Inductor Fans - Is this One Useful or Useless?

Going to be beginning construction on my 150w HPS cabinet and was curious about the ventilation.

I found some great 6" inductor fans at Lowes. You can't find them on the website so I went and grabbed some pictures. They are 160CFM free air, with up to 250CFM boosted, fans that only cost around $35 dollars. They also have an 8" 500CFM boosted fan for around $45 if my memory serves me correctly. But, the 6" 160CFM seemed enough.

A lot of the larger cabinets I have seen use blowers instead of fans. However, I've also seen people using computer fans for all of their ventilation. So, I wanted to get opinions on some others who have ventilation for their cabinets.

The cabinet is going to be around 2'Dx3'Wx3'H and I was going to use this fan to pull air through my cooling tube and be the main ventilation for the flowering chamber.

Please check out the pics and let me know what you think:


Here's what the fan looks like. It's pretty well put together from the feel of it:

Those will NEVER push 250 CFM. 6" Fantech XL inline fans only push 200cfm, the 250 figure on the box relates to those type of fans ability to Boost cfm over that of a proper inline fan. Actually, the axial type fans used on computers and audio equipment will actually flow more air.

imnotcrazy said:

Those will NEVER push 250 CFM. 6" Fantech XL inline fans only push 200cfm, the 250 figure on the box relates to those type of fans ability to Boost cfm over that of a proper inline fan. Actually, the axial type fans used on computers and audio equipment will actually flow more air.

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Ahh quite right. Thanks for the tip. I looked around and found additional specs. It pushes 160CFM of free air. Up to maximum of 250CFM of boosted air.

Knowing that, would 160CFM be a decent amount for the price?

(editing my original post to reflect this)

Not to mention it will be loud as hell. I use the small lasko fan that is a squirrel cage in my 150w cab. It has the ability to blow through back pressure and suck/push through a 4" duct. This really cuts down on the airflow though since I'm bottlenecking all that air into a small 4" duct.

During this summer I had a summer intern position at a wastewater treatment plant in the engineering department and I saw something that would improve my cab. One of the treatment processes it to airate the water and they do this by having a giant 20' deep 'swimming pool'. Underneath the pool they have an open chamber that the air is injected to. Because the chamber is open, the pressure gets equalized before exiting the air diffusers.

So for my box, this is what I plan. Ample passive intake. I just added another 8"x8" darkroom louver so now I have 2. Currently my cooling sucks from a cooltube (4") goes into fan, then blows through another 4" duct to a scrubber. Lots of loss here...So I'm going to mimic the treatment plant.

First, remove my squirrel cage fan. Instead of exhausting into a small 4" duct, I'm going to cut a 3"x15" rectangle out of the top of the box in the back for the exhaust. Just below this cut I will make a screen to hold the carbon. This will be a 13"x18" bed of carbon which will equate to about the same surface area as my 6"x16" carbon scrubber in a can. Just below this 2" thick layer of carbon I will leave a 2-3" gap. This gap acts like the boxes below the basin at the treatment plant---to allow the air to be equal pressure before going through the carbon. At the bottom of the gap, I will put another layer of cardboard and make cutouts for the 4 120mm computer fans I just ordered.

Essentially I'm making a box inside my box that will only be about 6" below the top of my cab. At the bottom of the box will be the 4 fans. A few inches above the fans will be a layer of carbon being held by a screen. Just above that will be a large exhaust. There will be no restricting 4" ducting. Because heat naturally rises, it will also help the dynamics of the box sucking cool air from the bottom and easily exhausting it out the top back of the box.

This will be about revision 5 for my cooling system with each time getting more efficient and quieter. One of the bonuses doing it this way is I will have the fans connected to variable ac/dc converters so I can adjust the speed of the fan easily based on my needs.

Hope this helps and gives you another idea. I'll be making this upgrade in a week or two and will post some pics as my plants develop.

160 cfm of "free air" means with no load (ie: ducting runs) on the fan. Adding any kind of ducting will significantly reduce that number.

imnotcrazy said:

160 cfm of "free air" means with no load (ie: ducting runs) on the fan. Adding any kind of ducting will significantly reduce that number.

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Gotcha.

Thanks a ton. You've definitely helped me understand what I'm looking for when it comes to ventilation.

Quazi, did you end up buying the fan (I'd imagine so since the pics show an open box) If so, and you hooked it up, how loud was it? I was looking in to those pretty hardcore the other day... Helps that a lot of cool tubes/air cooled hoods are made with 6" openings.

I know you can get 120mm (about 4.7 inch) computer fans pushing 110+ CFM and it is pretty easy to control the speed on those, some come with speed controllers, others you can just get an adjustable AC adapter and take em down to say, 9volts rather than the full 12...

check out Newegg.com for a VERY good computer fan selection: here is the direct link to their fan section.

http://www.newegg.com/Store/SubCategory.aspx?SubCategory=573&name=Case-Fans

It's very nice because you can sort by sound level and CFM on the left hand side.

