6 Tips When Installing a Ductless Heat Pumps in Your Garage

Both central heat pump systems and ductless mini-splits use the same process to remove heat from a home or commercial building through the vapor-compression refrigeration cycle. The problem with traditional systems is they utilize bulky ductwork requirements. Ductless mini-split heat pumps are quiet, consume less energy, are also loud, and consume excess energy, but they can be quite challenging to install.

Ductless mini-splits offer convenient solutions for spaces such as garages. When installing these ductless heat pumps in your garage, I recommend consulting an HVAC specialist for best results. Ductless heat pumps have several DIY installation options if you like doing home projects.

The innovation behind ductless heat pump systems has grown in popularity in the last ten years. Installing ductless units where ductwork is not feasible makes these style units a must-have when controlling targeted areas and boosting heating and cooling efficiency.

Here’s some information that helped me when I had a ductless heat pump installed in my garage:

How Well Do Ductless Heat Pumps Work?

If you’re not quite familiar with how ductless heat pumps work, a trip down to memory lane can help you understand them better. The history of ductless heat pumps says a lot about how they work.

In 1954, the Japanese made it their mission to reinvent the air conditioning. Following WWII, the United States introduced air conditioning technology to the Japanese. However, loud system noises combined with extensive ductwork running through smaller homes did not work well for the Japanese.

The Japanese responded by innovating their HVAC solution, starting with Mitsubishi’s invention of the ductless mini-split. Years later, ductless mini-split technology made its way to the west and eventually worldwide. Mini-split units are found in various businesses and homes around the globe.

With added energy-efficient innovations, mini-split heat pump systems utilize simplified space conditioning, significantly increasing home energy first cost savings. Mini-split manufacturers offer both residential and commercial building solutions.

Top brands include Mitsubishi Electric, Daikin, Mr. Cool, Fujitsu, and LG provided by wholesale distributors worldwide. Do-it-yourself (DIY) equipment brands are available at retailers such as Home Depot and various online distributors.

Can a Heat Pump be Installed in a Garage?

Yes, you can install a ductless mini-split system in your garage. Ductless units provide targeted comfort solutions not connected to your existing HVAC system. Connected by a line set (refrigerant lines, communication wire, and drain tubing), mini-split systems are convenient to install.

Problematic areas of your home such as the garage, single rooms, additions, and even complete home solutions will benefit from a mini-split system. You should provide around six feet from the floor to the wall-mounted indoor unit.

Line set refrigerant lines, communication wire, and drain tubing must be inserted through a predrilled hole leading to the exterior of the garage space. Depending on the slope conditions where the outside unit will be placed, either a wall bracket or equipment pad will need to be installed to stabilize the equipment. Study the space outside of the garage that you wish the outdoor unit to go.

The flattest solution available should be explored while remaining aware of where the line set will need to travel to.

How Much Does it Cost to Install a Mini-Split in a Garage?

Considering a two-car garage, the cost for mini-split heat pump equipment averages around $2,000. This cost does not include any installation labor costs when hiring a certified HVAC technician.

There are various benefits to consider when seeking installation service.

Choosing a professional will unlock access to manufacturer warranty coverage, possible service guarantees, and overall ease of installation. Consulting with an HVAC professional will also ensure proper load calculations and extend access to quality mini-split equipment manufacturers like Mitsubishi Electric and LG.

The cost of the equipment and labor charges from a licensed contractor will always be lower than a botched DIY attempt. Damaging the system or vital components will void every manufacturer’s limited warranty. If you are inexperienced and new to equipment installs, the money and time required to install a mini-split in your home on your own are at your expense.

The equipment manufacturer does not cover troubleshooting and labor accrual from unprofessional installation efforts. Prices will fluctuate depending on your location involving taxes, distributor markups, miscellaneous installation costs, supplies, and equipment brands.

How Do You Install a Ductless Mini Split in a Garage?

Select ductless mini-split systems are marketed as “DIY” solutions and are available on the internet. It is important to note that supply houses are typically “wholesale only” and sell parts and equipment to licensed HVAC technicians.

Supply houses will also ask to see a chlorofluorocarbon (CFC) certification while working with refrigerants. Since all heat pump systems, including ductless mini-splits, require the use of R-410A refrigerant, a license will be required.

If you decide to follow the DIY route, the following outline 6 tips when installing a ductless heat pump in a garage:

1. Size the Equipment with a Cooling Load Calculator

The first step is to size the system required to properly satisfy a space’s heating and cooling needs (load calculation). A 2-car garage is approximately 22’-26′ wide with an 8’-16′ door (440-624 sq. ft.).

The importance of an adequately sized mini split for garage is essential. A system sized too small for a large space is doomed to fail even before installation. The larger the garage and increased exposure to the sun will increase the BTUs required to cool your garage efficiently.

2. Purchase a Full-Set Mini-Split System Carefully

It would be best to research multiple brands and the reviews that accompany them. The quality of the unit and its source is important. There are also various applications, such as wall-mounted and ceiling air handler units. It is also crucial to understand the supplier’s warranty policies (if applicable). Identify any additional required accessories such as equipment pads or decorative line set covering.

You can either purchase a mini-split heat pump from an HVAC professional, and they will do the installation.

Another option is to purchase a Mr. Cool mini-split ductless heat pump system from Amazon or a local building supply store and do the installation yourself. You’ll likely need to help of a friend to get the units in place and have a licensed electrician run the power wire and breaker if you’re not comfortable working with electricity.

3. Determine the System Location

Determine where your outdoor unit will be placed outside your home or garage space. An indoor unit will need to be located around 6 feet from the floor level. Measure the distance the line set will need to run from the outside unit to the indoor unit. Line sets are offered at 50′ and below, but 75′ and 100′ rolls are also available, depending on the manufacturer.

