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Growth Rooms

Building advanced growth rooms to maximize the quality of your yield.

CANTROL has a track record of designing and building grow rooms for a range of applications, with precise temperature, humidity, pressure and CO2 control. We can design your grow room for plant/botany studies, horticulture and natural herb science.

Features of Growth Rooms

Cantrol understands what your plants require to grow best and it’s walk-in growth chambers are designed to optimize the following environmental conditions:

  • Relative Humidity – The amount of water vapor in the grow room air
  • Atmospheric Temperature – How warm or cool the air in the room is
  • PPFD – The intensity of your grow lights reaching the canopy
  • Air Circulation – The movement of air throughout the grow room and plants
  • CO2 Concentration – The total amount of CO2 gas in your grow room’s air, represented as Parts Per Million

You’ll have different ideal levels depending on the point in the plant’s life cycle. For instance, clones and seedlings need much higher Relative Humidity than fully mature plants ready for harvest.

Grow Room Humidity Control

The ideal humidity is relative to temperature. The higher the temperature the higher the relative humidity your plants are going to need to perform well. But there are a lot of factors that can affect humidity. Open reservoirs, spilled water, leaking faucets, leaking air conditioners and even the plants themselves!

Healthy plants perform a process called transpiration, in which water evaporates from their stomata (similar to how we sweat). This creates water vapor and raises the overall relative humidity in the room. 

If humidity levels creep too high, a slew of issues become increasingly likely. Terrible diseases like black mold, powdery mildew, pythium, pests, and slow growth will quickly take hold of your weakened garden. Like I mentioned above, the ideal humidity is based on plant cycle and temperature. And that’s best shown in a chart called the Vapor Pressure Deficit chart.

Grow Room Temperature Control

Similar to humidity, temperature is essential for plant metabolism. Too low, and they don’t grow. Too high, and they dry out too quickly. Many things can affect temperature, the intensity of the heat your lights emit to the strength of your air conditioner to the construction of your grow room, all affect grow room temperatures. 

Grow Room Light Intensity

As I mentioned above, PPFD is a measurement of the intensity of the light reaching the canopy. If this is too high, the chlorophyll in the leaves will be destroyed. And that’s very very bad. Of course, if it’s too low for the plant, the plants won’t grow very well, or at all.

Often times, growers want to give their plants as much light as possible because more light is better, right?! Not so fast. Here the law of diminishing returns reduces the effectiveness of additional light after a certain threshold. That number will be different for each plant, but the reason I’m bringing this up is because we’re talking about grow room control here. 

Sometimes the added heat from the light is causing more damage to the plant’s ability to grow instead of  helping! In these cases dimming the lights, or turning off alternating lights, can get you great results and a lower energy bill.

Vapor Pressure Deficit Charts

A good vapor pressure deficit charts (VPD Chart) will tell you ranges of ideal temperature and humidity levels. Often this depends on exactly what stage your crops are in.

Using one of these charts is the simplest way to get a good baseline to work from when trying to optimize your grow environment to your plants.

There are different charts available depending on whether or not leaf temperature is being adjusted for. You can use these charts to adjust either your grow room’s temperature or humidity, or both, to get it into the ideal range.

Grow Room Dehumidifiers

Due to the nature of how plants grow, dehumidification is often a requirement in any grow room or green house. Using powerful fans to exchange the air with outside air can work, but that often creates a conflict with temperature and CO2 control.

Properly sized dehumidifiers are useful for maintaining desired humidity levels in your indoor grow room. They do use a good amount of energy, they are similar to air conditioners.

There are types that have built in controls, so you can set your desired humidity level, and it will automatically turn on and off. While others need to be plugged into an external control system.

Grow Room Temperature Control

Each 1000 watt light (uncooled ballast and bulb) will produce between 3,000 and 4,000 BTU of heat. That means you’ll need an air conditioner capable of cooling your lights.

Similarly to dehumidifiers, there are several options available to control the AC. Make sure you get the best unit you can afford. Don’t go cheap here. An unreliable, or improperly sized AC will cause you to loose money due to poor crops and small yields.

Grow Room Environmental Controllers

The minimum tools you need to take measurements is a digital thermometer and a hygrometer, and make sure you get a reliable model with min and max readings. 

The best thing you can get is a grow room controller, like the Maxi Controller with Datalogger, that will not only control your grow room’s temperature and humidity, but it will log the measurements onto a USB thumb drive that you can look at later on your computer.

It even has a plant temperature camera, produces (and logs) VPD measurements, and it controls your DimLux lights.When your grow room or plants get too warm, the Maxi Controller can automatically dim the lights, or turn on a special feature called Half Force. It’s a great safety feature. Any experienced grower will tell you, air conditioners and dehumidifiers can break. And that can be deadly.

