A Quick Guide to Mini-Split Air Handlers

A Quick Guide to Mini-Split Air Handlers


If you’re shopping for a ductless mini-split, you already know these small-but-mighty HVAC systems provide a comfort solution for many home applications–a room addition, a climate-controlled workshop or other flex space, or a bedroom that is always too hot or too cold. Once you have determined the size (capacity) of the mini-split system you need (check out our Ductless Mini-Split System Selector or reach out to one of our HVAC experts for help), it’s time to think about what type of air handler(s) will best suit your needs.

The Top 5 Air Handler Types

When it comes to air handlers (the indoor portion of the mini-split system), there are five main types to choose from. Your choice of air handler will impact performance, aesthetics, and budget. 

1) The Wall Mount

The standard wall-mounted air handler is the most common type and most popular option for our customers. It is typically the easiest to install, the most efficient, and generally the most economical choice. 

wall-mounted air handler mounted in room

These units are designed to be mounted about six feet above the floor and at least six inches below the ceiling. They are most commonly (and most easily) installed on an exterior wall but can also be mounted on an interior wall. Wall-mounted air handlers have a sleek profile and modern look. These units draw air in through vents at the top and release conditioned air directly into your space through louvers at the bottom.

2) The Ceiling Cassette

The ceiling cassette has proved to be our second most popular type of air handler, despite its higher upfront cost. Its popularity is likely due to its discreet appearance, which resembles a traditional ducted vent cover or grille. 

ceiling cassette style air handler

For those who either don’t have the wall space to accommodate a wall-mounted unit or want the body of the air handler to be hidden from view, the ceiling cassette provides an ideal solution. Install one of these units in a drop ceiling or nestle it in-between the ceiling joists. 

Ceiling cassettes are high-efficiency units on par with wall mounts. If installed in the center of a room, a ceiling cassette can better mix the air due to air disbursement in four directions.

3) The Low Wall

Low wall air handlers mount on the wall at or just above floor level. They have a low profile (slimmer than some wall mount styles), and some customers prefer the look of low wall units over the standard wall mount.

low wall air handler mounted near floor level

The image above shows how airflow in a low wall unit reverses direction in heating and cooling modes. In heating mode, warm air enters the room from the bottom of the unit for better heat distribution. In cooling mode, conditioned air blows from the top.

Low wall air handlers make a great choice when a higher wall placement is not an option, for example, when the ceiling height is lower than 7½ feet. A low wall unit may be the best option for an A-frame house, a finished attic, or a living area above the garage.

4) The Wall/Ceiling or Floor/Ceiling

Floor/ceiling (also called wall/ceiling) air handlers are similar to the low wall style in that they can be mounted to the wall at or near floor level. This makes them another good option for short wall applications. However, wall/ceiling units are more versatile because they can be alternately suspended from the ceiling in a horizontal position.

wall/ceiling style air handler mounted two ways

Floor/ceiling units are a good choice for those wanting to free up floor space or those with no wall space to spare. Note that, unlike the ceiling cassette, the body of the wall/ceiling air handler will hang down approximately 9 inches from the ceiling, making it visible in the space. When aesthetics is not a primary concern, the tradeoff is a lower price on these units compared to the ceiling cassette.  

5) The Concealed Duct

The last type of air handler for your ductless mini-split system is the concealed duct. But wait a minute–a ducted ductless mini-split? You heard us right. The concealed or hidden duct mini-split is an overlooked style that offers several advantages. But first, let’s take a look at how these units work.

concealed duct air handler installed above ceiling

Concealed duct air handlers can be installed above the ceiling, in an attic; below the floor, in a basement or crawl space; or behind a soffit. As such, they provide maximum flexibility for challenging applications. Attach flexible ducting, and the unit can heat and cool multiple rooms and provide a more even distribution of air within the home. 

Those with more than one space to heat or cool can save money with a concealed duct system. Because it utilizes just one air handler, it will cost less than a multi-zone system with two or three air handlers. 

Lastly, a concealed duct system is the most hidden of all air handler types; you will not see it at all in your space. The only visible part of the system is the air vent covers, which are the typical size and type found in traditional ducted HVAC systems.

Have Questions? We Can Help!

We hope this article has clarified the options available to you when choosing an air handler for your mini-split system. For more information or questions about your project, help is at your fingertips. Call, email, or LiveChat with an HVAC expert at Alpine today!

