Quest Supply Air Duct Collar for Overhead Style Dehumidifier – 105, 155, 205, & 225 Only

The Quest Supply Air Duct Collar is a 10-inch flange accessory designed for Quest Dual overhead-style dehumidifiers. It attaches to the air outlet on the dehumidifier so you can connect standard ducting and position the unit outside your grow space — keeping conditioned air moving through the garden without placing the machine inside it. Compatible with Dual 105, 155, 165, 205, and 225 models only.

Quest Supply Air Duct Collar Specifications

Physical and compatibility specifications for the Quest Supply Air Duct Collar (part #310784), sourced from manufacturer product data and the canonical product listing.

Why Choose the Quest Supply Air Duct Collar

This collar solves a specific layout problem: Quest Dual overhead dehumidifiers are built to hang above the canopy, but sometimes the most practical installation places the unit in an adjacent space, mechanical room, or hallway rather than inside the grow tent or room itself. The supply air duct collar makes that possible by giving you a standard 10-inch duct connection at the air outlet, so treated air can be routed into the garden through flexible or rigid ducting.

• Keeps equipment out of the grow space. Running ducting from the dehumidifier outlet means the machine can live in an adjacent room or utility space, freeing up space inside the garden and reducing heat load from the unit itself.
• 10-inch flange matches standard commercial ducting. The 10-inch diameter is a common size for commercial grow-room ductwork, so it connects to standard flexible duct without requiring additional reducers or adapters in most installations.
• Manufacturer-fit accessory for Quest Dual models. Designed specifically for Quest Dual 105, 155, 165, 205, and 225 overhead dehumidifiers — not a universal workaround. It mounts directly to the air outlet on these models.
• Pairs with the return air attachment for a complete remote setup. To fully relocate the dehumidifier outside the garden, you also need the return/intake air collar (#310786) to pull moist air from the garden back into the unit. The supply collar alone routes conditioned air out; both collars together allow fully ducted remote operation.

Compatibility

The Quest Supply Air Duct Collar is designed exclusively for Quest Dual overhead-style dehumidifiers. It is not a universal fit. Before ordering, confirm your dehumidifier model is one of the following:

• Quest Dual 105
• Quest Dual 155
• Quest Dual 165
• Quest Dual 205
• Quest Dual 225

This collar attaches to the supply (outlet) side of the dehumidifier — the port where conditioned, dehumidified air exits the machine. To complete a remote-installation setup where the dehumidifier sits outside the grow area, pair it with the Quest Return Air Duct Collar (#310786), which attaches to the intake side and pulls humid air from the garden into the unit.

For complete climate management in your grow space, you may also want to consider an Ideal-Air condensate pump for routing condensate drainage when the dehumidifier is positioned in a remote location. If your installation also involves air distribution or circulation equipment, an Active Air HD pedestal fan can help move conditioned air through the garden once it enters via the supply duct.

Usage Guidelines

The supply air duct collar is a passive fitting — it does not have operating settings of its own. Its role is to provide a secure, properly-sized duct interface at the air outlet. Follow these guidelines for a clean installation:

1. Power down the dehumidifier before attaching or removing the duct collar.
2. Attach the collar to the air outlet port on the Quest Dual dehumidifier per the mounting method specified in your unit’s installation guide. The flange seats directly onto the supply air opening.
3. Connect 10-inch flexible or rigid duct to the collar flange, routing it from the dehumidifier’s location into the grow space. Keep duct runs as short and straight as practical to minimize static pressure and preserve airflow volume.
4. Seal all duct connections with foil tape or compatible duct mastic to prevent conditioned air leaking before it reaches the garden.
5. Install the return air collar (#310786) on the intake side of the dehumidifier and connect return ducting from the garden back to the unit. Both collars are required for fully remote operation.
6. Verify airflow after startup. Confirm that supply air is reaching the intended area of the garden and that no condensation is forming inside the duct from temperature differentials.

Duct length, bends, and diameter reductions all reduce the effective airflow through the dehumidifier. Consult Quest’s installation documentation for the maximum recommended duct length and equivalent feet of resistance for your specific model.

Sources & Further Reading