How To Avoid HVAC Light Leaks

[Basic]

Newbie question here. How is it that light doesn't leak through the HVAC systems for grow set ups?

[ellz]

Hi Basic and welcome. What do you mean by HVAC systems? Do you mean the ducting?

[Basic]

Yes, I'm wondering how you avoid light coming through the ducting.

[Tersky]

Well i've never had a hvac system attached to my tent, but if you are just wondering how to stop light leaks, i use a cut to fit carbon filter to put over the tent vents. It helps filter air and blocks light, but you need a good exhaust fan or not enough air will get circulated. If you are not careful, light will leak into the tent. Dont know what you mean by HVAC light leaks if this doesnt answer your question.

[Basic]

Thanks for your response. If you have a passive intake, do you put a carbon filter on that as well?

[Tersky]

I only use passive intake and the filters i cut to cover the tent vents. This is what i used https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1 and used velcro strips to hold them on.

[ellz]

My advice for that would be to make sure not to have any long straight runs in your ducting. In other words, try to include some bends. Maybe use hangers or something to create 90º bends in the ducting. This should block light from entering because every corner drops the light down dramatically. It will cut down some of the CFM ability but it's negligible. Also, try to use some sort of black carbon-type filter in your intake to block any light coming in there OR shield the intake area from light by covering it on three sides with something thick. As long as you can draw air from the bottom, you should be okay. One way you can test your grow room for light leaks is to place a camera on a timer (I use a 10 second timer), turn off the flash and leave the camera in the room and close the door. Then check out the picture and see if you have any light spots. If not, you should be good to go!

[golfnrl]

I've had the same question. The answer is you may not be able to eliminate every bit of light leaking in through your intake ducting. But, from what I've learned on here the spectrum of the light that comes in that way isn't enough to trigger a response from the plant.