quest
Asset Protection and IAQ Solutions
quest
1-800-533-7533
Quest
DRY
150 Installation, Operation and Maintenance Instructions
www.thermastor.com
3.4 Ducting
3.4A Installing Duct Collars
The Quest
DRY
150 is equipped with 10" and 6" round inlet collars and a 10" round (ovaled) exhaust collar.
Follow instructions included with collars.
3.4B Ducting for Dehumidification
For the ideal installation, draw air from the central part of the structure and return it to the isolated areas
of structure. The duct work of the existing heating system can be used to supply air to the structure. If the
existing supply goes to isolated areas of the structure, discharge the supply of the Quest
DRY
150 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 Quest
DRY
150 to each isolated area is recommended. DO NOT draw
air directly from the isolated areas. You may draw air from areas that are open to the structure. All flexible
ducting connected to the Quest
DRY
150 should be UL listed.
The inlet of the Quest
DRY
150 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 3.4C.
A 10" round (ovaled) collar is supplied with the unit for the outlet of the Quest
DRY
150.
A length of flexible ducting on all Quest
DRY
150 duct connections is recommended to reduce noise and
vibration transmitted to rigid duct work in the structure.
Ducting the Quest
DRY
150 as mentioned in Sections 3.4A-3.4G 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 Quest
DRY
150. If the Quest
DRY
150 is ducted to the supply ducting air handler,
it is recommended that the check damper be placed in the Quest
DRY
150 supply duct. Contact the factory
when connecting to a static pressure of greater than or equal to +.5" WG.
3.4C Ducting for Fresh Air
Fresh air can be brought into the structure by connecting an insulated duct from outside to the 6" Quest
DRY
150 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 and humidity control panel to bring
in fresh air. Refer to Section 4.5 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 Quest
DRY
150 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. Adequate exhaust fans are recommended throughout the structure (e.g., rest rooms).
FOR HVAC INSTALLER ONLY
