Moisture Purge Cycle; Drain Pans; Cdq Cleaning; Vacuuming The Wheel - Trane CSAA Installation, Operation And Maintenance Manual

2. Blow the coil out as completely as possible with
compressed air.
3. Fill and drain the coil several times with full strength
glycol so that it mixes thoroughly with the water
retained in the coil.
4. Drain the coil out as completely as possible.
5. To ensure no water remains in the coil, do not replace
the vent and drain plugs until the coils are put back into
service.
Note: Use care in removing header plugs from Type P2,
P4, and P8 coils. Over-torquing may result in
twisted tubes.

Moisture Purge Cycle

By it's very nature, any HVAC unit with a cooling coil serves
as a dehumidifier, reducing the surrounding air's ability to
hold water vapor as its temperature falls. This normally
doesn't present a problem when the unit is running.
However, when the fan stops, water vapor condenses on
the cold metal surfaces inside the air handler and remains
there until the air warms sufficiently to re-evaporate it.
This damp, dark environment—though temporary—can
encourage the growth of mold, mildew, and other
microbial contaminants.
Providing a moisture purge cycle 15 to 30 minutes after
shutdown disperses the cold, humid air inside the air-
handling system more evenly throughout the building.
This four-step cycle:
• Closes the outdoor air dampers.
• Turns off the cooling coil.
• Opens any variable-air-volume terminals connected to
the air handler.
• Operates the supply fan for 10 to 15 minutes.
Air movement discourages water condensation and
hastens re-evaporation of any condensate that does
happen to form. This simple preventative measure
effectively combats microbial growth and curbs moisture-
related deterioration of air-handling components.

Drain Pans

WARNING
Hazardous Chemicals!
Failure to follow all safety instructions could result in
death or serious injury. Coil cleaning agents can be
either acidic or highly alkaline and can burn severely if
contact with skin occurs. Handle chemical carefully and
avoid contact with skin. ALWAYS wear Personal
Protective Equipment (PPE) including goggles or face
shield, chemical resistant gloves, boots, apron or suit as
required. For personal safety refer to the cleaning agent
manufacturer's Materials Safety Data Sheet and follow
all recommended safe handling practices.
CLCH-SVX07K-EN
WARNING
No Step Surface!
Failure to follow the instructions below could result in
death or serious injury. Do not walk on the sheet metal
drain pan. Walking on the drain pan could cause the
supporting metal to collapse, resulting in the operator/
technician to fall.
The condensate drain pan and drain line must be checked
to assure the condensate drains as designed. This
inspection should occur a minimum of every six months or
more often as dictated by operating experience.
If evidence of standing water or condensate overflow
exists, identify and remedy the cause immediately. Refer
to "Troubleshooting," p. 165
solutions.
To clean drain pans:
1. Disconnect all electrical power to the unit.
2. Wearing the appropriate personal protective
equipment, remove any standing water.
3. Scrape solid matter off of the drain pan.
4. Vacuum the drain pan with a vacuum device that uses
high-efficiency particulate arrestance (HEPA) filters
with a minimum efficiency of 99.97 percent at
0.3 micron particle size.
5. Thoroughly clean any contaminated area(s) with a
mild bleach and water solution or an EPA-approved
sanitizer specifically designed for HVAC use.
6. Immediately rinse the affected surfaces thoroughly
with fresh water and a fresh sponge to prevent
potential corrosion of metal surfaces.
7. Allow the unit to dry completely before putting it back
into service.
8. Be careful any contaminated material does not contact
other areas of the unit or building. Properly dispose of
all contaminated materials and cleaning solution.
CDQ Desiccant Dehumidification
Wheel

CDQ Cleaning

If there is dirt or dust buildup in the wheel, clean the wheel
using the following procedure:

Vacuuming the Wheel

1. Disconnect all power.
2. Using a standard shop vacuum, vacuum any debris
from both faces of the wheel. Slowly work around the
entire face of the wheel to complete the procedure. Do
not damage wheel face by excessive pressure of the
vacuum nozzle on the wheel face.
Routine Maintenance
for possible causes and
147