HVAC Air Filters

We manufacture them. We are one of the few companies internationally to manufacture both cleanroom equipment and the air filters that go into it, from premises of about 12,000 sq ft near Mumbai. In practice this is why the filters inside our air showers, pass boxes and laminar flow units are our own, and why replacement elements can be made in sizes that are no longer generally available.

HEPA stands for High Efficiency Particulate Air. For a filter to qualify as HEPA it must remove 99.97% of particles greater than or equal to 0.3 micron. That specific figure and particle size is the definition, not a marketing claim. HEPA filters correspond to grades H13 and H14 of EN1822 and support ISO Class 5 operation as per ISO 14644.

The difference is how the filter seals to its housing, not how the media performs. A gasket seal uses a compression gasket; a gel seal uses a channel of gel into which a knife edge on the housing sits. In a terminal filter position, air leaking around the frame is often a larger contributor of contamination than air passing through the media, so a gel seal is specified where that bypass path has to be eliminated, such as in semiconductor fabrication.

Economics, mainly. A pre filter captures coarse dust, pollen and lint that would otherwise be removed by the HEPA filter downstream. Since a washable pre filter costs a fraction of a HEPA and can be cleaned and reused, letting it absorb the coarse load extends the life of the expensive final filter and lowers total maintenance cost. Skipping the cheap stage makes the expensive stage a consumable.

Yes. Filters and cleanroom equipment are manufactured in standard and customised sizes. For filters, the standard size tables on each product page are the sizes held as standard; other dimensions are made to order, and refill types are manufactured to customer requirement.