Quest Dual 155 Overhead Dehumidifier

The Quest Dual 155 is a high-capacity overhead dehumidifier built for commercial cultivation spaces where floor space is at a premium and moisture control is non-negotiable. Running at 7.3 pints per kWh — roughly twice the efficiency of conventional units — it removes 155 pints of water per day while consuming significantly less energy. MERV-11 filtration, an insulated cabinet for reduced noise, and a patent-pending dual outlet design make it one of the more complete dehumidification packages available for serious indoor growers. Plug and play operation means no installation is required out of the box.

Quest Dual 155 Specifications

All specifications below are drawn from manufacturer product data and supplier documentation for the Quest Dual 155 Overhead Dehumidifier.

Specification	Value
Brand	Quest Climate
Model	Dual 155 Overhead
Dehumidification Capacity	155 pints/day
Energy Efficiency Rating	7.3 pints/kWh
Standard Dehumidifier Comparison	3.8 pints/kWh (typical)
Weight	140.1 lbs
Cabinet Design	Insulated, horizontal configuration
Outlet Design	Patent-pending dual outlet
Filtration	MERV-11 (captures particles to 1 micron, including mold spores)
Installation Type	Plug and play — no installation required
Mount Options	Overhead (primary) or ground level
Optional Accessories	Condensate pump, ducting kits
Country of Origin	Made in the USA

Why Choose the Quest Dual 155 Overhead Dehumidifier

The Quest Dual 155 is engineered specifically for high-humidity cultivation environments where generic residential dehumidifiers fall short on both capacity and efficiency. Several design decisions distinguish it from standard units:

• Efficiency that matters at scale: At 7.3 pints per kWh, the Quest Dual 155 operates at nearly twice the energy efficiency of conventional dehumidifiers, which typically rate around 3.8 pints/kWh. Over weeks and months of continuous operation, this difference has a direct impact on electricity costs.
• Overhead placement recovers floor space: The horizontal cabinet is designed to be mounted overhead and out of the way — a meaningful advantage in tightly managed grow rooms where every square foot of canopy matters. It can also run at ground level when overhead mounting is not possible, giving growers placement flexibility without purchasing a different unit.
• Dual outlet air distribution: The patent-pending dual outlet configuration distributes processed dry air to two zones simultaneously, reducing the need for multiple units to cover a larger space evenly.
• MERV-11 air filtration included: Standard on every unit, the MERV-11 filter captures airborne particles down to 1 micron in size, including mold spores. This matters in grow environments where mold pressure is a persistent concern. The filter is a built-in feature, not an upgrade.
• Insulated cabinet for quieter operation: The insulated housing reduces operating noise compared to uninsulated units, which is relevant for facilities that run lighting and dehumidification on overlapping cycles or where staff work in close proximity.
• No installation required: The Quest Dual 155 ships as a plug-and-play unit. There is no licensed contractor requirement to get it running, reducing setup time and cost.
• Made in the USA: Quest manufactures this unit domestically, which typically means more predictable parts availability and support compared to overseas-sourced alternatives.

Best Uses for the Quest Dual 155 Overhead Dehumidifier

The Quest Dual 155 is a commercial-grade unit sized for spaces that exceed what residential dehumidifiers can handle. Appropriate applications include:

• Commercial indoor cultivation rooms: Large-scale cannabis, vegetable, or herb cultivation rooms running multiple lights generate substantial transpiration load. At 155 pints per day, the Quest Dual 155 can serve as a primary dehumidification unit in medium to large grow rooms or as a supplemental unit in very large facilities.
• Vertical farming and rack systems: Overhead mounting is particularly well-suited to multi-tier rack systems where floor space is occupied by grow trays and equipment. Mounting the unit overhead keeps it out of the working area while circulating dry air downward.
• Flower and late-veg stages: Humidity management during late vegetative and flowering stages is critical for preventing botrytis and powdery mildew. The MERV-11 filtration provides an added layer of defense by removing mold spores from the air supply.
• Space-constrained grow tents and rooms: When ducting kits and an optional condensate pump are paired with the Dual 155, it can manage condensate drainage remotely, accommodating spaces where running a drain line directly is inconvenient.
• Facilities prioritizing operating costs: Growers who run dehumidification 24 hours a day will see the efficiency advantage compound over time. The 7.3 pints/kWh rating means the Quest Dual 155 costs roughly half as much to run per pint removed compared to a standard-efficiency unit.

