More than 30,000 high efficiency ductless heat pumps have been installed in Maine homes and businesses over the past five years. Long used for cooling in warm climates, heat pumps are now one of the most popular technologies for heating in cold climates. Efficiency Maine offers rebates for high-efficiency ductless heat pumps for residential and commercial customers. Click here to learn how to get the most out of a heat pump.
How do they work?
Ductless heat pumps provide heat by extracting heat from outside air and delivering it indoors as needed. Because they are moving heat, rather than generating it through combustion or resistance, heat pumps can achieve efficiencies well above 100%. Long used for cooling in warm climates, heat pumps are now able to provide efficient heating in cold climates even at outdoor temperatures as low as -15 °F.
Ductless heat pumps consist of an outdoor unit connected to indoor air handlers by refrigerant lines, which carry heat between the two units. There are four types of indoor units:
Note: Your costs and savings may vary.
Why get a high-efficiency model?
If you’re considering heating your home or business with a ductless heat pump, make sure to install a high efficiency model. Compared to standard efficiency ductless heat pumps, high efficiency units have lower operating costs and provide more heat at lower temperatures.
What are the advantages?
- Low-cost heat – Heat pumps are one of the lowest cost sources of heat at current energy prices. Heating with a heat pump is equivalent to heating with oil at $1.99/gal*. Click here to compare heating costs of different heating systems.
- Comfort – With advances in controls, heat pumps can maintain very constant temperatures.
- Safety – Because heat pumps are electrically powered, there is no risk of combustion gas leaks.
- Air quality – Heat pumps filter indoor air all year and dehumidify it in the summer, improving air quality.
- Room-by-room control – When installed with multiple indoor units, heat pumps allow for room-by-room temperature control.
- Low-cost air conditioning – Today’s best heat pumps are twice as efficient as typical air conditioners.
What are other considerations?
- Cold temperature performance – Because heat pumps extract heat from outside to provide warm air inside during the heating season, as it gets colder outside, the heat pump must work harder to keep up, making them less efficient. For example, a unit that delivers four units of heat for every unit of electricity at 50°F, may only deliver two units of heat for every unit of electricity at temperatures below zero. There is evidence of the highest performance units operating and providing heat even below -15 °F in Presque Isle. But if the temperature drops low enough, the system may turn off completely. Be sure to check out the lower operating temperature listed for your heat pump. If you experience prolonged periods below that temperature, consider a secondary backup heating system to maintain your desired comfort level through the chilliest nights. If you use a backup system, just be sure to switch back to your heat pump once temperatures rise, or you could quickly lose your savings.
- Air movement – Heat pumps circulate air to heat and cool spaces. This is nice for cooling but can cause cooling sensations while the heat pump is heating. Take a look at Efficiency Maine’s ductless heat pump user tips to learn the recommended fan settings for the heating and cooling season.
- Heat distribution – Ductless heat pumps rely on air movement to move heat out into a room. This can make it hard to get heat around corners and into dead-ends. Take a look at Efficiency Maine’s ductless heat pump user tips and installation considerations to learn how to get the most from a heat pump.
- Interactions with the primary heating system – If you are thinking about using a heat pump as a supplementary heating system, make sure to locate it in an area where it won’t interact with the thermostat for the central system: that could result in your primary system shutting off your heat pump or your heat pump shutting off your primary system. This is not a concern if you are using a heat pump as your primary heating system. Take a look at Efficiency Maine’s ductless heat pump installation considerations to learn where to install your heat pump.
* Assumes $0.16/kWh, 270% heat pump efficiency, and an oil boiler with an overall system efficiency of 83%.