HEPA Turbulent Flow Filters

Filter Class - H13
Filters global efficiency % for MPPS particles - ≥ 99.95 %
Local Efficiency % for MPPS particles - 99.75%

Filter Class - H14
Filters global efficiency % for MPPS particles - ≥ 99.995 %
Local Efficiency % for MPPS particles - 99.98%


MEDIA - Glass fibre paper
SEPARATORS - Hot melt glue
FRAME - Anodized aluminium profile 68-115 mm deep or MDF wooden frame
FACE GUARDS - Metal frame has epoxy painted expanded aluminium grids on both sides. Special Grid lock keeps the mesh away from the filter pack. Not fitted as standard to wooden frame, optional extra.
SEALANT - Two components cold moulded polyurethane

Each filter Grade H13 and above is individually leak tested and certificates are issued. We can also test and certify to EN1822 if required. Every HEPA is issued with a unique serial number which allows full traceability right back to the filter media Batch and Roll. Each roll of HEPA filter media is individually tested and certified.

HEPA (High Efficiency Particulate Air) filter can remove a minimum of 99.97% of dust, pollen, bacteria, mold and any other types of airborne particle with a size of 0.3 micron which is generally known as the MPPS (Most Penetrating Particle Size).

It is at this point that people start scratching their heads and looking a little confused, what is MPPS and why haven't I heard this term before? MPPS is a term that is used with HEPA filters but not with many other types of filter such as pleated panels or Procart extraction filters as these filters will capture particles to a certain size and anything smaller will, in theory, pass through. So they are Top Down filters, they capture big things but not small.

HEPA filters, on the other hand, will capture both big particles and small particles and they can do this as they capture the different sizes in different ways. Firstly, the largest particles fly into a HEPA filter but they are too big to get through the fibres so they get stuck. This type of filtration is called 'straining' and is generally for particles of around 10 microns. For smaller particles that can pass through the fibres, the larger ones will follow the flow of air but will be too heavy therefore too slow to pass all of the way through the panel so will drop out of the airflow and be captured. This type of filtration is called 'interception'. Then we have the smallest particles which are generally below 0.3 microns. These are very small have so have such little mass that don't travel in straight lines with the flow of air, they rebound when they hit gas molecules so they move in random patterns which results in them bouncing around and hitting the fibers of the HEPA filter and getting stuck. This type of filtration is called 'diffusion'.

This all sounds great, and it is, however there is a size of particle that falls between the filtration methods and this weak spot is known as the MPPS. This is around 0.3 microns which is too small for straining and too large for diffusion and so this is why we show the MPPS filtration efficiency percentage of our HEPA filters.

Can I use HEPA filters in my spray booth?

Please don't use these to filter air entering a spray booth. You will not require air that has been filtered to this quality for a booth in which you are conducting standard spraying. Our Pleated Panels or Protop will provide perfectly adequate air quality. HEPA filters will also offer far too much resistance for a spray booth so the extraction fan will not function properly.