What is a Heat Pump and How Does it Work?
People that aren't in the HVAC business tend not to know the specifics of the systems in their home. If you don't know what a heat pump is, let alone how it works, don't worry-most people don't!
Do you know that heat pumps can be used as an alternative to your air conditioner? That's because both a heat pump and cooling appliances, such as your refrigerator, follow a similar process. Heat pumps can also be used for both heating and cooling.
Generally, here's how a heat pump operates: In the winter, a heat pump will pull heat energy from the outside into your home to heat it. In the summer, a heat pump will pull heat from inside your home and pump it to the outdoors.
Heat pumps will either collect heat from the air, water, or ground outside; then concentrate it for use inside your home. It essentially transfers heat energy in order to either heat or cools a space. Think of a heat pump as an air conditioner that can also work in reverse to provide heating as well.
In the Winter
But wait; let's back up. Did we just say that a heat pump extracts warmth from the chilly winter air in order to heat your home? How is that even possible?
In the winter, a heat pump works like a reverse air conditioner. An air conditioner extracts heat from the space. The heat is then absorbed into the indoor unit's refrigerant. The refrigerant then transfers the heat to the outdoor A/C unit where it is finally pushed outside.
A heat pump uses a similar process, just in reverse, pulling from out to in, rather than in to out. When it comes to a heat pump, believe it or not, heat can be extracted even during freezing temperatures. In the winter, a heat pump takes heat from the outdoor air and brings it in to heat your home.
When you understand what refrigerant does, it's easier to understand how a heat pump works. Refrigerant changes from liquid to gas. Heat pumps use refrigerant to absorb and release heat energy, pressurizing the gas to heat it up and depressurizing the gas to cool it down.
There are several different types of heat pumps:
- Air-source heat pumps
- Ductless mini-split heat pumps
- Geothermal heat pumps
- Absorption heat pumps
A huge benefit of heat pumps is that they are highly efficient. And when a major appliance is efficient, your bills are going to be lower.
This is good to know, especially in the summer when energy bills tend to be higher than anticipated.
In the Summer
In the summer, a heat pump will work differently than it does in the winter but still relies on the method of absorbing heat. Using the evaporator of the indoor unit, a heat pump releases indoor heat to the outdoor unit.
Liquid coolant (aka refrigerant) goes to the evaporator, becomes depressurized and then turns into a gas. When refrigerant changes state from liquid to gas, the temperature changes. The gas gets cold and absorbs the heat inside your home. It then gets pushed to your compressor in the outdoor unit where it shifts back to a hot liquid.
The cycle continues as the hot coolant now goes through the outdoor condenser coils as a powerful fan kicks on. The air flows over the condenser coils, releasing heat energy to the outdoor environment. Once the refrigerant heat has been released outdoors, the refrigerant simply cools back down and recycles back to the evaporator. This process continues over and over.
Maintain your heat pump
Here are some tips to keep your heat pump efficient for years to come:
- Filters should be replaced every 30-60 days
- Bi-annual professional HVAC maintenance will ensure top performance and safety (annual cooling maintenance in the spring and heating maintenance in the fall)
- Keep the area around your heat pump clean to avoid blockage (a minimum of 2-foot clearance is recommended)
- Providing shade with trees and trellises can improve the efficiency of your heat pump
Learn more HVAC maintenance tips here.
The best way to keep up your heat pump operating at peak efficiency levels is to sign up for a Maintenance Service Plan.