Fan filter for rear 140mm fan

[Valantar]

Given that it has two large side vents, I've decided that setting all fans on my Fractal Design Node 304 as intakes is the best option for cooling, to ensure optimal airflow and positive pressurization - the two 92mm intake fans behind the HDD cages aren't really cutting it. However, I'm very, very averse to dust, and this PC sits just off the floor, in a corner, where it's both quite inaccessible for cleaning and easily collects dust. What are my options for fitting a filter on the outside of the rear fan? The fan grille on the back protrudes slightly (perhaps 2mm), so any flat/flush filter won't fit properly. Any ideas what I can use, and where I could get it? I'd prefer something easily removable as pulling the case out to clean the filter is not really an option.

 

[BonzaiDuck]

Given that it has two large side vents, I've decided that setting all fans on my Fractal Design Node 304 as intakes is the best option for cooling, to ensure optimal airflow and positive pressurization - the two 92mm intake fans behind the HDD cages aren't really cutting it. However, I'm very, very averse to dust, and this PC sits just off the floor, in a corner, where it's both quite inaccessible for cleaning and easily collects dust. What are my options for fitting a filter on the outside of the rear fan? The fan grille on the back protrudes slightly (perhaps 2mm), so any flat/flush filter won't fit properly. Any ideas what I can use, and where I could get it? I'd prefer something easily removable as pulling the case out to clean the filter is not really an option.

Maybe I'm the dummy here. But all intake and no exhaust makes Jack's PC a dull pressure-cooker, in my opinion.

You MUST have airflow! Which means that you should exhaust air somewhere. Changing the balance of intake CFMs and exhaust CFMs will allow you to pressurize the case. But as air is recycled within the case, it is not being exhausted very fast (except through seams and any unblocked vents). It will warm up.

For filtering, you might want to filter the intake fans. Leave the exhaust fan(s) unfiltered -- if you choose to accept my observations about this.

If, on the other hand you have significant top-panel vents which passively exhaust air, you may have some pressurization -- or you may not. But it would be better to have fan-assisted exhaust.

For filters, if you don't want to spend anything much, you could get your standard fiberglass AC filters that come in 18"X24" sizes for approximately $2 or $3. You can cut pieces from that. The fiberglass will fray. You might want to put a bead of silicon-sealant around the edge of your cutouts.

After that, you could stick them on any way you want. They won't look very stylish, unless you can insert them between a case-panel-vent and a fan -- and keep them from being sucked into the blades ( not a hard problem to solve.)

There are also some fan screens for certain cases available with magnets, making it easy to remove them for maintenance and cleaning.

 

[Valantar]

Maybe I'm the dummy here. But all intake and no exhaust makes Jack's PC a dull pressure-cooker, in my opinion.

You MUST have airflow! Which means that you should exhaust air somewhere. Changing the balance of intake CFMs and exhaust CFMs will allow you to pressurize the case. But as air is recycled within the case, it is not being exhausted very fast (except through seams and any unblocked vents). It will warm up.

For filtering, you might want to filter the intake fans. Leave the exhaust fan(s) unfiltered -- if you choose to accept my observations about this.

If, on the other hand you have significant top-panel vents which passively exhaust air, you may have some pressurization -- or you may not. But it would be better to have fan-assisted exhaust.

For filters, if you don't want to spend anything much, you could get your standard fiberglass AC filters that come in 18"X24" sizes for approximately $2 or $3. You can cut pieces from that. The fiberglass will fray. You might want to put a bead of silicon-sealant around the edge of your cutouts.

After that, you could stick them on any way you want. They won't look very stylish, unless you can insert them between a case-panel-vent and a fan -- and keep them from being sucked into the blades ( not a hard problem to solve.)

There are also some fan screens for certain cases available with magnets, making it easy to remove them for maintenance and cleaning.

The case has a pretty large vent on one side (for large open-air GPUs, see the third picture here: http://www.fractal-design.com/home/product/cases/node-series/node-304-black) plus a smaller one on the other side (meant as an exhaust for the PSU, but not ducted or sealed in any way). I'm not all that worried about air not getting out. Should I be?

