The simple definition of a heat pump is a device that uses very little energy to move heat from one location to a different one. Typically, heat pumps are used to pull heat out of the ground or the air in order to heat a home, office or a building. They can also be reversed to cool the house, office or building. They operate similarly as an air conditioner.
If you have a heat pump, you will have more benefits than a person who has an air conditioner. With a heat pump, there will be no need to install separate systems for heating and cooling your home as it is with a standard heating, ventilating and air conditioning system. It has the ability to heat and cool your room without need of separate systems.
Since a heat pump works by simply transferring heat rather than burning fuel to create the heat, it works so efficiently. This makes it greener compared to a gas burning furnace since there are no harmful substances emitted into the atmosphere. It will also help you save a little money every month.
During the cooling mode of the heat pump, heat that is generated inside your house from the sun that shines through the windows and onto the walls and roof as well as heat from appliances and your body is transferred outside the house by the heat pump. At the beginning of the heat transfer cycle, the refrigerant is usually in a very cold liquid form.
The cold refrigerant enters the evaporator coil that is located inside your house. The hot air inside your house is then moved over the coil where it starts to lose its heat and then cools down. After absorbing heat, the refrigerant leaves the evaporator coil and becomes gas. Just like water being heated on a stove evaporates and becomes steam, the refrigerant gas evaporates when it absorbs all the heat that was in the house.
The refrigerant then enters the compressor where the gas is mechanically pressurized. The process causes the temperature of the gas to increase and as a result, the refrigerant leaves the compressor as hot gas. After that the refrigerant moves to the condenser coil that is located outside the house. Since the temperature outside the house is lower compared to the temperature of the hot gas, the heat is transferred from the refrigerant in the coil to the outside air. A liquid condensate will form as the temperature of the refrigerant cools.
The refrigerant leaves the outdoor condenser coil as warm liquid. This liquid has to be converted into cold form to enable it to absorb more heat. For that reason, it is taken to a metering device that puts pressure on it and as a result, its temperature drops. The refrigerant leaves the metering device in a cold form, and the whole cooling cycle is repeated.
During heating mode, what basically happens is that the reversing valve reverses the cycle and removes heat from outside of the house to the indoors. Air conditioners do not have a reversing valve.