A heat pump is a device that transfers heat from one place to another, typically to heat or cool a building. It works by using a refrigerant to absorb heat from a colder area (like the outside air, ground, or water) and release it into a warmer area (like inside a home).

How it works:

1. Evaporation: The refrigerant, a special fluid, absorbs heat from a low-temperature source (e.g., outdoor air) in the evaporator coil. This causes the refrigerant to evaporate into a gas.
2. Compression: The gaseous refrigerant is compressed by a compressor, which increases its temperature and pressure, making it very hot.
3. Condensation: The hot gas flows into the condenser coil, where it releases its heat to the indoor space (for heating) or outside (for cooling). As it loses heat, the refrigerant condenses back into a liquid.
4. Expansion: The liquid refrigerant passes through an expansion valve, which reduces its pressure and temperature, preparing it to absorb heat again in the evaporator.

Key points:

• Reversible: Most heat pumps can switch modes to either heat or cool a space by reversing the refrigerant flow.
• Efficiency: They’re highly efficient because they move heat rather than generate it, often using less energy than traditional heaters or air conditioners.
• Types: Common types include air-source, ground-source (geothermal), and water-source heat pumps, depending on the heat source.

For example, in winter, an air-source heat pump extracts heat from cold outdoor air to warm your home. In summer, it reverses to act like an air conditioner, removing heat from indoors.