Passive ventilation without light

Saint.Louis · Sep 29, 2021

My tent has the square vents with the screen, and the foldable velcro patch, that seems to be the norm with a lot of tents I've seen. I am using that as passive ventilation, but light leaks out more than I thought it would.

I ordered 2x 8" ducting and plan on using 2 of the vent holes on the bottom and run them out of that in an S shape, and then got a 8" ventilated cap that has a screen in it to put on the ends for dust/bugs.

I'm hoping enough air is pulled through, but I'm wondering what others have done to fix this problem?

Three Berries · Sep 29, 2021

Is the temp too high when the lights are off? Or is it the humidity?

On my small tent 3xx3x5 I found with the exhaust pointed straight up there was enough natural convective flow to drop my temp to room temp quite quickly. I put a flap in it and also have it horizontal now. This stopped the unwanted cooling. It's only a 4" intake and exhaust. I put a 90 on the intake too and painted the insides of it flat black. Stopped the light leaking. the exhaust is on a temp controller, it runs most of the time the lights are on. 14 hours out of 20 yesterday with mid 70fs for room temp, 85f for set point in tent.

Rurumo · Sep 29, 2021

Saint.Louis said:
My tent has the square vents with the screen, and the foldable velcro patch, that seems to be the norm with a lot of tents I've seen. I am using that as passive ventilation, but light leaks out more than I thought it would.

I ordered 2x 8" ducting and plan on using 2 of the vent holes on the bottom and run them out of that in an S shape, and then got a 8" ventilated cap that has a screen in it to put on the ends for dust/bugs.

I'm hoping enough air is pulled through, but I'm wondering what others have done to fix this problem?

I've done something similar. I have a 4x4 tent with three of the square screened vents on the bottom and two 8" duct holes. I buy "cut to fit" carbon furnace filter and tape that over the 3 vents AND I set a piece of cardboard at an angle over them, so air can freely enter but no direct light hits the carbon-tent remains pitch black inside during the daytime. Then I run about 4 ft of 8" ducting from the bottom/side duct holes right up along the sides of the tent-there is a single 90 deg turn-no need for an S shape. I put some panty hose on the ends of those to keep out dog hair. I use an 8" ac infinity fan on its second lowest setting-it's an incredible amount of air and I still get some sucking in of the tent walls, but not bad. If you get bad suction, you can attach some strips of wood halfway up the tent-PJ Diaz here gave me the idea. I think they are like 1" by 2" (by 4 ft) and you just cut them to fit perfectly between the poles, and I attached mine by drilling a hole near the end and running a zip tie through and around the pole. You might not need to do this. Also, just be aware, if you get a lot of sucking in, the filters ends you bought for your 8" ducting might be too thick, so you could always swap them out for pantyhose if you really need to. Good luck!

Saint.Louis · Sep 29, 2021

Rurumo said:
I've done something similar. I have a 4x4 tent with three of the square screened vents on the bottom and two 8" duct holes. I buy "cut to fit" carbon furnace filter and tape that over the 3 vents AND I set a piece of cardboard at an angle over them, so air can freely enter but no direct light hits the carbon-tent remains pitch black inside during the daytime. Then I run about 4 ft of 8" ducting from the bottom/side duct holes right up along the sides of the tent-there is a single 90 deg turn-no need for an S shape. I put some panty hose on the ends of those to keep out dog hair. I use an 8" ac infinity fan on its second lowest setting-it's an incredible amount of air and I still get some sucking in of the tent walls, but not bad. If you get bad suction, you can attach some strips of wood halfway up the tent-PJ Diaz here gave me the idea. I think they are like 1" by 2" (by 4 ft) and you just cut them to fit perfectly between the poles, and I attached mine by drilling a hole near the end and running a zip tie through and around the pole. You might not need to do this. Also, just be aware, if you get a lot of sucking in, the filters ends you bought for your 8" ducting might be too thick, so you could always swap them out for pantyhose if you really need to. Good luck!

So you're using all 3 vents and also two 8" duct holes all for intake, and that's not too much? I had assumed just 1 vent would have been enough for me, so since I was switching to the ducting then I thought I'd use 2 to compensate and have all the vents closed up still. I'm using a 3x3x6 tent with 6" inline and carbon filter.

Rurumo · Sep 29, 2021

Saint.Louis said:
So you're using all 3 vents and also two 8" duct holes all for intake, and that's not too much? I had assumed just 1 vent would have been enough for me, so since I was switching to the ducting then I thought I'd use 2 to compensate and have all the vents closed up still. I'm using a 3x3x6 tent with 6" inline and carbon filter.

It's all because I'm using an 8" exhaust fan, I just like to go with a bigger fan and run it on a lower setting. You'll be good with a 6" fan in that tent, but you'll still see what I mean when you crank it up. Good ventilation is essential.

xtsho · Sep 29, 2021

I have passive intake but I've never used the square side vents on my tent. I use two 4" and one 6" round vents at the bottom of the tent. I just use a piece of round ducting covered with some filter material I cut to fit. One side is green and the other is black.

This is what I've been using for my intake vents for years. No light gets through and the filter keeps dust, lint, dog hair, and other nasty stuff out of the tent and off the buds. The filter side goes on the outside of the tent. I use a 400 CFM fan turned halfway down and have a slight negative pressure but enough airflow for plenty of air exchange in a 4x4 tent.

LeastExpectedGrower · Sep 29, 2021

xtsho said:
I have passive intake but I've never used the square side vents on my tent. I use two 4" and one 6" round vents at the bottom of the tent. I just use a piece of round ducting covered with some filter material I cut to fit. One side is green and the other is black.

This is what I've been using for my intake vents for years. No light gets through and the filter keeps dust, lint, dog hair, and other nasty stuff out of the tent and off the buds. The filter side goes on the outside of the tent. I use a 400 CFM fan turned halfway down and have a slight negative pressure but enough airflow for plenty of air exchange in a 4x4 tent.

How is this filter material sold (like, what format/brand, etc). I have a 6" duct that's an intake (with AC Infinity S6) and I'd love to have a filter on the duct end...for both the filtration but also to buffer the air flow a bit.

Passive ventilation without light

Saint.Louis

Active Member

Three Berries

Well-Known Member

Rurumo

Well-Known Member

Saint.Louis

Active Member

Rurumo

Well-Known Member

xtsho

Well-Known Member

LeastExpectedGrower

Well-Known Member

Similar threads