Influence of background concentration on filtration efficiency of ductless self-filtration vented enclosure

Based on testing one ductless vented enclosure according to the Ductless self-filtration vented enclosure standard, studies and analyses the influence of background concentration on the filtration efficiency. The results show that with the relatively high laboratory background concentration the filtration efficiency decreased significantly. Recommends an appropriate laboratory background concentration limit for operating the ductless vented enclosure.