A heat pump draws heat from one environment and pumps it to another. It does not generate heat; it simply exchanges the heat between a heat source and a heat sink. When the pump is in the heating mode, the heat is pumped from the outside into the home or business. When the pump is in the cooling mode, heat is pumped from the inside to the outside.
The two most common types of heat exchange systems are air-to-air and geothermal. In an air-to-air system, the heat source is the outside air. In a geothermal system, the heat source is the ground or an underground pool of water. Each has advantages and disadvantages. Cox Air Conditioning & Heating can help you determine which is most appropriate for your needs. There are five main components in a heat exchange system:
- Coils
- Refrigerant
- Compressor
- Reverse valve
- Air handler
How heat pumps work
There are two types of coils: condenser and evaporator. Evaporator coils absorb heat from the air; condenser coils release heat into the air. When the system is in heating mode, a liquid refrigerant is pumped through the outside evaporator coils. A fan draws outside air over the coils; the refrigerant absorbs the heat in the air and changes into a hot vapor. The vapor flows through a compressor, which raises the temperature of the vapor, then flows to the indoor condenser coils where the heat is released. The heat is pumped into the air handler, which blows the warm air through a system of ductwork for distribution throughout the building. As the refrigerant loses its heat, it condenses back into a liquid and returns to the outside coil to pick up more heat from the outside air.
A reverse valve changes the direction the refrigerant flows when switching from heat mode to cooling mode. Warm air flows over the indoor coil, which now acts as the evaporator coil. The refrigerant absorbs the heat, changes into a vapor, moves through the compressor and releases the warm air to the outside through the outside coil, which now acts as the condenser coil. The refrigerant then returns to pick up more heat from the inside air.
Commercial systems that have the evaporator and condenser coils in the same unit are called single package units. These units are usually located on the roof and have ductwork that distributes the air throughout the building. Home systems are usually split systems with one coil unit located outside of the home and the other inside.
Heat pump repairs
Periodic inspection by a professional HVAC contractor will extend the life of your system and help you avoid ill-timed breakdowns, but every system needs repairs at one time or another. Noisy or leaky ducts, temperature difficulties, problems with low air flow and squeaks or grinding noises are indicators your heat exchange system needs maintenance. When you need heat pump repairs, Cox Air Conditioning & Heating will respond quickly at a price you can afford.
