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.
