question about ventilation and carbon filtering

Hey guys, i'm gonna be purchasing a tent here in a few weeks. I've already got my 400w hps ready to go but im still really confused about how i'm supposed to ventilate my grow area. i know its pretty self explanatory but which parts are supposed to hook up to my light? Am i supposed to be sucking in cool air with a squirrel cage and blowing it out with an exhaust fan?? where does the carbon filter fit into all this.?? I dont even know if my hood. my hood has these vent covers over the hole but i assume they can be taken off for ducting? Any help would be appreciated. pictures would be helpful also. How well do carbon filters remove oders?? It's critical i try and keep smells down as much as possible with where i live. thats the filter and fan im thinking about buying

FRICKITYFRICKTYFRESH said:

Hey guys, i'm gonna be purchasing a tent here in a few weeks. I've already got my 400w hps ready to go but im still really confused about how i'm supposed to ventilate my grow area. i know its pretty self explanatory but which parts are supposed to hook up to my light? Am i supposed to be sucking in cool air with a squirrel cage and blowing it out with an exhaust fan?? where does the carbon filter fit into all this.?? I dont even know if my hood. my hood has these vent covers over the hole but i assume they can be taken off for ducting? Any help would be appreciated. pictures would be helpful also. How well do carbon filters remove oders?? It's critical i try and keep smells down as much as possible with where i live. thats the filter and fan im thinking about buyingView attachment 3211501 View attachment 3211502 View attachment 3211504

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Does your hood have a piece of glass? Do you know what tent you are getting? Are you running soil or hydro? Doesnt really matter as most are very similar. I have a Secret Jardin and it seems well made, has light leaks u have to fix, but ive heard all tents have that problem. For a 400w HPS i would say a 3x3 or a 4x4 is ideal size. You have two options, carbon filter inside tent, or carbon filter at the end of the exhaust. If you have room for a 4x4 tent u can likely fit the filter inside the tent which is ideal IMO.


You may need buy a piece of TEMPERED glass for your hood (~$25 from a glass store or possibly a part made by the maker of the hood), i can see it is made to be able to be air cooled (unscrew the vent covers) but if u don't have a piece of glass it wont work. The first option i have will only work with an air-cooled hood.

Option 1:
Filter in Tent:
You will have your filter in the top of the tent, as far away from the air intake as possible (intake will be towards the bottom on all tents) connected with ducting to one end of the hood. Then use more ducting to run out of the other end of the hood and up to the top exhaust hole every tent will have. On top of the tent, or at the window, attic or wherever u are letting the exhast out u will put the fan. Centrifugal (like you are buying) fans work best when sucking air through ducting like a straw, not when pushing through it, keep this in mind. Then just use the bottom intake holes as passive intakes.

filter>duct>sealed hood>duct>fan>exhaust

Option 2:
Filter Not in Tent:
Unscrew the vent from one end of your hood, on your hood i have no clue which side is better, and hook ducting directly to the hole in the hood made by removing the vent. Hook the ducting up to this hole and then up through the exhaust hole. Once out of the tent the fan is connected and then the filter is connected directly to the fan, or more ducting runs to the filter. This method allows the heat to be pulled directly off the bulb which will help dramatically with the heat. Heat will be your enemy without a piece of glass in your hood but this should help.

open light>duct>fan>filter>exhaust

The Basics.

Carbon filter>>>>> ducting into your tent>>>>>>>>cool tube/vented hood>>>>>ducting out of your tent>>>>>>inline fan>>>>>ducting to wherever you are exhausting your tent

BTW, the airflow should be going from the socket to the tip of the bulb.

greenlikemoney said:

BTW, the airflow should be going from the socket to the tip of the bulb.

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that is how every hood i have ever seen is, i bet for a reason, listen to the man

thanks for the info guys. this is what makes this hobby fun is figuring everything out. im growing in soil until im more experienced and gonna be buying an Apollo 48x48x80. i should have more than enough room just wasnt sure of the correct steps

just checked hydrofarms website. they sell the glass for that model of hood for 20$. and a separate air cooling kit with plastic mounts and all that goodness for 20$

FRICKITYFRICKTYFRESH said:

thanks for the info guys. this is what makes this hobby fun is figuring everything out. im growing in soil until im more experienced and gonna be buying an Apollo 48x48x80. i should have more than enough room just wasnt sure of the correct steps

just checked hydrofarms website. they sell the glass for that model of hood for 20$. and a separate air cooling kit with plastic mounts and all that goodness for 20$

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the flanges and shit u probably dont need (i just duct tape the ducting straight to my hood), just the glass, it will REALLY help with temps allowing u to get the light closer.

greenlikemoney said:

The Basics.

Carbon filter>>>>> ducting into your tent>>>>>>>>cool tube/vented hood>>>>>ducting out of your tent>>>>>>inline fan>>>>>ducting to wherever you are exhausting your tent

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The carbon filter in this scenario seems to be outside the tent on the intake side. It needs to be either inside the tent or outside on the exhaust side. Yeah?

kryptoniteglo said:

The carbon filter in this scenario seems to be outside the tent on the intake side. It needs to be either inside the tent or outside on the exhaust side. Yeah?

