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Is a DIY Mini-Split HVAC System Right for Your Home Project?

DIY mini-split systems are ductless units that have two central components: an indoor air-handling unit and an outdoor condenser/compressor. The indoor air handler connects to the outdoor unit via a set of refrigerant lines and electrical wiring rather than ducts, making the system much simpler to install.

Why a Mini-Split?

Mini-split HVAC systems are the ideal choice for updating properties with non-ducted heating systems, such as hydronic (radiant) water heat systems, or homes that currently use kerosene, wood, propane or space heaters. These cost-effective, energy-efficient systems are perfect for multi-family homes and as retrofit add-ons for apartments and older construction, or for additions or renovations to your current home.

One big advantage of a ductless mini-split is that you can control the temperature in different areas of your home. For instance, you can turn off the AC in unoccupied rooms, or make it cooler in specific rooms independent of the rest of the house, giving you ultimate climate versatility and more control over your home’s energy usage.

To DIY or Not to DIY

Mini-split systems come in a variety of sizes, configurations and mounting options—many of them appropriate for DIY installation. However, it is important to note that not all mini-splits are DIY-friendly. As a rule of thumb, only single-zone systems are currently designated as suitable for DIY installation. So, if you are looking for a system to handle multiple rooms or areas (also known as “zones”), you will need to hire a professional to install both the indoor and outdoor units.

In addition to the type of system you need, you should also consider your confidence level as a DIYer before starting a project like this. Be honest with yourself. Is your level of knowledge enough to install a mini-split system? Many people are handy enough, or have enough experience with home projects, that they can easily install the units. But if you’re a novice at DIY, you may want to enlist help for this project. To determine if mini-split installation is the right project for you, see our helpful checklist below:

  • Are you comfortable using tools and following detailed instructions?
  • Do you have a basic understanding of electrical wiring and the color code system used in wiring schematics?
  • Do you own a basic set of hand tools, including a hammer, slotted and Phillips screwdrivers, standard set of drill bits, drill, needle-nose pliers, standard set of hex keys, adjustable wrench, torque wrench, 3" hole saw, utility knife, 24" level, safety glasses, and work gloves?

If you have decided that DIY installation is right for you, be sure to choose a model that has been marked as DIY-friendly. Do not try to install a system that does not have a pre-charged line set since special tools are necessary for safe and proper setup. Climate Right, Perfect Aire and MRCOOL are three popular brands that offer DIY-friendly systems in a range of sizes and configurations.

Selecting the Right Unit

As stated previously, mini-split systems are made up of two units: an indoor air handler and an outdoor condenser/compressor. When deciding on the correct indoor unit for your project, consider where you would like the unit in relation to the space. For example, wall-mounted units sit high on the wall, while ceiling-based units are seated in the ceiling, making them the least obtrusive. However, floor-mounted units are the easiest to access and maintain. Other choices include concealed duct and multi-positional units.

The outdoor unit comes in three main configurations: cooling-only for hot climates, a heat pump that can switch from AC to heat, and super-heat (including hyper heat, hypertek, extra-low temp, etc.), designed to work in outdoor temperatures as low as -15 degrees Fahrenheit.

Choosing a Size

Unit sizes range from a modest 6000 Btu to a more substantial 48,000 Btu. To accurately determine what size is best for your project, find the overall square footage of the area you want to cover with the mini-split system. To do this, simply calculate the square footage of each room you want to condition and add them together.

Your geographic location should also be taken into consideration. For example, a home in Florida will need a different type and sized unit than a property in Minnesota. Online calculators are available that take into consideration your location, size of dwelling and what level of temperature control you desire to determine the Btu size needed for your space.

Be aware that a heat pump mini-split will use both heating and cooling Btu (12000 Btu per ton of cooling), so keep this is in mind when choosing your unit. When sizing up a heat pump, you will want to take the larger of the two loads, either heating or cooling, and install that model to make sure your needs are covered.

With all this information at hand, installing a DIY ductless mini-split is an easy and economical way to upgrade your currently inefficient heating and/or cooling system. For more help choosing a system or information on DIY installations, call us at 1-800-397-1392. We’re here to help!