3
An optional condensate pump kit may be installed if a
lift is required to dispose of the condensate. The cond-
ensate pump kit can be ordered direct from the factory.
See the optional parts list for information on the kit.
2.4 Ducting
2.4A Installing Duct Collars
The DHV-150H is equipped with 10” and 6” round inlet
collars and a 10” round exhaust collar. The 10” and 6”
round inlet collars are designed with tabs that fold
inside the filter enclosure of the DHV-150H. The 10”
round exhaust collar is attached to the DHV-150H by
folding the tabs inside the end panel of the DHV-150H.
2.4B Ducting for Dehumidification
For the ideal installation, draw air from the central part
of the home and return it to the isolated areas of the
home like the bedrooms, den, utility room, or family
room. The ductwork of the existing heating system can
be used to supply air to the home. If the existing supply
goes to isolated areas of the home, discharge the
supply of the DHV-150H into the supply of the existing
heating system. If the existing heating system
incorporates a central supply, installation of a separate
supply duct from the DHV-150H to each isolated area is
recommended. DO NOT draw air directly from the
kitchen, laundry, or isolated basement. You may draw
air from a basement that is open to the home. All
flexible ducting connected to the DHV-150H should be
UL listed.
The inlet of the DHV-150H is the 10” diameter hole in
the filter enclosure of the unit. A 10” round collar is
supplied with the unit to attach to round duct. The duct
may be permanently attached to the collar. A 6” round
collar is provided with the unit to attach to the 6” hole in
the filter enclosure. The 6” collar should be capped if
fresh make-up air is not desired. If fresh make-up air is
desired see section 2.4C.
The outlet of the DHV-150H is located on the end of the
unit. A second 10” round collar is supplied with the unit.
Cut and remove the safety grid, then bend the tabs on
the collar inside the hole in the cabinet end.
A length of 10 feet or more of acoustical flex ducting on
the outlet of the DHV-150H will reduce air noise from
the fan. A length of flexible ducting on all DHV-150H
duct connections is recommended to reduce noise and
vibration transmitted to rigid ductwork in the structure.
Ducting the DHV-150H as mentioned in sections 2.4A-
2.4G requires consideration of the following points:
Duct Sizing:
For total duct lengths up to 25', use a
minimum 10" diameter round or equivalent rectangular.
For longer lengths, use a minimum 12" diameter or
equivalent. Grills or diffusers on the duct ends must not
excessively restrict airflow.
Isolated Areas:
Effective dehumidification may require
that ducting be branched to isolated, stagnant areas. Use
8" or larger diameter branch ducting to each of two or
three areas, use 6" or larger to each of four or more
areas.
Connecting to existing HVAC systems:
An optional
10" check damper is available from the factory to prevent
reverse flow through the DHV-150H. If the DHV-150H is
ducted to the supply of a high static air handler the check
damper may be placed in the DHV-150H supply duct.
2.4C Ducting for Fresh Air
Fresh air can be brought into the structure by
connecting a insulated duct from outside to the 6” DHV-
150H inlet and by turning on the fan switch or activating
the humidity control (on units with the humidity control
panel). Activate the ventilation timer on units with the
ventilating & humidity control panel to bring in fresh air.
Refer to section 3.5 for programming instructions for
the ventilation timer. Advantages of this form of
ventilation include:
1. Outside air is filtered before entering the building.
2. Outside air will be dehumidified before entering if
the DHV-150H is running in dehumidification mode.
3. Drawing air from outside and blowing inside aids in
slightly pressurizing the structure. This helps
prevent dirty and humid air from entering elsewhere.
It also reduces the potential for carcinogenic radon
gas to enter and provides make-up air for open
combustion and exhaust devices like the clothes
drier, fireplace, and water heater.
4. The need for an alternate ventilation device may be
eliminated.
In cold climates or areas where the outdoor dew point is
low at times, ventilation can be used to dehumidify the
structure. This approach is often more economical than
running the dehumidifier to remove excess moisture
from the structure. For example, in a house that
experiences condensation on the interior surface of the
windows during the winter, increasing the amount of
ventilation will often cure the problem.
An insulated 6" diameter duct is generally sufficient to
provide up to 150 CFM of outside air. Large quantities
of outside air will impact DHV-150H performance
