How to Heat a Garage Safely


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If your garage doubles as a home gym or workshop, freezing temperatures can make it downright unbearable. You might contemplate on pausing some projects because having an icebox for working space is no fun. Also, some tools might not perform as they should in the cold.

To heat a garage safely, you should insulate your garage door, walls, and ceiling if possible. Also install a heating source. Infrared heaters, forced air heaters, ductless mini-split systems, sealed combustion heaters, or radiant floor heating systems all ensure your garage stays nice and warm.

The wintry weather can also cause damage to your equipment. This is especially true if you’ve converted your garage into a living space. However, it doesn’t have to be that way. You can still keep your garage comfortably warm with a few great ideas. Let’s explore these options a little more closely.

How to Heat a Garage Safely

Assess your heating needs.

Before you try to winterize your garage, you first need to assess your heating needs. That way, you’ll know how much heat you need and the best heating option for your garage.

What’s your garage size? Or, how much space are you looking to heat? This is important because you don’t want to end up with a heater that’s too small for the job or too large that costs you more money upfront for power that you don’t need.

How cold does it get where you live? A garage is usually a few degrees warmer than the outside temperature. So it’s important to factor in the lowest area temperature to the temperature you want to maintain in your garage.

The difference between the two is what your heater is required to generate.

Is your garage insulated? How well is it insulated? The better insulated your garage is, the more the comfort in the colder winter months and the lower the energy bills.

Address any air leaks.

The next order of business is to fix any air leaks. There’s no point in heating your garage if the air just leaks out. It will only drive up your electricity bills. The common areas for leaks include the walls, doors, windows as well as ceilings.

Before you fix any leaks, give your garage a good wash it rarely gets but needs. This will make it easier for you to inspect and seal the leaks.

Caulking around windows and installing weather-stripping around doors and windows are inexpensive yet effective ways for keeping the cold air out. These are easy DIY tasks that take about an hour or so.

How to Heat a Garage Safely

And you only need a few materials and tools which are readily available in hardware and paint stores.

When it comes to caulking your windows, it’s up to you to decide whether to use latex or silicone caulking as well as apply caulk to an entire window frame or just the cracks. For best results, apply both inside and outside.

Weather-stripping gets brittle and cracks over time, allowing cold winter air to come in. So if your door weather-stripping is broken, it needs to be replaced. Make sure you first ascertain the kind of garage door seal that you have.

It’s important to get the correct replacement. You need the seal tight and secure to block out cold air. Take measurements and photos if you have to. You may as well take the old weather stripping with you to the hardware store. 

Also remember to fix small cracks and gaps in crawl spaces, roofs, ceilings, walls, and foundations. Use spray foam insulation. It’s a highly effective solution that seals warm air in and cold air out.

Add insulation.

After sealing air leaks in your garage, evaluate your insulation levels. If it needs upgrading, add more. If you’re not sure if you need more insulation, just look across the span of your garage. If the joists are very much visible, you need more insulation.

Insulating the garage walls and door also goes a long way in improving comfort by keeping the cold air out and heat in. It’s a worthwhile investment that can slash both your heating and air conditioning bills.

There are different types of insulation, but the most common for garages include fiberglass batts, spray foam, rigid foam, cellulose, and loose-fill fiberglass. Remember, you don’t have to use the same type of insulation as your existing one.

This means you can add fiberglass batts over loose-fill and vice versa. If you opt for fiberglass batts, use either kraft paper-faced or encapsulated insulation. These are wrapped in plastic, giving your walls a more finished look as well as preventing moisture problems such as mold and mildew.

How to Heat a Garage Safely

If you have a finished garage but not yet insulated, go for cellulose insulation. This recycled newsprint insulation is an excellent solution for enclosed walls. According to contractors, it provides better performance than fiberglass batts, if appropriately applied.

The cellulose is usually blown into walls and ceiling cavities using a blowing machine.

For a garage door, buy an insulation kit. Standard metal garage doors can use any type of insulation while wooden ones work well with rigid insulation. Opt for foil-faced and fire-rated rigid foam.

