If you need to replace your air conditioning or install a new central air system in your home, you may want to consider installing a heat pump instead of a standard AC unit. The main advantage of a heat pump is that it can keep your home comfortable throughout the year since it can provide both air conditioning and heating. To help you understand why installing a heat pump can be such a smart decision, here is an overview of how heat pumps work and the differences between heat pumps and standard ACs.
What Are Heat Pump Systems and How Do They Work?
At first glance, you usually couldn’t tell any difference between a heat pump and a standard central AC unit as most heat pumps look exactly the same as AC units. Not only do the two look alike, but they also function in the same way when cooling. Both types of units cool by capturing heat from the air inside the home and then transporting and releasing the heat outside.
They do this by supplying an extremely cold refrigerant liquid to the evaporator coil. The HVAC blower pulls warm air in through the home’s return air vents and draws the air over the evaporator coil. The laws of physics are such that heat energy always flows from a “heat source” into a “heat sink,” i.e., from a higher temperature area into any nearby area that is cooler. In an AC system, the warm air coming into the system is the heat source and the cold refrigerant is the heat sink. This means that as warm air flows over the evaporator coil, the heat energy in the air flows out and is captured by the refrigerant.
After capturing heat from the air, the hot refrigerant then moves back to the unit outside the home. The refrigerant is then compressed, which “superheats” the refrigerant causing it to start to boil and turn into a gas. When the refrigerant is superheated, it instantly becomes much hotter than the outdoor air temperature. The superheated refrigerant then moves into the condenser coil. The compressor fan constantly draws air through the unit so that it blows over the condenser coil.
Since the refrigerant is now much hotter than the air blowing over the coil, the refrigerant releases the heat so that it flows out into the air. Finally, the refrigerant flows through an expansion valve that decreases the pressure so that any remaining heat is released and the refrigerant again becomes cold enough before flowing back inside for the process to continue.
The thing that makes a heat pump different from a standard AC unit is that the heat pump has a reversing valve that enables the refrigerant to move through the system in the opposite direction. This enables the heat pump to capture heat from outside and transport it into the home to provide heating during the colder parts of the year. When heating, the coil outside acts as the evaporator coil and absorbs heat from the air being blown over it. The indoor coil then acts as the condenser coil and releases the heat into the cool air that the blower draws over it.
The reason that this process works is that the heat pump can cool the refrigerant down to around -15 degrees Fahrenheit. This ensures that the refrigerant can still capture heat energy even when the outdoor air temperature is below freezing. This may sound surprising, but air always contains some heat energy no matter how cold it is.
Capturing heat energy begins to raise the temperature of the refrigerant. Before moving inside, the refrigerant again flows through the expansion valve and is superheated to where it is then much warmer than the air temperature inside the home. When the blower pulls air over the indoor coil, the hot refrigerant releases the heat so that the air temperature instantly increases and hot air blows out of the vents to increase the indoor temperature.
Comparing Energy Efficiency and Effectiveness
Since heat pumps and standard AC units cool the same way, there is generally no difference between the two in terms of energy efficiency or effectiveness. If you were to do a side-by-side comparison of a heat pump and an AC unit that are both the same size and have the same SEER rating, both will cool at the same rate and will cost the same amount to operate. As such, the thing you should focus on if you’re considering a heat pump is how effective and energy-efficient the unit is when heating your home.
Heat pumps are much more energy-efficient than furnaces and all other types of heating. In most cases, a heat pump will use around two to three times less energy than a gas or electric furnace. Even though natural gas is generally cheaper than electricity, heat pumps will still often cost almost half as much to operate than a gas furnace.
The only issue when heating your home with a heat pump is that they aren’t as effective or as energy-efficient in colder temperatures. They work best and use the least amount of energy in temperatures around 40 degrees or higher. The performance then continues to decrease the colder it gets. Once the temperature drops below 0 degrees, a heat pump often won’t be effective enough to keep the home warm. Luckily, this isn’t something you need to worry about in Georgia. Since our winters are usually mild and somewhat warm, a heat pump is almost certain to effectively heat your home while using far less energy than any other option.
Cost of Heat Pump vs. Central AC Unit
As you might expect, a heat pump will almost always cost quite a bit more than a standard AC unit since it is a bit more complicated and can both cool and heat. On the other hand, a heat pump will always be quite a bit cheaper than if you were to need to install an AC unit and a furnace or some other type of heating at the same time. This means that heat pumps are usually the most cost-effective option and can potentially save you quite a bit of money in both the short and long term.
How To Know If a Heat Pump or AC Is the Better Choice
In warmer climates like Georgia, heat pumps are typically always going to be your better option. A heat pump will cool your home just as effectively as an AC while also allowing you to heat your home for far less than you’d spend if you had a furnace. The only time we’d recommend opting for a standard AC unit is if you’ve had a new high-efficiency furnace installed within the past five years or so. In this case, it probably doesn’t make sense to pay extra for a heat pump since your furnace will likely continue to function effectively for another 10 to 15 years. Considering that heat pumps and ACs will typically need to be replaced after 10 to 15 years, you’re probably best to wait to install a heat pump once your furnace needs to be replaced.
However, a heat pump could still be more cost-effective in the long run if you currently have a medium-efficiency 80 Annual Fuel Utilization Efficiency (AFUE) furnace. In this case, the amount you could save each year on heating can help offset the higher cost of the heat pump so that it eventually pays for itself over time. You also have the advantage of still being able to use your existing furnace should the winter ever get cold enough that your heat pump won’t work all that effectively.
Precision Heating & Air is the number one choice for heating and air conditioning installation in Dallas. Whether you’re in the market for a new heat pump, AC or furnace, we have a wide selection of high-quality, energy-efficient units to choose from. Contact us today to schedule an HVAC installation or consultation or if you need any repair or maintenance services.