How To Cool A Garage With No Windows In 11 Effective Ways

how to cool a garage with no windows

Have you ever walked into your garage ready to work on a personal project only to find the interior is too hot to work inside? Anyone who owns a garage has likely learned that an effective ventilation system is key to maintaining a desirable working temperature - particularly during the hot months of the year.

But what if your garage has no windows to help with cooling and ventilation?  Check out our detailed guide below to learn how to cool your windowless garage to make it conducive and comfortable for working.

How Much Cool Air is Needed for a Garage with No Windows?

Before you answer the above question and make a final selection from the various available cooling options, consider how you intend to use the garage space. This ensures your first choice of cooling solutions will meet your needs while working on a project in your garage.

These questions are designed to help decide which of the cooling mechanisms would be most suitable –

  • Where is your garage located?
    • Does the garage sit in the sun all day?
    • Does the garage get some shade during the day?
    • Does the general location have high humidity? Valuable goods stored in the garage, like electrical equipment, paintings, wooden furniture, etc., can be damaged easily if left in intense heat or high humidity.
  • Are there electrical appliances/tools that may raise the temperature in the garage?
  • How often will you use the garage?
    • How many hours would you likely use the garage each day?

With your answers to the above questions, you should be able to determine which approach to cooling a garage with no windows will work best –

  • If you only use your garage primarily for storage and only spend brief periods there, the most practical choice would be to employ a less expensive and movable cooling solution.
  • If you use your garage regularly as a workspace/hobby station, it only makes sense to install a more permanent option that offers a higher cooling output and long-term solution.

1. Install Ventilation and Fans

If the garage is windowless, garage ventilation is among the most effective ways of cooling your garage interior to comfortable temperatures - especially during warmer/hotter months. Strategically placed outflow vents help draw out rising hot air, which is then replaced by cool, dense air flowing through intake vents. Adding a fan or two is an inexpensive way to boost the effectiveness of the garage’s ventilation -

Portable Fans

  • Rough Estimate - $10 - $200
  • Temperature Range – Any temperature that begins to feel uncomfortably hot/humid.

Using portable fans, especially during the hot summer months, helps circulate the air, moving hot air out of the garage. The air movement allows for cooler air to flow into the garage. Portable fans are available in a variety of sizes and strengths (as shown by the wide range of costs). They improve ventilation and cool the garage space. Portable fans not only cool down the interior but also enhance ventilation and make the garage less stuffy. The fan should be placed inside the garage to ensure you maximize the flow of cool air from outside.

Pro-Tip - If you have a large garage, multiple fans may work best, or buy a garage ventilation fan.

Garage/Ceiling Ventilation Fan

  • Rough Estimate - $70 - $1,200
  • Temperature Range – Works well unless temperatures or humidity levels become extreme.

A garage ventilation fan, which tends to be larger, more powerful, and built to withstand the conditions of a garage (i.e., such as dust and potential exposure to fumes), circulates the garage air, which ensure the room temperature is optimal as it prevents heat from building up inside. Garage fans are suitable for workshops or garages where temperature regulation is crucial for maintaining comfortable working conditions.

Pro-Tip - For maximum airflow, place the ventilation fan across from the garage door and as near to the ceiling as possible.

2. Insulate Walls, Ceiling & Garage Door

Insulate Walls
  • Rough Estimate - $2,000 - $4,000 for a two-car garage.
  • Temperature Range – Helps in all temperatures.

Garages typically lack the insulation provided to living areas within a home. As such, they are subject to excessive heat in the summer and cold in the winter. Adding insulation is an efficient method you can use to cool a garage with no windows and should be among the first options to consider.

Pro-Tip – There are no recurring costs after installation.

3. Opening/Closing the Garage Door Offers a Natural Ventilation Method

  • Rough Estimate - $ N/A
  • Temperature Range - It's most suitable if the garage stands in a shaded area.

If the outside temperature is cooler compared to the inside of the garage, you can create air circulation that can cool a garage with no windows by closing/opening the garage door. Opening your garage door draws in cool air, which lowers the interior garage temperature. However, the use of this method is contingent upon the garage’s location in relation to the sun/shade.

Pro-Tip - If the garage is located in direct sunlight, it is best to keep the door closed to retain the cool internal temperatures. Opening the garage door when it is hot outside helps to prevent hot air from entering and raising the interior garage temperature.

4. Avoid Parking a Hot Car Inside

  • Rough Estimate - $0
  • Temperature Range – Depends on how far/long you have driven.

