Heat pumps are becoming more and more popular due to the many benefits they provide. These units are a good option in really any part of the country as they can save you money by both cooling and heating your home. Nonetheless, the benefits of using a heat pump are greatest in areas like California where the winter is usually fairly mild. With that in mind, here is everything you need to know about how a heat pump can heat your home and why they are such a great option.
Understanding the Parts of a Heat Pump System
A heat pump is a standalone HVAC unit that is installed outside of the home. It looks exactly like a central air conditioning unit, and it also works exactly the same as a central AC when cooling the home. The most important components of the heat pump itself are the compressor, condenser coil, expansion valve, and heat pump fan.
Two copper lines filled with refrigerant connect to the heat pump and then to the evaporator coil located within the air handler inside the home. One line runs from the compressor and feeds into the evaporator coil. The second line connects to the opposite end of the evaporator coil and is run back outside where it then connects to the condenser coil.
As with central air conditioning or any other type of central heating, there is a blower fan inside the duct system. This fan works to draw air in through the return-air registers and forces it into the air handler where it is heated or cooled. The conditioned air is then circulated through the duct system and eventually comes out of the supply registers in each room of the home.
How Does a Heat Pump Work?
When set to cooling mode, a heat pump captures heat from the air inside the home. This reduces the air temperature, and the cold air is then circulated throughout the building. The process works because the refrigerant inside of the evaporator coil is at a lower temperature than the air being forced over the coil.
As a result of this temperature difference, the heat inside the air naturally flows into the cold refrigerant. This heat energy is then transferred outside where the condenser coil and heat pump fan work together to release it into the surrounding air. This process works the same way for both heat pumps and central AC systems.
However, heat pumps are designed so that the heat transfer process can run in reverse and the refrigerant flows in the opposite direction. When this happens, the coil in the heat pump then serves as the evaporator coil and works to absorb heat from the air. The coil inside the home then functions as the condenser coil and transfers this heat into the indoor air as it passes through the air handler.
When set to heating mode, the process starts by compressing the refrigerant. This turns it from a gas to a liquid and instantly reduces the refrigerant’s pressure and temperature. The cold liquid refrigerant enters the outdoor evaporator coil. When cooling, heat automatically flows from the air into the refrigerant as long as it remains colder than the air.
Absorbing heat from the air raises the pressure and increases the temperature of the refrigerant. It then flows through an expansion valve that further raises the pressure and temperature, turning the refrigerant back into a gas. This gas flows into the condenser coil inside the building. As the blower fan circulates cold air into the air handler, the heat naturally flows out from the refrigerant into the colder air. This raises the air temperature, and the hot air is circulated throughout the building to raise the overall temperature inside.
Air-source vs. Ground-source Heat Pumps
Most heat pumps are air-source units, which means that they absorb heat from and release it into the air as we’ve just described. However, there are also ground-source, or geothermal, heat pumps that work using the natural heat energy from the earth. These work in basically the same way as an air-source heat pump. When cooling, the refrigerant transfers heat from inside and disperses it into the colder ground. When heating, heat is transferred from the ground and used to warm the air inside.
This type of system uses a series of flexible lines buried at least a few feet underground. They need to be buried below the frost level where the temperature always remains constant at approximately 55 degrees. The lines are filled with a special refrigerant liquid that is extremely efficient at absorbing and releasing heat. From the ground, they then run to a heat pump unit that sits inside the house and is responsible for absorbing or releasing heat.
Some ground-source systems use a series of horizontal loops that are buried just far enough to be below the frost line. The only issue with this is that this can require quite a large surface area, which means you will need to dig up most or all of the yard to install them. There are also heat pump systems that instead use loops that are run vertically and can extend as far as 200 to 500 feet below the surface. This type of system requires a deep hole to be drilled for the lines to run through.
The Benefits of Opting for a Heat Pump
The biggest benefit of opting for a heat pump over any other type of heating is energy savings. Heat pumps are typically at least two or even three times more energy efficient than gas furnaces, electric furnaces, baseboard heaters, etc. The only other heating option that even comes close to comparing is a ductless mini-split as this type of unit is basically just a smaller self-contained version of a heat pump.
The U.S. Department of Energy estimates that switching from any other type of electric heating to a heat pump can reduce your energy costs by around 50%. The only issue with air-source heat pumps is that their efficiency does begin to decrease once the weather drops below freezing. They can still continue to produce heat even if the weather drops a few degrees below zero, but they won’t be nearly as effective. As a result, the heat pump will need to run for much longer to warm the home and will use more electricity.
Heat pumps function the best when the temperatures are fairly mild and above freezing. This is why they are such an excellent heating option for places like California that rarely experience extremely cold weather. In higher elevation areas that experience colder temperatures, there may be some days when you will need another supplementary heat source like an electric space heater or baseboard heating to keep your home from getting too cold. Nonetheless, you still won’t need to run these nearly as often since the heat pump will continue to provide at least some warmth.
Another major advantage is that, unlike a gas furnace, a heat pump doesn’t produce any combustion fumes or carbon emissions. This is the main reason why California is now pushing hard for homeowners and businesses to switch to heat pumps as a way to help meet the state’s goal of being completely carbon neutral by 2045. The lack of emissions also means that heat pumps won’t create any possible carbon monoxide issues like gas furnaces can.
At Gallagher's Plumbing, Heating and Air Conditioning, our expert HVAC technicians install, service, and repair heat pumps as well as central AC systems, ductless mini-splits, and furnaces. Our team can also help you with any indoor air quality issues. We offer professional duct cleaning services and also install whole-home air purification systems. We also have professional plumbers who can manage any aspect of your plumbing system, including water heaters and water purifiers. We have locations in Sacramento, Los Molinos, and Olivehurst and are ready to help with any of your plumbing or HVAC needs. To learn more about heat pumps or to schedule any service, give us a call today.