Ventilation / CFM Experts Needed

[mikessong]

Hi,
I just bought a scrubber that may be under-rated for CFM for my setup and I'd like your opinions on how well it will perform. It's a Deau Passe 33 filter:

http://www.hydroasis.com/Merchant2/...e=H&Product_Code=2693000&Category_Code=CANFIL

On that page it says it's rated up to 350CFM, but on another part of their site it says it's max CFM is 210. WTF?! I'd guess the truth lies somewhere in the middle???

Anyway, my fan is a Vortex 6" rated at 440 CFM and I don't want to inhibit its airflow because it will be the only fan scrubbing and air-cooling a 1000w in a 4.5' square closet. Now I understand that the fan will be inhibited by the nature of a carbon filter, and additionally by the light, ducting, etc. So the system doesn't really have 440 CFM, maybe 350 or less. Therefore could the filter be sufficient? Or if I got a Can 55/66 that was rated at 420CFM, would I get more airflow?

Here's my planned setup:
Scrubber > Fan > Air-cooled Light > Insulated flex duct work functioning as a light trap and going to the exhaust.

I put the fan there to move it farther from the exhaust because noise going to the outside is a security concern for me. Also, I think that might be the best position for it anyway, as it's right between the two critical parts, and if they block airflow at least it's full power is right next to it. But then I'm thinking the scrubber will cut the Vortex to 350CFM from the get go, and it will just go down from there.

What do you experts on the math say, or just people with experience dealing with similar setups?

Thanks...

BTW, this is what the owner of the store wrote me about the unit compared to the Can filters:

The two companies use the exact same charcoal and the sizes are in fact equal—same thickness of charcoal, same overall weight.

Deau Passe has just broken through the market and eliminated the middle men. They will be making quite a splash with their pricing and quality.


EDIT: After checking out the fan and noticing it's light-blocking design, I think I may go
Scrubber > Light > Fan > Exhaust
It will be a little noisier to the outside, but would allow me to exhaust duct straighter depending on the light situation. And this way seems like it might lessen the original problem of the carbon scrubber being under-qualified, because the light's already blocking some of the fan's capacity. ?

 

[Arkaya]

Scrubber > Light > Fan > Exhaust is the best way to do it and looks like it will take care of light coming through from the light hood.

I have a 6 inch vortex with a 6 inch Eco-Plus Carbonaire Filter that is rated at 500 CFM. So in my case the carbon scrubber can flow more air then my fan can on maximum speed. This is all hooked up to cool a 1000 w MH/HPS. I think from just a gut feeling that you should go with the larger of the scrubber if you can. I mean 350 CFM is a lot of airflow but your still hooking it up to a fan that can flow a lot more air then the filter will allow. If you put the fan on a speed controller and slow it down a bit I think that would work well.
Good luck

 

[Guest]

Just curious Arkaya - based on your config (scrub > light > fan > exhaust), wouldnt this significantly lower the CFM's being pulled through the scrubber?

I mean if I take a (pretend) 300CFM inline and attach it directly to a scrubber, it's going to attempt to move 300CFM. Now if I take that same inline and, using duct, connect it to all those you listed the CFM's being pulled through the scrubber would be much lower.

If that's the case then I think you'd be ok with what you have, granted that you did not connect the inline directly to the scrubber...

 

[Arkaya]

I have seen it listed at various scrubber manufactures that they commonly inhibit the flow 5-10%. So in that case my 440 CFM vortex will only be flowing 400 CFM. Add in some ducting and it probably drops another 5-10% down to 360 CFM. That's still a good volume of air enough to exhaust a small area several times a minute. I always go with the bigger of the equipment because I know I can always have room for growth in the future.

 

[mikessong]

Thanks guys, I returned the Deau Pass and got a Can 66 38 Special which is rated at 420 CFM. Figure at least 10% loss to the Vortex from the scrubber and light and that scrubber should do nicely. The other scrubber might have worked but the store wasn't even sure if it was 350CFM or 200CFM and this isn't an area I want to play around in. I've just outfitted my first setup and I'm learning that with growing compared to other things, the cheaper solutions tend to not work or cost you more in the long run. After all, we grow pounds of stanky goodness under 1000w in a closet and ask that it be cool, odor-free, and not too noisy!

Klutter, I'm curious about what you said -

If that's the case then I think you'd be ok with what you have, granted that you did not connect the inline directly to the scrubber...

So that's to be avoided? I'm leaning towards putting the fan after the light but still considering between the scrubber and light for noise reasons.

 

[Guest]

Thanks guys, I returned the Deau Pass and got a Can 66 38 Special which is rated at 420 CFM. Figure at least 10% loss to the Vortex from the scrubber and light and that scrubber should do nicely. The other scrubber might have worked but the store wasn't even sure if it was 350CFM or 200CFM and this isn't an area I want to play around in. I've just outfitted my first setup and I'm learning that with growing compared to other things, the cheaper solutions tend to not work or cost you more in the long run. After all, we grow pounds of stanky goodness under 1000w in a closet and ask that it be cool, odor-free, and not too noisy!

Klutter, I'm curious about what you said -

If that's the case then I think you'd be ok with what you have, granted that you did not connect the inline directly to the scrubber...

So that's to be avoided? I'm leaning towards putting the fan after the light but still considering between the scrubber and light for noise reasons.

First off, it's a damn breath of fresh air to read someone else coming to the realization that cheaper in certain areas is a bad thing...

What I was referring to is the way in which the fan could be hooked up for exhausting. At one point I had my fan 'taped' on to my scrubber (pulling) and exhausting after that...so the CFM's were as close to 'factory listed' for the fan as it was going through little to no duct.

Now I changed my config to pull through the scrubber, then duct into the light, then duct into the fan and exhaust. This lowered my CFM's pulling through my scrubber quite a bit due to the ducting, turns in it, resistance of the added light hood, etc. My point was that if I have a scrubber rated for 250CFM, with the above config I actually need a fan that is around 300CFM due to the %'s lost by the extra items.

As far as the noise mine isn't bad... granted I've cut up my sungrow hood to allow a much better air flow through it, but the noise really seems to come from the fan itself and amount of air flow moving around.