While unfaced foam packs the highest R-value per inch of thickness over any other rigid insulation, it is combustible and may give off dangerous fumes if it burns.

Bonus tip: When selecting insulation, pay attention to the R-value. The higher the R-value, the better it is at insulating.

Add a heat source.

No matter how well insulated your garage door, walls, and ceiling are, it’s all useless without a heating source. You need to fill the space with heat.

Several heating options can safely heat your garage. Let’s explore them below.

Sealed Combustion Heater

Using a sealed combustion space heater is one of the best and safest ways of heating a garage. However, it’s only applicable to homes that are already equipped with propane or natural gas.

Unlike most garage heaters, a combustion heater heats air from the outside of the room rather than pulling in heated indoor air and exhausting it to the outdoors. This eliminates carbon monoxide danger, making it the best heating solution for garages.

These units are usually installed on the exterior walls of homes because they need outside air for combustion.

Since these types of heaters don’t take air from the inside the room, they are less likely to compromise the indoor air quality. This, of course, promotes comfort while protecting your health.

Besides its safety and efficiency, a sealed combustion unit warms up space very quickly. It also operates quietly due to its sealed compartment. Remember, some units are unsealed. Try not to confuse the two.

Low maintenance is another advantage of using this type of heater. However, it’s a good idea to have it inspected annually by a professional to ensure it’s working as it should.

Keep in mind; you require a permit from your local building authority before installing this heater. Unless you’re a licensed professional, leave the installation to the pros.

Even if you consider yourself the handiest of handymen, it’s best to have a professional handle the gas line. Improper installation can expose you to high levels of carbon monoxide.

If you spend a lot of time in your garage or store combustible and hazardous materials, a sealed combustion heater is perhaps the best option.

Infrared Heater

An infrared heater is another great alternative to heat your garage safely. The best thing about infrared heaters is that they heat objects, including people, rather than air. The heat is then radiated back to keep your surrounding environment warm.

It works similarly to the sun or coal fire. You feel the radiated heat from the sun or fire even if the surrounding air temperature is low. The swift transfer of heat is perhaps the biggest perk of using infrared heaters.

Besides, the heated objects will continue to release heat even if you turn off the heater or allow cold air into the garage.

While the word radiation scares a lot of people, infrared heating is entirely safe to use in homes. In fact, it’s considerably safer than other conventional heaters. This is because infrared heaters don’t burn anything to produce heat but rather emit infrared radiation.

Moreover, the surface temperature of these heaters is not as high as that of the sun. It is quite low, harmless, and does not penetrate the skin. Keep in mind we’re talking about far-infrared heaters and not the high-intensity ones that emit visible glowing red color.

Because these heaters don’t heat or circulate air, they don’t dry it out, thus eliminating the need for humidifiers during winter. Additionally, infrared heaters produce clean heat. So they do not add pollutants into the environment or move dust around.

How to Heat a Garage Safely

Infrared heaters are available in electric, natural gas, and propane models. Electric is the most common because not every home in the region has access to natural gas. However, when it comes to energy and cost efficiency, infrared heaters fueled by gas are cheaper than electric heaters. 

All the same, infrared is the most energy-efficient among conventional heaters as you only need to turn them on when necessary. This can save you a couple of hundred dollars per winter season.

Aside from this, they are quiet and do not require a lot of maintenance. On the flip side, they can be twice as expensive to buy as forced air heaters.

Bottom line? An infrared heater is the most basic but safe and effective form of heating. It’s a perfect heating solution, especially if you’re planning to do handy projects from the garage.

Forced-Air Heater

A forced air heater is perhaps the most popular heating option. As the name suggests, it distributes heat throughout a living space using air with the assistance of ductwork and vents.

A thermostat usually controls the system. So when it reaches your desired temperature, it shuts off. Then pick it up again when the temperature drops.

There are different kinds of forced air heaters available –the most common include heat pumps, gas, and electric furnaces. These heating systems operate using electricity, propane, fuel oil, or natural gas.