How to Choose the Right Mini-Split for your Garage

How to Choose the Right Mini-Split for your Garage

Ductless mini-split systems are a popular choice for garage conversions. Turning your garage into a livable space–a workshop, game room, gym, office, or home theater–can be a great way to get the most out of your home. 

the word "GARAGE" in neon lights

Photo by Patrick Fore on Unsplash


When converting your garage, one of the most important decisions is the type of equipment you will use to condition the space. Unfortunately, running new ductwork can be expensive and may require replacing your existing HVAC equipment.

Mini-splits are an ideal solution when it comes to this type of application, and they offer several advantages over traditional HVAC:

  • Typically cheaper than modifying or replacing existing ducted equipment
  • Straightforward installation (90-100% can be DIY if you are handy)
  • Year-round, energy-efficient heating and cooling 
  • Whisper-quiet operation
  • Independent climate control
  • WiFi connectivity and smartphone / smart home hub compatible

A mini-split can be customized to your specific garage and how you intend to use the space. Independent climate control is perfect for a flex space like this, as you may not want to heat or cool the garage if unoccupied for long periods. WiFi connectivity allows you to control the system directly from your phone: turn the unit off while you’re away, and turn it on before you arrive home so that your space will be ready when you are.

6 Sizing Considerations for your Garage 

The HVAC experts at Alpine recommend considering the following important factors when choosing the right size and type of mini-split for your garage:

  1. Square Footage
  2. Ceiling Height
  3. Insulation
  4. Air Escape through Gaps and Doors
  5. The Climate in Your Region 
  6. How Will You Use Your Repurposed Garage?

Square Footage

The first step in finding the right mini-split system for your garage is to know your square footage. Garages vary in size, with typical 1, 2, and 3-car garages being approximately 20’ x 12’ (240 square feet), 20’ x 20’ (400 square feet), and 20’ x 30’ (600 square feet), respectively. If we look solely at square footage, a simple mini-split sizing chart might suggest the following sizes for average 1, 2, and 3-car garages: 9,000 BTU, 12,000 BTU, and 18,000 BTU. However, in many cases, these units would not perform to expectations because the unique attributes of a garage were not taken into account. To avoid undersizing your system, read on.

Ceiling Height

two-car detatched garage with vaulted ceiling

Photo by Erik Mclean on Unsplash


The average ceiling height of a garage is 8-9 feet, though some are higher and may be vaulted. The extra air volume will require additional heating and cooling power. To adjust your square footage to take a high ceiling into account, use the following formula:


  • 9 feet or under is normal
  • For 10 feet, multiply the square footage by 1.1
  • For 11 feet, multiply the square footage by 1.2
  • For 12 feet, multiply the square footage by 1.3
  • For 13 feet, multiply the square footage by 1.4
  • For 14 feet, multiply the square footage by 1.5
  • For 15 feet, multiply the square footage by 1.6



Attached garages are not well-insulated compared to the rest of your house. Typically, the shared wall between the garage and the home is the only wall that contains insulation. With three out of four sides of the space uninsulated, it will take more power to maintain your desired temperature in the garage than in other rooms of your home. Detached garages usually lack insulation on all sides.


We recommend insulating your garage as much as is practical because it can save you from the higher upfront cost of upsizing your mini-split system and the ongoing energy cost of conditioning a poorly insulated space. A cheap and easy garage door insulation kit, which ranges from $50 to $100, will provide at least some protection from temperature swings. Lack of insulation, however, is not a deal-breaker. Upsizing your system by at least one size should provide ample power to maintain your desired temperature within the space.

Air Escape through Gaps and Doors

repurposed two-car garage with one door open

Photo by Marius Ciocirlan on Unsplash


Another significant difference between garages and the living spaces of your home is the large doors that open directly to the outdoors. If you plan to use the space with the door(s) partially or fully open, or if the door(s) will open and close with regularity, you’ll want to consider a more powerful unit that can overcome the loss of conditioned air. 

Even if you plan to keep the garage door(s) closed most of the time, keep in mind that the perimeter may not be tightly sealed, leaving gaps where air can escape. Check for gaps along the left and right sides of the door, and make sure that the weather stripping makes full contact with the floor along the bottom edge of the door.

