Q:What is the service life of HEPA generally?

Table 5-10 Lifetime test of clean bench HEPA

A. Methodology:
a. Set up clean bench in clean room with cleanliness class of 1,000,000, 10 and 10,000, respectively.
b. 24h running without processing production.
c. Wind speed at HEPA outlet: initial speed: 0.59m/s, final speed: 0.26m/s.
(Note: extent of pressure loss = loss of wind speed)
B. Results:

The service lifetime listed in Table 5-20 is test result of clean bench; in case of use of air connecting pipe in upstream HEPA, contamination of air pipe and infiltration exists, thus service lifetime will be poor or presence of caustic gas, then lifetime may be ≤1.5 years.