When you return home from running errands or traveling, your car/engine is hot -especially during summer. Much of this heat, in its cooling process, will radiate externally, so parking your car in a garage with no windows will create a sort of oven in which heat becomes trapped inside, which will ultimately raise the temperatures in the garage.

Pro-Tip - Let your vehicle cool down in the shade before parking it in the garage.

5. Change The Paint Color in the Garage

Change The Paint Color in the Garage
  • Rough Estimate - $1.50 to $3.30 per square foot
  • Temperature Range – This will help reduce heat retention anywhere.

While repainting the garage is not the most high-tech cooling solution, it is still effective in keeping the garage space cool. Choose lighter and brighter colors of paint as these tend to absorb and retain less heat than darker paint colors.

Pro-Tip - Ideally, it is best to tackle this project in the spring.

6. Install a Swamp/Evaporative Cooler

  • Rough Estimate - $100 - $1,500
  • Temperature Range – Most effective in Dry/Low Humidity Climates.

A swamp cooler, which exploits moisture to cool air, offers a practical yet inexpensive way to cool a garage with no windows. Unlike traditional air conditioners, which cost a whole lot more to operate and use refrigerants to cool the air, swamp coolers operate by evaporating water to cool the surrounding air.

Pro-Tip - These cooling options are not great options for highly humid areas.

7. Use a Dehumidifier

  • Rough Estimate - $140 - $1,300
  • Temperature Range – Temps with high humidity levels.

A dehumidifier lowers humidity levels by reducing the heat trapped in humid air and raising the temperatures in the process. Essentially, the garage space is cooled when hot air passes through the dehumidifier’s cooling coils. After it is dried and cooled, the air is released back into the garage or room – creating comfortable temperatures and humidity levels in which to work. Another benefit of a dehumidifier is that it helps remove moisture levels (i.e., rust, mold, mildew, etc. ), which can damage documents, photographs, furniture, and other items stored within the space.

Pro-Tip - A dehumidifier does not draw hot or cold air into the garage, so it might help to add a fan to this approach.

8. Declutter the Space

  • Rough Estimate - $0 – A few Hundred Dollars
  • Temperature Range - Works well in any temperature or humidity level.

A congested space, especially in your garage, typically means you have prohibited natural airflow. Decluttering the space offers a simple and effective method to improve airflow and help cool the temperature in the garage naturally.

Pro-Tip - You can consider installing storage racks or cabinets to help organize while improving airflow at the same time.

9. Install an Air Conditioning System

Air Conditioning System

There are a few options you can explore in the market, but note that depending on your skill level, you might need to hire a professional.

Mini-Split Air Conditioner

  • Rough Estimate - $150 - $1,500
  • Temperature Range – This can be effective for any high heat/humidity setting.

Installing a mini-split air conditioner is another efficient way to cool smaller indoor spaces, and it does so at breakneck speed. However, you will need to construct a vent for proper installation, as this allows an exhaust pipe to exit the room.

Pro-Tip - While mini split air conditioners make sense for cooling a garage without windows, a portable air conditioner may be a better choice.

Portable AC Unit

  • Rough Estimate - $200 – Several Thousand Dollars.

A portable air conditioner might not be as high-performing as other options, but it can still help cool the inside of the garage.

Pro-Tip - Portable air conditioning is not the most efficient cooling method as the units heat up quickly and increase your electricity bills. An air conditioner might be more practical.

10. Install Awnings or Shade Sails Over The Garage Door

  • Rough Estimate - $100 - $2,100 – depending on material and technology.
  • Temperature Range – Effectively reduces heat from the high sun.

Awnings create shade, which prevents direct sunlight/solar/UV radiation from penetrating indoor spaces, creating cooler temperatures.

Pro-Tip - The reduction in direct sunlight will likely reduce energy costs.

11. Replace Incandescent Bulbs

  • Rough Estimate – Several Dollars.
  • Temperature Range – This is effective for any garage space.

It is a good idea to replace incandescent bulbs with high-efficiency LED bulbs. Incandescent bulbs are less energy-efficient, and they dissipate more heat and raise the temperature inside your garage.

Pro-Tip -While the cost for an LED or CFL bulb may be higher than an incandescent, the useful life of these more expensive bulbs is often four times as long – making them both cost-effective and useful in terms of cooling a garage without windows.


Proper ventilation or a type of air conditioning system for your garage is vital to ensuring you have air temperatures that are comfortable whenever the weather gets hot. Whatever your specific situation may be, it is best to select a proper cooling system to keep you cool that is efficient while keeping the cost of running the system within a reasonable range.