Fan before or after filter i.e. push or pull

[gromit23]

Hi All,

I built a new grow cab and have a filter to put in-line venting to the outside. I have a light tube and fresh air for the cab on sep lines then t-ing together then venting outside. I have a filter to install in-line. I just received my S&P fan today (pretty quiet). ? Do I mount the fan before or after the filter? ?Push or pull the air?

Thanks for your help...

 

[GigaGrew]

borrowed this from some random hydroponics shop website, hope this helps you out =)

How to Set Up a Can-Fan / Can-Filter Combo

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CAN-FAN / CAN-FILTER COMBO SETUP SUGGESTIONS:

You can set CAN-FAN / CAN-FILTER combos up in several different ways.​

You can push or pull air through the filter, but the outer poly wrap is intended as a pre-filter to remove dust before it gets to the carbon, so it's better to draw air up through the filter. The carbon inside will last longer with a clean pre-filter. The pre-filters are pretty cheap to replace, but you can hand wash them too as needed.​

MOUNTING FAN AND FILTER:​

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We don't recommend mounting the fan directly onto the filter, as the vibration of the fan can cause settling of carbon in the filter. This settling may allow air pockets in the carbon to develop at the top, and untreated air to pass through the filter.​

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You can hang the fan from a couple of rubber bungee cords to absorb any vibration and cut down on fan noise. Then connect the fan to the filter with standard clothes dryer ducting (from a hardware store) securing them together with either duct tape or screw-clamps.​

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The filter can then be placed in a dry location either sitting on the floor, or hanging from a ceiling. The length of ducting between the fan and filter doesn't matter as long as the ducting is a clean, unrestricted shot between the two. ​

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Straight PVC pipe can also be used for longer distances if necessary. For maximum effectiveness, the closer the filter is to the fan, the better, and we'd recommend keeping them within a few feet of each other. You can get some distance between them if you have to but it cuts down on the air speed.​

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AIR FLOW OPTIONS:​

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There are two really good ways to use the CAN combos.​

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The first is as a 'polishing' filter where you put the connected fan and the filter into the same area together. By drawing air through the filter repeatedly in a closed area, it will effectively keep the air in that area free of odors. This is how they use CAN filters in airplanes, and in other closed environments.

The second way to use the CAN combo is as a pre-exhaust air cleaner to remove odors from the air as you exhaust air from your garden area to another room. You'll need a hole in a wall somewhere for this setup in order to exhaust the cleaned air out. All of the air that passes out of the room through the filter will be clean air. This setup is effective enough to use the heat from your growroom to help heat your home and not have to worry about organic fertilizer odor issues in the house. They use CAN filters this way in hospitals, auto body shops, chemical plants, and many other commercial applications. ​

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Remember, that in every exhaust application, you have to have an unrestricted intake somewhere in the enclosure. If you run an exhaust fan without another fan for intake (not always necessary), or without a passive intake (a hole) somewhere in the room, you may run into heat issues. Any exhaust fan is going to need an intake in order to work to it's best ability. A rule of thumb is that if you have one 6" exhaust fan, you should have the equivalent of 2- 6" holes for passive intake somewhere else in the enclosure or room.​

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GENERAL INFO:​

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All CAN-FILTERS last from 1 to 1-1/2 years - occasionally longer. ​

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The higher your humidity, and the dustier the environment, the shorter the life of the filter.​

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To prolong the life of your equipment, clean the poly pre-filter regularly, and every once in a while shake or roll the filter around to expose new carbon within the filter.​

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Your CAN-FAN will last for many years. We've been selling these fans for about 6 years now, and have never had a warranty issue yet. ​

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If you find that you need any additional fertilizer odor control try ONA PRO Gel. It's a good compliment to the CAN Combo if needed.​

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INSTRUCTIONAL VIDEOS:
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[JJ Bones]

Pulling (sucking) the air through the filter works best. You can do either though.