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A carbon filter, to be most efficient, needs to have air sucked thru it, not pushed thru it. So, your carbon filter either needs to be as previously posted no matter whether outside the tent or inside the tent. With or without a tent doesn't matter, what matters most is that you are pulling air into the filter, not pushing air thru the filter. Even if your filter is located outside of the tent, you are still scrubbing the air which would contain the odor ( imagine the cannabis odor leaking out of your tent, it still would get scrubbed. ) The reason I would recommend the filter being outside of the tent is twofold. A) You are pulling cooler air into the filter ( which then moves over your cooltube ) than you would have if you air pulling warmer "inside the tent" air thru your filter ( which then moves over your cooltube ) and B) you are nearly guaranteed that you have a smell-free environment outside of your tent.

greenlikemoney said:

A carbon filter, to be most efficient, needs to have air sucked thru it, not pushed thru it. So, your carbon filter either needs to be as previously posted no matter whether outside the tent or inside the tent. With or without a tent doesn't matter, what matters most is that you are pulling air into the filter, not pushing air thru the filter. Even if your filter is located outside of the tent, you are still scrubbing the air which would contain the odor ( imagine the cannabis odor leaking out of your tent, it still would get scrubbed. ) The reason I would recommend the filter being outside of the tent is twofold. A) You are pulling cooler air into the filter ( which then moves over your cooltube ) than you would have if you air pulling warmer "inside the tent" air thru your filter ( which then moves over your cooltube ) and B) you are nearly guaranteed that you have a smell-free environment outside of your tent.

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Ah, got it. So you're not scrubbing the tent air. You're scrubbing all the air in the room. That makes sense. Thanks for the clarification!

kryptoniteglo said:

Ah, got it. So you're not scrubbing the tent air. You're scrubbing all the air in the room. That makes sense. Thanks for the clarification!

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Well, either works, but in my opinion ( let's say you have a tent in a walk-in closet ) you are better off having the filter outside the tent so it is drawing room temperature are thru the filter and then thru the cool tube/vented hood, thus insuring that your cool tube/vented hood stays as cool as possible and ALSO making sure your closet is odor free.

There is a reason that everyone who is successful does it the same way.

Listen to purple and not to green.

You'll save yourself some ducting and probably your plants. You need to circulate the air inside your tent. Unless you are running co2. If not they will NOT be happy nor will they grow to their full potential. Plants like fresh air...Thus the intake ports on all your favorite grow tents ( located on the bottom quarter ) You also will still need to move the air out also. A HID light is basically an oven. 500+ degrees just baking in your grow room...yeah you can pull the direct heat off of the bulb with this method but you ever take your shirt off in the summer time...shit was warm on the skin right?...Same shit is going on with your plants. It's called radiation...not like godzilla or mutant stuff. More like having the rays of the sun come through your window in the winter time. Still warm right...Guess what. That's from a huge ass light 90 million miles away in a vacuum. It doesn't take a degree in thermodynamics.

So you don't need to buy the extra pieces but running it as an air cooled hood will help a lot.

You will need an intake and exhaust line just for the light, with an in line fan to blow air across the hood, people say blowing across the hood helps keep it cooler, makes sense to me. As apposed to sucking air across it. You don't need an intake and exhaust fan just an in line that will suck air in and push it across to exhaust.

Now for the exhaust fan, your going to set your carbon filter in the top of the unit, there are usually straps at the top of tents to help secure it. then your squirrel cage fan, and then a length of duct to get it where you want the exhaust going. The filter at the top of the tent helps remove excess heat as well as giving you more floor space. Heat rises and stinky heat rises all the same. It will also give you a good flow for a passive intake. A lot of tents have spots for passive intake around the bottom, so no need to have another fan sucking air in. Then all you need is 2 small clip fans to move air around, now most people will say that a good air flow through your carbon will move air around in the tent but the fans also help with creating stronger plants, plus there like a kick in the bucket after you have bought everything else.

Bomixius said:

So you don't need to buy the extra pieces but running it as an air cooled hood will help a lot.

You will need an intake and exhaust line just for the light, with an in line fan to blow air across the hood, people say blowing across the hood helps keep it cooler, makes sense to me. As apposed to sucking air across it. You don't need an intake and exhaust fan just an in line that will suck air in and push it across to exhaust.

Now for the exhaust fan, your going to set your carbon filter in the top of the unit, there are usually straps at the top of tents to help secure it. then your squirrel cage fan, and then a length of duct to get it where you want the exhaust going. The filter at the top of the tent helps remove excess heat as well as giving you more floor space. Heat rises and stinky heat rises all the same. It will also give you a good flow for a passive intake. A lot of tents have spots for passive intake around the bottom, so no need to have another fan sucking air in. Then all you need is 2 small clip fans to move air around, now most people will say that a good air flow through your carbon will move air around in the tent but the fans also help with creating stronger plants, plus there like a kick in the bucket after you have bought everything else.

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Passive intake usually causes a negative pressure that wants to implode your tent. It's really best if you pull air from a fresh source. This is why most people run co2 in grow tents and sealed rooms. You don't need co2 if you are pulling from a fresh source. Plus if your tent is in a grow room you can't really use a passive intake system. It leaks light horribly and you are pulling stale air into your tent. All of this is just advice. Do what ever you want to do.