The ductless mini split heat pump is a new choice for house heating that offers:
- Efficient operation at ambient temperatures of 17°F and below without help of electric backup heater
- Quiet operation, both indoors and outdoors
- Heating and cooling in one ductless system
- Simplified installation and maintenance
Ductless mini split heat pumps are appropriate for both replacement of existing heating systems, especially baseboard/wall heaters, as well as for new construction. Ductless heat pumps have been installed in commercial buildings for more than 25 years and are available from several manufacturers.
Ductless (also known as mini split, or mini-split) heat pumps are very efficient for several reasons:
- Since the heated or cooled air is delivered straight to the room, ductless heat pumps cut losses associated with conventional ductwork – up to 20%.
- Variable speed compressor models, also labeled “inverter technology,” prevent on-off cycling losses and are able to provide usable heat efficiency on all but very cold days.
- Because they provide heat/cooling to exact areas of the house, they can be more efficient since each “zone” can be heated to the preferred temperature.
Ductless heat pumps are consist of an outside compressor unit and one or more inside “heads” that deliver conditioned air to the room or rooms. Inside units are typically mounted high on the wall, but several models can be recessed in the ceiling (cassette type) or even installed with a short duct run (concealed type) to serve adjacent rooms. The inside and outside units are connected by refrigerant lines, usually concealed in the walls or ceilings or under a cover on the outside of the house. Some models allow several indoor heads to be connected to a single outside compressor. Ductless heat pumps operate on the same principle as traditional heat pumps - using electricity to move heat between outdoor and indoor air.
Possible Applications for Ductless Mini-split Heat Pumps
Ductless heat pumps are most appropriate for houses with open floor plans, since each indoor unit can serve the entire area, or “zone”, not blocked by doorways and walls. Some typical applications for ductless mini split heat pumps include:
- Replacing an existing zonal heating and cooling system – ductless mini split heat pumps can replace existing electric baseboard/wall heaters or woodstoves. A cost saving electric heat conversion in a small home might involve a single system serving the main area of the home, while leaving existing electric heaters in bedrooms and bathrooms.
- Room additions – another application for ductless mini split heat pumps is when a room is added to a home or an attic is converted to play or home office space. Rather than extending the house’s ductwork or pipes, or adding electric resistance heaters, the ductless mini-split heat pump can provide efficient heating and cooling in one unit.
- New construction – new houses can be designed, or adapted to take advantage of the ductless heat pumps features and benefits. Naturally one or more systems might be installed in various “zones” of the house to reduce installation costs and minimize refrigerant line length which increases system efficiency.