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Coil Cleaning
Regular coil maintenance, including annual cleaning,
enhances the unit’s operating efficiency by minimizing:
compressor head pressure and amperage draw;
evaporator water carryover;
fan brake horsepower, due to increase static pressure
losses;
airflow reduction.
At least once each year, or more often if the unit is located in
a “dirty” environment, clean the evaporator and condenser
coils using the instructions outlined below. Be sure to follow
these instructions as closely as possible to avoid damaging
the coils.
To clean refrigerant coils, use a soft brush and a sprayer
(either a garden pump-up type or a high-pressure sprayer). A
high-quality detergent is also required; suggested brands
include “SPREX A.C.”, “OAKITE 161”, “OAKITE 166” and
“COILOX”. If the detergent selected is strongly alkaline (ph
value exceeds 8.5), add an inhibitor.
1. Remove enough panels from the unit to gain access to the
coil.
2. Protect all electrical devices such as motors and control-
lers from any over spray.
3. Straighten any bent coil fins with a fin comb.
4. Mix the detergent with water according to the
manufacturer’s instructions. If desired, heat the solution to
150 F maximum to improve its cleansing capability.
CONTAINS REFRIGERANT!
SYSTEM CONTAINS OIL AND REFRIGERANT
Do not heat the detergent-and-water solution above
150
o
F. Hot liquids sprayed on the exterior of the coil
will raise the coil’s internal pressure and may cause
it to burst.
Failure to follow proper procedures can result in per-
sonal illness or injury or severe equipment damage.
5. Pour the cleaning solution into the sprayer. If a high-pres-
sure sprayer is used:
a. do not allow sprayer pressure to exceed 600 psi.
b. the minimum nozzle spray angle is 15 degrees.
c. maintain a minimum clearance of 6" between the
sprayer nozzle and the coil.
d. spray the solution perpendicular (at 90 degrees) to
the coil face.
6. Spray the leaving-airflow side of the coil first; then spray
the opposite side of the coil. Allow the cleaning solution to
stand on the coil for five minutes.
7. Rinse both sides of the coil with cool, clean water.
8. Inspect both sides of the coil; if it still appears to be dirty,
repeat Steps 6 and 7.
9. Reinstall all of the components and panels removed in
Step 1 and any protective covers installed in step 2.
10. Restore the unit to it’s operational status and check sys-
tem operation.
(1) Complete Unit Model Number:
(2) Unit Serial Number:
(3) Wiring Diagram Numbers (from unit control panel):
— schematic(s)
— connection(s)
Maintenance
