UL Class 1 or 2 Filters?

[PagoMitch]

Doing some air handling unit work in a hospital. I am suggesting that the contractor use UL Class 1 filters, which (when clean) do NOT support combustion. Class 2 filters WILL support combustion.

The contractor is of the opinion that once the filter loads up with lint, that it has lost the UL listing; therefore why install a Class 1 filter?

I am of the opinion that even though this may be the case, it would be foolhardy to specify a filter known to support combustion, when the same product is available that will NOT, even though that fire-proofness will only last, say for 3/4 of the filter life.

I cannot find any references in ASHRAE, ASHE, JCAHO, or even VA standards requiring the use of UL Class 1 filters.

Comments?

 

[ChasBean1]

Good question. Assuming the capacity is over 2,000 cfm, you have a smoke detector for automatic shutdown and smoke isolation damper, correct?

Also assuming this isn't the only building or AHU, I'd suggest using filters that match all their other units for maintenance sake, so they don't have to order a new kind for every project/fit-out etc.