A heat pump is a system that transfers thermal energy, or warm air, efficiently because it moves heat instead of burning fuel to create it. Choosing the right pump for your home can seem like an overwhelming task, but knowing the differences can help you make a more informed decision.

How Heat Pumps Work

Heat pumps work by absorbing heat from one space with the help of a refrigerant and releasing it into another space via a condenser. As the heat travels from one point to another, the refrigerant vaporizes in the evaporator, flows through a series of pipes and then condenses.

Types of Heat Pumps

Heat pumps fall into two main categories: compression and absorption. Compression heat pumps operate with mechanical energy like electricity. Absorption heat pumps may use electricity, burnable fuels or natural gas. The best type to choose depends on your needs. Absorption heat pumps, for example, may not be as efficient as compression heat pumps, but may be more economical to operate in areas where electricity rates are high and natural gas prices are low.

Among compression and absorption heat pumps are the following:

• Air-Source Heat Pumps (ASHP): ASHP systems transfer heat from the outside of a home to the inside, or vice versa to cool the air in a home. There are two ASHP styles: packaged heat pumps and split-system heat pumps. Packaged heat pumps are self-contained units that have the compressor and two heat exchangers on the exterior of a home. A split system has the compressor and the outdoor heat exchanger separate from the air-handling unit and the heat exchanger.
• Ground-Source Heat Pumps (GSHP): GSHP systems draw heat from the ground or groundwater at a depth of about 30 feet, where the temperature is constant year-round. A GSHP system may work as a good dehumidifier, but can be expensive to install because of the need to drill a well or dig a trench.
• Geothermal Heat Pumps: A geothermal heat pump is not the same as a GSHP. It’s a central heating and/or cooling system that pumps heat from or to the ground. Instead of absorbing heat from the ground, a geothermal pump absorbs heat from the sun.
• Exhaust Air Heat Pumps: An exhaust air heat pump absorbs heat from air that’s exhausted from a building and uses the heat to warm tap water, supply air or fuel a hydronic heating system (under-floor heaters or radiators). This type of heat pump isn’t ideal as a primary source of heat for a home.
• Hybrid Heat Pump (HHP): An HHP system absorbs heat from outdoor air when temperatures are above 40 to 50 degrees Fahrenheit. When the air is cold, the HHP uses a ground source for heat. This type of system can store summer heat and may cool warm air.
• Mini-Split Heat Pump:  The ductless version of a heat pump comes in the form of a mini-split system, which is good for room additions or retrofit add-ons in a home with a non-ducted heating system.
• Reversible Heat Pumps: Like an HVAC unit, a reversible heat pump can heat or cool an inside space because it uses a reversing valve that changes the flow of refrigerant.  

Heat pumps offer efficiency in areas with moderate climates and are generally less expensive to install than HVAC units. However, they may not offer enough warmth in places that have below-freezing temperatures during the winter. Talk to a heating and air conditioning contractor to determine if a heat pump is an economical and practical choice for your home.

Tony Spezza is the President of AAA Heating and Cooling located in Portland, Oregon. Since 1961, this family owned business has been providing heating and cooling systems for homes and businesses. Whether a heat pump or an HVAC unit, their technicians are experienced and trained on the latest techniques to ensure optimal service. You can follow AAA Heating and Cooling on Facebook and Google+.