Everything you always wanted to know about heat pumps but were afraid to ask

The Solar Initiative’s (tSI) heat pump subsidy program has proved to be very popular. Over 40 island families have signed up or are ready to learn more. tSI is offering up to $6,000 to offset the cost of a home heat pump installation. That sounds great, but what is a heat pump and how does it work? Some heat pump facts: 1. A heat pump does not generate heat; rather it moves (pumps) heat from one place to another, for example, from outside to inside your home. Because it does not generate heat, it is much more efficient regarding energy consumption than the old resistance type electrical heating systems. 2. Not surprisingly then, a heat pump system has two major components: the pump, which is located outdoors and an air-handler (which many folk call a minisplit), which is located indoors. 3. The outdoor unit contains a fan which blows air across a coil. Thus heat is transferred to the fluid in the coil. Then a condenser condenses the fluid making it even hotter and pumps it indoors. 4. At that point the indoor unit goes to work blowing air across the now fluid, heated coil and into the rooms of your home. 5. The fluid that conveys the heat is usually a refrigerant, thus necessitating licensed installers. 6. The connection between the outdoor unit and the indoor one are two pipes, usually about one inch in diameter. Often these pipes are hidden in a soffit for aesthetic reasons. 7. Now one of the magical things about this heat pump system is that it can work backwards! When the direction is reversed it takes heat out of your house and pumps it outdoors. So one heat pump system is a heater in the winter and an air conditioner in the summer. 8. And while cooling your house in the summer, it condenses moisture which is typically drained outside via--wait for it--a drainage hose. 9. Now heat pump systems are generally much more efficient than other heating sources. But when the temperature drops down below 10 degrees F, its efficiency declines. For homes with an existing heat source, the Solar Initiative recommends maintaining that system for use on extremely cold days. 10. Although heat pump systems use pre-manufactured components, the exact sizing and configuration needs to be customized to each home and the owner’s needs and wishes. Once COVID allows us to resume proposals, contracts, and installations we will do so, but it may be some time before we can install systems in every home that wishes one.