HVAC systems have two coils, a condenser coil in the outdoor unit and an evaporator coil in the indoor unit. The compressor extracts hot refrigerant gas and cools it in the outdoor coil, while the liquid refrigerant is cooled and expanded in the indoor coil to cool the air. In winter, the process is reversed to heat the air.
A heating, ventilation and air conditioning (HVAC) coil is part of an air conditioning and heating system. There are actually two HVAC coils in a typical system. There is a condenser coil in the outdoor air conditioning condenser and an evaporator coil in the indoor unit. Coils are what raise or lower the temperature and pressure of the gas or liquid refrigerant before passing it to another section of the HVAC system.
To understand how coils work, one must first understand how an HVAC system works. In the summer, the HVAC system draws warm air into the system, cools it, and distributes it throughout the building. In the winter, the system draws in cold air, extracts its heat, and passes the heated air through ducts into the building. HVAC coils play an important role in this process.
The compressor in the outdoor unit is a pump that extracts hot, low-pressure refrigerant or refrigerant gas from inside a building and converts it into hot, compressed gas. That hotter gas is forced up the outdoor coil and is cooled as the warm air from inside the building is blown out. The heat loss from the coolant, on the other hand, turns the gas into a still very hot and pressurized liquid form.
The liquid flows into the evaporator coil which is located inside the HVAC unit. As liquid enters the evaporator’s HVAC coil, it is able to expand and cool. It’s cooler than the surrounding air, so it absorbs heat from the ducts that are part of the HVAC system. This leaves cooler air in the ducts to be distributed throughout the building. As the cold air is dispersed through the duct system, the cooler, lower pressure gas is recycled back into the outdoor compressor’s HVAC coil to start the cooling cycle again.
In the winter, an HVAC battery works the opposite way. The heat pump draws in air from outside and passes it over the evaporator coil. The cooler air is heated by the evaporator coil and then pumped through the ducts to heat the building. While the air outside a building might be freezing, the HVAC system is able to extract some of the heat from it. In fact, an HVAC coil can extract heat from air that is well below the freezing point.
Protect your devices with Threat Protection by NordVPN
