How to Clean an Evaporator Coil

How to Clean an Evaporator Coil
September 3, 2015 nobleair

Your residential HVAC system keeps your home comfortable in the summer months and even during the other seasons. You probably know to replace the filter(s) every month to prevent debris from getting into your system. This is easy to remember because it’s located in a conspicuous place, you probably walk by it a few times each day. Another important preventative maintenance step you can take is to clean parts that aren’t visible. One of the more critical parts of your air conditioner are the evaporator coils.

How to Clean an Evaporator Coil

If the coils become dirty, the impact will be substantial. The system’s performance will decrease, and, it makes it more susceptible to breaking down. Dirty coils also cause reduce heat transfer, affect cooling capacity, increase energy use, raise or spike operating temperatures and pressures, put more stress on the system, and cause a buildup of ice.

The evaporator works the opposite of the condenser, here refrigerant liquid is converted to gas, absorbing heat from the air in the compartment. When the liquid refrigerant reaches the evaporator its pressure has been reduced, dissipating its heat content and making it much cooler than the fan air flowing around it. This causes the refrigerant to absorb heat from the warm air and reach its low boiling point rapidly. The refrigerant then vaporizes, absorbing the maximum amount of heat. —Southwest Wisconsin Technical College

You should also know that an air conditioner with dirty coils uses about 40 percent more energy than a system with clean coils. What’s more, the cooling function can be reduced by as much as 30 percent or more. Put another way, your system will be less efficient, use more energy, wear faster, and hit your wallet hard. To prevent this from happening, you can clean your evaporator coil by following these steps:

  1. Purchase a commercial cleaner. There are a number of commercial coil cleaners on the market, so, speak with someone that’s knowledgeable about which is best to use. In the alternative, you can a mild, household detergent.
  2. Gather your cleaning materials. You’ll need a spray bottle to apply the cleaner, soft brush, clean cloth, drill-driver or screwdriver, and a plastic bag. In addition, you should also have a bucket and sponge for dirtier coils.
  3. Turn your system off. Once you have your cleaner and materials gathered together, you’ll need to shut your system off at the thermostat. Do not attempt to clean the coils when the system is running because it will likely be damaged.
  4. Remove the access panel. Go out to your air conditioner and use a drill-driver or screwdriver to remove the access panel. Place the screws in a plastic bag so you don’t lose them.
  5. Apply the cleaner to the coils. Spray the coils with commercial cleaner, in the same direction they work (you’ll notice a “clean side” and a side where dirt accumulates). Allow it to dry as long as recommended by the manufacturer. If using mild household detergent, let it dry completely. Once dry, use a soft cloth or brush to wipe it off. Then, put the panel back on the unit.

If you discover the coil to be heavily caked with debris, it’s best not to attempt to clean it yourself. Instead, give us a call and one of our experienced technicians will clean your system’s evaporator coils. Heavy cleaning is actually a delicate process and you can easily cause damage to critical components.