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  • Writer's pictureEllyse Trethric

Understanding the Split HVAC System

I have certainly encountered numerous HVAC (Heating, Ventilation, and Air Conditioning) systems during my inspections. One type of system that is commonly found in homes is the split HVAC system. In this article, I will explain how a split HVAC system works and emphasize the importance of yearly upkeep to ensure optimal performance and longevity.

How Does a Split HVAC System Work? A split HVAC system consists of two main components: an outdoor unit (condenser) and an indoor unit (evaporator coil). Here's how they work together to provide efficient heating and cooling:

Outdoor Unit (Condenser):

The outdoor unit houses the condenser coil, compressor, and a fan. Its primary function is to dissipate heat from the refrigerant. When the cooling mode is activated, the compressor compresses the refrigerant, converting it from a low-pressure gas to a high-pressure, high-temperature gas. This gas is then sent to the condenser coil, where the fan blows outdoor air over the coil to remove heat. As a result, the refrigerant is cooled and condensed into a high-pressure liquid.

Indoor Unit (Evaporator Coil):

The indoor unit is typically located near the furnace or air handler. It contains the evaporator coil, a blower fan, and an air filter. The high-pressure liquid refrigerant from the outdoor unit is sent to the evaporator coil, where it undergoes a phase change and evaporates into a low-pressure gas. The blower fan circulates indoor air over the cold evaporator coil, cooling the air in the process. The cooled air is then distributed throughout the house via the ductwork.

Refrigerant Circulation:

The split HVAC system relies on a closed-loop refrigerant cycle. After the refrigerant evaporates in the indoor unit, it returns to the outdoor unit through copper refrigerant lines. There, it is compressed again by the compressor, restarting the cycle.

The Importance of Yearly Upkeep: Regular maintenance and yearly upkeep are crucial for the optimal functioning of a split HVAC system. Here's why:

Energy Efficiency:

An adequately maintained split HVAC system operates more efficiently, reducing energy consumption and utility bills. During yearly upkeep, a professional technician can clean the evaporator and condenser coils, ensuring maximum heat transfer and airflow. They can also check refrigerant levels and make any necessary adjustments, preventing energy-wasting issues like refrigerant leaks or undercharged systems.

Extended Lifespan:

Yearly maintenance can significantly extend the lifespan of your split HVAC system. By addressing minor issues early on, such as worn-out belts, loose electrical connections, or clogged filters, you can prevent them from escalating into major problems that could potentially damage the system beyond repair. Proper maintenance also helps reduce wear and tear on components, allowing them to operate smoothly and last longer.

Improved Indoor Air Quality:

The air filter in the indoor unit plays a vital role in trapping dust, allergens, and pollutants, ensuring clean and healthy indoor air. Yearly upkeep involves inspecting and replacing the air filter, which helps maintain good indoor air quality. A clogged or dirty filter restricts airflow, causing the system to work harder and potentially leading to decreased efficiency and increased indoor air pollution.

Safety and Comfort:

Ensuring the safety and comfort of your home is another critical reason for yearly upkeep. A well-maintained split HVAC system reduces the risk of malfunctions, such as electrical issues or refrigerant leaks, that could compromise safety. Additionally, regular maintenance helps identify and rectify airflow problems, temperature inconsistencies, or unusual noises, ensuring consistent and comfortable heating and cooling throughout


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