Heat pumps work by transferring heat from one place to another using electricity, rather than generating heat directly. They can both heat and cool buildings by moving thermal energy depending on the season.
How Heat Pumps Work
- Heating Mode:
- Heat pumps extract heat from a source such as outside air, ground, or water, even when it feels cold outside.
- A refrigerant liquid absorbs this heat and evaporates into a gas.
- The gas is compressed by a compressor, increasing its temperature significantly.
- The hot gas passes through indoor coils (acting as a condenser), releasing heat into the building’s air or heating system.
- As the gas cools, it condenses back into a liquid and cycles back to absorb more heat.
- This cycle repeats, effectively "pumping" heat indoors
- Cooling Mode:
- The process reverses using a reversing valve.
- Heat is absorbed from inside the building by the refrigerant evaporating into a gas indoors.
- The gas is compressed and then releases heat outside through outdoor coils.
- The refrigerant condenses back to a liquid and cycles again, removing heat from inside and cooling the building
Key Components
- Compressor: Pressurizes refrigerant gas, raising its temperature.
- Expansion valve: Lowers refrigerant pressure, cooling it before it absorbs heat.
- Reversing valve: Switches the flow of refrigerant to allow heating or cooling.
- Heat exchangers (coils): Transfer heat between refrigerant and air or water inside and outside the building
Efficiency
Heat pumps use less electricity than the heat they transfer, making them more efficient than traditional electric heaters. Their efficiency depends on the temperature difference between the heat source (outside air or ground) and the indoor environment. As outdoor temperatures drop, their heating capacity decreases, sometimes requiring supplemental heating
. In summary, heat pumps operate on a refrigeration cycle that moves heat from a colder place to a warmer place using a refrigerant and compressor, providing both heating and cooling efficiently by reversing the cycle as needed
