Quest 155 Overhead Dehumidifier


The Quest 155 Overhead Dehumidifier is a superb and energy-efficient commercial unit that can remove 155 pints of water over a day.

Add to Wishlist
Add to Wishlist

Quest 155 Overhead Dehumidifier

The Quest 155 Overhead Dehumidifier is a superb and energy-efficient commercial unit that can remove 155 pints of water over a day.

You can suspend the unit overhead above the plants, as is often done, or use ducting to allow the unit to be kept in a separate location. This product is ideal for use in any hydroponic system and offers growers several distinct features and attributes, and they include the following:

  • Improves plant vigour, health and development
  • Enables precise environment control of temperature and humidity
  • Great for closed-loop systems, especially those with split air conditioners
  • Quest 155 performs at 7.3 pints per kilowatt-hour.
  • Superb air filtration operation (MERV-11 standard)
  • Quiet in use with excellent high static pressure performance
  • Designed to be located over the growing area plant canopy
  • Plug-and-play functionality and all powered from a standard 3-pin mains socket.
  • It provides usable water with very low mineral content, which is ideal for your reservoir.
  • It increases the quality and weight of yields.
  • Robust and durable and made from premium quality materials
  • Tested for the most extreme situation: used in military applications and industries.

How Does it Work?

The Quest 155  is a military-grade unit that assists in maintaining an optimal growing environment for your plants, accelerating growth and eliminating such issues as mildew and rot.

High humidity, unfortunately, can ruin entire crops by slowing down plant growth rates and encouraging mould, rot and mildew. This product solves this problem by sucking large volumes of water from the ambient air very effectively and efficiently, and it can go wherever it’s needed most.

It’s built to high specifications making it very popular in several industries and government departments. These dehumidifiers work in military installations, including naval destroyers.

Ensuring your environmental metrics remain within optimal ranges is critical to successful growth. Relative humidity (RH) is vital when determining the growth rates of plants. When these humidity levels fall too low, the transpiration rate increases, causing your plants to shed too much water.

Similarly, plant growth rates slow down quite dramatically when the relative humidity levels climb too high. Several moisture-related problems, such as botrytis (rot) and powdery mildew, can arise.

As plants develop into the later stages of their lifecycle, they can expel a lot of water vapour into the surrounding air. If the humidity levels within the growing room or tent remain too high, you will certainly need extra help.

A dehumidifier unit should be capable of removing enough water, equivalent to three-quarters of the water you give your plants daily. So if you give your plants 100 litres daily, you’ll need to ensure that the dehumidifier you choose can remove at least 75 litres.

How to Use?

The Quest 155 works using several different options, and some scenarios for installation are as follows:


Suspend the product out of the way to give you more growing space with the overhead installation option; this is how you’ll see them working in many hydroponic setups. With the dehumidifier out of the way up near the ceiling, you’ll be free to use the extra space for more growing capacity and plants. Install the overhead dehumidifier with additional hanging brackets and secure these with chains.


You can add additional ducting to the existing dual exhaust vents with the supply or return duct kit (available separately) to add good air to several different rooms.


Growers can decide to locate the product on the floor of the growing room. This option will allow users better access to the units’ control panel and integral humidistat for use on a day-by-day basis.

What are the optimum conditions for temperature and humidity?

In sealed environments (such as growing rooms with no extraction and dosed with CO2), temperature and humidity levels should remain close to the following guidelines:

  1. During the lights-on period in vegetative growth and early flowering, maintain around 28°C and 75% RH at the plant canopy.
  2. During the lights-off period in vegetative growth and early flowering, maintain around 22°C and 65% RH at the plant canopy.
  3. During lights-on in full flower, maintain around 26°C and 65% RH at the plant canopy.
  4. During lights-off in full flower, maintain around 20°C and 55% RH at the plant canopy.
  5. During the last two weeks of the bloom phase, you should seek to maintain a low temperature and RH during both day and night to encourage a healthy finish and avoid botrytis; keeping around 22°C and 50% RH would be ideal.

This product pairs up very nicely with the GAS Enviro Controller V2.


  • Terminal block with 24-V wiring for external control options
  • Dehumidification: 71 Litres/Day at 26.7°C and 60% RH
  • Power: 3.5A
  • Efficiency: 3.7 Litres per kWh
  • Dimensions: 510mm x 550mm x 970mm
  • Weight: 61 KG

Where Do I Buy The Quest 155 Overhead Dehumidifier?

You can easily buy the Quest 155 Overhead Dehumidifier from our online store.

Browse Caliponics

No products in the basket.