passive intake?

[sweetestsin420]

1.

2.

Which one of these,if any,can i use to allow airflow during lights on,pretty much a passive intake lol.Which one of these wont let light in once its dark time?I was hoping one of these will work..

but if not,ill just use a small run of ducting,and curve it a few times..but its bulky,so can i use any of these things?the damper closes itself when theres no air movement,and the "duct elbow" is a 90 angle..thanks guys so much for we help peace!


oh and will these also work for grow tents?

 

[SeaMaiden]

We just used some ductwork that's turned, but then for that application the basement I use is pretty dark anyway. If you're very concerned about light entering during lights off, you can install a darkroom vent (or whatever it's called). I personally do not like the idea of no air movement.

 

[sweetestsin420]

yeah iv looked at the darkroom louvre theyr called lol,but they are very expensive,and iv heard they limit airflow..plus i plan on closing off the closet with b&w film.,so ill just cut a hole and install either plumbing,or one of those^^^if they work

ill prolly use some ducting,but id like a more stealthy way,so will the elbow work?ill spray paint it black on the inside,and use it upside down

thanks seamaiden!

 

[SeaMaiden]

Couple of turns should do the trick for keeping light leaks to a minimum.

 

[DrFever]

number 1 will work good fresh air in room low and hot air out high

Note ** if your bringing in fresh air from outside into room your going to have lots of condensation forming around your fresh air in which has happened to me causing lots of water on floor cold air coming into warm air = condensation
so what i did was made a vented box with heater inside set thermostat to 60 so rather then have - 20 air coming into a hot room direct it was warmed up
the condensation problem solved

 

[sweetestsin420]

dr.fever,im just thinking abouit pulling in air from inside my room,into the closet,and exhausting into the attic.so will number1 prevent light leaks?

also im looking into passive intake for tents,would number1 work for that as well?im going to pull in air low,so the plants can get fresh air,and have my exhaust up,cus warm air rises sounds good?thank you

 

[Big Sky]

i dont believe in using any passive intakes myself-
Theres a misconception about the way MJ breaths at night vs day a lot of the time thats usually overlooked-
They like o2 at night not co2-
they do a switch-
so having an air intake on 24/7 really does wonders to your overall plant health because of the delivery of fresh air both day and night-
This delivery makes the transition much easier on the plants adding to overall heath and growth rate-

That being said-
just buy a 4" inline fan for about 50$ turn it on, and be done with it- no light escapes- air is exchanged very well 24 hours a day- This will make climate control easier in the overall grow to-

 

[sweetestsin420]

^^good advise..but still i prefer passive intake,i find it more easy,simpler,less things running so its cheaper on the elec bill..idk,i dont wanna buy an elbow,then find it doesnt even block light lol,ill have a 6in exhaust through a filter,with passive.the only question is WHAT method do i use for the intake lol thanks anyways

and yeah what i can do it run a few 5 minute exhaust at night,to remove stale air.

 

[Big Sky]

i think my 4" inline burns 65w...
lol
about half of a incandescent light bulb in power use-
Also..if you ever want to upgrade lighting etc in the future-
You will be biting the active intake bullet anyway-
been doing this a looooong time my man-
i learned to go big or go home real quick- especially with your setups and equipment-
buy cheap stuff, have problems only to replace it later and end up spending double the money in the long run-
Skimp out on ventilation only to be forced in the future to upgrade anyway-
its a never ending circle lol-
Take my advice -
lol
just kidding man you do what you want its your grow and i wish you the best grow ever! but passive intakes dont work very well imho-
only when you have a big inline exhaust that of a large CFM rating- once you pop that filter on, you loose about 1/2 your cfm's-
instantly-
then your looking at loss of pressure due to your elbows etc on your intake- waste + more waste-
50$ bucks-
seems pretty cheap imho to do it right the first time ya?
and remember!
all things seem like a good idea when your high lol

 

[DrFever]

think of it this way a box with 4 holes same size one side is passive other side has exhaust you turn it on as much as it exhausts will be same amount of whats coming in
i run passive only using exhaust end to actually vent room it works like a charm as for light leaks aslong as you make the holes right size you can duct tape and squeeze fit it in for my room i got the white film made my holes put in the 90 degree vent outlet and there is no light leak period

 

[Granger2]

Neither item pictured will stop the passage of light-at all. Three 90 degree turns will usually do the trick. Also, it you spray paint the inside of the duct or the inside of 3 90's linked together flat black, it will really help.

