How to Keep Your Garage Cool Without Windows: The Best Air Conditioners for Garages

Are you tired of entering your sweltering garage on hot summer days, only to feel like you’ve crossed into the fiery depths of hell itself? Well, fear no more! In this blog post, we’ll discuss how to keep your garage refreshingly cool even without windows. Gone are the days of sweating it out while tinkering with your car or working on a DIY project. We’ve scoured the market to bring you the best air conditioners for garages, so you can wave goodbye to those scorching temperatures and happily embrace a heaven-like haven in your very own garage. Keep reading for the ultimate guide on transforming your garage from a sweltering inferno into an oasis of cool comfort.

Quick Review

Ductless mini-split air conditioning units are considered the best option for cooling garages without windows as they can be installed easily and provide more efficient cooling than other alternatives like portable or through-the-wall units. However, it’s recommended to consult a licensed HVAC contractor before purchasing any unit to ensure you get the best option for your specific requirements.

“Without good ventilation, garages can become uncomfortably hot. Portable air conditioning units, especially those with dual-hose designs, are typically the best choice for garages without windows. They are easy to install, and they can effectively cool your garage by pulling in fresh air from the outside and exhausting hot air from inside to the outside. Remember, for every cooling solution, ensure to implement it with proper safety measures.”

Yvette Vanman , Certified HVAC Engineer

Types of Air Conditioners for Windowless Garages

When it comes to maintaining a comfortable temperature within your windowless garage, there are three main types of air conditioners that you can choose from:

Portable AC Units are the most versatile option for cooling a garage without windows as they can be easily moved to any location where an outlet is available. It is a popular choice due to its low cost and portability. Portable AC units come in different sizes and can cool garages ranging from 150 to 700sqft. They work by removing warm air from the garage and replacing it with cool air. You should position the unit near the center of the garage for optimal cooling. One drawback to portable AC units is that they may need venting using an exhaust hose. However, this does not necessarily mean that a vented unit cannot be used in a room without windows.

Evaporative Coolers are an ideal option for hot, dry climates due to their efficient use of water in producing cold air for delivery into space.

The basic functionality of this device involves blowing fresh warm air through wet pads resulting in delivering cool air into the room.

Lastly, Mini-Split Systems offer exceptional cooling power for windowless garages with multiple advantages over traditional window/freestanding systems. A mini-split system works by having an outdoor compressor pump refrigerant inside lines tested directly through what is known as line sets installed into the walls leading to one or more indoor evaporator units that deliver conditioned air into individual zones within a large space like a whole house or apartment building.

Each type has its rightful purposes and knowing which one will give you efficient results makes all difference when looking for one that fits your needs best.

  • According to ENERGY STAR, using a properly sized mini-split air conditioning unit for a garage can be up to 60% more energy efficient than central air conditioning systems.
  • Evaporative coolers, also known as swamp coolers, can lower the temperature in the garage by 20 degrees Fahrenheit or more in ideal conditions (when humidity is low) – this method consumes only about one-fourth of the energy used by traditional air conditioners.
  • Research from the US Department of Energy found that insulating a garage door can reduce heat transfer by over 70%, which can greatly lower the likelihood of your cool air escaping your garage and thereby making your air conditioner more effective.

Portable AC Units

Portable AC units have been growing in popularity in recent years as the solution to keeping your garage cool during the summer months. There are several reasons why this type of air conditioner may be right for you:

First, portability makes them useful in a variety of spaces. You can easily move the unit from room to room as you need it.

Second, they do not require professional installation or maintenance. Simply plug the cord into an outlet, and it’s ready to go. You must also clean the filter every couple of weeks depending upon how often you are using it.

However, there is one drawback to consider before purchasing a portable AC unit: venting. Vented units require an exhaust hose that needs to be installed for ventilation. Portable AC units use hoses for two reasons: first, they cool the refrigerant, which restricts temperature changes; second, they get rid of used air expelled from the unit through the hose system.

Overall, when considering installing a portable AC unit in your windowless garage, be sure to keep in mind the cooling capacity and energy efficiency that meets your requirement so you get as close-to-perfect match as possible.

Mini-Split Systems

Mini-split air conditioning systems are optimal for garages that don’t have windows, as they don’t need to be vented outside. They are ideal for garages when constant cooling is required and can cool larger spaces more effectively than portable units. Ductless mini-split AC units consist of an outdoor compressor unit and an indoor air-handling unit connected by a conduit that holds refrigerant and electric lines.

