Crawlspace Installation:
Install a separate return for the UA-90H
in a central area of the structure. Optional: Duct the supply of the
UA-90H to a 10" x 10" x 10" tee/damper that is 20% open to
the crawlspace if desired. Duct the other side of the tee to the
air supply of the existing HVAC system with a backdraft damper.
Connect an insulated duct from outside to the 6" collar of the UA-
90H if you wish to provide optional ventilation air.
Instead of installing a separate return to the UA-90H, and if the
existing system has multiple returns, it is possible to select one to
disconnect from the existing forced air system and use it for the
dedicated Ultra-Aire return. Always select a return from a central
location in the structure in an area that is always open to the rest
of the structure. Do not use a return from a room that may have
its door closed much of the time or, alternatively, install a separate
return from the open part of the house.
4.4D Installation in an Attic with an Existing Forced Air
HVAC System
IMPORTANT
ALWAYS install a catch pan with a drain or float interrupt for
condensate under the UA-90H in an attic or condensate may
damage the living space below.
The interrupt switch should be installed in series with the field wire
that connects the blue (#5) lead from the UA-90H to the blue (#5)
lead on the control panel. If overflow occurs, this switch opens
the compressor control circuit and stops water production before
the catch pan overflows. The UA-90H will continue to ventilate or
circulate air as normal, but will not dehumidify until this switch
closes.
The preferred method of installation is to create a separate return
for the UA-90H in a central area of the structure. Duct the supply of
the UA-90H to the air supply of the existing HVAC system. Connect
an insulated duct from outside to the 6" collar of the UA-90H if you
wish to provide fresh make-up air. Adjust a damper in the duct to
provide the desired.
4.4E Installation in a Structure with No Existing Forced
Air HVAC System
When installing the UA-90H in a structure that does not have a
forced air HVAC system, a single return for the UA-90H should
be installed in central open area of the structure. DO NOT locate
the return in a bathroom or a kitchen. The supplies of the UA-
90H should be located in the remote areas of the structure (such
as bedrooms, den, etc.). By ducting this way, the air inside the
structure will circulate through the UA-90H to be filtered and
dehumidified. 6" diameter duct is recommended for branches to
the bedrooms, 8" diameter duct is recommended for branches
to larger areas. Connect an insulated duct from outside to the 6"
collar of the UA-90H if you wish to provide ventilation. See Figure 4.
4.4F Ducting for High Efficiency Filtration
The standard filter included with the UA-90H is a very effective
MERV 11 media filter. Additional filtering options, including charcoal
filtration and 95% efficient filtration, are available with an optional
external filter housing that may be installed with the UA-90H. The
filter box is ducted to the intake of the UA-90H, and the intake
ducting is then connected to the intake side of the filter box. See
the optional accessories list or call the factory for details.
4.5 Noise Abatement
A length of 10 feet or more of acoustical flex ducting on the outlet
of the UA-90H will reduce air noise from the fan. A length of flexible
ducting on all UA-90H duct connections is recommended to reduce
noise transmitted to rigid ductwork in the structure.
4.6 Controls
All control panels should be mounted in a central area of the
structure where it can accurately sense the humidity of the air in
the living space and be accessed. All controls require field wiring
from the unit location to the panel mount location.
FOR HVAC INSTALLER ONLY
Figure 1:
Humidity/Fan Control Panel
Part No. 4024155
Figure 2:
Ventilation Timer
and Humidity Control Panel
Part No. 4024125
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Ultra-Aire 90H Installer’s & Owner’s Manual
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Ultra-Aire 90H Installer’s & Owner’s Manual
