240M3h Carbon Filter for 200CF room?

I don't know the answer, but I wish I did because I have the same problem. At lights out, the smell from exhaust will knock you down. After discussing the problem with some folks here at RIU the conclusion was that my carbon filter was inferior. I got a new kit a while back but it was only about $130 USD for 6" filter and fan. The fan is great - quiet and well made but I guess they made up for it with a crappy filter.

I originally thought I might have some tiny air leaks after the filter but if i do they are very small - no way they could account for the volume of smell. I will buy a better filter after this grow and see if it helps.

If you can smell marijuana from your exhaust (as in, air that was supposed to already been filtered), then your carbon filter is crap.

That's not my case. I don't smell anything from the filter itself, just the surrounding room. Which should mean that the filter can't exchange the air quickly enough, but according to my math, it should.

So your fan is

530m3/h

Your filter is

240m3/h.


Your fan pulls twice as much air than your filter can handle.



J

jondamon said:

So your fan is

530m3/h

Your filter is

240m3/h.


Your fan pulls twice as much air than your filter can handle.



J

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Yes, but it's a Delta fan, essentially a supped up PC fan, so its air pressure is much lower than an inline fan.

I guesstimated that it's about equivalent to a 240M3H inline fan, or at least somewhere in the area.

Trackr said:

Yes, but it's a Delta fan, essentially a supped up PC fan, so its air pressure is much lower than an inline fan.

I guesstimated that it's about equivalent to a 240M3H inline fan, or at least somewhere in the area.

Click to expand...

Obviously not if you're getting leaks in smell.



J

jondamon said:

Obviously not if you're getting leaks in smell.



J

Click to expand...

How do you figure? That makes the fan TOO GOOD not bad.

Trackr said:

How do you figure? That makes the fan TOO GOOD not bad.

Click to expand...

Your filter is rated at 240m3/h.

If your fan kicks anything over 10% more power, then the air is passing too quickly over the carbon bed to effectively be cleaned.


You assumed it would be around 240m3/h as its not an inline fan.

Your fan is obviously running more powerfully than you guesstimated that's how I figured its not what you thought because you are getting smell leak.


For example.

240m3/h filter running with a 240m3/h fan = no smell.

240m3/h filter running with a 400m3/h fan = smell issues.

Smell issues occur when equipment is incorrect.



J

jondamon said:

Your filter is rated at 240m3/h.

If your fan kicks anything over 10% more power, then the air is passing too quickly over the carbon bed to effectively be cleaned.


You assumed it would be around 240m3/h as its not an inline fan.

Your fan is obviously running more powerfully than you guesstimated that's how I figured its not what you thought because you are getting smell leak.


For example.

240m3/h filter running with a 240m3/h fan = no smell.

240m3/h filter running with a 400m3/h fan = smell issues.

Smell issues occur when equipment is incorrect.



J

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No, but that still doesn't make sense because:

The fan is exhausting smell into the attic. This means that if it really too strong, there still shouldn't be any smell in the room next to it and instead only in the attic.

Since this is the case, it's obviously not a case of a fan being too powerful. On top of that, there is no smell in the attic, meaning the carbon filter is doing just fine with the fan.

Clearly, then, there is another culprit here.

Ok are you using an intake fan?

If so what type?

If not it could be your Osc fan is moving more air inside than is being sucked through the filter.


Smell leaks like this happen because there is positive pressure.


Positive pressure occurs when less air is exhausted than what's being taken in via intake or moved around inside.




J

jondamon said:

Ok are you using an intake fan?

If so what type?

If not it could be your Osc fan is moving more air inside than is being sucked through the filter.


Smell leaks like this happen because there is positive pressure.


Positive pressure occurs when less air is exhausted than what's being taken in via intake or moved around inside.




J

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No, that's also impossible. The fan I'm using for intake is rated at 75CFM. There is no way it's pushing more air in. In fact, I was thinking of doubling up and getting another one.

Have you tried turning off your intake fan and see if the smell persists.




J

Have you tried turning off your intake fan and see if the smell persists.




J

jondamon said:

Have you tried turning off your intake fan and see if the smell persists.




J

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I increased the intake last night and the smell definitely went away.. although, I also shut off the lights at the same time, so maybe that was it?

Overnight, I left the exhaust funneling air into the house, and I definitely smell marijuana in the house.

One more thing - the sleeve on the filter seemed to have been burned by the lights. It was stained with this orange stain, but it came off when I washed it.

All I know is, a 140CFM carbon filter should definitely be enough for a 200CF room..

I know for a fact that when it was in a 10CF box, it did its job perfectly well.. so maybe it's not strong enough..?

Question is - should I get a proper inline fan or a bigger carbon filter?

Let me tell you this much.

I use a 250CFM fan in my 180CF room.

I use a 500CFM filter on my 250CFM fan.

I always overspec my filters compared to my fan.


The numbers for your filter should ALWAYS be higher than your fan.


If you increased the intake fan speed, this would simply push more air into your grow and would not help smell issues.


Have you tried turning off your intake fan and only running your exhaust?

This would be classed as a passive intake setup (I run my own room passive intake) by turning off the intake fan would make sure that all air is going through the exhaust filter/fan setup and then you could confirm whether your filter is effective enough by smelling the exhaust air.




J

jondamon said:

Let me tell you this much.

I use a 250CFM fan in my 180CF room.

I use a 500CFM filter on my 250CFM fan.

I always overspec my filters compared to my fan.


The numbers for your filter should ALWAYS be higher than your fan.


If you increased the intake fan speed, this would simply push more air into your grow and would not help smell issues.


Have you tried turning off your intake fan and only running your exhaust?

This would be classed as a passive intake setup (I run my own room passive intake) by turning off the intake fan would make sure that all air is going through the exhaust filter/fan setup and then you could confirm whether your filter is effective enough by smelling the exhaust air.




J

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Yes, I have. I have been funneling the air into the house, and the smell outside the house has disappeared. However, the smell in the house persists, even without an intake. I had to leave the door to the grow room open for intake, of course, otherwise there would be no intake, so again, it's not 100% correct.

But it does seem like the carbon filter isn't up to the task.. which is unfortunate. That, or the fan is too strong, as you have pointed out.. which I suppose still means that the carbon filter isn't up to the task.

So, I have decided to go out and buy a bigger carbon filter today. I looked online for Rhino and Can Lite, but they just don't seem as good to me.. they have a lower amount of carbon and a thinner layer of carbon compared to other manufacturers. Perhaps the carbon is higher quality, but I just don't trust it.. the Rhino 500M3h filter is the exact same size as my Max Filter 240M3h. I don't trust Max Filter now either so I'm going for a Dutch company.. I forget their name.

Either way, I'm going to keep the Delta fan and see what happens. Maybe I'll even get a 760M3h filter, because it's a similar price, but I'm afraid the fan won't be able to handle it.

And that's another thing.. if the fan isn't able to handle it.. is that really so bad? I mean it will still evacuate enough air out of the room, and that air will have plenty of time to travel through the carbon, right?

If the big filter won't cut it, I guess I can always use both filters instead of selling the small one, but two Delta fans at the same time is going to be suspiciously noisy..

I use a RHINOPRO filter 150x600mm.

It has a warranty of 2 years so if failure occurs I just take it back.

My last filter was a CANLITE 600. It lasted me 18months.


It does sound suspiciously like your filter isn't capable of cleaning the air that the fan is pulling.

You could close the door as the ductwork and fan that you have for intake would become the passive intake automatically. Unless the intake fan has a backdraft damper on it.