Dedicated grow room advice

So we are going to build a garage/shop and I am going to add a dedicated grow room with a concrete floor with a drain. I plan on putting in a room about 10’x10’. It will have a mini split for environmental control. I am going to put these pvc wall panels and ceiling that should be easy to clean. Should I have an exhaust system of some sort? Or is there anything else I should add or do?

IME you want an exhaust fan as you won' t need the AC all the time and just fan is an energy saver.
Circulation fans also.
My AC is also a heater that is needed in winter during lights out.

steamroller said:

IME you want an exhaust fan as you won' t need the AC all the time and just fan is an energy saver.
Circulation fans also.
My AC is also a heater that is needed in winter during lights out.

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How do you have an exhaust fan set up? Is it on a timer or a temperature controller?

Mine is on temp control.
I use AC infinity.
I also use a humidifier during veg.

Garbage_bear said:

So we are going to build a garage/shop and I am going to add a dedicated grow room with a concrete floor with a drain. I plan on putting in a room about 10’x10’. It will have a mini split for environmental control. I am going to put these pvc wall panels and ceiling that should be easy to clean. Should I have an exhaust system of some sort? Or is there anything else I should add or do?

Click to expand...

Fresh air in and transpired air out so yes both intake and exhaust unless you gas with CO2.

Ideally, a complete air exchange in 5 minutes or less.

Air comes in from outside, is conditioned by the AC and or dehumidifier and blown over the plants with air mover fans, then exits thru the exhaust.
Arrange air movers across from each other and in a crossfire pattern to prevent bud rot later and for good air mixing.

There's a lot of calculators online to figure out what you need.
Here's one that you enter the size of the space and it will calculate what you need in CFM power to make it happen then you shop for fans that meet those standards.


This one adds in more variables to calculate and is probably the most advanced



Variables such as the heat from lights and ambient conditions from the intake as well as the cooling and humidity created by the plants themselves all factor into the control.
Another factor is that for every 90 degree turn in duct, you lose 50% of the CFM so if there's turns in your duct run you need a bigger than usual fan.

I usually focus on the most destructive variable and control it first.
For most of the grow my exhaust speed and run time on is controlled by a thermostat since heat is my biggest problem.
When plants are in flower I change the control to RH and around midway thru flower to prevent bud rot I take it off all control and run exhaust max speed 24/7 until harvest.

I have my exhaust fan plugged into an temp inkbird ,exhausts my room every minute.i use heat to control my room.,if the exhaust doesn’t come on for a couple minutes my rh gets high so that’s why I have a finned heater in there.get the temps up before the rh does..that calculator that bandit put up will help you choose the right cfm to exhaust your room every minute.I’d say you will b looking at an 10’ exhaust fan or bigger..for my room I went over size so I don’t have to have my fan up flat out..quieter too if you need to keep noise down..the exhaust filter you choose needs to b 50 cfm more than your fan so it doesn’t struggle sucking air through the filter..usually you put your passive vents on the opposite side or where your exhaust is..