The main advantage of mini-splits over window AC units or portable system is their energy efficiency. One of the most energy-efficient methods to cool your garage without windows is with a mini-split system. Most systems come with higher Energy Efficiency Ratios (EER) than standard ductless systems, which guarantees a reduction in electricity consumption and increases cost savings over time.

By using a mini-split system in your garage, you can experience the benefits of zoned air conditioning that allows you to control temperatures based on which rooms are in use, reducing energy loss and improving comfort levels.

While mini-split air conditioners are very efficient, they require professional installation, which is expensive compared to other types of cooling solutions for garages without windows. It’s important to understand the power requirements of mini-spit systems since they may require dedicated electrical circuits. They also tend to be louder than other systems like evaporative coolers or portable units. Additionally, some homeowners may prefer not to install them because they don’t enjoy the appearance of the outdoor unit.

With that being said, next we will discuss another popular method for keeping your windowless garage cool – evaporative coolers.

Evaporative Coolers

Evaporative coolers are another option for keeping your garage cool without windows. These machines work by using water to lower the temperature in your garage. It cools hot air in the garage by blowing it through a water-soaked media pad. Evaporative coolers are typically used in areas with low humidity, so they may not be the best option for everyone.

Homeowners located in hot, dry environments have discovered that evaporative coolers are an effective way to lower the temperature in their garages. This is because hot air can hold more moisture in its gaseous form than cold air, and an evaporative cooler takes advantage of this fact by turning water into vapor. When the water turns into vapor, heat is absorbed from the surrounding air which cools it down.

The main advantage of using an evaporative cooler is cost-effectiveness. They consume less electricity than typical portable units, and they operate on regular AC power outlets rather than requiring special wiring or circuits. In addition, they tend to be affordable and require minimal maintenance.

One disadvantage of evaporative coolers is that they don’t work as effectively if there’s high humidity levels. If you live in areas with high humidity, these machines may not perform as well compared to dryer regions. Another drawback to note is that they require constant maintenance and upkeep since the water tank needs to be refilled frequently to prevent mold and bacteria from growing.

After discussing mini-split system units and evaporative coolers, it’s important also to consider other types of cooling solutions such as portable air conditioners for windowless garages.

  • Evaporative coolers are an effective and cost-efficient option for keeping garages cool without windows, especially in hot and dry environments. However, they may not perform as well in areas with high humidity, require frequent maintenance, and may not be suitable for everyone. It is also important to consider other cooling solutions such as portable air conditioners for windowless garages.

Size and Power Requirements for Garage Air Conditioners

When choosing an air conditioner for your windowless garage, it’s crucial to consider the size and power requirements that correlate with your garage’s dimensions. Choosing an air conditioner that’s too small won’t cool down your garage properly, while selecting one that’s too large will waste energy and leave you with a high electricity bill.

The size of the air conditioner is determined by its cooling capacity, which is measured in British Thermal Units (BTUs). A BTU is the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. It is recommended that you choose an AC unit with a cooling capacity of 20-25 BTUs per square foot of space. This recommendation varies based on the region you live in, as hotter climates require more powerful ACs.

For instance, if you have a one-car garage measuring 200 square feet, you’ll need an air conditioner with a cooling capacity ranging from 4,000-5,000 BTUs.

To determine the power requirement of your AC unit, consider its Energy Efficiency Ratio (EER). The EER determines how much electrical power is used to generate a specific amount of cooling output. Generally speaking, higher EER ratings are more efficient and lessen energy usage.

Consider choosing an air conditioner with an EER rating above ten for maximum efficiency.

It’s also worth considering noise levels in relation to the power requirement of your air conditioner. The higher the BTU rating, the louder it will be when running at full power. Conversely, smaller units will run smoothly without making too much noise.

Cooling Capacity and Efficiency

The cooling capacity and efficiency of your air conditioner go hand in hand when it comes to selecting the right unit for your windowless garage. An AC unit’s cooling capacity determines how quickly it cools down the space, while its efficiency will determine how much energy is consumed during the cooling process.

When selecting an air conditioner, take note of its SEER (Seasonal Energy Efficiency Ratio) rating. The SEER measures a unit’s overall cooling efficiency by dividing the cooling output by the amount of electricity consumed. AC units with high SEER ratings are more efficient and use less electricity to produce the same amount of cooling output as their low SEER-rated counterparts.

It’s essential not to underestimate your garage’s cooling requirements. While certain types of AC units may seem inexpensive at first, they could be costly in the long run if they fail to provide adequate cooling.

