Understanding Your Air Conditioning Unit’s Expansion Valve

Summertime in Buffalo Grove, IL, is hot and muggy, and you’ll no doubt turn to your air conditioning system for relief. Air conditioners use a chemical refrigerant that changes state between a vapor and a liquid as it cools and dehumidifies your home. The unit’s expansion valve plays an important role in this process. Read on in order to understand your air conditioner’s expansion valve, why it’s important and signs that it needs to be replaced.

What the Expansion Valve Does

The expanding valve regulates the amount of chemical refrigerant that flows into the evaporator coil of your air conditioning system. The valve has a rod that moves up and down. When the rod is down, the refrigerant cannot flow into the coil. The movement of the rod meters the amount of refrigerant flowing through the coil. This affects how much heat it can absorb from your home’s air.

How the Expansion Valve Helps Cool Your Home

When the rod opens, it releases pressure from the refrigerant. With the pressure released, the vapor turns into a liquid and cools down. The cold refrigerant can then cycle through the evaporator coil. The air is blown over the evaporator coil, which is filled with low-pressure, cold refrigerant. The refrigerant absorbs heat and the pressure once again nincreases. It then moves to the outdoor unit, where it releases the heat through the condenser coil.

Signs of Problems with the Expansion Valve

A problem with the expanding valve may cause your AC unit to blow warm air, constantly cycle, or fail to cycle. You may notice frost or ice buildup on the AC unit. Expansion valve rods may get stuck or crack. According to the Department of Energy, replacing an old one with a thermal expanding valve boosts the AC’s energy efficiency.

To learn more about your air conditioning unit’s expansion valve, take a look at Assurance Heating & Air Conditioning, Inc.’s expert AC services, or call us today for additional details.