Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4620560.
This is an air shroud for adapting a Supermicro SC826 chassis into providing adequate cooling for the CPU and memory in an HP Z420 motherboard. It was designed out of the fear that the ECC memory would not be receiving adequate airflow otherwise, but the system seems to do fine without the shroud.
I went through the trouble of verifying this shroud through temperature measurements, since using PLA in a thermal solution is a questionable decision that can lead to fires if the temperatures in question are too great. Where possible, I used software monitoring, but memory had to be measured with thermocouples. For load, I just used mprime (aka prime 95) to torture test the memory and CPU at near 100% utilization. These are the only components to be directly worried about due to the shroud, but I should mention that one of the memory ducts exhausts directly into the PCIe slots. If there's anything temperature sensitive there, it might need further attention.
For memory temperature, I was seeing DRAM package temperatures near 40 C on the memory closer to the fan wall, and near 50 C on the memory further from the fans. Considering that Micron specifies a "self reset" package temperature of 85 C, this is fairly temperate. It's also nowhere near damaging the air shroud.
As for CPU temperature, when using an active cooler (SM # SNK-P0048AP4) on a 165W TDP CPU (Xeon E5-1603), I was seeing core temperatures peaking near 60 C, which isn't going to hurt the air shroud either.
It's worth noting that I'm using the stock fans, which are rated near 75 CFM each. I tried using quieter fans as well, and got memory temperatures and CPU temperatures that were about the same. However, I didn't think the noise got below the threshold that would have made it worth the trouble, as the power supplies for these chassis are very loud.