Barnt said:

So for my box, this is what I plan. Ample passive intake. I just added another 8"x8" darkroom louver so now I have 2. Currently my cooling sucks from a cooltube (4") goes into fan, then blows through another 4" duct to a scrubber. Lots of loss here...So I'm going to mimic the treatment plant.

First, remove my squirrel cage fan. Instead of exhausting into a small 4" duct, I'm going to cut a 3"x15" rectangle out of the top of the box in the back for the exhaust. Just below this cut I will make a screen to hold the carbon. This will be a 13"x18" bed of carbon which will equate to about the same surface area as my 6"x16" carbon scrubber in a can. Just below this 2" thick layer of carbon I will leave a 2-3" gap. This gap acts like the boxes below the basin at the treatment plant---to allow the air to be equal pressure before going through the carbon. At the bottom of the gap, I will put another layer of cardboard and make cutouts for the 4 120mm computer fans I just ordered.

Essentially I'm making a box inside my box that will only be about 6" below the top of my cab. At the bottom of the box will be the 4 fans. A few inches above the fans will be a layer of carbon being held by a screen. Just above that will be a large exhaust. There will be no restricting 4" ducting. Because heat naturally rises, it will also help the dynamics of the box sucking cool air from the bottom and easily exhausting it out the top back of the box.

Click to expand...

That sounds like a pretty nifty setup. I am having a little trouble envisioning it though. You should take some pictures of your completed setup as it seems pretty interesting and possibly helpful to me or others.

jdog12 said:

Quazi, did you end up buying the fan (I'd imagine so since the pics show an open box) If so, and you hooked it up, how loud was it? I was looking in to those pretty hardcore the other day... Helps that a lot of cool tubes/air cooled hoods are made with 6" openings.

I know you can get 120mm (about 4.7 inch) computer fans pushing 110+ CFM and it is pretty easy to control the speed on those, some come with speed controllers, others you can just get an adjustable AC adapter and take em down to say, 9volts rather than the full 12...

check out Newegg.com for a VERY good computer fan selection: here is the direct link to their fan section.

http://www.newegg.com/Store/SubCate...&name=Case-Fans

It's very nice because you can sort by sound level and CFM on the left hand side.

Click to expand...

No, I have not purchased it. I just cracked open the box and snapped a picture in the store.

Thanks for the link for the computer fans. I've been considering going this route as well. Although I haven't ruled out this fan completely, it sounds like alternatives may be beter

Sweet thanks for the link. I was wondering about computer fans as well.

I haven't purchased the fan yet, by the way. I just opened the box and took a picture. I'm definitely considering alternatives at this point but I haven't ruled it out completely yet.

Quazi said:

That sounds like a pretty nifty setup. I am having a little trouble envisioning it though. You should take some pictures of your completed setup as it seems pretty interesting and possibly helpful to me or others.

No, I have not purchased it. I just cracked open the box and snapped a picture in the store.

Thanks for the link for the computer fans. I've been considering going this route as well. Although I haven't ruled out this fan completely, it sounds like alternatives may be beter

Sweet thanks for the link. I was wondering about computer fans as well.

I haven't purchased the fan yet, by the way. I just opened the box and took a picture. I'm definitely considering alternatives at this point but I haven't ruled it out completely yet.

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Let us know what you go with and how it worked out for you.

FWIW I vented my 150 HPS with a 4" 76 CFM axial and a single 4" passive intake. I then upgraded to a 250 CMH that turned my cab into an easy bake oven. The addition of a second 4" passive intake brought temps back under control.

That duct booster fan is used in homes when you have a room that takes a long run of ducting say over 50 feet. Floor vents that are close to the furnace will have good pressure to them but those that are a greater distance away may have low to almost no flow to them because the length of the ducting adds more resistance. The air is going to take the path of least resistance instead of long runs of ducting with turns or sharp bends as those add resistance too.... so to assist the primary fan that being a furnace in a home or perhaps a vortex type in a grow room you could use one of these booster fans to assist pushing the air thru that exceedingly long piece of ducting.

These are not very powerful fans and only used to assist or boost already moving air. If your talking about sucking air out of a cab of the bottom thru small holes into one chamber then the next and into an air cool tube and then finally out into a carbon filter.....my advise would be to buy a small squirrel cage fan and a speed controller for just a little bit more money and then you will be certain that you can pull and flow the proper amount of air....

The only situation I can see that booster fan being used for is perhaps if you have a cool tube setup in your grow box and you wanted to have separate ventalation systems so you could use C02 and to cool the lighting you have a short piece of duct that runs from one side of the cool tube to the outside of the cabinet for fresh air intake and another short piece of ducting off the other side of the cool tube and out of the cabinet and to the booster fan then perhaps this fan might flow enough air to simply keep a 150w or perhaps a 250w bulb fairly cool but I cant see it doing much more than that....

I actually used a 4.75" x 2" 150 or 200CFM Axial (PC) type 120Vac fan for cooling this box that had 4 x 3' 32Watt and 2 x 15Watt fluorosand it worked extremely well:


You can kind of see the fan housing box in the back of this picture: