A heat pump is a device, similar in principle to a refrigerator, capable of transferring heat in either direction. Energy (heat as it applies to a heat pump) naturally flows from high to low (hot to cold), but a heat pump is able to reverse this process with the input of additional energy. Heat pumps are able to take heat energy from a cold reservoir and transfer it to a hot reservoir. Using a fluid-like refrigerant, a specialized evaporating and condensing liquid used to move heat, this process is reversible allowing for both heating and cooling depending on the need. Heat pumps are efficient because they do not create heat, merely transfer it.
- Condenser: Hot vapor, discharges stored energy (heat)
- Vapor cools, condensing back into liquid
- Evaporator: Cold liquid, absorbs energy (heat) from surroundings, liquid boils
- Compressor: Cycles new vapor back to the condenser (1)