Angie’s List: Should I install a ductless mini-split system?
You may have heard of ductless mini-split air conditioners or heat pumps recently. They’re one of the more recent developments in HVAC technology. But is one right for your home?
Ductless mini-splits do exactly what the name implies: They provide heating and cooling without requiring large metal ducts to snake through the entire house, and without requiring intrusive window units. Small ductless units install directly in the rooms they’re servicing, connected to the outdoor unit that houses the compressor and fan. Several ductless units can connect to a single outdoor unit.
You can purchase ductless systems that offer only air conditioning, or a dual ductless heat pump that provides both heat and air. Ductless wall units are generally unobtrusive compared to traditional window air conditioners. Some can even be installed flush against the ceiling in recessed mounts.
Benefits of ductless systems
Mini-splits carry multiple benefits, including high efficiency, a more consistent and constant temperature and a better dehumidifying effect.
Ductless systems allow highly customized zoned control over heating and cooling. You can have higher or lower temperatures in rooms right next to each other.
As an added bonus, ductless pumps operate more efficiently. Standard ductwork contributes around 25% of energy loss because of cracks and poor insulation. Overall, mini-splits are between 20 and 60% more efficient than central air.
If you already have ductwork in your home, a ductless system might now be the best for you. Your HVAC provider can give you good advice for more efficient options.
They’re particularly well-suited for all-electric homes. Mini-split systems work less well in extremely cold temperatures, though, so they’re best used in areas that don’t get bitterly freezing in winter.
A new ductless system tends to cost about $3,000 for a 12,000 BTU system. You can end up spending thousands of dollars more for a large system or a complicated house. Overall, ductless systems and installation run about 30% more than a new ducted system. You will also need a dedicated electrical circuit and an outdoor concrete pad to place the exterior unit.
Two-floor homes will require more labor and installation cost, since electrical and refrigerant lines need to run from the unit to the exterior condenser, and that takes more time on higher floors.
To determine the size of external condenser (measured in BTUs) and number of units you’ll need, contact an HVAC pro, who will conduct a heat load calculation. You can make a rough estimate by calculating between 17 and 24 BTUs per square foot. However, things like kitchen space, number of people in the home, and insulation quality all impact heating and cooling requirements.
It is possible to purchase ductless mini-split systems as a kit and install them yourself. However, it’s usually a better idea to contact a professional, who will know all the ins and outs and possible things that can go wrong.
Paul F. P. Pogue is a reporter for Angie’s List, a trusted provider of local consumer reviews and an online marketplace of services from top-rated providers. Visit AngiesList.com.