Fan cfm vs filter cfm

[Markus]

So I'm preparing for my 2nd grow. First one went pretty well. One thing I did have a problem with was the smell outside the tent whilst flowering.

 

I have a fan rated at 350 m3 per hr (210 CFM) and the filter was only 120CFM. Could this have been my problem? Fan too powerful for the filter?

 

It was a 4 inch filter. Would I be better off getting a higher rated filter like a 5 inch or 6 inch?

 

The smell got pretty bad towards the end and I had to use odour neutralisers etc

 

Cheers!

[Sir PsychoHashy]

I have a vague memory of something to do with optimal flow rates through carbon filters, but wouldn't want to assert anything.  But I would recommend matching filter roughly to fan size and strength, and the bigger the filter the more carbon surface area the stinky air passes over.

 

Other possible issues to check before dropping coin are:

 

• Make sure there's no leaks between fan and filter, that's a big one.  Loose joins, pin holes in the ducting, poor filter construction, leaks through cool tube housing, blah blah.  And remember, duct tape is your friend, buy the big rolls
• Make sure you have a decent brand filter designed for scrubbing smells.  In my experience the cheap filters aren't 100% effective, and get worse fast.  A good one will cost twice as much, but will work properly for at least twice as long, a very good investment that more than pays for itself, and actually works properly.

 

Best of luck 

[Markus]

I have a vague memory of something to do with optimal flow rates through carbon filters, but wouldn't want to assert anything. But I would recommend matching filter roughly to fan size and strength, and the bigger the filter the more carbon surface area the stinky air passes over.

 

Other possible issues to check before dropping coin are:

 

• Make sure there's no leaks between fan and filter, that's a big one. Loose joins, pin holes in the ducting, poor filter construction, leaks through cool tube housing, blah blah. And remember, duct tape is your friend, buy the big rolls
• Make sure you have a decent brand filter designed for scrubbing smells. In my experience the cheap filters aren't 100% effective, and get worse fast. A good one will cost twice as much, but will work properly for at least twice as long, a very good investment that more than pays for itself, and actually works properly.

Best of luck

Thanks for the info mate.

 

The brand is filteroo which is a growlush brand I believe which could be the problem.

 

The tent is down now because I'm about to move for work but I did have a good look and couldnt find any leaks.

 

I'm not sure how smell proof the tent is but I could smell weed coming out the ducting coming from the fan and filter so I think there's a good chance it's that.

 

Perhaps the the filter couldn't scrub the air at the rate the fan provided.

[Jim420]

Thanks for the info mate.

 

The brand is filteroo which is a growlush brand I believe which could be the problem.

 

The tent is down now because I'm about to move for work but I did have a good look and couldnt find any leaks.

 

I'm not sure how smell proof the tent is but I could smell weed coming out the ducting coming from the fan and filter so I think there's a good chance it's that.

 

Perhaps the the filter couldn't scrub the air at the rate the fan provided.

We had one of those . It's utter rubbish . We've switched to a phresh 6" 150mm. No more dramas. The carbon filter on those filteroo ones are so small it's a wonder they work at all .. get a phresh fan and filter , you'll see the difference . [emoji1308] Edited May 21, 2017 by Jim420

[Sir PsychoHashy]

Yep, I run the Phresh filters these days, quality product, but there are others that are just as good.

 

I also had a no brand, and Growlush brand, filters briefly, and suspect the no brand was Growlush as they looked exactly the same.  The Growlush was sold as unbranded as well, so even then sellers knew they were shit.  They were about 95% effective out of the box, but steadily got less and less effective very quickly.  Waste of money.

 

If it's on Ebay, and it doesn't have a known quality brand on it, assume it's Growlush, and that pretty much goes for all hydro products on Ebay IMO.