Feature
THE ART OF AIR HANDLING
TO COMBAT AIR POLLUTION
By Michael Young, sales engineer, Trox
Effective and highly efficient filter systems filter dust, bacteria and pollen
out of the ambient air, ensuring that we can breathe clean air in enclosed
indoor spaces.
T
he standard for testing large and fine dust particles has
changed where filter performance is no longer accessed on
laboratory test methods but with real application conditions.
The new ISO 16890 standard is based on a range of particle
fractions, and tests are conducted using Di-Ethyl-Hexyl-Sebacat
(DEHS) and potassium sensitivity testing (KCI) test aerosols
where filters are now divided into four different groups:
• ISO course filters which has a rated containment capacity
against ISO A2 dust.
• ISO PM10 which filter fine dust particles that are less
than 10µm
• ISO PM2.5 which filter fine dust particles that are less than
2.5µm
• ISO PM1 which filter fine dust particles that are less
than 1µm
Alongside the filter performance, another important aspect
to consider is the energy performance of the filter in day-to-
day use.
Filters are more than just an investment in room air quality,
they are an investment in efficiency too. High quality filters
with patented NanoWave technology features a wavy profile
that creates a larger filter area which reduces differential
pressures. This is all accomplished without reducing the dust and
containment performance.
NanoWave filters are more complex to produce than
standard synthetic filters which is clearly indicated by the higher
price premium. However, when the overall costs for industrial
applications are compared to those of for a standard filter,
it is clear that the product is more than worth the additional
investment.
Air conditioning contractor, Trox, constructed two identical
air handling units (AHU) to perform filter differential pressure
testing in parallel. One of the systems (AHU 1) was fitted
with a synthetic filter and the other with NanoWave filter
technology (AHU 2). The differential pressures were measured
over the course of one year to take into account all seasons
and weather conditions.
www.hvacronline.co.za
The energy consumption of both systems was calculated on
the fan volume flow rate, its efficiency (50%), the number of
operating hours (8 760 hours) and the average differential
pressure which ranged between 61.8Pa to 146.9Pa.
To compare the two systems, the energy consumption in
kWh/a was calculated for the specific operating volume flow and
applied as a specific value in cents per m 3 of processed air per year.
The AHU containing the synthetic filter had an associated
cost of R182.24 to deliver 1m 3 /hr of air while the AHU containing
the NanoWave had an associated cost of R76.67 to deliver the
same 1m 3 /hr of air. Use of the NanoWave filter reduced the
operation costs by 51%.
Performing the return on investment calculation and noting
that NanoWave filter come with a 50% premium compared to a
synthetic filter. One can expect to recover the capital investment
cost of the filter in less than one month.
Trox understands that different filters perform differently,
so a life cycle cost (LCC) tool helps you determine the economic
efficiency of fine dust filters. With the tool, customers are able
enter the volume flowrate of the system and the programme
will indicate the approximate annual energy consumption of a
specific filter. RACA
RACA Journal I February 2020
Filters are more
than just an
investment in
room air quality,
they are an
investment in
efficiency too.
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