How exactly does a heat pump work? In this YouTube video, the channel, The Engineering Mindset explains some of the different heat pumps you would find in an HVAC system.
The first of the different types of heat pumps is an air to air heat pump. These have an indoor and outdoor unit. It can work as just a heating device or a heating and cooling device. This type of heat pump has many different parts including a controller, reversing valve, compressor, indoor heat exchanger, outdoor heat exchanger, expansion valve, non-return valve, filter drier, and sight glass.
The refrigerant leaves the compressors, moves to the reversing valve, and onto the indoor heat exchanger. Heat is then provided to the room. Then, the refrigerant turns from a hot high-pressure vapor into a slightly cooler vapor. The refrigerant passes through the non-return valve, the filter drier, the sight glass, the next non-return valve and eventually, enters the outdoor heat exchanger and a low-temperature liquid/vapor mix. The refrigerant is then heated so it is boiling and the thermal energy is drawn out by the fan. The refrigerant heads back to the first reversing valve as a low temperature, low pressure slightly superheated vapor. The cycle then repeats.
There are a couple more heat pumps that are explained later on in the video. Continue watching to discover how each one works and which one may be best for you and your home.