Quest and Anden are both built by Therma-Stor, the Madison, Wisconsin parent that also owns Aprilaire and Phoenix. After years of speccing both: Quest is the workhorse for industrial-scale rooms that prize raw water removal and serviceability, Anden is the grow-optimized line built around quieter operation, Title 24 efficiency, and tight controller integration. I default to Anden for sealed flower rooms under roughly 5,000 sq ft, and Quest the moment a room scales past that or needs ducting flexibility. For category fundamentals, the complete guide to dehumidifiers and climate management covers sizing math and VPD targets.
Are Quest and Anden the Same Company?
Effectively, yes. Both Quest and Anden are owned by Therma-Stor LLC, a Wisconsin manufacturer that has been building commercial dehumidification equipment since 1977. Therma-Stor also owns Phoenix (restoration dehumidifiers) and Aprilaire. So when growers ask "is Anden made by Quest", the accurate framing is that both brands roll up to the same parent and share engineering DNA, but they target different rooms.
Quest came first and built its reputation on industrial-grade overhead dehumidifiers for commercial growers, mold remediation contractors, and indoor pools. Anden launched later as a grow-optimized line, engineered around cultivation-room workflows: lower noise, better integration with environmental controllers like TrolMaster and Growlink, and Title 24 compliance for California operators. Parts overlap is real on the back end, but front-of-house design diverges. Pick the brand whose interface fits your operation; the engineering pedigree is shared.
The Quest and Anden Lineups Side by Side
Both brands ladder from light commercial portables up through industrial-scale units. Capacity is measured in pints per day (PPD) at AHAM conditions (80°F / 60% RH). Here is the curated tier-by-tier breakdown of the units I see growers actually choosing between, with a relative price band rather than a static number because both lines see seasonal pricing shifts.
The brands match tier-for-tier through ~700 PPD, so most growers are choosing between two genuinely comparable units. Quest extends beyond Anden at the top end: the Quest 746 has no direct Anden equivalent in cultivation-spec form, which is why Quest dominates at large licensed producer facilities.
Capacity and Sizing: Which Brand at Which Grow Size
Sizing math is identical between the brands (PPD is a standardized AHAM measurement). Budget 5 to 7 pints per day per square foot of canopy for flowering rooms at 75°F / 60% RH, then add headroom for transpiration spikes.
For single-tent and small-room operators (4x4 to 5x10), both brands compete head-to-head. A grower running one or two tents usually picks on noise: the Anden A70 runs quieter than the comparable Quest Hi-E Dry 140. I'd put Anden ahead at this scale.
For mid-commercial rooms (10 to 30 lights), the comparison shifts to the 200-330 PPD overhead bracket. The Quest Next-Gen 225 and Anden A320 V3 are the workhorses. Quest has a slight edge in raw water removal at the warmer/wetter end of the operating envelope (drying rooms); Anden has the edge in efficiency and controller integration for steady-state flower rooms.
For large-room and industrial operators (50+ lights), most rooms run multiple units in parallel. I lean Quest here because the Quest 506 and Quest 746 have a longer track record under restoration-grade duty cycles. Anden's A710 V3 closed most of the gap, but Quest still wins on serviceability at the largest scale.
Energy Efficiency and Title 24 Compliance
Efficiency is measured in pints removed per kilowatt-hour (PPD/kWh). Anden has historically led because the line was engineered around California's Title 24 building energy code, which sets minimum efficiency thresholds for commercial dehumidifiers installed in California cultivation facilities. The current V3 platform pushes Anden's mid-range and flagship units above the Title 24 threshold.
Quest closed most of the historical gap with the Next-Gen series. The Next-Gen 225, 335, and 506 post efficiency figures that compete directly with the A320 V3 and A710 V3. If you are building in California, verify the current Title 24 compliance status of the specific model you are speccing because compliance lists update annually.
If you are sizing a California facility, default to Anden unless you need capacity beyond the A710 or specific ducting that pushes you to Quest. Outside California, treat efficiency as one factor among several. Annual energy savings on a single mid-commercial unit is real but rarely large enough to override warranty or service-network considerations.
Build Quality, Controls, and Controller Integration
Both brands build commercial-grade equipment: galvanized steel cabinets, rotary compressors, hot-gas defrost cycles, serviceable refrigerant circuits. The divergence is in onboard controls and external controller integration.
Anden's V3 platform standardized on a 0-10V analog control input across the cultivation-spec lineup, which makes integration with TrolMaster, Growlink, and Argus genuinely plug-and-play. Set the RH target on the controller, wire the 0-10V signal, done. This is the single biggest reason I steer commercial growers toward Anden when they have a full controller stack in the budget.
