- Joined
- Oct 8, 2012
- Messages
- 28,276
- Reputation
- 10,118
- Reaction score
- 85,061
- Points
- 0
- Website
- www.autoflower.org
Hey fellas I don't mean to shave against the grain here but I don't quite agree with some of this advice.
That's not exactly true bro. The bigger the filter = generally the larger the fan required to maintain efficiency. You can't stick a 150 CFM can fan on a 400 CFM capacity rated scrubber and expect it to do it's job the way a 350-400 CFM fan would work on that same scrubber. You're correct that an oversized fan will pull air through the filter too quickly for adsorption to occur, but underpowering it won't effectively pull the air through the entire canister, on top of making the fan work harder.
It's my understanding the CFM ratings on scrubbers are the maximum CFM capacity rating PER scrubber (it's not a constant static number, look how many sizes and types and fatboys and slim versions of scrubbers there are, usually all with their own CFM rating or manufacturer recommended fan combo.) Personally, I would get as close to that number as I could. There's at least a 10-20% CFM reduction from the output of your fan just from attaching it to the scrubber, not to mention reduction based on using flex duct vs rigid, 45 and 90 degree bends, length of duct, etc etc. Start factoring those things in and suddenly a lower power fan on a high CFM rated scrubber doesn't seem like a good idea at all.
That's incorrect. An 8 inch filter is designed to be run with an 8 inch fan. If you run it with a 6 inch fan and reducer (emphasis on reduction); most likely you're going to be running it underpowered (causing the fan to work harder, reducing it's life, it's efficiency in scrubbing air, and it will generate more heat under load.)
The larger surface area of the scrubber would be only utilized effectively if you had the appropriate sized fan to pull the air effectively through the canister. Scrubbing efficiency is determined by the quality of the carbon used, the size of the carbon particles, the amount of carbon, the amount of VOC's and other contaminants in the area and the size of THOSE particles, the temperature and humidity, contact time of odor causing particles on the carbon, etc. Lots of variables in there. Personally, would not bank solely on the size of the scrubber in terms of "well it's bigger, so it should work better, right?"
Most calculations I've seen for choosing the scrubber is to base it off the air exchange requirements for your grow space + lights, then choose the scrubber appropriately based on that (I know Phresh and a few others recommend that.)
No. It doesn't work that way. At all. Here's an example: If I take 2 napkins and put them to my mouth and blow through them, I can feel the resistance. If I take 10 napkins and put them to my mouth and blow, there is much more resistance (requiring me to blow harder) to push air through.
A fan that's underpowered to it's application is not going to work more efficiently.
I see part of your problem. Your pre-filter is filthy. Take it off, put it in the washing machine on delicate cycle (cold water) with no detergent and give it a good wash. Air dry or tumble dry in your dryer on low.
The purpose of the air filter is to catch larger micron particles (like dust, dirt, smoke, etc) before they hit the carbon. Those larger particles will coat the carbon, rendering less surface area for adsorption to occur. Pre-filter catches them, smaller particles pass through and hit the carbon, carbon does it's job
Anyways fellas, don't mean to disagree with you, just wanted to throw in my two cents. Happy smell adsorption!
That's not exactly true bro. The bigger the filter = generally the larger the fan required to maintain efficiency. You can't stick a 150 CFM can fan on a 400 CFM capacity rated scrubber and expect it to do it's job the way a 350-400 CFM fan would work on that same scrubber. You're correct that an oversized fan will pull air through the filter too quickly for adsorption to occur, but underpowering it won't effectively pull the air through the entire canister, on top of making the fan work harder.
It's my understanding the CFM ratings on scrubbers are the maximum CFM capacity rating PER scrubber (it's not a constant static number, look how many sizes and types and fatboys and slim versions of scrubbers there are, usually all with their own CFM rating or manufacturer recommended fan combo.) Personally, I would get as close to that number as I could. There's at least a 10-20% CFM reduction from the output of your fan just from attaching it to the scrubber, not to mention reduction based on using flex duct vs rigid, 45 and 90 degree bends, length of duct, etc etc. Start factoring those things in and suddenly a lower power fan on a high CFM rated scrubber doesn't seem like a good idea at all.
You'd need a top end fan that's happy pushing and pulling air from your tent, or go the easy way and get a filter the next size up from your fan plus a ducting size adaptor and you'll improve everything much more easily plus your fan will be less stressed than before
That's incorrect. An 8 inch filter is designed to be run with an 8 inch fan. If you run it with a 6 inch fan and reducer (emphasis on reduction); most likely you're going to be running it underpowered (causing the fan to work harder, reducing it's life, it's efficiency in scrubbing air, and it will generate more heat under load.)
The larger surface area of the scrubber would be only utilized effectively if you had the appropriate sized fan to pull the air effectively through the canister. Scrubbing efficiency is determined by the quality of the carbon used, the size of the carbon particles, the amount of carbon, the amount of VOC's and other contaminants in the area and the size of THOSE particles, the temperature and humidity, contact time of odor causing particles on the carbon, etc. Lots of variables in there. Personally, would not bank solely on the size of the scrubber in terms of "well it's bigger, so it should work better, right?"
Most calculations I've seen for choosing the scrubber is to base it off the air exchange requirements for your grow space + lights, then choose the scrubber appropriately based on that (I know Phresh and a few others recommend that.)
No. It doesn't work that way. At all. Here's an example: If I take 2 napkins and put them to my mouth and blow through them, I can feel the resistance. If I take 10 napkins and put them to my mouth and blow, there is much more resistance (requiring me to blow harder) to push air through.
A fan that's underpowered to it's application is not going to work more efficiently.
I see part of your problem. Your pre-filter is filthy. Take it off, put it in the washing machine on delicate cycle (cold water) with no detergent and give it a good wash. Air dry or tumble dry in your dryer on low.
The purpose of the air filter is to catch larger micron particles (like dust, dirt, smoke, etc) before they hit the carbon. Those larger particles will coat the carbon, rendering less surface area for adsorption to occur. Pre-filter catches them, smaller particles pass through and hit the carbon, carbon does it's job
Anyways fellas, don't mean to disagree with you, just wanted to throw in my two cents. Happy smell adsorption!
