Removed Fan Filters in PXI and PXIe Chassis

Updated Dec 30, 2022

Reported In


  • PXI Chassis

Issue Details

I have a new PXI or PXIe chassis that was ordered recently, but it didn't ship with the cooling fan's foam filter. Why is this? Was it supposed to have been included?


As of March 2011, NI no longer ships PXI or PXI Express chassis with foam filters on the main cooling fans of the chassis.

This change was implemented for the following reasons:
  1. PXI systems will operate properly and reliably without the foam filters in their specified operating environments.
  2. The foam filters require routine cleaning in order to ensure proper operation of the PXI system. By removing the filters, the maintenance of the PXI system is reduced and will improve the user's overall experience.
  3. Not performing the currently recommended maintenance of cleaning the filters may lead to insufficient cooling of the PXI system due to filter blockage. This can cause PXI modules to operate at higher than recommended temperatures and in some cases result in unwanted system downtime.

Additional Information

Several models, including the NI PXI-1031, PXI-1036, PXIe-1065, PXIe-1071, PXIe-1078, PXIe-1085 and PXIe-1095 have never incorporated a foam filter as part of their respective designs.  

You can continue to use a chassis with a filter installed. NI recommends following the specified maintenance of cleaning the filter routinely (every 6 months) or simply removing the foam filter completely. You can clean the foam fan filter by washing it in a mild soap solution and then vacuuming or blowing air through it. Rinse the filter with water and allow it to dry before reinstalling it in the chassis. Note: Some chassis have metal filters - these should not be removed.

If you need new filters, they can be purchased from The Filter Factory (formerly known as Air Filtration Products). The material should be 3/32" thick reticulated polyurethane foam with a porosity of 30 ppi.

The images below show the difference between a chassis with a filter (Figure 1) and one without a filter (Figure 2):

Figure 1: PXI(e) with Fan Foam Filter 

Figure 2: PXI(e) without Fan Foam Filter