If you’re looking for a way to keep your home warm during the winter, a heat pump is one of the best, most energy-efficient options available. They are an especially great choice in Arizona or anywhere else that typically experiences mild winter weather. Although they are often a bit more expensive than furnaces, the beauty of heat pumps is that the same unit can provide both heating in the winter and air conditioning in the summer. To understand why heat pumps are so perfect for Arizona, let’s look at what they are, how they work, and how they compare to furnaces.
What Is a Heat Pump?
A heat pump is a type of forced-air HVAC unit that sits outside of the house and looks almost identical to a central AC unit. Like central ACs, heat pumps use refrigerant to capture heat energy from the air and transfer this heat to another location. The difference between a heat pump and an air conditioner is that the heat pump can reverse the heat transfer process so that it can also be used to both cool and keep your home warm.
As with central air conditioning systems, the heat pump is connected to an evaporator coil and air handler inside the building. Two copper refrigerant lines run from the heat pump outside through the exterior wall of the building. The lines then are routed through the basement ceiling or crawlspace and run to the evaporator coil inside the HVAC air handler. The two lines are run in a loop, with one line supplying refrigerant to the coil while the other line brings refrigerant back out to the heat pump.
Understanding the Heat Transfer Process
The laws of physics state that heat energy always naturally flows from a high-temperature area into any area or surface that is colder. This heat transfer process is what allows air conditioners to cool and also how heat pumps cool and heat.
Many people mistakenly believe that air conditioners somehow create cold air, but this is only partially true. Instead, air conditioning works by capturing and removing latent heat from inside the building. The heat is dispersed into the air outside, and this process slowly lowers the indoor temperature. The reason that the air coming out of the vents feels cold is because the AC system removed most of the heat energy from it.
When cooling, heat pumps and ACs compress the refrigerant into a liquid. This decreases the pressure of the refrigerant, which also reduces its temperature. The outdoor unit pumps the cold refrigerant through the copper line and into the evaporator coil.
When the HVAC system is running, the blower fan draws hot air into the return-air ducts. This forces the hot air over the evaporator coil. Since the temperature of the refrigerant is much colder than the air, the heat energy in the air is transferred into the refrigerant. As the refrigerant absorbs heat, its pressure and temperature are raised, and it turns into a gas.
The gas refrigerant travels through the copper line back out to the condenser coil in the AC or heat pump. This coil works in conjunction with the fan in the outdoor unit to release most of the heat from the refrigerant. The refrigerant then goes back through the compressor, which again compresses it to further lower its temperature.
With an air conditioner, this process can only run in one direction. However, heat pumps can reverse the flow of refrigerant in order to provide heating. When this happens, the indoor coil becomes the condenser coil, and the outdoor coil is then the evaporator coil. Again, the evaporator coil absorbs heat, and the condenser coil releases it.
When heating, the heat pump first compresses the refrigerant so that it is colder than the outdoor air temperature. The cold refrigerant travels into the outdoor coil, and any heat in the air automatically flows into the refrigerant. An expansion valve then increases the pressure of the refrigerant, which instantly makes it much hotter and turns it into a gas.
The heated refrigerant is then pumped into the coil inside. As cold air is forced over the coil, the heat flows out of the refrigerant and into the air. The heated air then travels through the ducts and out of all of your supply vents.
Heat pumps are incredibly efficient at compressing the refrigerant so that it is extremely cold. This allows them to continue absorbing heat energy from the air outside even in temperatures below 0 degrees Fahrenheit. However, the colder the outdoor air temperature is, the less heat energy the refrigerant can absorb and the harder the heat pump has to work. As a result, the energy efficiency of the unit decreases as the air temperature drops.
Heat pumps work most efficiently when the outdoor air temperature is around 40 degrees or higher, and this is the reason why they are such a fantastic option in Tucson or anywhere else where you rarely see below-freezing winter weather. Heat pumps can still be a decent choice in colder northern climates, but it is usually necessary to supplement them with some other heating source whenever the weather is much colder.
How Do Heat Pumps Compare to Other Heating Options?
No other heating system even comes close to matching the energy efficiency of a heat pump. Even the absolute best gas furnace is at most 98.5% efficient, which means that some energy is always wasted. Electric furnaces don’t waste any energy, but they are still nowhere near as efficient as heat pumps.
With an electric furnace, every unit of electric energy is directly converted into one unit of heat energy. Due to the heat transfer process, a heat pump is capable of producing two or three units of heat energy for every unit of electrical energy it consumes. This means that as long as the outdoor temperature is above freezing, a heat pump can be as much as 200 to 300% efficient. Compared to using an electric furnace or any other type of electric heating, upgrading to a heat pump can reduce your electricity usage by as much as 50%.
Another advantage of heat pumps compared to gas furnaces is that they don’t produce any carbon monoxide or other emissions. This means that they don’t need to have an exhaust vent, and you’ll never need to worry about carbon monoxide poisoning. This factor makes heat pumps not only a great way to reduce your energy costs but also to lower your carbon footprint.
Tucson’s Home Heating Professionals
At Fusion Plumbing & Air, our certified HVAC technicians are highly trained and have years of experience servicing, repairing, and installing heat pumps. We also work on all brands of residential and commercial furnaces and air conditioners. If you need any plumbing service, we can help with that as well. Our licensed plumbers specialize in drain and sewer cleaning and repairs, and we offer camera inspections for plumbing systems and hydro-jetting for removing clogs and tree roots. We also work on water heaters and filtration systems. To learn more about the benefits that a heat pump can provide for your home, contact Fusion Plumbing & Air today.