Quest's Next-Gen series added cleaner onboard digital controls and a dry-contact remote interface, but the integration is on/off relay rather than proportional. For a grower running a simpler setup, Quest's onboard panel is the better interface: bigger display, intuitive setpoint adjustment, fault codes surfaced plainly. I default to Quest for owner-operated rooms without a controller stack, Anden for any room with TrolMaster or equivalent.
Warranty and Long-Term Reliability
This is the question every r/microgrowery thread on the brands gets stuck on. Both carry warranty terms in the 5-year range on the sealed refrigeration system and 1-2 years on parts. The real-world difference is what breaks and how the service network responds.
Compressor longevity on both is strong. I've watched first-generation Quest units run past warranty without compressor failure, and older Anden A100 and A130 units are still in service. Field failures cluster on control boards, fan motors, and condensate pumps, all wear parts. Quest's US parts supply is faster on these items because the Therma-Stor network has distributed Quest parts the longest. Anden's pipeline has improved since the V3 launch but lags on legacy V1 units.
The r/microgrowery consensus across threads: buying new from authorized dealers and documenting install conditions gets warranty claims handled cleanly on both brands. Off-platform purchases report longer queues and occasional voided coverage. For a 7 to 10 year horizon, Quest is slightly ahead on parts availability and Anden slightly ahead on warranty terms after the V3 sealed-system extension. Close enough that neither should be a deal-breaker on warranty alone.
Verdict: Which to Buy by Scenario
Here is how I default by scenario.
Sealed flower room, mid-commercial: Anden A320 V3 if you have a controller stack, Quest Next-Gen 225 if you do not.
Drying or curing room: Quest. Drying-room duty cycles run wetter and warmer, and Quest's overhead units handle the high-load envelope with more headroom. Quest 335 or 506 covers most drying spaces.
Multi-room facility with in-house techs: Quest. Parts availability and serviceability at scale lean its way past ten units.
California operator building new: Anden, unless capacity exceeds the A710 V3 or ducting forces Quest. Title 24 is engineered in.
For deeper reads, see the complete guide to Quest dehumidifiers, the complete guide to Anden dehumidifiers, and the grow-room temp and humidity chart for RH targets across growth stages.
Frequently Asked Questions
- Are Anden and Quest the same company?
- Both are owned by Therma-Stor LLC, the Wisconsin commercial dehumidifier manufacturer founded in 1977 (also parent to Phoenix and Aprilaire). They share supplier and engineering DNA but target different rooms: Quest leans industrial and restoration-grade, Anden is grow-optimized with Title 24 efficiency baked in.
- Which is better, Quest or Anden?
- Neither universally. Anden wins for sealed cultivation rooms under 5,000 sq ft with a controller stack or California Title 24 compliance. Quest wins for drying rooms, industrial-scale operations, and facilities where in-house techs need fast parts availability.
- Is Anden made by Quest?
- No. They are sister brands under Therma-Stor LLC. Anden launched after Quest as a separate grow-optimized line with its own engineering team. Same parent, not the same production line.
- What size dehumidifier do I need for a grow room?
- Budget 5 to 7 pints per day per square foot of canopy for a flowering room at 75°F / 60% RH, then add headroom for transpiration spikes. A 200 sq ft tent room typically needs 100-150 PPD; a 1,000 sq ft commercial room needs 500-700 PPD. The complete dehumidifier guide has the full sizing formula.
- How long do Quest and Anden dehumidifiers last?
- Both routinely run 7 to 10 years in cultivation duty cycles when bought new, installed correctly, and maintained on schedule (coil cleaning, condensate pump checks). Common failures are control boards, fan motors, and condensate pumps, not compressors.
- Are commercial Quest or Anden units worth the premium over consumer portables?
- A consumer portable in a single-tent grow runs continuously at peak transpiration, throws heat, and typically fails within 2 to 3 years. A Quest or Anden cultivation unit costs more upfront but pulls more water per kWh, runs at lower duty cycle, and lasts 5x to 10x longer. The math favors commercial-grade for any consistent flower-cycle room.
- Do Anden and Quest work with TrolMaster or Growlink?
- Anden's V3 platform uses 0-10V analog control across the cultivation lineup for proportional integration with TrolMaster, Growlink, and Argus. Quest's Next-Gen series supports dry-contact on/off relay control. For a sealed room with a master controller, Anden's integration is meaningfully cleaner.
