Air Conditioning Your Garage

Keeping your garage cool during the hot summer months is important for comfort and protecting your belongings. Air conditioning your garage can seem daunting, but with careful planning and the right equipment, you can create a comfortable garage space all year round.

Why Air Condition Your Garage?

There are several key reasons you may want to install air conditioning in your garage:

Protect Valuable Items

Fluctuating temperatures and humidity can damage items stored in your garage over time – things like tools, sports equipment, furniture, and more. Air conditioning regulates the temperature and humidity levels to prevent warping, rusting, cracking, and other damage.

Make the Garage More Usable

During the summer, garage spaces without air conditioning can become unbearably hot. Air conditioning allows you to comfortably use your garage workshop, parking area, or living space without overheating.

Improve Air Quality

Air conditioning improves air circulation and filters out pollutants like dust and pollen. Thiscreates a healthier environment, especially if you use your garage frequently.

Challenges of Cooling a Garage

Garages present some unique challenges when it comes to cooling:

  • Garages tend to be large, open spaces that are more difficult to efficiently climate control.
  • Most garages have minimal insulation, allowing outdoor temperatures to easily influence the interior.
  • Garage doors are often opened and closed frequently, letting cool air escape.
  • Garages contain equipment, vehicles, chemicals, and other contents that produce heat.
  • Garage environments and activities create dust that can clog air conditioners.

The right ac system and setup can overcome these challenges.

Air Conditioning Options for Garages

There are several types of air conditioning systems to consider for your garage:

Wall-Mounted AC Units

  • Self-contained systems installed on garage walls
  • Offer cooling for small to mid-size garages (up to ~500 sq ft)
  • Require minimal installation
  • Can be noisy

Mini-Split Systems

  • An outdoor compressor connected to one or more indoor units
  • Flexible – indoor units mounted on walls or ceilings
  • Quiet and energy-efficient
  • Cool larger areas (500 – 1000+ sq ft)
  • More expensive to install

Central AC

  • Utilizes the central air system of your home
  • Requires running ductwork to the garage
  • Provides whole-home comfort and efficiency
  • High installation costs

Portable AC Units

  • Freestanding systems that are fully self-contained
  • Easy to set up as needed
  • Only suitable for small spaces (<150 sq ft)
  • Can be loud and inefficient

Evaporative Coolers

  • Air is cooled as water evaporates into it
  • Lower energy costs than traditional AC
  • Only work well in dry climates
  • Doesn’t lower humidity

Key Steps to Cool Your Garage

Cooling your garage effectively takes some planning and preparation:

1. Determine the Size of Your Garage

  • Measure the total square footage and volume of the space
  • Factor in ceiling height – taller garages are harder to cool

This allows you to pick an AC unit with adequate cooling capacity.

2. Inspect Windows, Doors, Insulation and Seals

  • Identify sources of air leaks letting hot air in
  • Add weatherstripping around doors and windows
  • Install insulation in walls and ceilings if lacking
  • Sealing the garage reduces the load on the AC

3. Consider How You Use Your Garage

  • Workshop, parking, living space, storage, etc.
  • The use impacts the ideal temperature and AC needs
  • Consider isolating areas like a workshop from living spaces

Tailor the setup to your garage activities.

4. Choose a Suitable AC System

  • Consider AC types based on size, use, noise, costs
  • Wall units or mini-splits offer flexibility for garages
  • Ensure sufficient cooling capacity for the space

5. Strategically Place the AC Unit

  • Mount the AC high on a wall if possible
  • Avoid obstructing garage doors and work areas
  • Place portable units centrally if using them

Proper placement improves air circulation.

6. Get the Right Electrical Circuit

  • Most AC units require a dedicated 240V electrical circuit
  • The circuit must be properly sized for the unit
  • This often requires hiring an electrician

Insufficient power will prevent the AC from working properly.

7. Consider Supplemental Fans and Ventilation

  • Circulate air and eliminate hot spots for better comfort
  • Exhaust fans remove hot air and fumes from workshop activities
  • Open doors when practical to aid air exchange

Operating and Maintaining a Garage AC

Once installed, be sure to use and maintain your garage AC correctly:

  • Expect a moderate electrical load increase from running the AC.
  • Change filters regularly per the manufacturer instructions.
  • Have a professional annually service the AC before summer.
  • Use a protective cover on the outdoor unit during winter if applicable.
  • Adjust the thermostat to balance comfort and energy efficiency.
  • Keep windows and doors closed as much as possible.
  • Use smart features like timers and smart controls to optimize operation.
  • For portable units, empty the water tank on a regular basis.
  • Ensure proper drainage for any condensation from the AC system.

With routine upkeep, your garage AC should provide many years of reliable cooling.

Garage AC Troubleshooting

Some common garage air conditioning issues and their causes:

Problem: AC is not blowing cold air

  • Causes: Refrigerant leak, compressor failure, clogged filters

Problem: AC is inconsistently cooling

  • Causes: Insufficient air flow, dirty coils, freezing temp setting too high

Problem: AC is short-cycling on and off

  • Causes: Improper sizing, obstructed coil, very dirty filter

Problem: Water leaking from AC

  • Causes: Clogged drain line, condensate pan overflow, refrigerant overcharge

Problem: Unusual noises from AC

  • Causes: Loose parts, failing fan motors, compressor issues

Problem: High energy bills

  • Causes: Improper sizing, dirty filters, old AC, leaky garage

If you experience ongoing problems, hire an HVAC technician for diagnosis and repairs.

FAQs About Garage Air Conditioning

How much does it cost to install air conditioning in a garage?

The cost to add AC to a garage ranges from $1,500 – $7,000 on average, depending on the type of system and complexity of the installation. Mini-split systems typically cost $2,000 to $4,000.

What size air conditioner do I need for my garage?

The required cooling capacity depends on the size of your garage and factors like exposure and insulation. As a rule of thumb, you need 20-25 BTUs per square foot for a moderately insulated garage. An HVAC pro can help with proper sizing.

Is a wall AC unit good for a garage?

For small to mid-size garages (up to about 500 sq ft), a wall AC unit can provide sufficient cooling. Wall units are affordable, easy to install, and operate well in the temperature fluctuations of a garage. Just be sure to get one with enough BTUs for the space.

Should I insulate my garage before installing AC?

Adding insulation to your garage before installing air conditioning is highly recommended. Insulation reduces heat transfer which lowers the load on the AC. This allows you to get by with a smaller, less expensive AC unit.

Can I cool my garage with a portable AC?

Portable air conditioners are only suitable for cooling very small garage spaces, generally under 150 square feet. They lack the power and efficiency to effectively cool larger garages. Going with a permanently installed unit like a mini-split is a better choice for most garages.

Is it worth it to AC my garage?

Adding air conditioning can make your garage much more comfortable during summer. It protects your belongings from heat damage and allows you to use the space year-round. For garages converted to living spaces, workshops, or other active uses, the investment in cooling can certainly be worthwhile.


Installing air conditioning in your garage is an effective way to regulate temperatures and humidity during hot weather. Carefully considering your needs, choosing an appropriate AC system, and properly installing, operating, and maintaining the unit will provide years of reliable cooling. With some planning, you can turn your garage into a pleasant, conditioned space you can fully utilize all summer long.

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