Air Circulation

Good air circulation can help minimize micro-climates throughout your grow room,  and evenly spread out grow room atmosphere. This will also make mold and mildew issues less likely. And it can strengthen your plants in the process! 

It may sound too good to be true, but a few wall mounted oscillating fans, strategically placed, can help tremendously. Obviously, too much ventilation will damage the plants. Think of a gentle breeze.

Prune Your Plants for Air Flow

Continuing on the topic of grow room air circulation. Overlapping and bunched up leaves can cause what’s known as micro-environments to occur in sections of your crop, beneath the canopy. 

Even if you think the room has an ideal environment, if the leaves and branches are blocking air flow, those areas could be soaking wet at 90% humidity. And the chances of mold and mildew in those sections increases dramatically.

Proper pruning can prevent this problem from occurring by keeping plants from getting too branchy and preventing leaves that overlap substantially. 

Grow Room Light Intensity

We all start by planning out the light pattern in a grow room, then, why did I wait so long to talk about it. Remember, we’re talking about the entire environment of your grow room, and most lights today are dimmable. That dimming feature is really important to make sure your plants grow their best. Most of you know, smaller plants need less intense light than full grown plants.

When the grow room temperatures get out of hand, the lights are often an easy place to go. Dimming them only a little can have huge effect on the temperature on a hot day.

Light intensity, or PPFD, is an important thing to consider when arranging your pattern of lights in your grow room. Use the chart above to get a rough idea of the sizes we recommend for different spaces. Or just get the DimLux Light Calculator to create a detailed sheet automatically. 

Grow Room CO2 Levels

Finally, you need to consider the CO2 levels of your grow space, because healthy plants use a lot of  COin the grow room. 

Now this isn’t as effective if you’re constantly exchanging all the air in your grow room, but it works great if you haven an air conditioner and dehumidifier capable of controlling the grow room environment.

Generally, a level of 1000 to 1200 PPM is good enough, any more and the law of diminishing returns takes over.

Working With Can-Trol Environmental

Dedicated to exceptional design, manufacture, installation, commission and service of specialized environmental chambers.

Since 1989, we have worked alongside clients throughout North America in the design, manufacture, installation, commission and service of specialized environmental chambers. This experience has taught us the incredible importance of effective, reliable and stable incubators and controlled environmental rooms.

Organizations of all shapes and sizes in the healthcare, institutional, pharmaceutical, industrial, food sciences and research fields trust us for incubators, stability chambers, environmental chambers, cold rooms and more. Please contact a dedicated member of our team for more information. We’re looking forward to hearing from you.

30+ Years of Excellence

Industry leaders who understand the requirements of your project, with robust and reliable delivery processes.

Licensed & Insured

Certified in ISO 9000, CSA and Electrical Safety. We strive to stay ahead of the industry’s standards and regulations.

Timely Completions

Every project has a team of in-house engineers and validation managers who ensure a timely and flawless completion.

5-Star Service Record

Organizations around North America trust us to deliver solutions from our own commercial manufacturing facility.

Client Reviews


Glen P. Kenny (PhD)

Full Professor and University Research Chair (Environmental Medicine) Director, Human and Environmental Physiology Research Unit University of Ottawa

It is my pleasure to provide a letter of reference for Can-Trol Environmental Systems. Can-Trol Environmental Systems has fabricated and installed a number of environmental chambers for my research unit over the past 25 years. More recently they installed a state-of-the-art chamber that houses the world’s only fast response air calorimeter – a system for making very rapid and precise measurements of the heat emitted by the human body. The service we receive by Can-Trol Environmental Systems is outstanding. They provide dependable and rapid service when repairs are required. This is especially important for my research unit given the high volume of research activities undertaking in my research unit.

Many international scientists visit my laboratory and or inquire about my systems. Without hesitation, I have always recommended to my colleagues Can-Trol Environmental Systems to construct and install a chamber that meets for their specific scientific needs.


Murray M. Humphries

Associate Professor & NSERC Northern Research Chair Department of Natural Resource Sciences Macdonald Campus, McGill University

Can-Trol Environmental recently designed and installed a walk-in environmental room for use as an animal holding facility in a McGill research center. I am pleased to report that I found Can-Trol to be very competent, capable and helpful at all stages of the project, from initial design through to installation and service.

As a biological researcher, I knew what I needed the room to do, but nothing about the mechanics and construction required. Can-Trol staff were patient, flexible and innovative through the process, and, in the end, created the room I needed. I am pleased to recommend Can-Trol Environmental for similar projects.

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