Is an inline fan exhausting a 2x2x5 tent, enough to cool a 250w MH/HPS? [+rep4help]

[Sr. Verde]

So heres the deal:

Running a 250w hood inside a grow lab 2x2x5. Ballast outside.

I've got a 171cfm 4" inline fan running ducting & exhausting air away from the tent.

I'm wondering if JUST exhausting the tent through a carbon filter/inline fan setup would be enough to keep the LIGHT and canopy cool.



Right now, I'm pulling air through the hood, and out the tent.. but when I add a carbon filter I won't be able to do this, as the hood isn't air tight.. I'm not totally sure what to do when I get the carbon filter this is my first HID setup


Help is greatly appreciated. I googled my ass off, couldn't find anything about just using an exhaust to cool a tent

 

[BYLROY]

I think you should be OK. I've run a 250w HPS in an even smaller cabinet and just a 100CFM computer fan for exhause and didn't run into any real troubles with heat. My hood was just a regular batwing.

Sounds like you have a glass hood but the seal isn't all the way tight? If that is the case there are a number of ways to seal it (ie caulk, weatherstripping, etc).

 

[Sr. Verde]

But if I seal the hood how do I change bulbs?

Thanks for the info, what temps were you running & how far were you keeping it from the canopy? Any supplimental fans?

 

[legallyflying]

I would seal the hood with foil tape (foul tape is like duct tape for growers). Then put a small fan on the hood (pulling the air through the hood and exhausting the heat) then get a little fan for exhaust/ exchanging the air in the tent

 

[Sr. Verde]

Bump..

anyone else?

 

[420God]

Hey Sr. Verde, sounds like your setup will be similar to mine and it should work out no problem.

I suck air through my 400w and push it through the carbon filter outside of the tent.

I run a 190cfm inline in a 3x3x6.5 tent and it moves plenty of air.

 

[Bonzi Lighthouse]

Really there is not enough info to make the call. If the ambient temp at intake is 85* then no, if it is 70* yes. If you vent back to where your intake is no, if you vent to a separate space yes. You're leaving out the most important part of the equation.

I'm running 346w of CFL in a 2x2x5. With no exhaust it gets to about 90* with a desk fan stuck in the vent, exhausting to the room 82*. Exhaust to the Attic and it drops to 79*, this is with 70* at intake. I have a 400w HPS is a slightly smaller space and it stay at about 84*, with the same 70* at intake. AS THE TEMP GOES UP AT INTAKE THE ROOM TEMP INCREASES EXPONENTIALLY.

 

[GNOME GROWN]

push through the carbon filter ayy?....this might work for u vede! ^^^

that way u dont even have to seal ur hood and when the air blows out it passes through the filter to clean the air i never really thought of pushing air through the carbon filter since its made to suck air in... hows this work out for u 420god?

u can either do that or do what i did..buy a 4inch T or Y connector at ur local HVAC hardware store or home depot has them.. now this is real simple i'll break it down for u..

u can seal ur hood by tapein the outside of the hood like the post above says...kinda ghettos but w.e. it works!..if u ever need to change bulbs take a razor and cut the tape..

Buy a T or Y connector, connect it to the back of ur fan so its sucking air in through 2 holes now..

With flex ducting connect one side of the T or Y (w.e. u end up with) with the flex and run it to ur filter.

Then with the other open hole coming off the T or Y connect some flex going to ur hood..

Now just connect flex to the other side of ur fan (side blowing out) and run it out of ur tent and out ur window or some shit!..

If u do that set up u can suck air in through ur filter and hood!..

 

[420God]

Maybe a pic can help explain a little. I suck cool air through my air cooled hood then push it out the carbon filter located outside of the tent. Carbon filters work both way but it is more efficient to suck than blow and that's why you usually don't see them hooked up that way but in the case of air cooled hoods you really don't have many options.

My inline fan moves enough air that I don't need a fan inside the tent blowing on the plants. As long as the temperature outside the tent can be regulated you shouldn't have any problems doing it this way.

 

[GNOME GROWN]

btw im pushing a 6 inch 400cfm can fan and its sucking air through 2 hoods with 600w lights and a carbon filter!... my room that the tent is in stays at 70 degrees at all times.. my tent stays at about 77-78...i have a 16 oscillating fan in there too so that helps a lot!

 

[420God]

btw im pushing a 6 inch 400cfm can fan and its sucking air through 2 hoods with 600w lights and a carbon filter!... my room that the tent is in stays at 70 degrees at all times.. my tent stays at about 77-78...i have a 16 oscillating fan in there too so that helps a lot!

I like the Y splitter idea, might have to look into that myself.

So far it's been working pretty good the way I've been running it. I didn't lose as much airflow as I thought I would pushing through the filter.

 

[Sr. Verde]

Really there is not enough info to make the call. If the ambient temp at intake is 85* then no, if it is 70* yes. If you vent back to where your intake is no, if you vent to a separate space yes. You're leaving out the most important part of the equation.

