Carbon Filter

[jstone1633]

How big is just overkill for a carbon scrubber? If my grow room is 105 cubic feet should I get a 4" vortex, turn it down, and get a filter for 105 CFM or should I get a bigger filter and max my fan? Id like to keep the noise to a min. Does everyone go big or just big enough? How accurate are the ratings on the capacity of filters? I think Id rather have to cover a faint odor as a filter wears out and replace a filter more often then have to constantly try to mask the sound of fan.

 

[benign]

Personally I use a 4" Phresh Filter for my 4" fan in a 4x4 tent to cool a 1000w. So far seems to be working pretty well, although I did just upgrade to a 6" fan and with the fan I'm going to upgrade my filter as well. I made a bit of a mistake in not going big the first time...I've found it's actually cheaper in the long run to go big and dial down because no matter what it will be impossible to go up without having to make another purchase.

Good point on the noise thing, they do make duct mufflers that will dampen some of the sound. I'm not sure about how accurate the ratings are, mine seems to handle the 4" just fine

 

[jstone1633]

Personally I use a 4" Phresh Filter for my 4" fan in a 4x4 tent to cool a 1000w. So far seems to be working pretty well, although I did just upgrade to a 6" fan and with the fan I'm going to upgrade my filter as well. I made a bit of a mistake in not going big the first time...I've found it's actually cheaper in the long run to go big and dial down because no matter what it will be impossible to go up without having to make another purchase.

Good point on the noise thing, they do make duct mufflers that will dampen some of the sound. I'm not sure about how accurate the ratings are, mine seems to handle the 4" just fine

Thanks. Can I ask why you are upgrading if it was working? Is there any advantage besides more air movement? Im not worried about temps, just noise and smell. Is the noise from your 4" setup that noticeable? Im planning on growing in a closet. The fan and filter will be in the closet and the ducting exhausting through the back wall into a laundry room

 

[FootClan]

As a rule of thumb you always want your filter to have a higher CFM rating then your fan.... the slower the air moves through the filter the better it filters...So if your fan is rated to 105 CFM get a filter rated for 150 cfm or bigger,, this way you can run your fan at full speed and it will , one let air pass through your fan with less restriction and two it will filter better aswell... I use a 8" fan for my 1000w with a speed fan controller......Its always better to get a bigger fan then you need for many reasons...... One reason is that with a bigger fan you can move the same amount of air as a smaller fan but it will be less noisey.. EX. My 4" fan running at full speed is about 150 CFM and if i take my 8" fan that runs full speed at 600 cfm but turn it down to 150 it will be less nosiey then the 4" at full speed even though they both are pushing the same amount of CFM.....MAKE SENSE??

Another reason is that i can run my fan slow when its cold and i can turn it up to 600cfm if it gets hot.... This allows me to adjust my fan for the envierment. but if you had the 4" you are pretty much stuck just using it full blast all the time and if that ant enough then you are screwed...... So haveing a bigger fan then what you need is usually a good idea for the reasons i just stated above...

 

[jstone1633]

As a rule of thumb you always want your filter to have a higher CFM rating then your fan.... the slower the air moves through the filter the better it filters...So if your fan is rated to 105 CFM get a filter rated for 150 cfm or bigger,, this way you can run your fan at full speed and it will , one let air pass through your fan with less restriction and two it will filter better aswell... I use a 8" fan for my 1000w with a speed fan controller......Its always better to get a bigger fan then you need for many reasons...... One reason is that with a bigger fan you can move the same amount of air as a smaller fan but it will be less noisey.. EX. My 4" fan running at full speed is about 150 CFM and if i take my 8" fan that runs full speed at 600 cfm but turn it down to 150 it will be less nosiey then the 4" at full speed even though they both are pushing the same amount of CFM.....MAKE SENSE??

Another reason is that i can run my fan slow when its cold and i can turn it up to 600cfm if it gets hot.... This allows me to adjust my fan for the envierment. but if you had the 4" you are pretty much stuck just using it full blast all the time and if that ant enough then you are screwed...... So haveing a bigger fan then what you need is usually a good idea for the reasons i just stated above...

