Are you in the mood to learn more about how different kinds of air conditioners work? You must be since you’re here. Maybe you’re considering purchasing a new model to replace an old system that has long since ceased to be cost-effective, or perhaps you’re contemplating the purchase of your very first AC unit and want to know what your best option is going to be. Regardless, you’ll have to consider several available types of air conditioner and decide which one will suit your needs best. Learning how a heat pump AC unit works can help you determine whether you can make practical use of one in your home, or if you would be better served by a different type of air conditioning system.
Heat pumps are becoming increasingly popular with many American homeowners because they can be extremely efficient and provide significant cost savings over long periods of use. However, there are several circumstances that homeowners in specific areas should consider before they decide to use a heat pump AC unit in their home. Below, we’ll explain each of these factors in detail so that you can make an informed decision for your heating and cooling needs.
What is a Heat Pump AC Unit?
When it comes to cooling, heat pumps have much in common with standard air conditioners. They use a series of components to cause state changes in refrigerant that circulates throughout the system, allowing it to absorb heat from inside the building where it is housed and release it to the air outside. However, heat pumps are also able to reverse this process when the building needs to be warmed — causing the refrigerant to absorb heat from the outside air and release it into the home instead. As such, heat pumps do not rely on the methods that standard furnaces use, such as burning gas or heating oil.
Here’s a more detailed breakdown of the refrigeration cycle so that you can better understand the cooling process:
- Refrigerant begins in your system as a cool, low-pressure gas. The compressor in your air conditioner compresses the refrigerant until its pressure rises.
- The refrigerant, now a high-pressure gas, makes its way into the condenser. Here, it condenses into a liquid and absorbs heat from the air in your building (or from the outside when a heat pump is set in reverse).
- The hot, high-pressure liquid refrigerant passes through the expansion valve, where its flow is restricted. The expansion valve allows only a small portion of the liquid to pass through at a time, which forces its pressure to drop.
- The low-pressure liquid refrigerant ends up in the evaporator, where it releases the heat it has collected to the air outside (or in) and reverts into a gas, ready to enter the compressor again and repeat the cycle until the desired temperature in your building has been achieved.
Heat Pump Pros and Cons
Because heat pumps must be able to reverse the cooling process that standard air conditioners perform, they tend to have considerably higher upfront prices. As such, some homeowners find the costs associated with purchasing a heat pump prohibitive. Heat pump owners in regions that have balanced climates are likely to offset these costs eventually with the savings from their winter utility bills, since reversing the cooling process uses fewer resources than burning gas or oil in a furnace.
Here’s the catch: in regions with unusually cold winters, heat pumps often cannot draw enough heat from the outside air to warm the interior of a building effectively. For this reason, many heat pumps are augmented with miniature heating coils to supplement heat production during cold snaps. However, these coils are meant to be used sparingly — not relied upon for an entire winter. Using them for a whole winter can cause the system to drain much more power than a standard furnace, making it more expensive to operate and negating the usual cost savings. Heat pump coils can also be difficult to clean unassisted.
Should You Buy a Heat Pump AC Unit?
In most of California, a heat pump makes sense if you can afford one. Winters throughout the state tend to be mild, and there is usually enough heat in the air that it can successfully be pulled into the home when necessary. For Americans living close to the Canadian border, a heat pump might not be the best choice. It could be a smarter move to simply rely on a conventional HVAC and take steps to make it as energy efficient as possible.
No matter what kind of heating and cooling equipment you use in your home (or commercial facility), make sure you hire a licensed professional contractor to check it over at least once each year and perform service as needed. Doing so will ensure that you enjoy reliable heating and cooling for many years to come.