As of now, it has the standard setup: 2x92mm fans as intakes in the front (filtered), with the 140mm at the back as an exhaust. The front fans have a pretty tough job as they are more or less flush with the hard drives, so I'm guessing airflow is getting impeded quite a lot. The current setup has enough negative pressure for there to be significant dust buildup on the side vents. I'm actually pretty sure the 140mm is pulling the PSUs exhaust air into the case, as there is dust buildup on the PSU exhaust vent as well. I have a couple of Noctua NF-B9s to replace the stock Fractal fans, which should in theory deliver more intake air than the 140mm exhausts. However, given how these fans are situated, I doubt even these will give me a balanced or positive airflow setup. Reducing the speed of the 140mm is of course an option, but this will reduce airflow overall.

My thought was to simply switch the orientation of the 140mm around, smack a filter on the outside of it, and let the vents take care of exhausting the air. Will that not work? What do you think?

 

[PhIlLy ChEeSe]

Move the case off the floor, unless you plan on cleaning it regularly. Hopefully you shut it off when not in use, why filter one fan? So the vents a basically on both sides?
If you can place a good CFM fan equal to the rear(Id consider replacing it with a high volume fan) then I could see your ideal working to blow out both sides. If you have carpeting in the room, I would at least place a milk crate under it to move it away from the fibers. Dust can be a computer's enemy, and in certain situations can even be conductive(see my Photo) killed a great board.

 

[Charlie98]

Check out the magnetic dust filters at Frozen CPU, they may have a set for the 304, or you might be able to get a generic one to work. To get it to work over the grille hump, you may have to use double-sided tape or something similar.

 

[PhIlLy ChEeSe]

I thought that case came with them?

 

[Valantar]

Move the case off the floor, unless you plan on cleaning it regularly. Hopefully you shut it off when not in use, why filter one fan? So the vents a basically on both sides?
If you can place a good CFM fan equal to the rear(Id consider replacing it with a high volume fan) then I could see your ideal working to blow out both sides. If you have carpeting in the room, I would at least place a milk crate under it to move it away from the fibers. Dust can be a computer's enemy, and in certain situations can even be conductive(see my Photo) killed a great board.

The PC isn't on the floor, it's on the bottom shelf of my AV setup, about 5cm off of the floor. This helps, but there is still a bit of dust. Luckily, the room isn't carpeted. Moving it is not an option, and it will be running more or less 24/7. I've explained the fan options quite extensively. I'm going to be replacing the stock 92mms with the Noctuas whenever I get around to it, but other than that, there is really nothing that can be done - this is a living room PC, so high RPM/noisy fans are not an option. Two NF-B9s running at max (1600) RPM should ideally produce ~130 M3/h. One Fractal Silent Series R3 140mm is just below 100 M3/h. However, the 140mm is impeded only by its fan grille, while the 92mms are blowing more or less directly onto the hard drives - in other words, they would probably deliver far less than 130 m3/h in real life. Running the 92mms at full speed while slowing down the 140mm can probably be done. Unsure of the effect this would have on overall air flow, though.


Charlie98: Yeah, that's what I was thinking of, but taping them down would kind of ruin the ease of cleaning/maintenance, which is why I asked here. I suppose I could somehow get some steel/magnetic shims in between there, or just see if it somehow will fit around the hump. I actually just discovered a store selling similar filters here in Norway (after looking for months), so I might just order one and see how it goes.

I thought that case came with them?

The front 92mms are filtered, the rear isn't. Which is the whole point of this thread.

 

[Mantrid-Drone]

I'm not understanding the description of the 140mm exhaust fan pulling in (supposedly dust laden air) from the PSU exhaust.

It depends on the PSU design but most typically the PSU fan draws air IN and vents it out the back of the case. The case design and orientation of the PSU at the top or bottom may determine whether it is drawing in air from outside or inside.

If from outside then it is a probably a good idea to filter it for the PSU's sake. But that filtered air never gets inside the case it passes straight through the PSU and out of its own exhaust vent.

But if the PSU is orientated to draw air from inside the case that should have already been filtered at the intakes. Adding a filter to the PSU would just reduce its efficiency. As it is sucking in already warm air reducing the airflow further could lead to an additional temperature rise.

The point is that in neither circumstance does the case exhaust fan need to be filtered. The only thing that might do is as a result of it affecting the fan's efficiency leading to an increase in the positive air pressure but, possibly, also a temperature rise inside the case.

But in neither orientation can I see how an exhaust fan could be drawing dust laden air from the PSU exhaust into the case.

