Clean coils minimize required fan brake
horsepower and maximize efficiency by keeping
coil static pressure loss at a minimum.
Clean coils keep the motor temperature and
system pressure within safe operating limits for
The following equipment is required to clean
condenser coils: a soft brush and either a garden
pump-up sprayer or a high-pressure sprayer. In
addition, a high-quality detergent must be used.
Follow the manufacturer's recommendations for
mixing to make sure the detergent is alkaline with a pH
value less than 8.5.
Specific steps required for cleaning the condenser
coils are as follows:
1. Disconnect the power to the unit.
Open the unit disconnect switch. Failure
to disconnect the unit from the electrical
power source may result in severe
electrical shock and possible injury or
2. Remove enough panels from the unit to gain
access to the coil.
3. Protect all electrical devices, such as motors and
controllers, from dust and spray.
4. Straighten coil fins with a fin rake, if necessary.
5. Use a soft brush to remove loose dirt and debris
from both sides of the coil.
6. Mix the detergent with water according to the
manufacturer's instructions. The detergent and
water solution may be heated to a maximum of
150°F to improve its cleaning ability.
Do not heat the detergent and water
solution to temperatures in excess of
150°F. High-temperature liquids
sprayed on the coil exterior raise the
pressure within the coil and may cause it
to burst. Should this occur, the result
could be both injury to personnel and
7. Place the detergent and water solution in the
sprayer. If a high-pressure sprayer is used, be
sure to follow these guidelines:
Minimmum nozzle spray angle is 15 degrees.
Spray the solution perp endicular (at a
90-degree angle) to the coil face.
Keep the sprayer nozzle at least 6 inches from
Sprayer pressure must not exceed 600 psi.
Do NOT spray motors or other electrical
components. Moisture from the spray
can cause component failure.
8. Spray the side of the coil where the air leaves
first; then, spray the other side (where the air
enters). Allow the detergent and water solution
to stand on the coil for 5 minutes.
9. Rinse both sides of the coil with cool water.
10. Inspect the coil and if it still appears dirty, repeat
Steps 8 and 9.
11. Remove the protective covers installed in Step
2. Replace all unit panels and parts, and restore
electrical power to the unit.
Inspect periodically for excessive vibration or
temperature. Operating conditions vary the frequency
of inspection and lubrication. Motor lubrication
instructions are found on the motor tag or nameplate. If
not available, contact the motor manufacturer for
To re-lubricate the motor, complete the following:
Disconnect the power source for motor
lubrication. Failure to do so may result in
injury or death from electrical shock or
1. Turn the motor off. Make sure it cannot