condenser coil

How to Properly Clean a Condenser Coil

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1) Read the equipment service manual. Some manufacturers will specify additional cleaning steps, identify which chemicals are approved / not approved for their equipment, and help you identify how frequently your coils should be cleaned based on the environment.

2) Based on the manufacturer’s recommendations, assemble the equipment needed to perform the cleaning, safely. Standard personal protection equipment and safety measures dictate that you wear long pants and long sleeve, wear gloves, and a face shield if you are doing a chemical cleaning. The standard tools required will be rubber hoses, a coil gun, and in some instances a pressure washer.

condenser coil

3) Before cleaning the equipment, notify your alarm company that you are going to turn off the system and to put the alarm in test mode for a few hours.

4) Turn the power of feeding the equipment to the off position. If the systems attempts to run during the coil cleaning process it can be harmful to both you and the system on which you are working.

5) Remove any cleaning access panels and set them to the side. These are typically held on by 5/16″  or 3/8″ hex screws. Set the screws and the panels somewhere that they will not be forgotten and in such a way where they will not cause roof damage.

6) If the coil is entirely obstructed with dirt and debris, use a soft nylon brush to try and expose the coil surface. If you are brushing the coil always do so in the direction of the fins. Bent fins on a condenser coil will cause inefficient operation and can lead to component damage.

7) Once the coil surface is exposed, fill your coil gun with manufacture approved cleaner. If your system has microchannel coils then a pressure washer running at less than 1400 psi, using hot water, and no chemicals are what you will need for cleaning. Set the chemical mix rate on the coil gun to the lowest setting and then increase the mixture if needed. Most coil cleaning chemicals are caustic so they should be used sparingly on equipment. Spray the coils with the approved cleaner from top to bottom, not side to side. The goal is to push the mixture into the coil, coat the entire surface evenly, and do so in a way where the fins are not bent. Again, on microchannel coils, do not use a chemical cleaner and on all coils make sure your cleaner has been approved by the equipment manufacturer.

8) If a cleaner is used it will foam and push debris out of the coils. This foam is from a chemical reaction which also produces heat. If you notice that the coil is steaming then start rinsing the coil off immediately. You could be doing damage to your condenser coil from using too strong of a chemical mixture. Once the cleaner has foamed and pushed dirt out of the coils, use clean water to rinse the coil from the top to the bottom. Be cautious not to allow the cleaner to come into contact with any system components other than the coils. The chemical can cause component damage resulting in failure.

condenser coil

9) when rinsing the coil be careful not to bend any fins. It is important that the coil is thoroughly rinsed to ensure cleanliness and to ensure to the chemical is left on the system after cleaning. If you are unable to rinse the coils until the water runs out of them as clear as it went in, then you may need to perform another round of chemical cleaning.

10) Once the coils are sufficiently clean, rinse the coil debris and cleaner off of the roof and off of any walkways.

11) Pick up the cleaning access panels and screws and reinstall them on the system.

12) Clean your tools to make sure that they do not have any residue remaining on them from the chemical. Once cleaned and dried, put tools back in storage so they can be easily found and used for the next cleaning.

13) restore power back to the system and check the system for proper operation.


If you need assistance ensuring that your systems are being maintained in accordance with manufacturer recommendations, then please fill out a request form and we would be happy to schedule a time to meet and evaluate your facility, its equipment, and your maintenance needs.