While mini-split system heat pumps have been used for many years around the world, the technology is relatively new in the U.S. market. Depending on your situation, the technology may be appropriate to use in your home, whether you are constructing new, remodeling an older home, or building an addition.
What is a mini-split system heat pump?
As the name suggests, these are small units often used to heat and cool small areas, such as a single room or a “zone” in a home. Like standard air source heat pumps, they have two main components: an outdoor compressor/condenser and an indoor air-handling unit. A conduit that houses the power cable, refrigerant tubing, suction tubing, and a condensate drain, links the outdoor and indoor units.
Advantages of a mini-split system
According to ENERGY STAR®, these systems are less expensive to purchase and to operate than most other heating and cooling systems, and allow you to “zone” your home’s heating and cooling according to your needs. In other words, you can heat and cool only those areas in the home that you want to, closing off unused bedrooms or storage areas, for example. You can have up to four zones connected to one outdoor unit and can adjust temperature for each zone independently. And because ENERGY STAR estimates that duct losses can account for more than 30 percent in other heat sources, ductless mini splits can conserve that energy, costing less to heat your home in areas you choose.
According to Brad Adams, HVAC manager, Plumb Supply, a wholesale company with 17 branches in Iowa, not only are the units more economical than other HVAC systems, but they are also less costly to install - especially in new construction - where installing ductwork can be a major expense.
In addition, Brad adds that the units are extremely quiet; have a very high SEER rating (Seasonal Energy Efficiency Ratio - a higher number is better); and have modulated output, based on load conditions. Remodeling magazine says that most wall-mount mini-split models have a SEER rating of 16-22.
In what situations might you consider using a mini-split unit?
Brad says that mini-split units are versatile, but it’s important to recognize both their positive and negative aspects.
He explains that for air conditioning a home, there is no problem relying solely on the mini-split. So if your older home doesn’t have AC and you want to add it, a mini-split is an ideal choice. ENERGY STAR suggests that the units are also a safer choice than window air conditioners, which may provide easy access for thieves. In contrast to a window-sized opening, mini-splits require only a 3-inch opening in the wall.
Heating with mini-split units is not as clear-cut. “If you are building a new home, it’s possible to build without ductwork if you plan properly,” he says. For supplemental heating in a new home, you can rely on radiant in-floor heating, and you won’t need to install ductwork. The mini-split will provide all air conditioning, and some heating, in this instance.
A mini-split unit is also a good choice for heating and cooling a home addition (sunroom or family room, for example). Rather than expanding ductwork or installing a baseboard resistance unit, a mini split can be tucked into a small space at the ceiling or along a wall.
If you are thinking of installing a mini-split to heat your older home, Brad suggests that it may not be feasible to rely solely on a mini split. You might use an energy-efficient mini-split as your primary system, but retain your old HVAC system as a backup for cold days, or make sure you have an alternative backup (wood or pellet stove, for example).
• Hire the right contractor. It’s important to size and locate mini-split units correctly, so be sure that your contractor is familiar with the units.
• Purchase an ENERGY STAR rated unit. Check out this directory.
• Contact your electric cooperative for details about rebates and advice on appropriate uses and installation of mini-split units.
• Some units may qualify for federal tax credits. Check with your contractor and supplier for details.
• Check out ENERGY STAR for basic information and for purchase details.