Heat pumps are an energy-efficient alternative to furnaces and air conditioners for all climates. That's right; heat pumps can heat AND cool your building or home. Like your refrigerator, heat pumps use electricity to transfer heat from a colder space to a warmer space rather than generating heat.
- In winter, heat pumps gather heat from the outdoors and move it into your building or home to warm it.
- In summer, heat pumps collect heat from your home and transfer it outside to cool your building or home.
- Heat pump water heaters collect heat from the area outside of the unit and use that heat to heat water.
Since heat pumps move heat instead of creating it, they achieve 200-300% efficiency. While natural gas is currently less expensive than electricity, more efficient heat pumps use 2-3 times less energy than gas heating systems.
There are five main types of heat pumps:
- Air Source Heat Pump and Cold Climate Air Source Heat Pumps (ASHP/ccASHP)
- Mini-split Heat Pump and Cold Climate Mini-split Heat Pumps (MSHP/ccMSHP)
- Ground Source Heat Pump (GSHP)
- Heat Pump Rooftop Unit (RTU)
- Heat Pump Water Heater
Air Source Heat Pump

A ducted air source heat pump system has four components:
- An outdoor heat pump unit.
- An indoor air handler.
- Ductwork that distributes hot and cold air throughout the home.
- A thermostat.
This equipment is most suitable for buildings that have an existing central air conditioner or furnace, where you can continue using the existing ductwork and air handlers. These units will often replace both the furnace and air conditioner, or may be compatible with the existing furnace in certain conditions.
If you already have a furnace, it might be compatible with a heat pump addition. The existing furnace should not be near the end of life (20+ years old) and should have a variable speed motor or electronically communicated motor (ECM). If these conditions apply, a heat pump might be compatible with the existing furnace, but an HVAC contractor must confirm.
Cold climate models can operate in heat pump mode for most of the year, reducing the use of less efficient backup heat (natural gas or electric resistance). A cold climate model can eliminate the need for backup heating source for some homes.

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Mini-Split Heat Pump
A mini-split (non-ducted) system has three components:
- An outdoor heat pump unit
- Indoor head(s) that deliver hot or cold air
- A thermostat
Refrigerant lines connect the two units to transfer heat between them. During the winter, a mini-split extracts heat from the outside air and transfers it to the indoor head(s) via the refrigerant. The indoor head(s) then distributes heat throughout the building. During the summer, the process is reversed: the heat pump extracts heat from the indoor air and releases it outside.

A mini-split is a great option to add heating/cooling to a single space in a building. Often mini-split heat pumps are ductless, which means they need no ductwork to deliver heating or cooling to the building. Instead the indoor heads have fans and directly deliver the heating or cooling. They are often mounted on a wall or ceiling.

A mini-split may be the most cost-effective heat pump option for buildings without ductwork or where adding ductwork is cost-prohibitive. Because each head is controlled individually, mini-splits allow you to keep different spaces at different temperatures. They are suitable for infrequently used rooms.
Single zone MSHPs are best suited for spaces less than 1,500 sq. ft. and lend themselves to open concept spaces. An MSHP will not effectively condition rooms sectioned off by doors or bends. You may need an additional MSHP to maintain the desired temperature.
Ground Source Heat Pump
A ground source heat pump system has an internal heat pump unit that can serve forced air or hydronic systems. The heat pump is connected to a piped heat exchanger underground or in a body of water.
- GSHPs transfer heat from the ground, maintaining a more constant temperature than outside air. They offer high efficiency and capacity year-round. GSHPs are the heat pump technology with the lowest operating costs.
- The drilling and bore field required for GSHPs makes them the most expensive heat pump technology to install. Local geological characteristics can limit GSHPs' feasibility.
- GSHPs are the most likely system not to require backup heat.

Heat Pump Rooftop Unit
A heat pump rooftop unit is a type of Heating, Ventilation, and Air Conditioning (HVAC) system. They are often installed on the roof of a commercial or industrial building, but they can also be ground mounted.

These units are most commonly used for larger commercial or multifamily buildings. They provide both heating and cooling to the building using heat pump technology. They extract heat from the outside air during the winter and release heat outside during the summer. Rooftop units usually either have a gas or electric resistance backup heat source. Heat pump rooftop units typically contain:
- A compressor
- A reversing valve
- A fan
- A heating and cooling coil
- A back-up heat system
- Controls that regulate the temperature and airflow
Heat Pump Water Heater
A heat pump water heater pulls heat from the surrounding air and uses it to heat water in a storage tank. They use the same technology as heat pumps that heat air and apply it to water heating instead.
