intake or exhaust?

[jdmnismo300]

hey guys im slowly but surely DOIN WORK to get this grow of mine going but Im at a bit of a roadblock and wanted to know what you guys think. My grow will consist of 1 400w hps in a closet measuring 3.5ft L x 2ft W x 9ft H. Iv cycled the lights on for a day and my room temperature is around 93˚F to 95˚F with just a standard squirrel cage fan to simulate wind. Obviously this is not the adequate temperature for growing my ladies in. Ive gone creeping around in my attic and have been measuring all day and ive come up with a couple ideas that i just wanted to hear your opinions on

1st. install a inline duct fan drawing air into my grow through a vent in another room. i thought about just rerouting an existing a/c vent to the grow but my a/c is always being fiddled with so that wont work.

2nd.run a inline duct fan almost directly near my hps to exhaust the hot air into my attic. winters here are a joke so i dont think ide have to worry about mold.

also ive been hearing alot of bad things about those duct fans like the home depot ones is this true? must i go broke trying to afford a vortex? lol

as im writing this im starting to realize im gonna have to most likely do both of these lol but just wanted to hear some alternatives or different opinions

thanks alot guys!

 

[jdmnismo300]

...

 

[NorCalHal]

You will need to set up an exhaust. Use your squirll cage to do it. You can get a fitting for the square end so you can hook up 4"ducting.

Don't just use your fan to blow air around, tou need an exhaust. As far as intake, just a small intake, with no fan attached will work fine.

It is better to have a good Exhaust and a passive intake, rather then just air blowing in.

 

[fellowsped]

I agree with NorCalHal set up a good exhaust system and then worry about intake. If you have to open the door to your closet a couple times a day and just use a regular house fan to blow some fresh air in there. I run 2 vortex fans and i only have my intake on half the time. As long as the room is cool enough i just leave the door open a bit and it keeps a good temperature. Anyways good luck with your grow.

 

[4u2sm0ke]

great answers here...yes exhaust is key I use temp controllers..but when i started i had just vortex at top and 6 inch duct to outside at bottom...it drew fresh air in and i had 9 inch oscalating fan iside room..But we need to exhaust that and bring in fresh air okay? Thanks for posting..KEEP M GREEN

 

[jdmnismo300]

thanks alot guys! i will most likely fit 4inch ducting to the side of my reflector with a inline duct fan exhausting into my attic connected to the same timer as my lights

my room will prob be getting sealed off and will get very minimal fresh air intake. will running ducting from the vent in the other room to my grow without a fan work? or wil i need another duct fan to draw the air in?

here a little pic so you guys get what im doin here

 

[fellowsped]

I would think if you were going to vent it through the light you would want an exhaust end on the other side of that light going somewhere outside the closet. That way you will be able to flow the heat from the light outside the tent.

 

[LegendaryGT]

I would think if you were going to vent it through the light you would want an exhaust end on the other side of that light going somewhere outside the closet. That way you will be able to flow the heat from the light outside the tent.

Did you look at the picture? If I understand right, he is doing exactly what your saying.

You would rather always have negative pressure in your closet so more exhaust than intake!

 

[4u2sm0ke]

i agree with fellosped..you should be pulling cool air threw the light and out of tent,,your diagram shows you trying to pull air right outta light hood..and with the room beeing sealed off and no fresh air..are you planing co2? sorry my friend but feel you are heading for trouble if you dont have intake of fresh air..and the air from the other room has to be cooler then the tent or your wasteing your time..IMO..keep us posted and will love to see some pics wghen you have it running..Hope this helps..KEEP M GREEN

 

[fellowsped]

All you need to do is continue your ventalation pipe in your drawing from the other side of your light right out the grow closet. But i would suggest making sure that it doesn't go into the room the closet is in if you are only planning on cracking the door to get some fresh air in there. But good luck and keep us posted.

 

[jdmnismo300]

you guys obviously didnt get the picture. The exhaust (ducting on the right side of the picture) is drawing the hot air through the side of the reflector and venting off into the attic. the intake (left side of drawing) will draw air from another room usually 77˚ into the grow aimed right at the plants.

so im getting rid of that hot air generated by my light while also sucking in fresh air from my bedroom. im sure itll work just fine

 

[jdmnismo300]

All you need to do is continue your ventalation pipe in your drawing from the other side of your light right out the grow closet. But i would suggest making sure that it doesn't go into the room the closet is in if you are only planning on cracking the door to get some fresh air in there. But good luck and keep us posted.

do yo mean dedicate both exhaust and intake to the light alone?

blowing cool air through the left of the reflector than exhaust on the otherside? seems a like overkill my 400w shouldnt be giving off that much heat

 

[4u2sm0ke]

ok...thanks for shareing with us.KEEP M GREEN

 

[The Hemp Goddess]

you guys obviously didnt get the picture. The exhaust (ducting on the right side of the picture) is drawing the hot air through the side of the reflector and venting off into the attic. the intake (left side of drawing) will draw air from another room usually 77˚ into the grow aimed right at the plants.

so im getting rid of that hot air generated by my light while also sucking in fresh air from my bedroom. im sure itll work just fine

Your plan looks good, however, IMO, you are going to need your incoming air to be substantially lower than 77 F to get any significant cooling to your light and room, which you want to keep below 80.

 

[LegendaryGT]

I knew what you meant.

 

[jdmnismo300]

Your plan looks good, however, IMO, you are going to need your incoming air to be substantially lower than 77 F to get any significant cooling to your light and room, which you want to keep below 80.

i might go with a bigger exhaust system maybe 6inch duct fan (250cfm) that alone should be good to keep my grow at a stable temp. the intake will just bring in fresh air and im sure that will help just enough.