The Quest Next-Gen 225 is the volume model in the Quest commercial dehumidifier line: 225 pints per day AHAM, overhead-mountable, and built to run flat-out in sealed flower rooms. I default to the 225 for 8 to 12 light sealed rooms where one machine should do the work of two consumer boxes. I'd skip it for a single 4x4 tent (too much unit) and for 16-plus light rooms (you want the 335). For brand context, start with the complete guide to Quest dehumidifiers.
Quest 225 Specs at a Glance
Quest publishes two pint ratings: AHAM (80F / 60% RH, the appliance industry test) and grow-room (73F / 60% RH, what you actually see in flower). The 225 names itself after the AHAM figure; at grow conditions it produces closer to 165 pints per day. Size from the grow-conditions number.
Who the Quest 225 Is For
Sizing by light count is rough but reliable: plan 12 to 16 pints per day per 1000W-equivalent light during peak transpiration. At ~165 grow-conditions pints, the 225 covers 8 to 12 lights cleanly in a sealed room, with headroom for irrigation evaporation. Vented rooms with negative-pressure exhaust trim the upper end because make-up air brings outside moisture.
The 225 fits 8 to 12 light sealed rooms, fully sealed 10x20 tents, and small commercial rooms. I'd skip the 225 for a single 4x4 or 5x5 tent: Quest 155 territory. I'd also skip for 16-plus light operations, where the Quest 335 wins on per-pint cost.
Real-World Performance
In my experience the 225 surprises growers on two fronts: noise and footprint. It is quiet by commercial standards, but it is still a hot-gas-defrost refrigeration unit. Expect steady fan hum at idle and louder compressor cycles every 30 to 45 minutes. If the room sits next to living space, hang it overhead with vibration isolators rather than floor-mounting.
Footprint matters too. At 39 inches long and ~165 pounds, the 225 is not casual to move once installed. I plan ducting runs and condensate drain routing before lift day. Efficiency holds up: at ~6.7 pints per kWh, it pulls roughly the same per-watt as the 335 and beats consumer-grade units by a wide margin.
Setup and Ducting Notes
Electrical. The 225 runs 208/230V single phase, not standard 120V. Plan a dedicated 15A circuit, hardwired or via a NEMA 6-15 receptacle. If your room is 120V only, factor electrical work into the timeline before purchase.
Overhead mounting. Integrated brackets attach to ceiling joists or a unistrut grid. Use threaded rod with vibration isolators to decouple the compressor from the structure; this kills most of the perceived noise in the room below.
Condensate. The 225 pulls roughly 20 gallons per day at peak. Plumb the drain port to a floor drain, condensate pump, or sealed reclaim reservoir. Pair the unit with an environmental controller for closed-loop RH setpoints rather than running the internal humidistat alone, the temperature and humidity chart covers the targets I dial in.
Quest 225 vs 335 vs Anden A210
The cross-shop usually comes down to the 225, the next-size-up Quest 335, and the Anden A210 V1.
The 335 wins when the 225 is borderline, two 225s cost more and run less efficiently than a single larger unit. The Anden A210 is the cross-brand competitor: similar capacity, 240V only, wall-mount design instead of overhead. I default to the 225 for rooms where overhead mounting matters and 208/230V flexibility simplifies the install. For the full lineup, the industrial dehumidifiers page covers Quest and Anden side by side.
Verdict
The Quest 225 is the dehumidifier I default to for 8 to 12 light sealed flower rooms. Efficient, overhead-mountable, and backed by a 6-year warranty that matters when the unit runs 18 hours a day for the life of the room. Skip it for tents and small rooms (oversized, noisy, more machine than needed), and skip it for 16-plus light operations where the 335 wins on per-pint cost. For everything in between, this is the unit I recommend without hesitation. Check the live Quest Next-Gen 225 page for current cost.
Frequently Asked Questions
- How many lights can a Quest 225 cover?
- Plan 12 to 16 pints per day of removal per 1000W-equivalent light in flower. At ~165 grow-conditions pints per day, the 225 covers 8 to 12 lights in a sealed room. Vented rooms or rooms with significant envelope leakage trim the upper end of that range.
- Does the Quest 225 need 240V power?
- The 225 runs 208/230V single phase, not 120V. It will not operate on a standard wall outlet. Plan a dedicated 15A circuit, hardwired or via a NEMA 6-15 receptacle depending on local code.
- What is the difference between AHAM and grow-room capacity?
- AHAM is measured at 80F / 60% RH, the standard appliance test condition. Grow-room capacity is measured at 73F / 60% RH, closer to flower room conditions. The 225 produces 225 ppd AHAM and approximately 165 ppd at grow conditions. Always size from the grow-conditions number.
- Can the Quest 225 be mounted overhead?
- Yes. The 225 ships with integrated mounting brackets for overhead suspension from ceiling joists or a unistrut grid. Use threaded rod with vibration isolators to decouple the compressor from the structure. Overhead mounting is the recommended configuration for sealed rooms where floor space is at a premium.
- Quest 225 vs Quest 335: which should I buy?
- The 335 produces 335 ppd AHAM versus the 225's 225 ppd, with similar pints-per-kWh efficiency. The 335 is the right call for 14 to 20 light rooms, the 225 for 8 to 12 light rooms. For borderline 12 to 14 light rooms, a single 335 typically beats two 225s on cost and electrical load.