One of the primary advantages of using these heaters is that they heat space evenly, quickly, and effectively, keeping your garage warm and comfortable all day long. However, if the air filter gets clogged, the rooms might not receive enough warm air, which will lead to uneven heating.

To avoid the temperature imbalances, the system, more so the filter, needs regular maintenance.

These heaters can also be a problem if you’re using the garage for your woodworking projects. They blow air around, which can be a nuisance, not unless you install the system in a strategic location. Also, they can be quite noisy compared to other heating options.

But, forced air heaters are among the best garage heating systems when it comes to energy efficiency and air quality. The filters trap allergen, dust, and other particulates, significantly improving the air quality in your garage.

Additionally, most of these systems, especially the newer models, come with a safety shut-off switch. If it detects any errors, it shuts off the system.

Ductless Heating System

Ductless heating systems are an excellent choice for garage heating. Also referred to as a ductless mini-split system, it can offer an efficient and safe solution for your heating needs.

Unlike forced air heaters that use ductwork to disperse warm air, a ductless system uses an indoor air-handling unit and an outside compressor to distribute heated air. The indoor unit can either be mounted on the wall or suspended from the ceiling.

Since the systems don’t use air ducts, the risk of energy loss is highly unlikely. According to HVAC experts, ductwork loses around 25 percent of the energy produced, especially if the space is uninsulated or leaks air. 

How to Heat a Garage Safely

Another advantage of ductless systems is that it allows you only to heat occupied spaces, hence saving you money on energy bills.

These systems also offer greater security as opposed to through- the- wall air heaters. Only a small hole is drilled into the wall for the conduit. 

On the downside, ductless heating systems are quite expensive to install. Regular maintenance and professional cleaning also required.

If your home doesn’t have a ductwork system, you should definitely consider installing a ductless heating system. Its lack of aesthetic appeal might also not go down well with some people.

Radiant Floor Heating System

If you’re building or renovating your garage, you should consider installing a radiant floor heating system. In this setup, the system warms the floor with hot water tubes or electric wires installed under the garage floor. Its design makes it a safe heating source.

This “invisible” system is especially great if you have an auto repair shop in your garage or love working on cars. It eliminates the cold floor that draws heat from you.

While the cost of installing radiant floor heating systems is quite high, low operational costs, energy efficiency, and increased comfort make them one of the best garage heaters. What’s more, they’ll keep your garage space free of dust, allergens, and other air contaminants.

Garage heating sources to avoid.

Portable Electric Heaters

Do not attempt to buy a portable electric heater for your garage. Operating it near flammable substances found in most garages like paint, brake fluid, gasoline, varnish, sawdust can be a fatal mistake. Also, leaving them unattended, overloading the circuit, and letting kids and pets near them can be very dangerous.

According to the National Fire Protection Association, these heaters are the leading cause of fatal house fires. Space heaters, for instance, account for more than two in five of these home fires.

Wood Stoves

While you might be tempted to go old school with wood stoves due to the rising cost of fuel, it might not be the best idea for your garage. Its installation and operation is a bit more complicated and not as straightforward as most people think. And if not installed properly, it can create some real problems.

Moreover, paint, gasoline, thinner and other flammables can’t be near or in the same room as wood stoves for apparent reasons.

Portable Propane Heaters

Portable propane heaters are also not the best choice when it comes to garage heating. They need adequate ventilation to avoid the risk of fire and carbon monoxide poisoning. So this means you have to deal with drafts and cold air coming from the outside while you work.

It can be especially tricky if you spend long hours in your garage and need to keep your heating on all the time.

Wrap Up

Heating your garage is a process. And it’s not that cheap either. However, it’s one of the best investments you can make in your house. It will keep your garage warm and comfortable in winter and cool in summer days while saving you money on energy bills. 

Now that you know how to heat a garage safely, get to it. You can either tackle the project yourself or hire a professional contractor. It’s up to you to decide.

Vincent Steele

Vincent is a freelance writer based in Santa Ana, California. When he isn't writing articles for Temperature Master, he can be found biking or hanging out with his cat, Shelly.

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