All of that makes a lot of sense. But now my question is this...can a fan be too small for a filter? It makes sense that it should "scrub" better at a slower air flow but can it be too low? If I understand you correctly you are saying is that I need a filter that exceeds my max fan speed but what if I turn my fan down? Can it be turned too low that the filter doesn't function properly?

 

[WattSaver]

I agree with footclan. By going bigger you will make less noise (fan bigger than space needs & filter bigger than fan) I wouldn't go with anything less than a 4" inline fan, And if you're really concerned about fan noise then get a hi quality fan like a Vortex or Can, this will make a big difference

 

[WattSaver]

All of that makes a lot of sense. But now my question is this...can a fan be too small for a filter? It makes sense that it should "scrub" better at a slower air flow but can it be too low? If I understand you correctly you are saying is that I need a filter that exceeds my max fan speed but what if I turn my fan down? Can it be turned too low that the filter doesn't function properly?

Yes a fan can be too small. The filter causes drag on the air flow, which will place a larger load on the motor and bearings, hence more wear and more noise.

 

[jstone1633]

Yes a fan can be too small. The filter causes drag on the air flow, which will place a larger load on the motor and bearings, hence more wear and more noise.

So how do you adjust a vortex's speed and know how many CFM's its pushing?

 

[WattSaver]

So how do you adjust a vortex's speed and know how many CFM's its pushing?

Get a speed controler
http://www.amazon.com/Sun-System-Sunlight-Supply-SPEEDSTER/dp/B004AOVQ3W/ref=sr_1_7?s=home-garden&ie=UTF8&qid=1324683582&sr=1-7

4" vortex 175 cfm
http://www.globalindustrial.com/p/hvac/exhaust-fans/in-line-duct-fans/vortex-inline-duct-blower-fan-4-in

4" can 155 cfm
http://www.canfilters.com/fan_metal_rs4.html

watch this video you'll see why I bought a 6" can
http://www.youtube.com/watch?v=fYbLub3Iw2c

 

[jstone1633]

Get a speed controler
http://www.amazon.com/Sun-System-Sunlight-Supply-SPEEDSTER/dp/B004AOVQ3W/ref=sr_1_7?s=home-garden&ie=UTF8&qid=1324683582&sr=1-7

4" vortex 175 cfm
http://www.globalindustrial.com/p/hvac/exhaust-fans/in-line-duct-fans/vortex-inline-duct-blower-fan-4-in

4" can 155 cfm
http://www.canfilters.com/fan_metal_rs4.html

watch this video you'll see why I bought a 6" can
http://www.youtube.com/watch?v=fYbLub3Iw2c

Thanks a million. I saw a video similar comparing vortex to valueline. The valueline actually beat the vortex.

I have a couple threads on here that have kind of ran together and I apologize. They were meant as separate questions and I appreciate everyone's responses.

 

[FootClan]

so what size light are you going to use?? you seem to really want the 4" fan but if it a 600w or bigger i must insist you get a bigger fan for your own good.......

 

[LaudanumRx]

Yes a fan can be too small. The filter causes drag on the air flow, which will place a larger load on the motor and bearings, hence more wear and more noise.

I'm with this dude.

For a dual 600w room I use an 8" Phresh with an 8" inline and a 6" Phresh with a 6" inline - both constantly scrubbing and recirculating. I should use an 8" Phresh on the outtake too but it really only gets bad the last ten days of flower. I also have a 4" Phresh and a 4" inline with a duct silencer sitting just outside the door to the room and Ona blocks strategically placed. You can stand right next to the room and no smell with a few pounds of live flowers kicking out fragrance. As a matter of fact, you can even go into the room and only smell the flowers when you put your nose in the canopy - - - if you turn the scrubbers off for even a minute though the whole room, garage, yard, NEIGHBORHOOD starts to wreak.

Go big. Sleep easy.

 

[Warlock1369]

Bigger filtter is always better. IMO

 

[cannabineer]

Yes a fan can be too small. The filter causes drag on the air flow, which will place a larger load on the motor and bearings, hence more wear and more noise.

Since a larger filter has less drag at a given flow rate ... I would say No. A fan can be too small for a space ... but a 4" fan pulling 80 cfm through a filter designed for 2000 cfm would be happy as a clam ... less drag that from a "proportional" filter. Jmo ... cn