 

[Micrornd]

Given that it has two large side vents, I've decided that setting all fans on my Fractal Design Node 304 as intakes is the best option for cooling, to ensure optimal airflow and positive pressurization - the two 92mm intake fans behind the HDD cages aren't really cutting it. However, I'm very, very averse to dust, and this PC sits just off the floor, in a corner, where it's both quite inaccessible for cleaning and easily collects dust. What are my options for fitting a filter on the outside of the rear fan? The fan grille on the back protrudes slightly (perhaps 2mm), so any flat/flush filter won't fit properly. Any ideas what I can use, and where I could get it? I'd prefer something easily removable as pulling the case out to clean the filter is not really an option.

Either of these will probably work for you.
They come with magnetic "stickon" that the filter can adhere to, which will probably compensate for the 2mm or the 160mm version may span over the projection or you can use the filter without the "stickon" as the filter "frame is magnetic.
(The "stickon" is provided for use if the case is plastic or aluminum)

The filter material is very flexible and will accommodate that 2mm projection, but the magnetic "frame" should stick to a flat surface (it too is very flexible)
I use these myself in the 300mm round size and they work great and are super simple to clean.

http://www.performance-pcs.com/demciflex-140mm-magnetic-fan-dust-filter-black.html#Features

http://www.performance-pcs.com/demciflex-160mm-magnetic-fan-dust-filter-black.html

BTW - FROZEN CPU has been out of business for quite some time now, as is noted on their home page.

 

[Valantar]

I'm not understanding the description of the 140mm exhaust fan pulling in (supposedly dust laden air) from the PSU exhaust.

It depends on the PSU design but most typically the PSU fan draws air IN and vents it out the back of the case. The case design and orientation of the PSU at the top or bottom may determine whether it is drawing in air from outside or inside.

You've misunderstood. The PSU intake is on the bottom of the case, and is filtered. However its exhaust is inside the case (the PSU sits in the front of the case). There is a corresponding vent, but there is a ~3 cm gap between the actual PSU exhaust and this vent (due to, I guess, the need to fit the PSU extender cable inside the case). And, as I've noticed dust building up on the outside of this vent, I get the feeling that in reality, the PSU isn't exhausting air here, but rather that the PSU exhaust air is being pulled into the main chamber of the case due to poor airflow from the 92mm fans. I could, of course, rig some sort of duct (cardboard or something) to make sure the PSU exhaust gets out of the case properly.

I'm not talking - at all - about filtering an exhaust fan. Why on earth would I want to keep dust inside the case? I'm talking about turning the rear exhaust into an intake, and filtering this. If you're still confused, please, take a look at the pictures of the case layout in the link a few posts up.

Either of these will probably work for you.

[...]

The filter material is very flexible and will accommodate that 2mm projection, but the magnetic "frame" should stick to a flat surface (it too is very flexible)
I use these myself in the 300mm round size and they work great and are super simple to clean.

http://www.performance-pcs.com/demciflex-140mm-magnetic-fan-dust-filter-black.html#Features

http://www.performance-pcs.com/demciflex-160mm-magnetic-fan-dust-filter-black.html.

Thanks! Those are actually the exact filters that I (finally!) found a Norwegian store for the other day. The kind of info you just provided was just what I was looking for, though. I guess I'll get the 140mm version and see how well it fits. Thanks!

 

[Charlie98]

BTW - FROZEN CPU has been out of business for quite some time now, as is noted on their home page.

Jeepers! They aren't real obvious about it, however... Hope they get things squared away.

 

[Micrornd]

Jeepers! They aren't real obvious about it, however... Hope they get things squared away.

Actually, it made big hews on many of the tech forums (except here for some unknown reason) when it happened.
Google for it, it's quite an interesting read, as apparently many squirrely things went on.

 

[Valantar]

Actually, it made big hews on many of the tech forums (except here for some unknown reason) when it happened.
Google for it, it's quite an interesting read, as apparently many squirrely things went on.

I remember reading about that in these forums, although not in its own thread. Not news to me, at least.

 

[PhIlLy ChEeSe]

Nothing a good rehab can't fix I'm sure.........................

 

[BonzaiDuck]

Well, let me add these remarks to dovetail "filtering," "reseller choices" and "globalization."