The Climate in Your Region

exterior view of garage door with snow falling

Photo by Kelly Sikkema on Unsplash


If you live in a moderate climate without prolonged temperature extremes, then a standard mini-split system should be adequate to condition your garage. However, if your region experiences periods of sub-freezing or sub-zero temperatures, then a 4 or 5 Series Blueridge mini-split will keep you comfortable during the coldest months. These sophisticated units can provide heat down to -22℉ outside. In extremely hot climates, these same units will help keep the sweat off your brow while you work or play.

How Will You Use Your Repurposed Garage?

Two key factors that may affect your system size are: what you plan to do in your space and how often you will use it. Consider the following:

  • Will you be generating heat in the same area you’re trying to cool?

welder in garage wearing heat-protective gear

Photo by Rob Lambert on Unsplash


For instance, will you use any equipment that creates a significant amount of heat? Or will you regularly hold gatherings of more than 4-5 people in your space? If yes, we recommend upsizing your system to provide adequate cooling. Let’s imagine the following two scenarios:

dice and playing cards on table

Photo by Josh Appel on Unsplash


  1. You have a garage that normally needs 12000 BTUs of cooling. However, you host a weekly game night with 15 friends. When all 15 friends are in your space, they add approximately 400 BTUs of heat per person, per hour. (That’s 15 people x 400 BTUs = 6000 BTUs of heat generated!) Therefore, if you want to stay cool on game night, you’ll need to size up to an 18000 BTU system.

person putting pottery in kiln

Photo by Kampus Production on Pexels


  1. Your workshop usually needs 18000 BTUs of cooling, but you have a small kiln that adds 5000 BTUs of heat per hour to your space. If you use your kiln during the summer months, then you would need 23000 BTUs of cooling power (18000 + 5000) to stay cool in your space.


  • Will you use the space frequently or occasionally?

Mini-split systems have a well-deserved reputation for efficient heating and cooling. They achieve maximum efficiency when maintaining a set temperature over time, on a low-and-slow mode. If you plan to use your space often and keep your mini-split running in this high-efficiency mode, then there is no need to increase the size of your system. 

However, if you will only use your garage space occasionally and plan to turn the system off when the room is not in use, then you may want to size up. Here’s why. As soon as your system turns off, the temperature and humidity of the room will change as conditioned air escapes and unconditioned air enters. When it’s time again to use the space, you’ll want it to feel comfortable right away. The mini-split will work extra hard to achieve your desired temperature (many units have a “turbo” mode for this very purpose), but it may not happen as quickly as you would like. We recommend going up a size  to rapidly heat and cool your space.

Air Handler Type and Location

Mini-split systems consist of two units–the outdoor condenser or heat pump and the indoor air handler. Air handlers come in various styles to suit both practical and aesthetic purposes. With a garage space, the choice comes down to functionality. Where is the best place to put your air handler, based on the layout of your room? In some cases, your placement needs may determine the type of air handler best suited to your space. 

The Wall-Mounted Air Handler 

The most popular type, and our top recommendation for a garage application, is the wall-mounted air handler. These mount directly on a wall 6 feet or more above the floor and at least 6 inches below the ceiling. 

wall-mounted air handler mounted in room

As long as you have the wall space, wall-mounted units are typically the easiest type to install. They mount on exterior or interior walls, and you can even position them close to where you will be within the room to further enhance your comfort level. Standard wall-mount air handlers range from 9000-36000 BTUs of heating and cooling and can cover most garages.

The Wall/Ceiling Air Handler 

garage walls covered with tools, gadgets, spray cans, etc.

Photo courtesy of Unsplash


Not much wall space to spare? Wall/Ceiling units provide flexibility during the installation process, allowing floor-level placement or suspension from the ceiling. 

wall/ceiling style air handler mounted two ways

These units offer between 18000-60000 BTUs of heating and cooling capacity, so they are also an excellent choice for oversized garages or when you have upsized your system to account for lack of insulation or other factors, discussed above.

The Ceiling Cassette

What if your wall space is at a premium, and you have a lower ceiling height? Or perhaps you’re looking for a more discrete unit. 

ceiling cassette style air handler

Although the priciest style of air handler, the ceiling cassette mounts flush with the drywall and has louvers on all four sides to distribute air evenly within your space. The inner workings of the air handler are cleverly concealed above the ceiling, in-between the joists. No wonder it is our second most popular style!

Dual-Zone Mini-Split System (2 Air Handlers)

For oversized or L-shaped garages, you might consider two air-handling units to cover the space. Our multi-zone systems pair one outdoor heat pump with two or more air handlers (same or different styles) to more efficiently mix the air in a larger space.

