Why Every Garage Needs a Mini Split and How to Install One

Learn why every garage needs a mini split for year round comfort and how to install one efficiently to improve climate control and energy performance.

Your garage is more than just a place to park your car. For many homeowners, it's a workshop, gym, home office, or storage space. But one big problem keeps people from using their garage all year round — the temperature. In summer, it feels like an oven. In winter, it's freezing cold. A mini split system solves this problem completely.

We'll explain why every garage needs a mini split and walk you through exactly how to install a garage mini split system — step by step, in plain and easy language.

What Is a Mini Split System?

A mini split system is a type of heating and cooling unit that works without needing ductwork. It has two main parts: an indoor air handler (mounted on your wall) and an outdoor compressor unit. They connect through a small hole in the wall using refrigerant lines, a power cable, and a drain hose.

Mini splits are very popular for garages, workshops, and rooms that don't have access to a central HVAC system. They're energy-efficient, quiet, and easy to control with a remote.

Why Every Garage Needs a Mini Split

Here are the top reasons why installing a mini split in your garage is a smart decision:

• Year-Round Comfort: Whether you use your garage as a workshop or home gym, a mini split keeps it comfortable in all seasons.

• No Ductwork Needed: Most garages don't have air ducts. A mini split works perfectly without them.

• Energy Savings: Mini splits are very efficient. They only heat or cool the garage when you need it, saving you money on energy bills.

• Protects Your Belongings: Extreme heat and cold can damage tools, electronics, and other items stored in your garage. A mini split keeps the temperature stable.

• Adds Home Value: A climate-controlled garage is a selling point that can increase the value of your home.

What Size Mini Split Do You Need for a Garage?

Before you install a garage mini split system, you need to choose the right size. Size is measured in BTUs (British Thermal Units). The bigger your garage, the more BTUs you need.

Here's a simple guide:

• 1-car garage (up to 300 sq ft): 9,000 BTU

• 2-car garage (300–600 sq ft): 12,000–18,000 BTU

• 3-car garage or large workshop (600+ sq ft): 24,000+ BTU

Also consider insulation. If your garage is not well-insulated, you may need a slightly larger unit to compensate for heat loss or gain.

Tools and Materials You'll Need

Before starting the installation, gather these tools and materials:

• Mini split system (indoor unit + outdoor unit)

• Mounting bracket for the indoor unit

• Refrigerant line set (usually included)

• Electrical conduit and wiring

• Hole saw (usually 2.5–3 inches)

• Drill and bits

• Level

• Pipe cutter and flaring tool

• Vacuum pump and manifold gauge set

• Torque wrench and screwdrivers

How to Install a Garage Mini Split System: Step-by-Step

Here is a complete step-by-step guide to install a garage mini split system. Always follow local codes and the manufacturer's instructions.

Step 1: Choose the Right Location

Pick a spot on the wall for the indoor unit. It should be high up (at least 7 feet from the floor) and away from direct sunlight or heat sources. The outdoor unit should be placed on a flat surface near the wall — ideally on a concrete pad — with at least 12 inches of clearance on all sides for airflow.

Step 2: Mount the Indoor Unit

Use a level to make sure the mounting plate is straight. Drill holes into the wall studs and attach the mounting bracket securely. Then hang the indoor unit on the bracket. Don't connect anything yet.

Step 3: Drill the Wall Hole

Drill a hole through the wall (usually 2.5 to 3 inches wide) at a slight downward angle toward the outside. This angle helps water drain out properly. Feed the refrigerant lines, electrical wire, and drain hose through this hole.

Step 4: Connect the Refrigerant Lines

This is one of the most important steps. Use the flaring tool to prepare the copper line ends, then connect them to both the indoor and outdoor units. Tighten all connections with the torque wrench to the manufacturer's specifications. Loose connections cause refrigerant leaks, which is expensive and bad for the environment.

Step 5: Connect the Electrical Wiring

Run the electrical wiring from the indoor unit to the outdoor unit following the wiring diagram in your manual. You'll also need a dedicated circuit from your electrical panel. Most mini splits require a 240-volt circuit. If you're not confident with electrical work, hire a licensed electrician for this step.

Step 6: Install the Outdoor Unit

Place the outdoor unit on its concrete pad or wall bracket. Connect the refrigerant lines and electrical cables to the outdoor unit. Make sure all connections are tight and the unit is level.