I'm running 346w of CFL in a 2x2x5. With no exhaust it gets to about 90* with a desk fan stuck in the vent, exhausting to the room 82*. Exhaust to the Attic and it drops to 79*, this is with 70* at intake. I have a 400w HPS is a slightly smaller space and it stay at about 84*, with the same 70* at intake. AS THE TEMP GOES UP AT INTAKE THE ROOM TEMP INCREASES EXPONENTIALLY.

Heads up!

Sorry guys I'm running out the door so I can only respond to one very good question: ambient temps!

I've got a/c running straight to this room. So temps can be held at any reasonable temperature!

But Ambient, It's probably around 75. I found that after running for an hour or two, temps would MAX at 84. Without any a/c running to the room.


Now I've been running the air conditioner (with the air running through the hood) and found that temps are holding at 79F with room temp at 70. It seems to run consistently 9F higher than room temp. WITH the air being pulled through the light.

Sorry i will be back to reply to all your replies in about 4 hours! thankyouthankyouthankyou in advance i love you guys <3

 

[GNOME GROWN]

get some kind of small clip fan or somthing inside the tent..the temp should drop a couple degrees!

 

[GNOME GROWN]

I like the Y splitter idea, might have to look into that myself.

So far it's been working pretty good the way I've been running it. I didn't lose as much airflow as I thought I would pushing through the filter.

it works nice man!..i just hooked up my other light lastnight, theres a bunch of 90's and turns in the flex and its still sucking in a shit ton of air!..maybe cause my fan is 400 cfm lol..

 

[uFarm]

why not have the filter between the hood and fan?

hood>duct>filter>duct>fan

 

[GNOME GROWN]

why not have the filter between the hood and fan?

hood>duct>filter>duct>fan

Please explain how this would work!?!

duct filter duct?..2 holes to connect flex and still be able to filter?..lol,either ur really stoned or its me?

 

[GoldenGanja13]

~Be popping in from time to time

 

[Sr. Verde]

fuck I just typed up a long response to all you guys then i hit submit and it said "post entered too short", then all I typed was gone


Here we go again:

push through the carbon filter ayy?....this might work for u vede! ^^^

that way u dont even have to seal ur hood and when the air blows out it passes through the filter to clean the air i never really thought of pushing air through the carbon filter since its made to suck air in... hows this work out for u 420god?

u can either do that or do what i did..buy a 4inch T or Y connector at ur local HVAC hardware store or home depot has them.. now this is real simple i'll break it down for u..

u can seal ur hood by tapein the outside of the hood like the post above says...kinda ghettos but w.e. it works!..if u ever need to change bulbs take a razor and cut the tape..

Buy a T or Y connector, connect it to the back of ur fan so its sucking air in through 2 holes now..

With flex ducting connect one side of the T or Y (w.e. u end up with) with the flex and run it to ur filter.

Then with the other open hole coming off the T or Y connect some flex going to ur hood..

Now just connect flex to the other side of ur fan (side blowing out) and run it out of ur tent and out ur window or some shit!..

If u do that set up u can suck air in through ur filter and hood!..

Wouldn't splitting the air draw between hood/ filter also result in stinky air being mixed with clean carbon filtered air?

I almost want to tape it up to make it easier, but I realllly don't want to rely on tape to ensure good ventilation.. I HATE messing with/checking tape.. thats kind of what I do for a living

My inline fan moves enough air that I don't need a fan inside the tent blowing on the plants. As long as the temperature outside the tent can be regulated you shouldn't have any problems doing it this way.

What size inline fan are you using, and whats it rated at?

So far it's been working pretty good the way I've been running it. I didn't lose as much airflow as I thought I would pushing through the filter.

Is your fan on the outside, right against the carbon filter? I'm trying to keep my inline fan inside the tent, as it already makes a lot of noise.. Really good idea though I'm definitely considering it, I'm just running out of places to run shit...

get some kind of small clip fan or somthing inside the tent..the temp should drop a couple degrees!

I plan to in the next few weeks here On the next store run I will.. got a 6 inch clip on picked out for $25.. going to have that running on the canopy... do you think that blowing towards the hood would cool the hood down? I could buy 2 clip on fans, and have ONE dedicated to blowing on the hood, and one dedicated to the canopy... then if I have the inline fan inside, running exhaust through the carbon filter, that could keep it pretty cool right? that might be what I need to do if I don't hook up the hood through the ducting? Yeah?

Please explain how this would work!?!

duct filter duct?..2 holes to connect flex and still be able to filter?..lol,either ur really stoned or its me?

Yeah I think he's stoned I wish I could do that problem solved if I could

~Be popping in from time to time

Sweet! Thanks my good friend

I'm about to PM you back golden





Here is a picture, growing some dank ass 'cat grass' under a 250w MH

 

[420God]

I run a 4 inch 190 cfm inline fan.

 

[GNOME GROWN]

nah if u did the set up like i have then u would be sucking air from outside ur tent in through ur hood..no stink! as long as ur hood is air tight!..just use foil tape,that shit does not come off!