Therma-Stor Ultra Aire XT105H, Owner'S Manual

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6. Maintenance
6.1 Standard Air Filter
The Ultra-Aire XT is equipped with a pleated cloth air filter. This
filter should be checked every six months. Operating the unit with
a dirty filter will reduce dehumidifier capacity and efficiency and
may cause the compressor to cycle off and on unnecessarily on the
defrost control.
To access the air filter, remove the filter access panel from the end
of the Ultra-Aire XT. The filter should be readily visible and can be
removed by pulling them straight out of the Ultra-Aire XT.
The pleated cloth filter can generally be vacuumed clean several
times before needing replacement. DO NOT operate the unit
without the standard filter or with a less effective filter than the
standard filter. The heat exchange coils inside the unit could
become clogged and require disassembly to clean. Filter non-
compliance invalidates the product warranty.
6.2 High Efficiency Air Filter – MERV 14
An optional high efficiency pleated microglass paper filter is
available for the Ultra-Aire XT. This filter is rated as 90%-95%
efficient by the ASHRAE Dust Spot test method 52-76. The
high efficiency pleated microglass paper filter should be used
in conjunction with the standard filter.
The filter housing is a
seperate accessory
that must be used with the MERV 14 filter.
An additional MERV 11 pre-filter is sold with the filter housing.
This filter is able to remove allergy causing particles from the
airstream. The high efficiency filter has a much larger surface area
than the standard filter, thus the standard filter may need to be
cleaned or replaced several times before the high efficiency filter
requires replacement. Be careful not to damage the fabric media
when handling the high efficiency pleated paper filter. Do not
attempt to clean the high efficiency pleated paper filter. It should be
replaced when it becomes restrictive.
6.3 Impeller Fan Oiling
The impeller fan motor is factory lubricated for many years of
normal operation, and no further oiling is required.
6.4 Optional Fresh Air Return
Check and clean the screen on the outdoor fresh air return
seasonally. The screen may become plugged during the seasons
when there are many particles in the outdoor air.
7. Service
7.1 Warranty
A warranty certificate has been enclosed with this unit; read it
before any repair is initiated.
If a warranty repair is required,
call the factory first at 1-800-533-7533 Ext. 8459 for warranty
claim authorization and technical assistance.
7.2 Technical Description
The Ultra-Aire XT uses a refrigeration system similar to an air
conditioner's to remove heat and moisture from incoming air, and
add heat to the air that is discharged (See Figure 15).
Hot, high-pressure refrigerant gas is routed from the compressor
to the condenser coil (See Figure 3). The refrigerant is cooled
and condensed by giving up its heat to the air that is about to be
discharged from the unit. The refrigerant liquid then passes through
a filter/drier and capillary tubing which causes the refrigerant
pressure and temperature to drop. It next enters the evaporator
coil where it absorbs heat from the incoming air and evaporates.
The evaporator operates in a flooded condition, which means that
all the evaporator tubes contain liquid refrigerant during normal
operation. A flooded evaporator should maintain nearly constant
pressure and temperature across the entire coil, from inlet to outlet.
The mixture of gas and liquid refrigerant enter the accumulator
after leaving the evaporator coil. The accumulator prevents any
liquid refrigerant from reaching the compressor. The compressor
evacuates the cool refrigerant gas from the accumulator and
compresses it to a high pressure and temperature to repeat
the process.
7.3 Troubleshooting
Neither fan nor compressor running. Dehumidification is being
called for. No fan call.
1. Unit unplugged or no power to outlet.
2. Humidity control set too high.
3. Loose connection in internal or control wiring.
4. Defective Compressor relay.
5. Defective control transformer.
Figure 15: Refrigeration System of Ultra-Aire XT
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Ultra-Aire XT105H, XT155H, and XT205H Installer’s & Owner’s Manual