How to Install an Air Conditioner in a Garage? Main Rules

Ever entered your garage on a sweltering summer day and felt as though you had walked into an oven? Have you discovered your tools corroded and your possessions deformed due to harsh weather? Seating an air conditioner in your garage can change the space entirely. It can turn your garage into an inviting, pleasant area—ideal for hobbies, workouts, or simply protecting your belongings from the heat.

However, it’s important to note that installing air conditioning in a garage differs significantly from setting it up in your living room. To ensure your AC operates effectively, remains efficient, and doesn't lead to high energy costs, adhere to certain guidelines.

The key elements required to effectively finish the task will be covered in this guide. Whether you enjoy do-it-yourself projects or are thinking about hiring a professional, you will learn all the basics to create a space you will actually enjoy using.

Choose the Right Air Conditioner for Your Garage

1. Understand the Types of Air Conditioners

There are several types of air conditioners to consider, each with its own pros and cons:

• Window Units: These are affordable and effective for smaller garages with windows. They’re easy to install but require a proper mounting spot.
• Portable Air Conditioners: Ideal for flexibility, a portable air conditioner can be moved as needed. Just keep in mind they require venting through a window or door.
• Mini-Split Systems: These are perfect for garages without windows. They’re energy-efficient and powerful, but they require professional installation.

2. Measure Your Garage Size

The size of your garage directly impacts the cooling capacity (measured in BTUs) you’ll need. Here’s a rough guide:

• Small garages (150–300 sq. ft.): Look for units with 5,000–6,000 BTUs.
• Medium garages (300–600 sq. ft.): Opt for 7,000–10,000 BTUs.
• Large garages (600+ sq. ft.): Consider 12,000 BTUs or higher.

3. Check Your Garage’s Insulation

The degree of cool air retention in your garage depends on insulation. To offset temperature swings, poorly insulated garages require a more potent air conditioner. Insulating your doors and walls will increase cooling efficiency and help you save energy.

4. Consider Local Climate and Usage

Is your climate more moderate, or do you live in a hot and humid area? If you live with intense heat, you will want a larger cooling capacity air conditioner. Consider also your regular use of the garage. While daily use would justify a permanent mini-split system, occasional use may make a portable air conditioner the best option.

These elements—type, size, insulation, climate, and frequency of use—allow you to select an air conditioner that keeps your garage comfortable while maintaining energy efficiency.

Prepare Your Garage for Installation

Before you can install an air conditioner in your garage, it’s important to get the space ready. Proper preparation ensures the unit works efficiently and keeps your garage cool without wasting energy. Here’s what you need to do:

1. Assess and Improve Insulation

Insulation is mostly responsible for keeping cool air in and heat out. Look for insulation on the walls, ceiling, and garage door.

• Upgrade Garage Door Insulation: Should your garage door lack insulation, think about installing foam panels or a garage door insulating kit.
• Check Walls and Ceiling: To cut heat transfer, add or upgrade insulation and reduce the walls and ceiling. Good possibilities are materials like spray or fiberglass.

2. Seal Gaps to Prevent Air Leaks

If air leaks exist, even the most powerful air conditioner cannot cool efficiently. Look for openings around windows, doors, and vents in your garage:

• Seal openings and cracks with caulk or weatherstripping.
• Look for holes around pipe entries or electrical outlets, and foam sealant will help close them.

3. Ensure Proper Ventilation

Good airflow is essential for cooling efficiency and air quality. Make sure your garage has adequate ventilation:

• Install exhaust vents if your garage tends to trap heat or moisture.
• Ensure the air conditioner has a clear area for intake and exhaust, especially if you’re using a portable air conditioner.

4. Check the Electrical System

Most air conditioners require a dedicated electrical circuit. Before installation, confirm your garage’s electrical system can handle the load:

• Inspect the Circuit: You might want an electrician to install a dedicated line if your garage lacks enough outlets or the circuit is overloaded.
• Verify Voltage and Amperage: To be sure your AC unit will fit your electrical configuration, review its specifications.

5. Clear the Area

Lastly, make sure the installation site is clean and free of clutter. A clear area ensures safe and efficient installation, especially for units like mini-split systems or window-mounted ACs.

By taking these steps to prepare your garage, you’ll create the perfect foundation for a safe and effective air conditioning setup.

