If you use your garage as a workshop or social area year-round, you will need a way to heat and cool it. There are a few alternatives, but the ductless mini-split system is probably the best long-term solution.

Using Your Existing Whole-House System Is a Bad Choice

Since your garage is closed off from the rest of your house, the air that is pumped in has no way to return to the air handler to be recirculated. Not only can this create the danger of backdrafting carbon monoxide into your home, but the uneven distribution of air creates negative pressure, which strains your unit and can shorten its life. Economically, it makes no sense to heat and cool an area that is not being regularly used.

Window and Wall Units

The most commonly used option is a window or wall unit, with the main benefit being their inexpensive cost. The disadvantages are that they are noisy and not very energy efficient. However, if the unit is used seldom, this may be an acceptable alternative. If, however, you use your garage frequently, you should install a separate HVAC system for that space.

The Advantages of a Mini-Split System

A mini-split is a ductless system that consists of a small wall-mounted evaporator/blower unit and an outdoor compressor. It runs on heat-pump technology, with single-speed and multi-speed units. The single-speed units are better for areas with more moderate winter temperatures, whereas the multi-speed units are recommended for colder areas. They are designed to heat temperatures down to -15F and cool in temperatures up to 115F. In the garage, their small size allows you to install them higher up, where they won't take up needed wall space. Another advantage is that with an individual thermostat, the garage can be kept at a different temperature than the rest of the house. While a mini-split system costs more to install, its energy efficiency will offset the cost with lower power bills.

Installation of a Mini-split System

A mini-split system is best installed by a licensed HVAC professional, because of the expensive specialized tools and knowledge required. Your local installer will come to your house, measure your space and recommend a unit that fits your needs. He may recommend that you further insulate your garage before installing the unit for added energy efficiency.

There are several options for heating and cooling your garage, but the mini-split system is one of your best overall options. While a bit more expensive to install, it lasts longer than window or wall units and provides energy savings that helps offset the cost. Call your local HVAC services specialist and have him come out and see if a mini-split system is what is right for your garage space.