The shorter the line set run, the better. A short line set will reduce the amount of time required to install the system and lessen the stress placed on the system. Understanding where the outdoor unit will be placed will also allow planning for mounting bracket kits and equipment pads.

4. Establish a Routine Maintenance Schedule

After installing a ductless mini-split, take note of the specific manufacturer’s required maintenance. Most mini-split systems feature a washable filter that will require attention routinely. Removing the cover of the indoor air handler unit and cleaning out dust, debris, and collected dirt will help prolong the life of the system combined with routine filter cleaning.

5. Be Aware of Local Permit Requirements and Laws

State and local laws may apply when installing a new HVAC system. Check with your local contractor to obtain proper guidance on what laws and permits apply. You may be violating applicable state and local laws and face potential fines, increasing the time, cost, and headache of installing the equipment yourself.

6. Consult with an HVAC professional

Mounting the outdoor and indoor units are DIY tasks for the most part. When it comes to electrical wiring and working with nitrogen and refrigerant, consulting with an HVAC service professional is the best practice. Wiring for both the outdoor and indoor unit is essential to the proper operation of the mini-split system.

Follow manufacturer’s instructions at a comfortable pace and consult with your local HVAC service company if you become unsure and uncertain. Installing an HVAC system is complex and a skilled trades specialty. If you plan to remove an existing system, it is critical to cover the existing refrigerant adequately. It violates federal law and safety hazards to release the refrigerant into the environment without proper recovery procedures.

How Many BTUs Do I Need for a 2-Car Garage? 

As mentioned above, a typical 2-car garage is around 440-624 sq. ft. Depending on your region, the size of the unit will fluctuate. Mini-split load calculators can be found online by querying a search or clicking here.

We will add this information in the load calculator based on a Maryland (region #3) location. The following table details more example information asked to perform the mini-split load calculation:

DescriptionExample Given
Climate RegionRegion #3 – Yellow
Area (sq. ft.)624 sq. ft.
Height (ft)22 ft
Insulation GradeStandard
Sun ExposureAverage Exposure
Number of WindowsAverage Amount
Windows/Doors Air SealantAverage Design
Glass Sunroom?No
Occupants4
Kitchen?Yes
Extra Wattage0

The results reveal that a 624 sq. ft. space occupied by three people with average sun exposure, the average numbers of windows, and standard insulation calls for 30,000 BTU calculated cooling load, or 2.5 tons for a 2-car garage (Pioneer, 2021).

The load calculator will run calculations for almost every residential situation. If you are hesitant regarding the estimate, consult with your local HVAC technician company and load calculation professionals.

Best Mini Split Heat Pump for a Garage 

There are various ductless mini-split options available online through trusted retailers. It is best to research each website and manufacturer’s credibility, including reviews and product specifications. Creating a checklist for what is needed to install a mini-split system in your garage correctly is best practice.

Higher quality equipment brands such as Mitsubishi are only available to Mitsubishi dealers. Be aware that although your local HVAC contractor may be licensed, they may not be authorized to buy Mitsubishi Electric products. You can search for a Mitsubishi dealer by clicking here. The following is a breakdown of a few online equipment brands available:

Mini Split Kit (50′ Installation Kit)BrandBTU (Tonnage)Price
WYS012AMFI19RL-16Pioneer12,000 (1)$868.00
74GW2Ramsond24,000 (2)$1,647.00
WYS030GMFI17RL-50Pioneer30,000 (2.5)$2,308.00
BM30Y18Alpine30,000 (2.5)$1,923.00

Are Mini Split Heat Pumps Noisy?

One of the reasons why the Japanese engineered the ductless mini-splits that feature their refrigerant loops is noise reduction. Traditional central air condition and heat pump units are noisy and not as quiet and energy-efficient as mini-split technology.

Mini-split heat pumps feature low Seasonal Energy Efficiency Ratios (SEER). SEER ratings generally range from 13 to 30+ for both traditional and mini-split heat pump systems, with mini-split technology on the higher end. Older systems are rated lower, and newer central heat pump systems are around 16-SEER.

Mini-split systems are rated at 19-SEER and higher. The higher the SEER rating, the higher efficiency, and quieter operation. You can learn more about our complete guide on heat pump SEER ratings.

Will a Mini-Split in the Garage Add Value to Your Home?

Having a garage in your home instantly adds value to the overall value. If a garage space features a heating and air conditioning capability, the garage will be more valuable. The mini-split addition will contribute to the state of the current HVAC system and will expand the home’s ability to heat and cool. Specific home buyers who enjoy spending an extended amount of time in their garage will value a properly installed, functional ductless mini-split in the garage space.

If you are removing an older system and swapping it out with a ductless mini-split heat pump, the value of your home will increase. A new mini-split system is the equivalent of installing a brand-new energy-efficient heating and cooling system.

Final Thoughts 

Ductless mini-split systems have come a long way, first originating in Japan before moving to the United States. Mini-splits are popular heating and cooling options by offering energy-efficient solutions and targeted comfort solutions that do not require tying into existing HVAC heat pump systems.

Ductless mini-split heat pumps can be installed in both insulated and uninsulated garage spaces. Mini splits for heating and cooling make these systems versatile and virtually available for every application.

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Hubert Miles

I've been conducting home inspections for 17 years. I'm a licensed Home Inspector, Certified Master Inspector (CMI), and FHA 203k Consultant. I started HomeInspectionInsider.com to help people better understand the home inspection process and answer questions about homeownership and home maintenance.
DISCLAIMER: The content published on HomeInspectionInsider.com is not professional advice. You should consult with a licensed professional and check local permit requirements before starting any project.
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