If you think learning about your air conditioning system is impossible, think again. All it takes is breaking down the basics of your AC system into small, manageable pieces. Take your air conditioning evaporator, for instance. This part plays an interesting and important role in keeping your home comfortable throughout the year.
Air Conditioning Explained
Contrary to popular belief, your air conditioning system doesn’t “make” cold air. Rather, it creates the conditions for cooler air through the power of subtraction. By removing the latent heat found in indoor air, your AC system is able to keep your home cool.
To achieve this, your AC system runs refrigerant through a pair of coils, usually made from copper, aluminum and/or steel. These coils contain the refrigerant as it changes from a gas to a liquid at various points. These phase changes make it easier for the refrigerant to absorb heat as it passes from one coil to another.
How the Evaporator Works
Let’s take a look at the evaporator coil, which resides in the indoor portion of your air conditioning system. Just before entering the evaporator coil, the refrigerant passes through an expansion valve. True to its name, this valve expands the refrigerant, relieving pressure while turning it from a high-pressure liquid to a low-pressure liquid.
This expansion drops the refrigerant’s temperature, making it easier to absorb heat as it passes through the evaporator coil. The more heat it absorbs, the warmer the refrigerant gets. The now-cold air is pushed through the ductwork (or directly out of the air handler for ductless systems) and into your home’s living spaces.
In addition to removing heat, the air conditioning process also removes moisture from the surrounding air. This appears in the form of condensation, which collects in a tray below the evaporator coil and is eventually funneled through a drain tube.
Common Evaporator Issues
Here are a few common issues you could run into with your air conditioning evaporator:
- Pinhole leaks – These can develop over time as corrosion forms on the coils. Such leaks will eventually cause your AC system to be low on refrigerant, which could cause other problems in the long run.
- Debris buildup – Even a thin layer of dust on the evaporator coil can prevent it from absorbing heat effectively, resulting in poor efficiency and increased energy consumption, among other issues.
- Frost/ice buildup – The same issues can even lead to a heavy buildup of frost or ice on the coil. That’s due to the condensate coming into direct contact with the coil, allowing it to freeze over.
- Drainage issues – Mildew and algae buildup can clog up the condensate drain line, preventing water from draining out of the condensate tray properly. Backups can cause water leaks around the indoor cabinet.
