What is a Heat Pump?
A heat pump is a mechanism that can exchange heat from one fluid at a low temperature to another fluid at a higher temperature. It is a heating system that is made up of a heat source system, the heat pump unit itself and a system that will distribute the heat and store it. They are called heat pumps because they enable heat to be transported from a lower temperature level to a higher one.
How Does it Work?
The heat pump cycle goes like this:
- The cycle begins with a refrigerant (like Freon). It is liquid, just as the propane that fuels a barbeque grill is liquid until it leaves the pressurized tank. The Freon is very cold when it enters what’s called an evaporator coil that is located inside your house. Any hot air that is inside your house is moved over this coil and the air starts to get cool.
- Once the refrigerant, which has absorbed the heat, leaves the evaporative coil, it turns to a gas rather than a liquid (hence, the term “evaporative”). An example of the process would be when you heat water on your stove and it turns to steam as it heats up. The refrigerant goes into the compressor, which pressurizes the gas, which heats it up even more, and the refrigerant will leave the compressor as hot gas.
- Now the refrigerant moves outside the home to what is called a condenser coil. The temperature outside is lower than the temperature of the gas, so the heat is booted right out of the gas and into the atmosphere. When the gas cools down, condensation occurs on the lines (hence, the name “condenser”), just as a cold glass of water sweats in your home due to condensation.
- The refrigerant leaves the outside condenser coil as warm liquid, and must be made cold again so that the heat absorption can happen once again. It goes through a metering device that decreases the pressure on the warm refrigerant, thus cooling it down. It leaves the metering device in the form of a cold liquid, and the cycle is ready to repeat.
To gain a better (and not so technical) understanding of how the heat pump functions, imagine a fire under a metal bucket that’s heating up the water inside. A pump forces the hot water from the bucket into a radiator, which heats up quickly. A fan pushes cold air over the radiator, and the air is heated. The water in the radiator becomes cool because the heat has been transferred to the air passing over the radiator. The cooled water flows out of the radiator and is allowed to flow back into the bucket for the process to start over again.
In the example above, the fire is what creates the heat. The water is what transfers the heat to the radiator, and the fan pushes or pumps the heated air. This is not unlike a heat pump, only the water is a refrigerant (such as Freon), and the water pump would actually be a compressor.
Difference Between a Heat Pump and an A/C
Heat pumps don’t create heat; they use the heat that already exists in the home. Just like an air conditioner, the heat pump moves the heat from one place to another. Really, the only difference between a heat pump and an A/C unit is that there is a Reversing Valve on a heat pump that will allow the operator to switch from moving the warm air to the outside (cooling mode) to moving the warm air from outside to the inside (heating mode). Also, the thermostat is different on a heat pump than on an air conditioner.
Advantages of a Heat Pump
A heat pump has several advantages over other systems, given the right conditions and situations. Here are a few of these advantages:
- Heat pumps can be used to heat or cool a home
- A heat pump controls the climate in your home quickly and easily
- Heat pumps are safe. There are no flames or hot surfaces
- Heat pumps don’t burn oxygen, so rooms don’t get stuffy or humid
- Heat pumps improve air quality, no smoke or fumes
- Heat pumps are very energy efficient
- Heat pumps are eco-friendly, as there are no carbon emissions
At Hassell Air Conditioning, we are heat pump experts. You don’t have to know very much about them; you can leave it to us for all your heat pump installations or service.Tags: advantages of a heat pump, hassell air, heat pump