For months, I've been toying with the idea of buying those DEMCIFilter filter kits for my HAF 922's. These had been available, among other sources, from Frozen CPU:

http://www.frozencpu.com/cat/l3/g47...Fan_Filters-DEMCi_Flex_Fan_Filters-Page1.html

Initially, I thought that you had to buy the "HAF 922" kit. Since I have specific filtering needs with those cases, and since I block off unused vents with precision-cut black foam-art-board, I could see that I could maybe use two kits for three HAFs. I still balked at spending the money. You can make your own fan filters from nothing more formidable than a $2 fiberglass AC panel -- cut into pieces of a prescribed size. You could glue "borders" on the filters with more precision-cut art-board.

I already knew about the Frozen CPU troubles, and another web-search a few days ago turned up this page:

http://www.demcifilter.com/

The URL doesn't indicate "country of origin," which escaped me until I figured out what "SA" means: South Africa. Among the shipping choices were USPS -- US Mail, DHL and FedEx. I could pick and choose which filters I wanted. Further, the front-panel filters for the HAF 922 feature the filter itself, and a form-fitting rubberized "magnet" to hold it in place.

So I ordered three side-panel filters, three "magnets" with one front-panel filter, and a single top-panel filter. The bill came to $87 and change, including shipping. If I'd bought kits, either from a Frozen CPU competitor of DEMCiFilter, The price-tag would have been closer to 3x $60 or $180. I was actually buying one item that I didn't need: I only wanted it in anticipating a water-cooling build over the next year.

I chose to buy the magnets @ ~$4 each because the filters for them are more like $15 each, and I thought I could manufacture my own to use with the magnets.

Somehow, choosing the DHL shipping option twice only resulted in the order's shipping for a $1 less with USPS. Then I discovered the point of origin . . . . and the wait time.

I guess I waited long enough to either make or buy filters.

However, if you want more DEMCiFilter products with the magnets and other features, you can get them at Performance PCs:

http://www.performance-pcs.com/catalogsearch/result/?q=DEMCiFilter

And! Performance PCs, as far as I know, ships from Florida.

 

[Micrornd]

BonzaiDuck -

http://forums.anandtech.com/showthread.php?t=2424287&highlight=

I order mine direct from DEMCiFilter, as I plan ahead and the shipping time is not a factor.

The important thing to remember also is that DEMCiFilter will custom make ANY size and shape filter you want.

And, yes, Performance PC ships from Palm Bay, FL., about an hour's drive from me.
Anything I have shipped from them, gets here normally next day, day after at the absolute latest.

Oh, and while those $2 fiberglass filters are cheap, they are not really cleanable and reusable, like the DEMCiFilter filters are.
Mine take a whole 1 minute to clean

 

[BonzaiDuck]

BonzaiDuck -

http://forums.anandtech.com/showthread.php?t=2424287&highlight=

I order mine direct from DEMCiFilter, as I plan ahead and the shipping time is not a factor.

The important thing to remember also is that DEMCiFilter will custom make ANY size and shape filter you want.

And, yes, Performance PC ships from Palm Bay, FL., about an hour's drive from me.
Anything I have shipped from them, gets here normally next day, day after at the absolute latest.

Oh, and while those $2 fiberglass filters are cheap, they are not really cleanable and reusable, like the DEMCiFilter filters are.
Mine take a whole 1 minute to clean

On the fiberglass filters, if I prepare them properly, I can blast them with a garden hose, or I can hit them with my ED500 Metro-Vac, and they stay fairly clean.

The real problem with the fiberglass shows with the way it frays when cut, and the way it bulges depending on how it's fitted to the case-panel vent. One solution is to cut a frame for them of two matching pieces of black foam art-board. You would glue the fiberglass cutouts between the black frames. If you needed them to be half as thick, you could clamp and compress the art-board.

Also, I'm looking at this from the "need" versus "want" angle. HAF 922's already have a filter screen for the lower-front-panel 200mm fan, but you need to remove six self-threading screws with the plastic case facie to service it. You have to release the lock on any upper-drive-cage parts like an optical drive or hot-swap-bay -- pushing them into the case, then pull down on the facie a certain way as you pull it away from the case at the bottom.

P-I-T-A.

But they're still working filters. I can take my time to play around with my ideas, and choose to order 2x $15-each panels later.