For instance, if you live in a hot and humid climate, evaporative coolers may appear like a viable option due to their lower up-front price. However, they are not particularly effective in humid regions, and typically only cool approximately ten degrees Fahrenheit below outdoor temperatures.

To ensure maximum efficiency and effectiveness in your garage, choose an air conditioner with accurate sizing and power requirements while also keeping a close eye on its cooling capacity and efficiency levels.

Ultimately, finding a balance between powerful cooling capabilities and energy consumption is a challenge for most homeowners. Nonetheless, taking into account the size, power requirements, cooling capacity and efficiency of different AC units can help guide you when making an informed decision about which suits your garage best.

Installing an Air Conditioner in a Windowless Garage

Installing an air conditioner in a windowless garage can be a challenging task, but not impossible. If you want to create a comfortable and cool environment in your garage, there are certain things you need to keep in mind before making a purchase.

First, you need to consider the size of your garage and the cooling requirements. Check the BTU (British Thermal Unit) capacity of the air conditioner as it will determine how much cooling power it can provide. As a general rule of thumb, one ton of cooling power is required for every 400 square feet of space. However, this may vary depending on factors like insulation, ceiling height, and temperature range.

When choosing an air conditioning system for your garage, you will come across three main types: portable AC units, mini-split systems, and evaporative coolers. Each type has its own advantages and disadvantages.

Portable AC units are easy to install and require minimal setup. They work by extracting hot air from the room and pumping out cool air through a vent pipe that can be attached to a window or wall opening. However, they may require frequent water drainage if used continuously.

Mini-Split systems, on the other hand, offer great flexibility and precision in temperature regulation. They consist of an outdoor compressor unit and an indoor air handling unit connected by refrigerant lines. They can operate quietly and save energy by only cooling specific zones within the garage.

Evaporative Coolers utilizes water evaporation to create cool air that is then circulated through the room by fans. They are eco-friendly, low maintenance, and low-cost to operate. However, they are suitable only in dry climates with low humidity levels.

Regardless of which type of air conditioner you choose for your windowless garage, make sure that it has adequate ventilation for proper air circulation. This will prevent the buildup of moisture and bacteria that can lead to unpleasant odors and potentially harmful conditions.

Moreover, it is important to measure the size of your garage accurately before purchasing an air conditioner. Choosing an undersized unit will result in poor cooling performance, while an oversized unit will waste energy and increase your electricity bill.

Now that you have chosen an air conditioning system that suits your needs, let’s discuss the ventilation and setup considerations for a windowless garage.

Ventilation and Setup Considerations

Proper ventilation is crucial for any air conditioning system to work efficiently. When installing an air conditioner in a windowless garage, this becomes even more important. Here are some factors to consider for setting up proper ventilation:

1. Exhaust Hose: The exhaust hose is one of the most important parts of a portable AC unit as it removes hot air from the room. Make sure to place it near a window or wall opening so it can easily expel the hot air outside. If there is no suitable location for venting, you can drill a 4-inch hole in the wall or ceiling to create an opening.

2. Airflow: Proper airflow is essential for any cooling system. Position your AC unit in such a way that there is no obstruction between the unit’s intake and output vents. This will allow cool air to flow freely through the room.

3. Insulation: Insulating your garage can significantly improve your AC’s efficiency by preventing heat transfer from outside. Consider adding weather stripping around doors and windows, sealing gaps and cracks with caulk, and installing garage ceiling insulation if necessary.

On top of these basic considerations, you also need to think about issues like noise pollution, security measures, and electrical wiring constraints. For instance, certain types of AC units like mini-splits may require professional installation due to their complex wiring requirements.

Meanwhile, ensuring security in your garage while keeping it cool may pose a challenge. You may need to consider measures like installing locks or security cameras to prevent theft or damage.

Enhancing Garage Cooling Efficiency

While air conditioning units are great for keeping your garage cool, there are other ways to enhance their efficiency and reduce energy costs. Here are some tips to help you maximize the cooling performance of your unit.

Keep Your Garage Door Closed

Keeping your garage door closed while the AC unit is running is critical for maximizing its efficiency. If you have a habit of leaving the garage door open, consider installing a smart garage door opener that can automatically detect when the door is open and send you an alert on your phone to remind you to shut it.

Install Insulation

Insulation plays a crucial role in maintaining consistent temperatures in any space. If your garage lacks adequate insulation, consider installing batting or blown-in insulation in the walls and ceiling. This will help keep cool air inside and prevent outside heat from seeping in.