Step 7: Vacuum the Refrigerant Lines

Use a vacuum pump and manifold gauge set to remove air and moisture from the refrigerant lines. This process is called 'pulling a vacuum.' Connect the manifold gauge to the service ports on the outdoor unit, run the vacuum pump for at least 30 minutes, and check that the vacuum holds before releasing the refrigerant.

Step 8: Release the Refrigerant

Once the vacuum holds, use the service valve tool to open the refrigerant valves on the outdoor unit. This releases the pre-charged refrigerant into the system. Most new mini splits come pre-charged and ready for lines up to a certain length.

Step 9: Power On and Test

Turn on the power at the breaker panel and power up the unit using the remote control. Set it to cooling mode first and check that cold air comes out. Then test the heating mode. Listen for any unusual noises and check for refrigerant leaks using leak detector spray around all connections.

Step 10: Seal and Clean Up

Seal the wall hole with foam or caulk to prevent air leaks and pests from entering. Cover the exterior lines with a line set cover for a clean, professional look. You're done!

Professional Help from TLS Air Conditioning Services

If you're not comfortable handling the electrical wiring or refrigerant work yourself, it's always a good idea to call in professionals. TLS air conditioning services is a trusted HVAC contractor known for helping homeowners install mini split systems quickly and safely. Their team handles everything from system sizing and mounting to refrigerant charging and electrical hookup — ensuring your garage mini split is installed correctly the first time. Working with experts like TLS air conditioning services not only saves you time but also protects your warranty and gives you peace of mind that the job meets all local codes and safety standards.

Common Mistakes to Avoid

• Choosing the wrong size: Too small and it won't heat or cool properly. Too large and it short-cycles, wasting energy.

• Skipping the vacuum step: Air and moisture in the lines can damage the compressor.

• Poor location choice: Avoid placing the indoor unit near heat sources or in direct sunlight.

• Ignoring permits: Some areas require a permit and inspection for HVAC installation. Check with your local authority first.

How Much Does It Cost to Install a Garage Mini Split?

The total cost to install a garage mini split system depends on the unit size and whether you do it yourself or hire a professional.

• DIY installation: $700 – $1,500 for the unit, plus tools

• Professional installation: $1,500 – $3,500 total (unit + labor)

DIY can save you $500–$1,000 in labor, but only do it yourself if you're comfortable with the electrical and refrigerant steps.

Frequently Asked Questions (FAQs)

Q1: Can I install a mini split in my garage myself?

Yes, it's possible to DIY the installation if you have basic mechanical skills. However, the electrical wiring and refrigerant handling steps are best left to licensed professionals unless you are certified. Many homeowners do a partial DIY — mounting the units and running the lines — and hire an HVAC tech just for the refrigerant work.

Q2: How long does it take to install a garage mini split?

A professional can usually complete the installation in 4 to 8 hours. If you're doing it yourself for the first time, expect it to take a full day, especially if you're learning as you go.

Q3: Do I need a permit to install a mini split in my garage?

It depends on your local building codes. Many areas require an electrical permit and inspection. Always check with your local city or county building department before starting. Skipping a required permit can cause problems when selling your home.

Q4: What is the best mini split brand for a garage?

Popular and reliable brands include Mitsubishi, Daikin, LG, Senville, and Pioneer. For garages, a single-zone unit from any of these brands will work well. Look for a model with a high SEER rating (above 18) for better energy efficiency.

Q5: Can a mini split heat a garage in very cold weather?

Yes! Most modern mini splits work in temperatures as low as -13°F (-25°C). Look for a model that is labeled 'cold climate' or 'hyper heat' if you live in an area with very cold winters.

Q6: How often does a garage mini split need maintenance?

You should clean the air filter every 4–6 weeks if you use the unit regularly. Have a professional service the unit once a year to check refrigerant levels, clean the coils, and make sure everything is running properly.

Q7: Will a mini split work in an uninsulated garage?

Yes, but it will have to work much harder. If your garage has no insulation, the mini split will use more energy and may struggle to maintain the temperature on very hot or cold days. Insulating your garage walls and door before installing a mini split will make a big difference.

Final Thoughts

Installing a garage mini split system is one of the best upgrades you can make to your home. It turns an uncomfortable, barely-usable space into a fully functional room you can enjoy all year long. Whether you're a DIY enthusiast or prefer to hire a pro, the process is straightforward when you follow the right steps.

If you take the time to choose the right size unit, follow a careful installation process, and avoid the common mistakes listed above, your garage mini split will serve you well for many years to come.