Critique my concept: PC fan carbon scrubber

[mycabinetisgreen]

I see you already figured out that CPU fans won't cut it. They can't even move air when fighting heavy temp differences. I've tested this in my ice shack and they can't pull 30 degree celcius air down 8ft to the floor if the floor air is only 5 degrees celcius. The cold air is too heavy/hot air is too light. I inlined 4 fans exactly like you were talking about using, with nothing restricting them but the air temperature itself and it barely moved the air.

CPU cooling uses the "hot air rises" science to work... the fans can't really do much at all when restricted. They won't pull air through a carbon filter. They can pull it through those cooking filters(in oven range hoods).

Anyway, now that you've settled on going with an inline fan like the one pictured above. I'd suggest wrapping the fan, and the venting with noise deadening material. Foam works. Pink insulation works too. Anything soft that can soak up the vibration. You'll be surprised how much a little pink insulation can go to help deaden the sounds. Also, when bolting the fan to the case, I would suggest using rubber grommets. This will virtually eliminate the vibration transfer from the fan housing to the cabinet.

HTH
MJ.

A fellow Canadian...how aboot that, eh?

Appreciate the feedback and tips. I have every intention of mounting anything and everything that might vibrate with rubber gaskets/grommets. Further dampening....likely taking your advice...will come once I hear the beast in action.

As an aside, my last hope for PC fans resided with the type optimized for pressure. But yeah, it appears the in-line is the only way to go. And that's alright. Consider the cost of better-quality PC fans, the in-line BHMC is using isn't all that pricey.

 

[mycabinetisgreen]

Got my new fan installed. It's definitely louder than the previous setup, but works much better as well. Temps in my box are in control now, and I have zero smell. I'll play around with the dimmer to see how quiet I can get it while still keeping temps in check

Looks super clean, like the rest of your build. Is it always on, or do you have it set to fire up at a given temperature limit?

 

[MJCanada]

If you find a way to get that fan across the border besides driving to get it let me know. Best Canadian version is $120 CAD...

 

[mycabinetisgreen]

If you find a way to get that fan across the border besides driving to get it let me know. Best Canadian version is $120 CAD...

Yeah, the cheapest I've seen elsewhere is about that much, unless you're looking to buy online. That fan was listed on ebay for $100 CAD. The same listing is now up over a grand for whatever reason, obviously an error. No filter included for the $100 price, of course.

 

[xX_BHMC_Xx]

Looks super clean, like the rest of your build. Is it always on, or do you have it set to fire up at a given temperature limit?

Humidity was out of control at night, so it's running constantly. I have it dimmed way down now and it seems to be doing just fine, definitely quieter than the 100cfm muffin fan I was running before. Don't really know what I'm going to do with the temp controller now, maybe run it in the veg area once that's set up.

 

[CCreQQ]

Just so you know, you've got the right concept with the fans in series vs parallel, but you'll create even more static pressure by stacking 2 fans directly on top of each other before and after the filter, and pressure is what you need
Optionally you could add 2 more fans, one at the inlet and one at the outlet

But If you go [duct][fan|fan]][filter][fan|fan][duct] you'll have a better pressure flow and can push the air through a longer run of carbon.

An even better bet would be to make two filters and set it up like this:

[Fan|fan][filter][fan|fan][filter] <<airflow <<

And reducing the bed thickness by half

By far the best option would be to have two exhausts and two completely separate filters though, with two stacked fans each (2 has the best efficiency)

Google fan series vs parallel to find a graph

Best regards,
CreQ

 

[mycabinetisgreen]

Just so you know, you've got the right concept with the fans in series vs parallel, but you'll create even more static pressure by stacking 2 fans directly on top of each other before and after the filter, and pressure is what you need
Optionally you could add 2 more fans, one at the inlet and one at the outlet

But If you go [duct][fan|fan]][filter][fan|fan][duct] you'll have a better pressure flow and can push the air through a longer run of carbon.

An even better bet would be to make two filters and set it up like this:

[Fan|fan][filter][fan|fan][filter] <<airflow <<

And reducing the bed thickness by half

By far the best option would be to have two exhausts and two completely separate filters though, with two stacked fans each (2 has the best efficiency)

Google fan series vs parallel to find a graph

Best regards,
CreQ

Much appreciated for your advice, this is exactly what I was hoping to hear. My trouble, however, is that my attention has shifted to lighting and I pretty well resigned myself to budgeting for an in-line fan for the sake of guaranteed results without the effort required, thus enabling me to devote my time to DIYing the lighting. If you think it would be worthwhile, I'm open to suggestions, but at this stage if I'm stacking 4 decent PC fans, I'm thinking the cost difference for an in-line will be negligible.

 

[mycabinetisgreen]

Humidity was out of control at night, so it's running constantly. I have it dimmed way down now and it seems to be doing just fine, definitely quieter than the 100cfm muffin fan I was running before. Don't really know what I'm going to do with the temp controller now, maybe run it in the veg area once that's set up.

You could always send it to me! XD

That's very good to know, though, thanks for keeping me informed.

 

[SonsOfAvery]

I kept my cab simple 1x 200mm pc fan on intake, 2x 200mm pc fan on out take both with 210mm cooker hood carbon filters on the out side of the fans, near enough silent and no smell. Filters cosy £9 the pair and 4x fans £19 off eBay.

Hey, I have recently made a similar set up for a micro grow area, almost identical to what you say above. But I was wondering if you have the filters setup so the fan pushes or pulls the air through it?
I have mine set up at the moment to push the air through, but it seems a little weak.

 

[torontoke]

Hey, I have recently made a similar set up for a micro grow area, almost identical to what you say above. But I was wondering if you have the filters setup so the fan pushes or pulls the air through it?
I have mine set up at the moment to push the air through, but it seems a little weak.

Pulling air through is the path of least resistance on the fan so u would get a few extra cfm

 

[KrazyG]

Hey, I have recently made a similar set up for a micro grow area, almost identical to what you say above. But I was wondering if you have the filters setup so the fan pushes or pulls the air through it?
I have mine set up at the moment to push the air through, but it seems a little weak.

I use the fans on top of each other( in series?) to push the hot air through, they don't have enough guts to pull through the filter. When connected in series they work a lot better and seem quieter.

 

[SonsOfAvery]

@KrayzG Ahhh okay, that makes sense. I have mine set up separately at the moment. I'll have to re-adjust and stack them up.
Thanks!

 

[Chech]

If it helps ..

I have a 120mm Vedar pc fan rated at 77cfm - pushing through a 100x150mm carbon scrubber from ebay, no smell, great airflow, no heat issues (cob led lights)

Although my space is only 1x1x2.5 they do work,

Ive noticed at 12v the fan makes noise that you can just notice..

But running at 9v it STILL does the job great but is Silent! - if i was not going to work id stack another fan to increase the pressure ..

im not sure of the cfm after adding the scrubber but if you get a desktop fan and put your hand in front of it, its the similar type of air force you could expect being vented..

 

[xX_BHMC_Xx]

The thing to stress here if you are going to run a PC style fan; make sure you're running RO or distilled water in your humidifier (if you have one) and in your plants as well of course. If you have high levels of calcium in your water it will form carbonate and plug your filter enough that the fan won't be able to overcome it. Then one day you'll come home to check on your plants and find that humidity hit 92% overnight and temps are now cresting 90F with the lights on because there's no airflow at all...