Hear is my layout, what should I do about exhaust?

Here is a rough layout of my space, it is 4'x4'x7'. The light I am getting is a 400w cool tube HID with a 6 inch duct size. The fan I have been looking at is a 240 cfm inline 6". I want to connect a carbon filter that is important for both indoor and outdoor smell. Where should I connect the fan and the carbon filter? Also, would a DIY carbon filter do the trick?

Side note: I'm super excited about that shelf, it's going to keep everything off the floor. It's like they had closet grows in mind when it was built haha.

Carbon filter>>>>>ducting>>>>>cool tube>>>>>ducting>>>>>>>exhaust fan>>>>>> ducting to outside.

And put the exhaust at the top at the opposite corner and wall of the intake at the bottom.

FYI cool tubes suck imo. You might want to get a proper vented hood. The reflection characteristics of the cool tube are poor. You also must remove ductwork connection to change a bulb and clean glass.

Sativied said:

And put the exhaust at the top at the opposite corner and wall of the intake at the bottom.

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Agreed, unless he's hiding his heat siganture from FLIR by exhausting under a structure.

Passive intake should be at least 2x area of exhaust.

greenlikemoney said:

Carbon filter>>>>>ducting>>>>>cool tube>>>>>ducting>>>>>>>exhaust fan>>>>>> ducting to outside.

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Is there a certain reason the carbon filter comes before the light? Also, should I use a certain type of ducting?

Sativied said:

And put the exhaust at the top at the opposite corner and wall of the intake at the bottom.

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I put the exhaust at the bottom because it's a lot easier to do so. I don't have much of a means to get on my roof and I don't want something sticking out of the side. My neighbors are really nosey, so I want to avoid that, if it's possible. I was going to do a little DIY to redirect the vent that is 2 feet outside the room to inside the closet for intake. If it gets too hot during a trial run, I will add another inline fan. I chose that corner so that it's easy to get to for filter changes and to check the seal regularly.

SnapsProvolone said:

FYI cool tubes suck imo. You might want to get a proper vented hood. The reflection characteristics of the cool tube are poor. You also must remove ductwork connection to change a bulb and clean glass.

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The cooling is a big concern for me. This is a bag seed first time grow, so I'm not too worried about it. Also, I have read that the tube does create a slight loss, but with the cooler temp the lamp can be closer to the plant. But I don't have experience in the area. Have you tried both?

All I know is I just finished 3 sour turbo diesels all seed grow, all next to each other same environmentals.... one under a 400w wing reflector, and 2 under 600w cool tubes...

I shit you not and exaggerate not at all.... 4oz of the 400w (2'x2' scrog) and only 2oz off each of the ones under the 600w. (shared a 2'x3' scrog)

I'm working on perfecting fan placement to allow one of my 600w lights go back to a wing reflector for the next round...

Your carbon filter goes at the "in" end of the line. It has to, or its not serving its purpose. The air being exhausted must first pass thru the filter, and only if its a concern, as it will greatly diminish airflow.

Now, about physics... physics doesn't give two gooey shits if its "a lot easier to do" your exhaust being at the lowest point in the room is silly, heat rises. Also, air can't exit, unless its replaced, thats "pressure"

You need another hole. Put it at the top like they said. Use the bottom hole as fresh air intake, or you'll just burn you fan motor up exhausting from a closed room.

If discretion is a concern, do what I did, pipe it outside, and add a dryer duct cover to it. Neighbors will never know its not a dryer exhaust so long as ur filter keeps working.

Imo, a hood like a 6" Daystar AC would beat a cooltube for even light dispersion.

Also, whats with the half power fan? You should get damn near 240cfm from a 4" in-line, a 6 pushes like 400-460cfm.... if youre looking at a 6" 240cfm, you're looking at prices, not at products... $73 on amazon for a 440 6"....

I would not worry about a outside exhaust, as the odor will be gone once it leaves the filter so you can vent anywhere. More important is the outside the room air temp that you are pulling in. It should be in the low to mid 70's range, and then you wouldn't need cool tubes. That is critical. Hot air outside the room, a shitload hotter in the room. Peace

LemonLily said:

Is there a certain reason the carbon filter comes before the light? Also, should I use a certain type of ducting?

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You want to PULL air thru your carbon filter, not PUSH air thru it, for it to be most efficient.

Never undersize your carbon filter if you're exhausting outside. If late flowering is stinky and CFM is too much for the filter to scrub, your neighbors will likely know your venting stench before you do.

Apparently I'm a big dumbie! The grow room does have a gap between the roof and room. So, I'm definitely going to put the exhaust in the ceiling.

The room that intake air will be coming from runs no higher than 75 (avg. 70 to 73) degrees at any point.

SnapsProvolone said:

Never undersize your carbon filter if you're exhausting outside. If late flowering is stinky and CFM is too much for the filter to scrub, your neighbors will likely know your venting stench before you do.

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Here is where I might sound (more so) ignorant, so just bear with me. I am not super concerned about the noise, but I would like it to be quiet if I can do so cheaply. With the intake temp avg. would 240 CFM be good enough for a ceiling vented setup? If it isn't good enough for flowering, could I just switch the fan to 440 CFM when the time comes?

I can't tell if the air cooled reflectors have glass or some covering below the bulb. If they do I am most definitely interested!

Could someone tell me how to become established member as want to create a post and dont have permissions thanks guys