Silencing my Dell T340 – Part 3

At long last, part 3 of my journey to try and cool my T340 with out having to listen to a hair dryer.

Here is part 1 and part 2 if you’re curious about what I’ve done so far.

I ended up getting a 3D Printer sometime after I wrote part 2 and one of the projects I had in mind was designing and printing a shroud that I could attach fan(s) to and slide over top of the heatsink in my T340 to create a better seal for airflow and get rid of the zap strap solution from part 2.

I was hoping that having a proper shroud would increase cooling efficiency, unfortunately I don’t think it did much for my overall temperatures BUT it did make it so my fan is now easily replaceable and just slides overtop the heatsink. More on that later (or just scroll to the bottom).

Here is what I came up with:

It’s hard to tell in the photos but there is a tiny lip at the bottom that snugly tucks over the base of the heatsink to prevent the whole shroud from just sliding off over time.

I used the rubber fan holders that Noctua includes with their fans and they fit very nicely in the holes. If you’re going to use a different fan I can’t guarantee the screw holes will hold up to standard case fan screws. A M4 screw and nut should work just fine though.

When mounting the fan be very careful. I printed at 0.3mm layer height and found that if I yanked too hard when installing/removing the rubber stoppers the layers would peel apart. This might be solved by printing at 0.2mm.

Here it is installed:

I used a Noctua NF-A9 PWM (92mm*92mm*25mm). I originally planned to buy two and set them up in a push/pull configuration but Amazon sold out. Turns out this was lucky for me because it appears Dells engineers left a really sweet hunk of plastic sticking up from the motherboard which prevents mounting a 25mm thick fan to the back of the shroud:

I see Noctua sells 92mm*92mm*14mm fans that might fit in there. If someone wants to donate two I will totally update the shroud design with two fan mounts and post an update. Based on my reading I don’t think a push/pull setup will benefit overall temperatures much though since this heatsink is pretty small and has a simple design.

Ok, what you probably care about, was there a performance improvement in cooling over my original zap strap design? Possibly.

I say possibly because I stupidly didn’t blow out my server of dust before starting all of this. I ended up blowing the dust out during some size checks but before installing the shroud. Here are my recorded temperatures:

1. Transcoding a Bluray, all CPU workload with the old cooling setup, average temperature of 80c
2. I blew the dust out of the case. You can see I ended up dropping my average idle load temperatures by 5c
3. Point where I installed the new shroud
4. Transcoding a Bluray, all CPU workload with the shroud installed, there is a 15c drop compared to (1) at an average temperature of 65c. This is probably partially the shroud and partially blowing out all the dust

Another discrepancy between (1) and (4) is the fan itself. Originally I installed a NF-B9 redux-1600 PWM which only runs at 1600RPM and pushes 64.3m³/h of air. The new fan is a NF-A9 PWM that runs at 2000RPM and pushes 78.9m³/h of air.

All that being said, I’m happy with ~65c at peak load and I can’t hear a thing. Idle temps seem to be roughly the same.

Now for what you’re probably here for, the STL file: Dell T340 Heatsink Shroud v1.6

You can also find it on Thingiverse.

I printed at 0.3mm. I’d recommend doing 0.2mm to hopefully make it a bit stronger so you don’t have to be as careful when installing the fan. 100% infill. You might also want to rotate the print so the fan screw holes are flat on the bed.

Alternatively you can skip ALL of this and try CJ’s suggestion he recently posted on my Part 1 which is a BIOS setting change.

Update 2022-08-12 – Here is the last 365 days of temperatures. The spike to 72c is likely the CPU under 100% load for a sustained amount of time. I think my Cookie Clicker VM was causing it.