Quest Dual 155 vs Similar Products

The Quest Dual 155 occupies a specific position in the commercial dehumidifier market: it targets growers who need meaningful capacity (155 pints/day) without the infrastructure commitment of hard-ducted HVAC-integrated systems.

Compared to standard portable dehumidifiers in the 70–90 pint/day range commonly sold for home use, the Dual 155 removes roughly twice the moisture per day while operating at nearly double the energy efficiency. Standard residential units in this class typically rate at 3.8 pints/kWh; the Quest Dual 155 rates at 7.3 pints/kWh. For a facility running a dehumidifier 20 hours per day, that efficiency difference translates to meaningful energy savings each month.

Compared to other commercial overhead dehumidifiers, the Quest Dual 155’s distinguishing features are its dual outlet configuration and the inclusion of MERV-11 filtration as standard equipment. Many units at similar price points treat filtration as an optional add-on. The insulated cabinet is also not universal in this category — it reduces operating noise without sacrificing airflow performance.

The plug-and-play design is a practical differentiator for facilities that want to avoid contractor work. Larger capacity Quest units or competing brands with similar capacity often require ducted installation and electrical work beyond a standard outlet connection.

If you are comparing dehumidifier options and also need to monitor environmental conditions independently, pairing a standalone dehumidifier like the Quest Dual 155 with an environmental controller can automate on/off cycling based on actual RH targets rather than running the unit continuously.

Compatibility

The Quest Dual 155 is designed to operate in indoor cultivation environments and similar high-humidity commercial spaces. Key compatibility considerations:

• Power: The unit is plug-and-play, meaning it connects to a standard outlet. Verify the specific voltage and amperage requirements for your electrical circuit before installation — at 140+ lbs and commercial-grade draw, it should be on a dedicated circuit.
• Condensate management: By default, the unit collects condensate in an internal reservoir or can gravity-drain if a drain line connection is available. For overhead mounting, an optional condensate pump is available to move collected water to a drain. An aftermarket condensate pump compatible with Quest units can also serve as a replacement part if needed.
• Ducting: Optional ducting kits are available from Quest for the Dual 155, allowing intake and exhaust to be routed to specific locations within a facility. This is useful for spaces with restricted airflow or where the unit cannot be positioned for direct room-air exchange.
• Environmental controllers: The Quest Dual 155 can be integrated with compatible humidity controllers that switch the unit on and off based on RH readings. Most controllers with a standard outlet-switching relay are compatible with plug-and-play dehumidifiers of this type.
• Room size: Quest does not publish a single square footage rating for this unit, as effective coverage depends on the number of plants, lighting intensity, irrigation volume, room insulation, and ambient temperature. At 155 pints/day, it is generally appropriate for grow rooms in the 1,000–3,000+ sq ft range, depending on transpiration load.

Usage Guidelines

Getting consistent results from a commercial dehumidifier depends on placement, target setpoints, and maintenance. The following guidance applies to the Quest Dual 155 based on its design characteristics:

Humidity setpoints by growth stage: Most indoor cultivators target 60–70% RH during vegetative growth and drop to 45–55% RH during flower to reduce mold pressure. The Quest Dual 155 should be run on a controller or its built-in humidistat to maintain target RH rather than running continuously, which wastes energy and can over-dry the environment.

Overhead mounting recommendations: When mounted overhead, position the dual outlets to distribute airflow evenly across the canopy. Avoid directing airflow directly onto plant tops at close range during sensitive growth stages. The unit’s horizontal configuration is designed to spread airflow laterally when ceiling-mounted.

Filter maintenance: The included MERV-11 filter should be inspected regularly — at minimum monthly in high-dust or high-pollen environments — and replaced when it shows visible loading or when airflow appears reduced. A clogged filter reduces both efficiency and effectiveness.

Condensate drainage: If using gravity drain, ensure the drain line maintains a consistent downward slope with no traps or loops that would cause standing water. For overhead installations, a condensate pump is required. Check the condensate line or pump reservoir weekly to confirm it is draining properly.

Air circulation pairing: A dehumidifier works most effectively when room air is circulating. Running oscillating fans or a wall-mount fan — such as an Active Air HD pedestal fan — alongside the Quest Dual 155 helps distribute the processed dry air and prevents moisture pockets near the canopy.

Sources & Further Reading