The fiberglass AC filters also may come in colors you don't like. However, I found a source where I can get a dozen or so for $10 to $15, with a choice of white. The LED fans obscure any slight hint of gray on the fibers.

 

[BonzaiDuck]

Comment for Micrornd:

My filters from DMCIFlex arrived from South Africa today.

NOW I understand something of either why you advised buying the filter component for the HAF 922 front-panel, or why I should've followed your advice regardless of such intention.

Those "magnet" components stick on the plastic front panel with their own adhesive, and provide a magnetic contact for the magnet in the actual filter.

Looks as though I'll need to buy two more filters. This time, I'll order from Performance PCs.

But I acknowledge this. The South African firm is very reliable and good with customer relations. Very nice folks, indeed. I just don't think I want to wait three weeks for the next parts! :biggrin:

 

[Micrornd]

BonzaiDuck

You can get them quicker, but you do have to pay more for shipping.
Any item or shipping not on their webpage is still available, just call and talk to them.
Very easy to deal with, polite and willing to work with you.

My initial order of custom-made filters took only 9 calendar days to arrive in FL, but it was wrong.
(I got someone else's order (from Germany) and he got mine)

I simply notified DMCIFlex, and from the time they received my e-mail until the time my custom-made filters were in my hands was just a little under 2 days.
Customer service doesn't get better than that!

 

[BonzaiDuck]

BonzaiDuck

You can get them quicker, but you do have to pay more for shipping.
Any item or shipping not on their webpage is still available, just call and talk to them.
Very easy to deal with, polite and willing to work with you.

My initial order of custom-made filters took only 9 calendar days to arrive in FL, but it was wrong.
(I got someone else's order (from Germany) and he got mine)

I simply notified DMCIFlex, and from the time they received my e-mail until the time my custom-made filters were in my hands was just a little under 2 days.
Customer service doesn't get better than that!

Ah! For a once-upon-a-time "free-market" economist turned darker than pink, it bolsters my faith in a private sector -- globalized or national. But for the performance of the "public corporation" known as USPS in this case, I made sure to bolster their morale when I received the package. Surely, it was a win-win-win-win for everyone.

 

[Micrornd]

The "just a little under 2 days" from SA, through customs, to FL, was by FedEx International Priority, so I consider that a "national" "public corporation" win :biggrin:

 

[thetuna]

Hey OP.
I see you already bought something, but I'll just share what I did as well.
My case is an nzxt h440, which also has some bulging on the rear 140mm fan grill.

I have 3 filtered 120mm intake fans on the the front of the case, 1 140mm intake fan on the rear, and 2 140mm exhaust fans on the top.

I bought a white (to match the case) silverstone 140mm magnetic mesh filter in the hopes it would simply stick to the rear.
Sadly, the magnets are weak as a noodle.
So I attached the filter using the fan mount screws.
The filter bent over the hump just fine, it's just not as convenient as magnets.

 

[BonzaiDuck]

Hey OP.
I see you already bought something, but I'll just share what I did as well.
My case is an nzxt h440, which also has some bulging on the rear 140mm fan grill.

I have 3 filtered 120mm intake fans on the the front of the case, 1 140mm intake fan on the rear, and 2 140mm exhaust fans on the top.

I bought a white (to match the case) silverstone 140mm magnetic mesh filter in the hopes it would simply stick to the rear.
Sadly, the magnets are weak as a noodle.
So I attached the filter using the fan mount screws.
The filter bent over the hump just fine, it's just not as convenient as magnets.

That sort of defeats the purpose of the item, but for the filtering. I had a similar problem, but not nearly as serious. I had to make my own "shock-absorber" mounts for case-side-panel fans. I used two black nylon wire-ties (with the buckles) so that a buckle on the exterior and a buckle on the innermost side of the fan are cushioned by a split black rubber "donut" sold to prevent wire-chaffing in metal holes. The exterior buckles -- four of them -- are nearly invisible for matching the case color, but they "bulge" the filter mesh so that in maybe one place around the magnetic border the magnet is separated by about 1/16" from the case panel.

We used to fuse the ends of nylon climbing rope in the Park Service by setting the frayed end on fire and blowing it out. So I'm wondering if I can do something similar to put four neat little holes in the filter mesh -- perhaps with a soldering iron. Not exactly a "must-do" requirement, and so I'm only "thinking about it."