet feel chilly, add a baseboard heater under your workbench. Hydronic baseboard heaters like the Slant/Fin Fine/Line 30 Series use a home boiler. Hot water runs through pipes, radiating warm air to floor level and beyond.
Insulate the walls with fiberglass batt and paneling.
No matter how strong your heater, cold walls make it hard to keep warmth. Many garage walls have only studs, covered by sheathing and siding. Without insulation, cold air moves in quickly and weakens heating efforts.
Most homeowners can do this themselves. Install fiberglass batt insulation—like Johns Manville R-19—in each stud space. Then finish with drywall, plywood, or OSB. Insulated walls help retain heat and reduce heating costs.
Insulate the garage door.
Garage doors are often made of thin metal and stay cold in winter. In northern climates, frost may form on the inside. Insulating the door blocks cold air from entering. It can raise the garage temperature by 10 to 12 degrees, even before turning on any heater. DIYers can buy insulation kits. Measure your doors carefully—oversized or multi-door garages need extra kits.
Best Garage Door Insulation Kit
Reach Barrier Garage Door Insulation Kit
Reach Barrier’s kit has a laminated bubble layer between aluminum layers. This creates a barrier between the garage and outside. Read the review.
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Photo: Amazon
Seal gaps and drafts.
Insulation and heaters help, but gaps let cold air in. Walk around your garage and check these three spots.
Garage door frame: Doors don’t fit tightly. Small gaps run all around. Use a weather-strip seal like M-D Building Products’ Vinyl Garage Door Top and Sides Seal. Self-adhesive strips close gaps and stop drafts.
Bottom of the door: If your door is over a few years old, replace the threshold seal. It blocks drafts but can crack and become brittle. Gaskets come in various sizes. Measure your door before buying, like DGSL’s Bottom Rubber Weather Stripping Kit.
Windows: Apply shrink film to the inside of windows. For the 3M Window Insulator Kit or other top picks, tape the film to the frame and use a hair dryer to heat it until it fits tightly. This seals out drafts.
Install a radiant floor heating system.
If you work on cars or tools, you likely dread cold concrete floors. A radiant floor system solves this. But it only works if you’re building a new garage or replacing an existing floor. Installation happens before pouring concrete. The process is:
- Install a reflective liner over sand in the excavation area.
- Position flexible piping in loops over the liner.
- Pour the concrete.
- Connect the system to a boiler. Hot water flows through pipes, radiating heat to the floor and objects above.
If you spend a lot of time in your garage and are renovating, this may be right for you. It’s not a DIY job. Hire a plumber with experience. Installation costs about $5 to $9 per square foot, plus a boiler. This system warms the space without blowing dust or chips—ideal for detail work.
Run a portable propane heater.
Many homes have gas lines, but garages often don’t. That limits heating options. Electric heaters work in most places, but electricity can be expensive. They also draw heavy power, which may overload circuits or trip breakers—especially when tools run at the same time. Adding circuits may be needed. Propane offers a cost-effective alternative. (See our tested guide to the best propane heaters.)
A 20-pound propane tank powers a small heater. For more heat, use a 500-gallon tank and have a plumber install a gas line. In ventless setups, choose a vent-free propane heater designed to burn safely and cleanly.
Warm up with a wood-burning stove.
For those who spend a lot of time in a garage in winter, a wood-burning stove offers real warmth and cozy ambiance. With a steady wood supply, it’s one of the cheapest heat sources. (Our researched guide to the best wood stoves shows models at various price points.)
Safety is key. Position the stove on a non-flammable surface—like concrete—and keep it away from walls, cabinets, and flammable items. Newer models have insulated shells that don’t overheat.
A wood stove must be properly vented to prevent smoke from backing up. Local codes usually require a triple-wall stovepipe installed vertically through the ceiling. Check with your local authority for rules.
Concentrate heat with a kerosene space heater.
Electric heaters work well for backup, but if a heater is your only source, it must be powerful. A kerosene-powered heater fits this need.
Known as a ‘torpedo’ or ‘salamander,’ these heaters generate strong heat and focus it in one direction. A mechanic or craftsman can stay warm. These heaters have electric fans, so an outlet is needed. The heat comes from kerosene.
Models like the Dyna-Glo 50,000 BTU Forced Air Heater can produce up to 215,000 BTUs—extremely powerful. Buy one designed for indoor use to avoid toxic fumes. Outdoor-only kerosene heaters don’t burn cleanly and aren’t safe indoors. Choose a model sized for your garage space.
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Radiate heat.
Some heaters blow hot air. Radiant heaters work differently. They use infrared energy—generated by a heating element, lamp, or flame. This is how you feel warmth on a sunny day—even when air temperature hasn’t changed.
In a garage, radiant heaters can be mounted overhead or on walls. Comfort Zone’s ceiling-mounted hardwired heater uses forced air to radiate heat outward, warming you and everything nearby.
Extend your mini-split system into the garage.
If you already have a ductless mini-split system, adding an indoor unit is possible—provided your compressor can handle an extra room. If you don’t have one, buying a mini-split compressor and indoor unit is a solid option. But it costs more than a few space heaters.
Reduce thermal transfer with a floor covering.
Even with insulation and heaters, the garage floor stays cold. Concrete floors are especially chilly when you kneel or crawl under a car.
Simple solutions exist. Use an indoor/outdoor rug that’s easy to clean with a leaf blower. For more comfort, install interlocking rubber mats—like those used in gym flooring. These mats insulate and cushion the floor, making long work sessions more comfortable.
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Where to Start
For more product testing and reviews, visit Bob Vila’s product testing page. Learn about the best energy-efficient space heaters at this guide. See a model example at Amazon.
Sources & further reading
Featured image: Photo: Agil via Adobe Stock. Via original publisher. Image source