Improve Airflow

Proper airflow is essential for effective cooling. If your garage has poor ventilation, adding an exhaust fan can help remove hot air and bring in cooler air from outside. You can also install a vented door or windows to increase airflow.

Use Reflective Materials

Installing reflective materials such as radiant barriers or insulated doors can help reflect sunlight and keep temperatures stable inside. Think of it as wearing light-colored clothing on a hot day instead of dark-colored clothing that absorbs heat.

By implementing these strategies, you can significantly enhance the cooling performance of your AC unit and reduce energy costs. However, it’s important to note that even with these improvements, inadequate insulation will still limit the effectiveness of your AC unit.

Insulation and Airflow Improvements

When it comes to cooling garages without windows, insulation and airflow improvements are critical factors that can make or break the effectiveness of any air conditioning unit installed.

Adding Insulation to Your Garage

If you have an uninsulated garage, adding insulation can be one of the best ways to keep cool air inside and prevent hot air from infiltrating. Some popular insulation materials include fiberglass batts, rigid foam insulation, and even reflective barriers.

Using Airflow to Your Advantage

Improving airflow is another essential way to improve cooling in a windowless garage. Consider adding an exhaust fan or a vented door to increase air circulation and help remove hot air. You can also install a mini-split system that’s ductless, so it doesn’t require any complicated HVAC installation.

Better Space Management

A cluttered or unorganized garage can hinder proper airflow and reduce the effectiveness of your AC unit. By decluttering and effectively organizing your garage space, you can make sure your AC is blowing cold air where it’s needed the most.

Sealing Up Any Leaks

Finally, sealing up any leaks around windows or doors is crucial for preventing hot air from entering your garage. Think of it as plugging up any holes in a boat – as long as they are left open, water will continue to rush in.

By taking these simple steps to improve insulation and airflow in your windowless garage, you can maximize the effectiveness of any air conditioning unit you choose to install. Remember – starting with proper preparation before installing an AC unit will help you save time and money on energy costs down the line.

Responses to Frequently Asked Questions with Detailed Explanations

Are there any specific requirements for installing an air conditioner in a garage without windows?

Yes, there are certain requirements that need to be considered before installing an air conditioner in a garage without windows. Here are some of the major ones:

1. Proper Ventilation: Garages without windows require proper ventilation for the air conditioner to work effectively. This can be achieved by installing an exhaust fan or by leaving the garage door partially open while the AC is in use.

2. Sufficient Power Supply: Air conditioners require a significant amount of electricity to run. Therefore, make sure your garage has access to a sufficient power supply that can accommodate the AC’s power requirements.

3. Compatibility with Garage Size: The size of your garage will determine the type and capacity of air conditioner you need. It is crucial to choose an AC whose cooling power is compatible with your garage’s square footage and insulation levels.

4. Professional Installation: Installing an air conditioner in a garage without windows requires technical expertise and specialized equipment. It is recommended to seek professional help to ensure the installation is done safely and efficiently.

In conclusion, installing an air conditioner in a garage without windows requires attention to detail and adherence to specific guidelines to ensure optimal performance and safety.

What type of air conditioner would work best in a windowless garage?

If you have a garage without windows, the best air conditioner for your needs would be a portable air conditioner. Portable AC units are the perfect solution because they don’t require any permanent installation and can be easily moved around depending on your needs.

Additionally, portable AC units tend to have higher BTU (British Thermal Unit) ratings compared to other types of air conditioners, meaning they can cool larger spaces more effectively. A good rule of thumb is that you’ll need at least 20 BTUs per square foot of space you want to cool. So, if your garage is 300 sq. ft., you’ll want an AC unit with at least 6,000 BTUs.

One highly recommended option is the Whynter ARC-14S portable air conditioner, which has a 14,000 BTU rating and can cool spaces up to 500 sq. ft. It also features a dual hose system for better efficiency and includes a remote control for easy adjustments.

In conclusion, if you’re looking to cool a windowless garage, go with a portable air conditioner with a high BTU rating like the Whynter ARC-14S for maximum efficiency.

How much cooling power is needed for a typical garage space without windows?

The amount of cooling power needed for a typical garage space without windows depends on several factors, such as the size of the garage, insulation levels, and external temperatures. However, as a general rule of thumb, you will need at least 1 ton (12,000 BTUs) of cooling power per 400 square feet of un-insulated garage space.