If you want to stop light passage with a fan, it must be a centrifugal fan. The term "inline fan' can mean different things to different people. Good luck. -granger

 

[noyd666]

hi,bit lol hard sitting in a cupbourd checking for light leaks, i still remember sitting in grow room, lights go out, ya shes' right, couple min later, you can see lil or big light leaks,must be done though to find leaks, ya both of those items wont do, ive' got both, you could put ducting on with more bends,90deg, even that silver ducting leaks, pin pricks of light a certain distance, can wrap a bit of panda around and tape. iv' allmost forgot lol what you asked.as he said flat black inside pipe helps.

 

[TribalSeeds]

In theory light cant bend 90 degree, but that thing is reflective. They also need to be sealed at the bends.
You could cap the elbow with the damper, but you still need to light proof your ducts.
Seamaiden answered your question in the first reply. You will need a couple of bends in the duct to stop the light from getting through.
You can also build a simple box with stagered sides inside the box

 

[sweetestsin420]

think of it this way a box with 4 holes same size one side is passive other side has exhaust you turn it on as much as it exhausts will be same amount of whats coming in
i run passive only using exhaust end to actually vent room it works like a charm as for light leaks aslong as you make the holes right size you can duct tape and squeeze fit it in for my room i got the white film made my holes put in the 90 degree vent outlet and there is no light leak period

so you use just the elbow bend attachment?as in option 1?..thats it?just stick into pandafilm and go?

 

[DrFever]

so you use just the elbow bend attachment?as in option 1?..thats it?just stick into pandafilm and go?

here is a picture well sorta lol i got my elbow 90 degree bend on top and facing down i go get dryer aluminum ducting then duct tape it together then stretch out my dryer duct your done
I also duct tape a few times around the other opening of your elbow and jam it in the wall opening problem solved air coming in no light period then run it down wall to floor bend it T it and get fresh air going in all of room at floor level

 

[noyd666]

no.2. is for use in ductting with fan use, fan on ,it opens, fan shut it closes. if its not right you should see glow of light. if you use the elbo and see aglow of light, i reckon you will, add short length of duct..

 

[CFP65]

light proofing a tent?
forget it man, no matter what you do there will be light leaks. only solution is to keep the tent in a dark room while the lamps are off. that is you cannot use the room for 12 hours a day.
i simply skipped the use of tents after living in a two room apartment with one room to no use for 12 hours aday. and bulit me a cabinet in wood.
for that i use double walls and these are functioning as both ligthtraps and sound proofing at the same time.
its quite simple but weighs a ton to construct.
on the outside its 12mm wood and on the inside its 22mm woodboard with 45mm in between where i have made rockwool labyrints to care for the sound and the light.
just above the pots in the tent its just a simple 50mm slot in each of the tree sides.
se if i can make a decent drawing of it just have to find a program that i can handle

 

[noyd666]

light proofing a tent?
forget it man, no matter what you do there will be light leaks. only solution is to keep the tent in a dark room while the lamps are off. that is you cannot use the room for 12 hours a day.
i simply skipped the use of tents after living in a two room apartment with one room to no use for 12 hours aday. and bulit me a cabinet in wood.
for that i use double walls and these are functioning as both ligthtraps and sound proofing at the same time.
its quite simple but weighs a ton to construct.
on the outside its 12mm wood and on the inside its 22mm woodboard with 45mm in between where i have made rockwool labyrints to care for the sound and the light.
just above the pots in the tent its just a simple 50mm slot in each of the tree sides.
se if i can make a decent drawing of it just have to find a program that i can handle

lol ya, i laughed,light all up through the stiching. anyway she said it is a closet. not tent.

 

[sweetestsin420]

yeah sucks about the tent and supposedly "pin pricks" of lights lol,either way ill have to use atleast one,if not two,and the closet yeah lol,i think the elbow,and maybe a small lenght of duct will be enough for the passive intake,forget the second option lol,
about the tent,i will only have my laptop on,maybe the tv,but no bright lights,

 

[noyd666]

hi, s 420 thousands of people have succesful grows in tents' , panda film 250 is tops for light proofing, keep at it. mine was in sep room, so was ok, really prefer to build my own out of panda. turn light off ,bamm, see light through stitching all over lol,buttt'