How do you both heat and cool a home? The usual answer is to use an air conditioner to cool the house and a furnace to heat the house. While this solution works well for climates that have an extremely cold winter, it may be overkill for areas that have a more moderate winter. Before you shell out for two separate pieces of machinery, you should see if you can get away with just one: an air-source heat pump.
The Commonality between an Air Conditioner and an Air-Source Heat Pump
One basic principle underlies the operation of both an air conditioner and a heat pump: When a liquid evaporates, it can absorb heat from its surroundings. An air conditioner will have a set of evaporator coils inside your house, which allows the coolant running through the conditioner to evaporate. As air moves over these evaporator coils, the evaporation process will extract heat from the air, which will have a cooling effect. A set of condenser coils located outside your home will convert the vapor back to a liquid, which will expel the heat into the outside air. A heat pump will use coolant, but it will have more capability than an air conditioner.
What Makes a Heat Pump Unique?
An air source heat pump will cool your home in exactly the same way as an AC unit, but unlike an air conditioner, you will have the option to reverse the process, which will allow you to extract heat from the air outside your home and expel it inside your home; thus, you can both heat and cool your home with the same piece of machinery.
Why Heat Pumps only Work in Moderate Climates
Even if the air outside your home feels chilly, it still contains heat, which your heat pump can extract. On the other hand, the colder it gets outside, the harder your machine has to work to extract heat from the air. If the air gets down to freezing, your heat pump will be extremely inefficient if it is able to generate any heat at all. Thus, heat pumps work best in areas that have moderate winters.
While it is ideal to use a heat pump in an area that only has the occasional cold night, you can use a heat pump with a furnace in colder climates. You will use the heat pump to keep your home comfortable for most of the year and then use the furnace to provide heat on the coldest nights. If you are looking to install a new HVAC system or replace an old air conditioner, you should consider using a heat pump in your home for heating and cooling.