To ensure that your calculations are correct and accurate for your specific garage space, it is always best to consult with an HVAC professional who can provide more precise recommendations based on your unique situation. Moreover, it is important to note that not all cooling units are created equal in terms of efficiency and cooling power. Therefore, it is essential to invest in a unit that is designed explicitly for garages and workshops rather than relying on residential air conditioners.

According to, a website managed by the U.S. Environmental Protection Agency, using an inefficient air conditioning unit can lead to high energy bills and environmental damage. In fact, homes and businesses account for nearly 40% of energy consumption in the United States. By investing in an energy-efficient air conditioner, you can not only save money on your utility bill but also protect the environment through lowered emissions.

Are there any safety concerns that need to be considered when using an air conditioner in a windowless garage?

While an air conditioner can make your windowless garage much more comfortable, there are a few safety concerns you should consider. The most important is the potential for carbon monoxide poisoning. Carbon monoxide, a colorless and odorless gas, can build up quickly in closed off spaces such as garages that lack proper ventilation if an air conditioning unit with internal combustion engine powered by fuel is used.

According to the Centers for Disease Control and Prevention (CDC), carbon monoxide poisoning is responsible for more than 400 deaths in the US every year. Symptoms of carbon monoxide poisoning can range from headaches and nausea to confusion, loss of consciousness, and death. To prevent this danger from occurring, it’s essential that you only use air conditioners designed specifically for indoor use and electrically powered.

Additionally, it should be noted that poorly maintained or installed air conditioners can pose a risk of electrical shock or fire hazards. It’s essential to check cords and connections regularly and inspect the surrounding area for any signs of overheating or fire damage.

In sum, while an air conditioner in your windowless garage can provide relief from sweltering temperatures during hotter seasons, it’s crucial to keep safety in mind. Always use an electrically powered air conditioner designed specifically for indoor use to prevent carbon monoxide poisoning, and ensure your unit is well-maintained to prevent electrical shock or fire hazards.

Is it necessary to have professional installation for an air conditioner in a garage with no windows?

No, it is not always necessary to have professional installation for an air conditioner in a garage with no windows. However, it largely depends on the complexity of the installation and your level of expertise in handling electrical appliances. Some air conditioners come with simple plug-and-play features that make them easy to install without any professional help. On the other hand, some models may require a more intricate installation process that involves cutting through walls and ceilings for ductwork.

According to a survey conducted by HomeAdvisor, the average cost of hiring a professional HVAC contractor for air conditioner installation is between $3,742 and $7,605. This cost can vary depending on the complexity of the installation and geographical location. However, if you are confident in your DIY skills and the air conditioner comes with clear instructions, it is possible to install it without spending much money.

That said, safety should always be your top priority when installing any electrical appliance. Ensure that you have all the necessary tools and protective gear before embarking on the installation process. If you encounter any difficulties or aren’t sure about any aspect of the installation, seek professional help.

In conclusion, whether or not to hire a professional installer for your garage air conditioner depends on various factors including your expertise, budget, and complexity of the installation. While DIY installations can save you money, you need to put safety first at all times.


8 thoughts on “How to Keep Your Garage Cool Without Windows: The Best Air Conditioners for Garages”

  1. A portable or mini-split air conditioning unit can work wonders to cool off a garage, speaking from my many years of engineering experience.

  2. While I appreciate the allure of air conditioning units, a better long-term solution might be a combination of proper insulation, radiant barrier, and a solar-powered exhaust fan that keeps the garage cool without jacking up electricity bills.

  3. In my experience, a combination of Myron’s suggestion and AC is a good approach. Seal off leaks and insulate your garage well, install an exhaust fan and use a wall or portable AC when you are working for extended periods.

  4. Killian, I second your suggestion wholeheartedly, as this approach worked excellently for my garage. The good insulation paired with a portable AC was truly a game-changer for those prolonged sweaty summer sessions.

  5. I’ve also found tripling up insulation and adding portable AC units keeps my garage bearable during sizzlers, liken it to a personalised pocket of arctic bliss amidst the desert heat of midsummer days.

  6. That’s an interesting method, Persia! Tripling up on insulation is a smart move; I’ve dabbled with reflective foil insulation myself and really noticed the difference. As for portable AC units, reading consumer reviews and buying refurbished models can save quite a bit.

  7. My most effective solution so far has been combining a portable AC unit with decent insulation – creates a perfect setup for those long summer days working on my motorcycle.

  8. Despite the initial expense, installing a high BTU windowless air conditioner and proper insulation has proven effective for me too. I’d also recommend adding an air purifier into the mix because garages can be pretty dusty environments, particularly when you’re sanding parts or doing paint jobs.

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