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The Perfect Environment

The perfect environment is having the capability to control temperature, humidity and air quality levels. Something that is extremely difficult when Mother Nature may have a different agenda. Most of these situations are out of our control; crazy weather such as mass rain, wildfires, heatwaves, you name it. That’s why sealed room growing is so important to creating consistent results 365 days a year. Here is a list of things to think about when looking to create your “perfect environment”;

  • Add up the total wattage consumption of your light load, pumps, machinery etc…

  • Divide the number of watts by 3000 and that will tell you how many TONS of cooling would be required to maintain 76-78F on an 80F outdoor day and have at least R12 insulation or better. This will be based on open bulbs with ballasts in the room, burning CO2.

  • Ideally you want to have a decent size room but try to navigate away from super tight rooms or extremely large rooms as large temperature swings could become an issue. With small rooms when a system cycles the temperature can swing extremely fast and in say large ceiling areas you’ll be turning over the volume of the room on a much longer timeline every 5-8mins vs. 1-3 mins which can lead to capacity issues.

  • Airflow management will be very important to consistent and even temperatures throughout your room which is why we recommend some sort of engineered ducting specific to your Indoor Air Handler and space. One solution we provide is a fabric duct which is very slick as it’s engineered to provide even airflow across the entire duct, it’s machine washable, easy to install and permeates 2CFM around the entire duct to stop dirt and debris from collecting on-top the duct and condensation from forming.

  • Dehumidification is always a tricky thing as a byproduct of air conditioning is dehumidification which is fantastic but only works during the “ON” cycle when the lights are on but then reeks havoc in the night cycle when temperatures drop and humidity spikes. The tricky part is when you add dehumidifiers to the space they will add a tremendous amount of heat to the environment which eventually leads to the main A/C units turning on battling each other. It’s a necessity and there’s a few things you can do to eliminate the spikes. Try and drive the temperature down the last hour before lights out to remove the massive spike when the room goes dark, some growers have found a “sunset” to help quite a bit where a portion of the lights turn off, then the rest 30 mins later. Make sure to reuse the condensation collected in your reservoir as you will recapture virtually all of the water you feed. We offer a fantastic system that can switch between A/C and Dehumidification on the fly and is designed to run 24hrs per day and is the largest all-in-one dehumidifier on the market.

  • Air quality is one of the fastest areas of interest as regulations have become much more strict and the overall evolution of growing continues to become more advanced. A few different parts of Air Quality Control are; airborne virus such as molds and mildews which can be cleaned by UV Air Purification, odor control and particle scrubbing, especially the harsh organic matter in your room

Obviously, there are still many other variables to cover within the space as not everyone has unlimited power, unlimited funds and a perfectly sealed room but these general things to consider will help you get a lot closer to creating the “Perfect Environment”.

Brandon Kion
Excel Air Systems


Great post!

This is the same as saying 4 BTU of cooling for every watt of light. This is the rule of thumb. but Fluence recommended 4.3btu/watt and my experience with HVAC contractors is they want to add 10-25% to assure the equipment keeps up.


Jaya, you’re right in the ballpark for sure! That being said, contractors and engineers do tend to go overkill as their neck is on the line, however, this approach is one of the fundamental issues we see with contractors who have little experience in grow room design. The reason I say this is because we’re already padding the BTU for heat produced by people, CO2, lack of insulation etc. as an actual BTU is 3.41 watts per BTU. So if we go with 4 BTU we’re already 17% over if our outdoor temperature is 80-85F max. If we start to move above that we would start to add an additional 20% roughly every 10F higher ambient. One significant issue to oversizing right out the gate is if your system is not designed as close as possible you’ll be reducing your dehumidification potential to a large degree. Systems that are properly sized should run virtually 12 hours a day to minimize wear and tear on the compressor starting and stopping which will also reduce amperage spikes on the grid along with long run times will maximize the amount of moisture you can remove in your room. I hope this gives you a bit more information to make the right choice for your room. Cheers!