HVAC Air Filter Media: A Buyer's Guide for Filter Manufacturers

An air handler usually has more than one filter: a coarse pre-filter that stops large dust, a fine bag or pocket filter that does the real cleaning, and sometimes a carbon stage for odours and gases. Each stage needs a different media, and the filter maker's job is to choose media that reaches the target class at the lowest resistance and cost.

This guide is for filter manufacturers and distributors buying air (HVAC) filtration media in rolls.

The media families

• Pre-filter, coarse and high-loft (G1–M6) – lofty media that catches large particles and protects the stages after it. Used in panel filters and pre-filter rolls.
• Bag, pocket and fine media (F5–F9) – denser media for bag and pocket filters, where most of the cleaning happens.
• Activated carbon media – carbon on a PET or PP carrier, for odour and gas control.
• Cabin media – PET, PP and PTFE media for cabin air filters.

Fibres and finishes

Media can be made from polyester, polypropylene, acrylic, PPS, meta-aramid, para-aramid, P84 and PTFE. For most HVAC work, polyester and polypropylene are the standard choices; the high-performance fibres are for heat and chemical conditions.

• Mechanical finishes – singeing, glazing, calendering and heat setting, to control the surface and stability.
• Chemical finishes – water repellent, oil repellent, PTFE and acid resistant.
• Scrim support – a supporting scrim adds strength for pleating and for bag pockets.

All our filter media is synthetic – no glass-fibre media – and produced to order to your specification. There are no stock grades.

Where it is used

• Commercial HVAC
• Bag and pocket filters
• Panel and pleated filters
• Air purifiers
• Paint booths
• Clean rooms

For the finest filtration layers, many filter makers combine these media with meltblown. For dust-collector bags in heavy industry, see our dust bag filter media.

How the stages work together

The stages protect each other. A good pre-filter media catches the large dust that would otherwise load the bag filter quickly, so the fine stage lasts longer and the fan works less. When you plan a range, think of pre-filter and fine media as a pair: the better matched they are, the longer the whole system runs between changes, which is what end users notice.

High-loft media is also bulky. Agree how rolls are compressed, wrapped and loaded, so the media recovers its loft after the voyage and you get as much media as possible into each container.

How to write the specification

• Target class – the filter class the finished filter must reach.
• Filter type – panel, pleated, bag, pocket, carbon or cabin.
• Fibre and weight – fibre, gsm and thickness.
• Finish and scrim – any mechanical or chemical finish, and whether a scrim is needed.
• Roll format – width, length and core for your production line.

How to test samples

• Test the finished filter. Build filters from the sample media and test them on your own rig, in the way your customers' class is measured.
• Check resistance. Compare pressure drop with your current media at the same efficiency.
• Check processing. Run the media through pleating, sewing or pocket making.
• Check evenness. Weigh pieces across the roll width.

Mistakes to avoid

• Specifying by gsm only. The filter class is what matters; agree the target with the media maker.
• Ignoring resistance. A media that reaches the class but at high pressure drop costs your customer energy.
• Skipping the scrim. Pocket and pleated filters often need it for strength.

What to ask a supplier

• Do you make the media in-house?
• Which classes and filter types do you supply media for?
• Which fibres, finishes and scrims are available?
• Do you make media to my specification?
• Can I combine media with other fabrics in one container?

How we supply air filter media

Samridhi Crreation has manufactured nonwovens in India since 2004, on its own needle-punch, meltblown, spunbond, SMS/SSMMS, spunlace and hot-air-through lines. We supply filter manufacturers and distributors worldwide. The minimum order is one 40'HQ container, and 5–6 different products can be combined in it. We ship FOB India from Mundra or Nhava Sheva, with CIF and DAP on request, and provide REACH and SVHC declarations for customers in the European Union. Samples are free, and we pay the courier.

See grades and fibres on our air filtration media page, or send us your specification for a quotation and samples.