Quest 335 Dehumidifier, 345 Pints/Day | 208-230V or 277V, R-454B

Quest 335 Dehumidifier for Heavy Moisture Loads

This Quest 335 unit pulls 345 pints of water a day from air at 80°F and 60% relative humidity. It does that at 8.2 pints per kWh while drawing about 1,700 watts. Two electrical versions are listed here: model 4046200 runs on 208-230V single phase, and model 4046210 runs on 277V. The 208-230V unit draws 8.4 A at 208V or 7.6 A at 230V, and the 277V unit draws 6.3 A. Both move 900 CFM through a variable-speed EC fan and a MERV-13 filter. Quest's patented M-CoRR multi-coil refrigeration recycles heat inside the unit, so less of it ends up in the room. DART control logic adjusts fan speed as frost conditions approach, slowing coil icing and keeping the compressor removing water. The unit runs on R-454B refrigerant and operates from 56°F to 95°F. The cabinet measures 32.9 x 24.6 x 23.7 in and weighs 215 lb, with integrated handles. Onboard digital controls include a dehumidistat and a low-voltage terminal block for external controllers. After a power outage, it restarts at its prior settings. Quest builds it in Madison, Wisconsin, and backs it with a five-year limited warranty. It is UL rated, ETL listed and meets California Title 24 for ducted and non-ducted installs.

Placing an Industrial Dehumidifier in a Flower Room

An industrial dehumidifier earns its keep in flower, where a full canopy gives back most of the water it is fed. A practical starting point is to total the daily irrigation volume and assume nearly all of it returns to the air. Quest rates this unit at 221 pints a day at 75°F and 50% RH, a common lights-off condition. Size the room on that cooler figure, not just the headline rating. Hang it overhead from 3/8 in threaded rod to keep floor space for benches, or set it on the floor where ceilings are low. Aim the discharge so dry air sweeps across the canopy instead of blasting one bench. With the matching duct kit, it can also sit in a mechanical space and move air through ductwork. Run condensate from the 3/4 in NPT drain to a floor drain or pump, and fit the P-trap Quest calls for. The lower-voltage model plugs into a NEMA 6-15 receptacle, while the higher-voltage model uses a NEMA L7-15 twist-lock. The higher-voltage version suits rooms already wired at that voltage for lighting and leaves amperage free for other gear. Check the filter often in flower, since pollen, dust and plant debris load it quickly. Wire a room controller to the terminal block to tie humidity to the light schedule. Watch the hour after lights-off closely, because humidity often climbs as the room cools.

Key Features

• 345 Pints per Day: Rated water removal at 80°F and 60% RH for heavy moisture loads.
• 8.2 Pints per kWh: High efficiency on roughly 1,700 watts of power.
• M-CoRR and DART: Multi-coil refrigeration recycles heat, and DART fan logic slows coil icing.
• MERV-13 Filtration: A 20 x 22 x 2 in filter captures dust, pollen and mold spores.
• Overhead or Floor: Hangs from 3/8 in threaded rod or stands freestanding on the floor.
• Two Voltages: Choose 208-230V (4046200) or 277V (4046210) to match the room's power.

Technical Specifications