Quest CDG 174
Installation, Operation and Maintenance Instructions
1-877-420-1330
6
www.QuestHydro.com
info@QuestHydro.com
2.10 Defrost Light
The DEFROST light turns on when the unit is in defrost mode indicating when the compressor is off.
DRYING TIP: Air’s ability to absorb moisture from wet surroundings and the Quest CDG 174’s ability to remove
moisture from that air is greatly improved at higher temperatures. We recommend that the area to be dried be heated
to over 70°F if possible. Less drying time will be required and efficiency will improve.
2.11 Defrost Cycle
If the evaporator coil’s refrigerant temperature drops below the defrost set point, due to excessive frost formation, the
thermistor activates the solid state control and the defrost light. The control cycles the compressor “off” and “on” by
monitoring thermistor temperature. The air mover will continue to run, causing air to flow through the evaporator coil.
The air will melt the ice that formed on the evaprator.
When the air temperature and/or humidity increases, the evaporator temperature will rise and the thermistor will end the
defrost cycle restarting the compressor.
If the evaporator temperature does not reach the desired temperature, the compressor will start after 15 minutes. The
system will start a timed defrost cycle. The timed defrost cycle ensures the unit will continue to remove water from the
air in cool ambient conditions.
2.12 Low Pressure Control
If the low side refrigerant drops into a low pressure situation that may harm the compressor, the solid state controls will
sense the refrigerant conditions and shut off the compressor until the system automatically resets itself.
The solid state control monitors the refrigerant conditions to ensure the system is protecting compressor at all times.
The control protects the compressor from damage by monitoring cycles, pressures, and system performance.
3 Maintenance
3.1 Air Filter
The Quest CDG 174 is equipped with a pleated fabric air filter that must be checked regularly. The standard filter is a
MERV-11 high efficiency filter. Operating the unit with a dirty filter will reduce the dehumidifier’s capacity and efficiency
and may cause the compressor to cycle off and on unnecessarily on the defrost control. Quest recommends changing the
filter with each grow cycle.
IMPORTANT: DO NOT operate the unit without the filter or with a less effective filter as the heat exchanger and coils
inside the unit could become clogged and require disassembly to clean.
