Every homeowner should have a basic understanding of how their central air conditioning system works. Knowing how the air conditioning system works will help a homeowner understand why regular HVAC maintenance is important to keep the keep the system working great for years while lowering their energy costs.
Most residential air conditioning systems are “split systems” that have an outdoor unit consisting of a fan, condenser coils, and compressor and an indoor evaporator coils located inside the duct system above the furnace. The two components are connected by coolant lines filled with refrigerant. A central air conditioner works by using the compressor to compress the refrigerant which makes it very hot. The hot refrigerant is pumped through the outdoor condenser coils where the fan cools the refrigerant by blowing air over the coils.
The cooled refrigerant is then pumped through coolant lines to the evaporator where it expands and gets very cold. The cold refrigerant flows through the indoor evaporator coil inside the duct system where the blower moves air over the coils. The air is cooled and also dehumidified as moisture in the cooled air condenses on the coils. This moisture drips into a pan below the coils and is drained through the condensate drain.
The cool dry air is then distributed throughout the home through your duct system and the registers (or supply vents). The return vents allow air to flow through the return ducts back to the air handler where the cycle is repeated.
A regular service visit once or twice a year by a professional HVAC technician will keep the system working efficiently. The coolant must be pressurized to the right pressure and the coils should be free of dust and debris. Your HVAC technician has specialized tools and equipment to adjust the system pressure and maintain the system.
