How do cut passive vents and fan holes without light leak.

Can anyone explain how to do this. I thought the room had to be 100% light leak proof, how is that possible with fan holes and passive vents?

i use 90 degree elbows placed back to back like the letter S and paint them flat black on the inside.

yeah, 90 degree elbows seems to be the best bet if you have the space and materials.

personally i had niether, i i grabbed 2 of those standard white palstic wall vents, with the diagonal vent slits, and put on in the cab, one outside, with the vents making an upside down V shape if you get me, only a fraction of light get's out and nothing get's in

tip top toker said:

yeah, 90 degree elbows seems to be the best bet if you have the space and materials.

personally i had niether, i i grabbed 2 of those standard white palstic wall vents, with the diagonal vent slits, and put on in the cab, one outside, with the vents making an upside down V shape if you get me, only a fraction of light get's out and nothing get's in

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Thanks guys, ill probably do the 90 degree elbow deal, cause I have the room. My grow area is like is probably a good 20 square feet by 4 ft tall, you think passive intake will work or should I use a fan?

Im going to run a 6 inch duct fan from my HPS if i get it this round of growing, an 8inch duct fan to vent the growing chamber and maybe just a cheap 110 cfm 120mm fan for an intake?

well people seem to say differently here, everything contradicts, but from experience elsewhere, not in the weed side of things, if you pull air out, then air will find a way in. depending on the size of your vents and such, you might get a litttle pressure loss in there, but nothing catastrophic unless you've got a 1K/cfm fan and drill holes for vents

i use a stanley blower with a 6" exhaust and an 8" passive intake. no intake fan. works like a charm. it vents a room that is about 200 cu. ft.

i ran into the same problem helping my buddy. we ended up putting a peice of charcoal padding (same as for a filter) in the end of a pvc elbow. worked like a charm

Mattplusness said:

i ran into the same problem helping my buddy. we ended up putting a peice of charcoal padding (same as for a filter) in the end of a pvc elbow. worked like a charm

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Question anyone have a good tutorial for makin a charcol canister so i dont have to pay 70 bucks for one?

less light than the moon would produce should be fine, if you have the ways and the funds to 100% it up though, go for it

How loud are those stanley blowers?

Iron Lion Zion said:

How loud are those stanley blowers?

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its quieter than i thought it would be. it has 3 speeds and i guess on high its not as loud as say a good bathroom exhaust fan.

WALL-CAP or wall flange you can get this at hardware stores if the hole is a common size
or at central-vacum manifacturers even ventilation companies probably like a 5-10$ piece

My growbox consist of panda film wrapped around a 4x4 frame. I have it placed in the corner of a bedroom. I just cut my holes on the 2 wall sides of the box so that any escaping light hits the wall instead of shining into the room. Works fine for me with no light traps of any kind.

I tried the 90 degree elbows but took room from my grow cab so I ended up getting shower drain caps instead and stuffed them with foam filters to prevent light leaks. You can see on the picture below that no light leaks out when the lights are on.

smoke and coke said:

its quieter than i thought it would be. it has 3 speeds and i guess on high its not as loud as say a good bathroom exhaust fan.

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hey smoke,

do you use the stanley blower for exhaust? if so do you think i can set it up so that it exhausts air out of my room threw a carbon filter and out through ducting?

trufaiz said:

hey smoke,

do you use the stanley blower for exhaust? if so do you think i can set it up so that it exhausts air out of my room threw a carbon filter and out through ducting?

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yes i dont see why not, other than will the blower handle it? i do not use a filter. i have been running this blower since early april. connected to a thermostat and timer both connected in parallel so that the fan would come on with the timer and or it got to warm in the room and the t-stat would makle it run. so for april and may and half of june the fan didnt run continous. crappy summer.
mid june warmed up and i connected the blower to 2- 400 watt cooltubes. since mid june the fan runs on high 24 hours a day and lights on 12 hours.

the blower sucks from the room and the passive intake lets air in.

intake side of blower
so i have the 2 lights- 4" flexible duct from both- to a 4" Y fitting- to a 6" to 4" reducer fitting(shown below)- to 6" insulated flexible ducting- to a 90 degree fitting- to a fitting that is connected to the side of the blower.(no pic i will get a pic of the fitting next trip to home depot.)

exhaust
out of the blower was a 6" duct boot( its a long rectangle end that will fit to the blower with some cutting and bending and tape) on the other side of the boot is is a 6" round fitting.-connected to 6" insulated flexible ducting-to back to back 90's and blows right outside.

passive intake
is an 8" duct boot. rectangle end is outside and has an 8" round on other end.- to some 8"insulated flexible ducting- couple of 90 degree elbows in there for light blocking.

my first cooltube. i need to modify them this winter and make a tutorial.


6" to 4" reducer. with holes drilled in so it can still suck from the ceiling and cooltubes. and the extra holes helps to the blower isnt trying to suck thru a 4" hole. i put extra holes so i can tape some and adjust.

good thinking that drain cap will do just fine i think