Dust Buildup with Extremely Positive Pressure?

[Ginger Penguin]

Hi all,

 

I'm currently working with my partner to build them a new system as their current system is from 2014 and preeeety sluggish. The plan was to reuse the case, PSU and GPU so I opened up the case to get a look at the cooling inside to see if anything should be updated. There was SO much dust in there despite dust filters being regularly cleaned. I don't think it had actually been opened and cleaned since the GPU was replaced in late 2016, I think. But still, I wouldn't have expected quite that much. The case is a Silverstone TJ08 with a 180mm fan up front and a 140mm fan out the back and the PSU is mounted upside-down effectively acting as an exhaust. Now, as far as I could tell (I'm pretty novice so this was supposed to be a fun project to do together), the 140mm rear fan is acting as an intake rather than exhaust which seemed off to me. I know positive air pressure is supposed to help with dust build-up but with no exhaust save for the PSU, is that a bad way to do things? My current plan would be to flip the rear fan and make it an exhaust and keep the PSU as is.

 

Any tips greatly appreciated!

[SupaKomputa]

i recommend negative pressure, as the hot air can be sucked out immediately.

With positive pressure you may risk having hot air pocket accumulated inside. 

[Eighjan]

Positive pressure IS supposed to prevent dust build up inside a case; but good overall airflow is just as important.

[Eighjan]

15 minutes ago, W.D. Stevens said:

Now, as far as I could tell (I'm pretty novice so this was supposed to be a fun project to do together), the 140mm rear fan is acting as an intake rather than exhaust which seemed off to me. I know positive air pressure is supposed to help with dust build-up but with no exhaust save for the PSU, is that a bad way to do things? My current plan would be to flip the rear fan and make it an exhaust and keep the PSU as is.

That doesn't sound like a great set-up, initially, but the planned rectification should solve it.

[Ginger Penguin]

Thanks for the advice! I was planning on aiming for a balanced leaning on positive air pressure. I haven't heard anyone recommending negative pressure and honestly, I don't think the new system is going to get all that hot. It's a fairly everyday PC with some occasional light gaming so after clearing out the dust before the rebuild, I think it's probably fine to just flip that rear fan and keep the front and PSU orientation the same.

 

Thanks everyone!

[freeagent]

I go for slightly positive myself. If dust is a concern, you won’t escape it. You can slow it down with filters, but you also starve your case for fresh air. Not ideal in the summer months. An air can or datavac should be on hand for dust control anyways.

[LogicalDrm]

Unless you are working with sealed box, there will always be some dust. Either coming from cracks and holes near exhaust fans. Or just falling in when PC is not used. So best is to look for neutral pressure and keep the actual room clean. This way the dust build-up stays at minimal and cleaning PC twice a year is enough.

[-rascal-]

If the rear 140mm is used as an intake, and there is no dust filter for that fan location, then the dust is probably coming in from there.

[Ginger Penguin]

6 hours ago, -rascal- said:

If the rear 140mm is used as an intake, and there is no dust filter for that fan location, then the dust is probably coming in from there.

Oh, yeah. Of course! Why didn't I think of that? Possibly because I really hadn't entertained the thought that the rear fan was an intake until I felt the air coming off of it. We're doing an interim upgrade (just adding a SATA SSD - yes, it's that slow - for now before the full upgrade in a couple of months) this weekend where I'll get rid of as much dust as I can and reverse the rear fan. Thanks for pointing that out.