Instructions for Installing the Air Conditioner in Your Garage

Tools and Materials You’ll Need

Before you begin, gather these essentials:

• Screwdriver set
• Measuring tape
• Level
• Drill and screws
• Weatherstripping or foam sealant
• Mounting brackets (for window units or mini-splits)
• Venting kit (for portable ACs)
• Dedicated power source (if required)

Step-by-Step Installation for Different Air Conditioner Units

1. Installing a Window Air Conditioner Unit

Window units are a popular choice for garages with windows. Here’s how to install one:

1. Choose a window that allows airflow and is close to a power outlet.
2. Clean the window frame and apply weatherstripping to seal gaps.
3. Mount the unit using the provided brackets, slightly tilting outward for condensation drainage.
4. Seal open spaces with foam or weatherstripping to prevent air leaks.
5. Test the unit by plugging it in, turning it on, and adjusting settings.

2. Installing a Portable Air Conditioner

A portable air conditioner is flexible and doesn’t require permanent installation. Here’s how to set it up:

1. Choose a location near a window or vent for clear airflow and power outlet proximity.
2. Install the venting kit and connect it to the window or vent opening.
3. Use an adjustable window slider to block air escape gaps.
4. Position the unit with 12-18 inches of clearance for proper airflow.
5. Regularly empty the water reservoir or connect the drainage hose if available.

3. Installing a Mini-Split Air Conditioner System

A mini-split system is a powerful, permanent solution ideal for garages without windows. Here’s how to install one:

1. Mount the indoor unit on an interior wall for even cool air distribution.
2. Choose an outdoor location with adequate ventilation.
3. Install the Mounting Bracket securely using a level.
4. Drill hole for wiring and tubing from indoor to outdoor unit.
5. Connect indoor and outdoor units following the manufacturer's instructions.
6. Secure the outdoor unit on a stable surface.
7. Test the system's cooling efficiency after powering it on.

Key Safety Precautions

• Ensure proper grounding and dedicated circuits.
• Hire an electrician if unsure.
• Direct exhaust air outside, especially for portable air conditioners.
• Double-check screws, brackets, and fittings for secure installation.
• Plan for safe condensation drain from a garage.

Ventilation and Drainage Requirements

For the safety and efficiency of your air conditioner unit, your garage must have adequate drainage and ventilation. In their absence, you run the danger of the system overheating, underperforming cooling, or possibly even water damage. Let me tell you what's important:

Ventilation Requirements

1. Portable Air Conditioners:

The vent hose should be connected to a window, vent, or wall opening to expel hot air outside, and placed 12-18 inches away from walls or obstructions for proper airflow.

1. Window Air Conditioners:

To effectively release heat, ensure the outdoor side of the unit has unobstructed airflow and seal the gaps with weatherstripping or foam.

1. Mini-Split Systems:

Place the condenser outdoors in a well-ventilated area, away from debris, and allow 2-3 feet of clearance. Mount the indoor unit high on the wall, allowing 6 inches of space above for airflow.

Drainage Requirements

1. Portable Air Conditioners:

Regularly empty the water reservoir in portable units and use a drainage hose to route it to a floor drain or container for continuous drainage.

1. Window Air Conditioners:

Install the unit with a slight tilt towards the outside for safe condensation drainage and check the built-in drainage hole for debris blockage.

1. Mini-Split Systems:

Install a drainage tube to transfer condensation outside the indoor unit. Avoid uphill routing to prevent water backup. Regularly inspect for clogs to prevent water from pooling inside.

Proper ventilation and drainage in a garage unit prevent system overload and water damage and improve efficiency by preventing overheating, preventing water accumulation, and reducing energy usage, ultimately resulting in a more efficient and energy-efficient garage cooling system.

Maintenance Tips for Garage Air Conditioners

If you want your garage air conditioner to keep working its best, regular maintenance isn’t just a nice-to-have—it’s a must. Luckily, it’s not rocket science. With a little effort here and there, you can avoid headaches like breakdowns, high energy bills, or an AC that just doesn’t cool like it used to. Here’s how to keep things running smoothly.

• Keep Filters Clean: Regularly check and replace filters to prevent clogging and ensure better airflow.
• Listen to Your AC: Listen for odd noises like rattling, buzzing, or hissing to identify potential issues.
• Check for Wear and Tear: Regularly inspect the AC for cracks, rust, and damage to the power cord and connections to prevent costly repairs.
• Get Seasonal: Clean the coils before summer to prevent dust buildup and heavy use. Cover outdoor units during winter for protection.
• Don't Forget About Drainage: Regularly check the drain line and empty the drain pan before overflowing to prevent potential mold problems.