Air Filtration & TCO

Local Lab Passes Certification after Pressure Issues Using Specialized HEPA Media




The local lab at location A produces …. and had to be shut down due to failing lab pressure tests.  Their local HVAC contractor verified equipment performance and ensured that damper positions were proper.  After confirming viability of room pressure sensors and building pressure, the ceiling HEPA filters within the fan filter units and their associated pressure drops seemed to be culprit.

Clean, new filters were on hand at location A and were used to replace the older ones, only to have the same lab pressure failure happen again.  

The customer was knowledgeable of how their facility should be working appropriately with a similar lab at another location, location B.  Unfortunately, it was found that the filters were not interchangeable between labs due to the differences of the fan filter units and their acceptance of specific filter sizes, which didn’t match. 

Location B lab’s filters do have lower pressure drops and seemed to be the proper solution.  The difference was in the depth of the HEPA media packs.  A deeper media pack provides a lower pressure drop, but a couple questions are begged: does the difference of filter pressures provide a long lasting solution if they were to fix the current situation?, are there other avenues to explore?  


The lab requested that the filters be replaced.  Another vendor was able to provide HEPA filters at a faster lead time with approximately the same pressure drop, but netted the same lab pressure test results – FAILURE.


ACI’s Critical Environments’ team discussed that replacement of filters with similar pack depths perform similarly, regardless of manufacture, and would net the same results in a short period of time.  An expensive endeavor to continuously, pre-maturely replace expensive ceiling HEPA diffusers.  With the customer’s bottom line as a priority, some deeper consideration was provided.  ACI’s offering of a better performing HEPA media would be the best solution.


The current installed clean HEPA filter performance:

0.52” @ 100 FPM

ACI’s HEPA Solution:

0.27” @ 100 FPM

Almost ½ of the current pressure drop.  This filter would solve the filter performance issue.


The superior performance was shown in the lab results showing better than needed Lab Pressures, and now with the added benefit of a lower total cost of ownership.  A longer life span and lower energy usage. 

One assurance with this solution is the fact that Camfil tests each filter individually with the actual filter test results on the filter vs others who show test results of the lot batch, which may not reflect the specific individual filter performance.