How Does a Heat Pump Work?
A heat pump can be one of the most efficient ways to heat your home. To fully explain how a heat pump works, you must first understand how an air conditioner works. The reason is that a heat pump in the heating mode is simply an air conditioner working in reverse. The main factor to consider when talking about heat pumps or air conditioners is to remember both units simply move heat.
Before we begin, let’s talk about the components of both the heat pump and the air conditioner.
As you see in the graphic to the right, the heat pump and the air conditioner are practically the same. Let’s break each component down:
Compressors “compress” the refrigerant and increases its pressure. Increasing the pressure of the refrigerant is critical since as the refrigerant passes through an expansion orifice in the evaporator (3) or condenser (2) the pressure very quickly reduces. Thanks to physics – when a gas rapidly expands, it absorbs heat like a massive sponge.
Condensers are a coil that absorbs or releases heat depending on which mode the heat pump is in. In the heat mode, the condenser becomes a “heat sponge” grabbing all the heat from the outside air as the refrigerant expands through the expansion device. It then sends this heat to the evaporator (3) to be released into your home as a fan blows air across it. In the cooling mode, the condenser becomes a “heat dumper” and as the outdoor fan blows air across the coil, heat is released outside.
Evaporators are coils that absorb or release heat depending on which mode the heat pump is in. In the heat mode, the evaporator acts as a “heat dumper” releasing heat to the indoor air as your indoor fan blows air across it. In the cooling mode, the evaporator again uses physics to become a “heat sponge” grabbing all the heat from the indoor air as the fan blows the air across the evaporator.
Air handlers are an indoor fan that blows air across the evaporator and into the ducts of your home. In the heating mode, the air handler is releasing the captured heat from the outside and in the cooling mode, it is grabbing heat from the indoors and then moving it outside.
Reversing valves are the valve that switches the heat pump back and forth between the heating and cooling mode. In the air conditioning mode, the valve directs the refrigerant so that it captures heat from the inside and moves it outside. In the heating mode, it directs the refrigerant so that it captures heat from the outside and moves it inside your home.
The best part? Heat pumps are amazingly energy-efficient.
The heat pump is actually quite efficient at grabbing the heat from the outdoors and moving it inside. When the outdoor ambient air is above 40 degrees Fahrenheit, the heat pump is the most cost-effective way to heat your home. When the outdoor ambient air drops below 30 degrees there is not enough heat in the air for the heat pump to grab and many times a backup heat source is required to provide your home with heat. Electric heat strips can prove this backup heat source if your home is totally electric.
The most efficient way to provide this backup heat however is to install a 90% furnace to provide backup heating. When a heat pump is installed with a backup fossil fuel furnace the combination is known as a dual fuel system. A dual fuel system provides the most efficient way to heat and cool your home and the energy savings each month will more than offset the initial investment of having a new high-efficiency dual fuel system installed.
Getting an effective, efficient heat pump system for your home is as easy as calling us.
Empire Heating & Air Conditioning offers many types of heat pumps and dual fuel systems. Call Empire today at 404-294-0900, and we will be more than happy to schedule your free consultation.