Comfort-Aire HBH Series 6-10 Tons - Manual (Page 42)

IOM Manual HBH SERIES Heat Controller, Inc.
41
Preventive Maintenance
Water Coil Maintenance -
(Direct ground water applications only)
If the system is installed in an area with a known high
mineral content (125 P.P.M. or greater) in the water, it is
best to establish a periodic maintenance schedule with the
owner so the coil can be checked regularly. Consult the well
water applications section of this manual for a more detailed
water coil material selection. Should periodic coil cleaning
be necessary, use standard coil cleaning procedures, which
are compatible with the heat exchanger material and copper
water lines. Generally, the more water flowing through the
unit, the less chance for scaling. Therefore, 1.5 gpm per
ton [1.6 l/m per kW] is recommended as a minimum flow.
Minimum flow rate for entering water temperatures below
50°F [10°C] is 2.0 gpm per ton [2.2 l/m per kW].
Water Coil Maintenance -
(All other water loop applications)
Generally water coil maintenance is not needed for closed
loop systems. However, if the piping is known to have
high dirt or debris content, it is best to establish a periodic
maintenance schedule with the owner so the water coil
can be checked regularly. Dirty installations are typically
the result of deterioration of iron or galvanized piping or
components in the system. Open cooling towers requiring
heavy chemical treatment and mineral buildup through water
use can also contribute to higher maintenance. Should
periodic coil cleaning be necessary, use standard coil
cleaning procedures, which are compatible with both the
heat exchanger material and copper water lines. Generally,
the more water flowing through the unit, the less chance for
scaling. However, flow rates over 3 gpm per ton (3.9 l/m per
kW) can produce water (or debris) velocities that can erode
the heat exchanger wall and ultimately produce leaks.
Filters - Filters must be clean to obtain maximum
performance. Filters should be inspected every month
under normal operating conditions and be replaced when
necessary. Units should never be operated without a filter.
Washable, high efficiency, electrostatic filters, when dirty,
can exhibit a very high pressure drop for the fan motor and
reduce air flow, resulting in poor performance. It is especially
important to provide consistent washing of these filters (in
the opposite direction of the normal air flow) once per month
using a high pressure wash similar to those found at self-
serve car washes.
Condensate Drain - In areas where airborne bacteria
may produce a “slimy” substance in the drain pan, it may
be necessary to treat the drain pan chemically with an
algaecide approximately every three months to minimize the
problem. The condensate pan may also need to be cleaned
periodically to insure indoor air quality. The condensate drain
can pick up lint and dirt, especially with dirty filters. Inspect
the drain twice a year to avoid the possibility of plugging and
eventual overflow.
Compressor - Conduct annual amperage checks to insure
that amp draw is no more than 10% greater than indicated
on the serial plate data.
Fan Motors - All units have lubricated fan motors. Fan
motors should never be lubricated unless obvious, dry
operation is suspected. Periodic maintenance oiling is not
recommended, as it will result in dirt accumulating in the
excess oil and cause eventual motor failure. Conduct annual
dry operation check and amperage check to insure amp
draw is no more than 10% greater than indicated on serial
plate data.
Belt - Check that the belt is tight. Retighten if needed.
Replace if it is split or cracked.
Air Coil - The air coil must be cleaned to obtain maximum
performance. Check once a year under normal operating
conditions and, if dirty, brush or vacuum clean. Care must
be taken not to damage the aluminum fins while cleaning.
CAUTION: Fin edges are sharp.
Refrigerant System - To maintain sealed circuit integrity,
do not install service gauges unless unit operation appears
abnormal. Reference the operating charts for pressures
and temperatures. Verify that air and water flow rates are at
proper levels before servicing the refrigerant circuit.