Using a carbon filter with no exhaust

Hey guys. In the process of designing a grow room for me and my bro. After alot of reading and talking, we really want to go with a more sealed approach (no exhaust/intake). We already picked up a pretty good minisplit AC and dehumidifer, but one thing I was concerned about is odor.

I like the idea of carbon filters over ozone generators, but is it possible to use a carbon filter if you dont have an exhaust? Like maybe just putting it high up in the room, with an exhaust fan pulling air through it.

Thanks in advance

kysmoker said:

Hey guys. In the process of designing a grow room for me and my bro. After alot of reading and talking, we really want to go with a more sealed approach (no exhaust/intake). We already picked up a pretty good minisplit AC and dehumidifer, but one thing I was concerned about is odor.

I like the idea of carbon filters over ozone generators, but is it possible to use a carbon filter if you dont have an exhaust? Like maybe just putting it high up in the room, with an exhaust fan pulling air through it.

Thanks in advance

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You need the carbon filter to be the start of your exhaust system. If its not pulling air trough that filter its not going to clean it.Dont cut corners when you are trying to hide smell. Cough up the $ for a can fan -fan and do it right and you will not be disappointed. Oh and they work VERY well if you do it right!!!! Worth every penny so I have heard

sweetsmell said:

You need the carbon filter to be the start of your exhaust system. If its not pulling air trough that filter its not going to clean it. Oh and they work VERY well if you do it right!!!! Worth every penny so I have heard

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Right, an exhaust fan would be pulling air through the filter, but, that would be it for the exhaust. There would be no air being ejected outside, it would simply be recirculating through the carbon filter. Or atleast thats what I hope happens lol.

kysmoker said:

Right, an exhaust fan would be pulling air through the filter, but, that would be it for the exhaust. There would be no air being ejected outside, it would simply be recirculating through the carbon filter. Or atleast thats what I hope happens lol.

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You need a exhaust an a intake for fresh air. You cant just circulate the air......well I take that back you can but its not the proper way to do things and your plants will prob................or will just die.They are just like us. You cant put someone in a sealed box and expect them to live. And if its sealed like you said then why would you need a carbon filter........?..........

I would scratch your idea of this sealed box idea and build a exhaust and intake and make it stealthy if you are worried about someone finding it.

sweetsmell said:

You need a exhaust an a intake for fresh air. You cant just circulate the air......well I take that back you can but its not the proper way to do things and your plants will prob................or will just die.They are just like us. You cant put someone in a sealed box and expect them to live. And if its sealed like you said then why would you need a carbon filter........?..........

I would scratch your idea of this sealed box idea and build a exhaust and intake and make it stealthy if you are worried about someone finding it.

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Well, smell will always permeate, and eventually it would get outside of a room, regardless of how hard you tried to seal it. That was why I was thinking of recirculating the air through a carbon filter.

The main benefit of sealing a grow room up is that you have complete control over it, outside weather wouldnt be able to effect your grow room, and also it allows very effective use of co2.

EDIT: Or so the story goes, I havent tried it, but ive seen people that use sealed grow rooms here on the forums.

Its your grow but I wouldn't do the sealed. I mean you say you have seen it done before like its rare. I can show you 1,000 threads where people are growing massive amounts and exhausting their heat from their light and old air not having ANY problems to the 1 sealed thread where they arn't.I mean I just dont know why you wouldn't exhaust it unless there is some strange reason you cant and you are not just telling us about it . I mean I guess if you want a 100% sealed room where you circulate your old air go for it and you tell us how it went. But I can say that I cant offer you anymore info on this topic. Maybe someone else can beat this horse.Best of luck

I do a "sealed room" and it works great. The only thing I didn't see mentioned is co2. That is the key to sealing a room. It does take some extra work and gets tricky trying to dial in the temps and humidity. But once its up n running its great. You cant even smell my plants when your standing in the room.

Oh and yes you can run your carbon filter just the way you mentioned.

Geneticfreak said:

Oh and yes you can run your carbon filter just the way you mentioned.

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Thats what I was thinking, or atleast hoping lol. And yea, Im gona be using tanked co2, so hopefully not having the room exhausted will preserve it. Its not that im cheap, I just hate going to the welding shop lol.

Try to get at least 2 20lb bottles. That way you will always have a tank on hand to swap out. What co2 ppm, temps, and rh are you shotting for?

Geneticfreak said:

I do a "sealed room" and it works great. The only thing I didn't see mentioned is co2. That is the key to sealing a room. It does take some extra work and gets tricky trying to dial in the temps and humidity. But once its up n running its great. You cant even smell my plants when your standing in the room.

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This is how I set up sealed rooms.

When you seal the room, make sure to seal the walls to the slab with silicone. I go through about 1 20lb tank of CO2/month, keeping PPM's between 1150 and 1300. Whereas I know people with sealed rooms going through 1 20lb tank per week due to not sealing the room well.

How do you cool the space?

Geneticfreak said:

Try to get at least 2 20lb bottles. That way you will always have a tank on hand to swap out. What co2 ppm, temps, and rh are you shotting for?

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Shooting for temps in the 75-80 range, around 50% rh, and building up to about 1500 ppm co2.

Its not going to be that big of a room honestly, just 3 600 watt lights over a 4x6 growing area (the room might end up being 10x10 at the very largest)

At 1500 you will see some stellar results. As long as your doing everything else right.

sweetsmell said:

well I take that back you can but its not the proper way to do things and your plants will prob................or will just die.They are just like us.

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The last time I checked plants are not just like us. We both need "air" but for the exact opposite reasons. If the OP is providing CO2, than fresh "Air" is not constantly needed. "Scrubbing" is where air is recirculated/cleaned. I bought a cheapo HTG filter and later found out that it could only handle low cfm draws because of the small physical thickness of the carbon layer. I first hooked it up in the traditional setup where the air is filtered than evacuated. I could still smell product. Once I set it up just to recirculate, the smell was gone. I was able to set the CFM to a low 150 cfm so the area was scrubbed every 5 minutes. In a closed system, a fresh air purge can be introduced during lights out when no co2 is used. If you wish, you could have a separate fan/filter that exhausts at a higher rate than the introduced fresh air during these purges.

You should shoot for higher temps if you are using CO2.

You don't need to exhaust the air outside the room, you can setup a carbon filter to recirculate and clean the air in the room.

Geneticfreak said:

How do you cool the space?

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Split AC, the compressor stays outside the grow, so all the heat stays away from the whole room and setup. Only the fan assembly is inside cooling the room for you.

ditto to everything genericfreak wrote, i grow in a sealed room with a free standing diy carb filter and can't smell a thing. don't forget the co2