Diagram of L-Shaped Garage

Questions About Your Project? Ask an Expert!

Friendly HVAC expert at Alpine awaiting your call

The HVAC experts at Alpine Home Air Products can help you find the best mini-split system for your space, your budget, and your particular needs. Here at Alpine, we’ve been making customers happy since 2002. We have thousands of 5-star reviews and an A+ rating from the BBB

Blueridge logo

Blueridge ductless mini-splits–Alpine’s exclusive brand–are made to our specifications by the world’s largest, most reputable HVAC manufacturer and have the highest online product ratings of all mini-split brands. When you purchase a Blueridge mini-split from Alpine, you get:

Whether you’re just starting to brainstorm a garage conversion or you’re ready to take back your garage from the elements, our team is here to help. Call or email us today! 


How to Install a Mini-Split in 4 Steps

How to Install a Mini-Split in 4 Steps


Thinking about installing a Blueridge ductless mini-split? Many of our customers choose to do the majority (90%) of the installation themselves and then hire a pro for the final start-up. Our DIY mini-splits allow customers to complete 100% of the installation on their own. 


In this article, Alpine’s HVAC experts explain the process of installing a mini-split system with wall-mounted air handler in four easy steps:

Step 1: Mounting a Ductless Mini-Split

Step 1: Mount

  • Outside: Install the condenser on a pad or bracket and in a convenient location.
  • Inside: Attach the included mounting plate on the wall where you want to install the air handler.
  • Using a hole saw, drill through your wall at a slight downward angle, adjacent to the lower right-hand side of the mounting plate. Insert wall sleeve, if desired.
  • Hang the indoor unit on the mounting plate while running the refrigerant lines, wiring, and drain tubing through the hole to the outside.

Step 2: Connecting Line Sets

Step 2: Connect

  • Using a torque wrench, secure the refrigerant lines to the connectors on the indoor unit and then the outdoor unit.
  • Connect the wiring between indoor and outdoor units. Make sure to match each color of wire to the corresponding terminal.
  • Discharge the condensate line away from the wall and to the outside.

Step 3: Electrical Work

Step 3: Electrical

We recommend hiring an electrician for this portion of the job if you are not trained to work with high voltage electricity.

  • Turn off power at the breaker box.
  • Depending on your particular model, run 220- or 110-volt power from a dedicated circuit on your breaker panel to a disconnect box located near the outdoor unit. 
  • Install an electrical whip (weatherproof power wiring) connecting the disconnect box to the outdoor unit.
  • Turn the power back on at breaker box.

Step 4: Start Up

Step 4: Start-Up

A. Conventional Mini-Split: Hire a Pro

Your HVAC contractor will:

  • Do a pressure test to check for leaks
  • Pull a vacuum on the refrigerant lines
  • Release the refrigerant from the condenser into the system
  • Add refrigerant if the refrigerant lines are longer than the factory precharge in the system
  • Startup and test the system


B. DIY Mini-Split: Self Start-Up

  • Release the refrigerant from the outdoor unit into the system using an Allen wrench.
  • Check for leaks: Use a spray bottle with soapy water where the line sets connect. 
    • If there are leaks, retighten the line set connections to the proper torque.
  • Turn on the system.

Mini-Split Installation Videos

Watch the installation of a conventional mini-split from start to finish:


Watch a DIY mini-split installation here:


*Note that in newer DIY models, the line set comes packaged with the condenser and must be attached to both inside and outside units.


We have answers! For more information about installing a Blueridge ductless mini-split, contact the HVAC experts at Alpine. We can help you find the best mini-split system for your space, budget, and particular needs. Here at Alpine, we’ve been making customers happy since 2002. We have thousands of 5-star reviews and an A+ rating from the BBB


Blueridge ductless mini-splits–Alpine’s exclusive brand–are made to our specifications by the world’s largest, most reputable HVAC manufacturer and have the highest online product ratings of all mini-split brands. When you purchase a Blueridge mini-split from Alpine, you get:

The exceptional Blueridge Ductless Mini-Split Warranty covers five years for parts and seven years for the compressor (heat pump). What’s more, Alpine’s in-house warranty processing means support or replacement parts are just a phone call away. But here’s where the Blueridge warranty really shines: while many mini-split brands warrant their product only when installed by a licensed contractor, Blueridge’s warranty covers the do-it-yourselfers as long as the unit has been installed correctly.

For more information, call or email us today!