
3HUMIDITY SOLUTIONS |
BEST PRACTICE REPRESENTATIVE
Indoor air quality
Indoor air quality is something of a
contentious issue, creating almost as
much debate as Brexit and, similarly,
not reaching a commonly agreed
conclusion. In the manufacturing,
processing and printing sectors,
acceptable humidity levels are clearly
defined because deviating from these
levels can have an adverse effect on
productivity, product quality and
profitability. However, when it comes
to standards for maintaining a healthy
environment for people, we are
fallingshort.
Unquestionably, we all need a healthy
environment in which to work, rest
and play – and humidity control
is a vital component of this. What
is required, therefore, is a defined
standard for humidity to ensure the
spaces we occupy are comfortable
andhealthy.
Humidity affects health and comfort
in a number of ways. High RH is
uncomfortable, encourages mould
growth and can create condensation
on cold surfaces, resulting in a slip
hazard. Low RH will dry out mucous
membranes in the respiratory system
and make eyes feel dry and itchy.
There are also links between humidity
levels and spread of infection. Dry air
enables bacteria and viruses to remain
suspended in the air for long periods,
so they can travel further and spread
infection across a wider area. Viruses
such as influenza and norovirus (the
vomiting bug) survive longer at low RH
(20 to 30 per cent), while a mid-range
RH between 40 per cent and 70 per
cent will minimise their survival rate.
Also, tests indicate that the infectivity
of the influenza virus is increased
by both low and very high RH, with
minimum infectivity at 50 per cent.
Relative humidity has been shown
to have a similar effect on airborne
bacteria, with intermediate levels
increasing the mortality rate of
airborne pneumococci, streptococci
and staphylococci.
For all of these reasons, the
Humidity Group of the Federation of
Environmental Trade Associations, the
World Health Organization and the
National Association of Optometrists all
recommend that the RH in workplaces
is maintained at 40 to 60 per cent. This
is also the range recommended by BS
EN 29241 as the optimum for visual
display terminals.
In many buildings, these humidity
levels cannot be maintained without a
humidity control system.
Looking ahead, there are exciting
opportunities for our company,
alongside the challenges of better
education about the role of humidity,
the uncertainty of future relations with
European trading partners and our
drive to see the introduction of indoor
air quality standards that reflect the
importance of humidity control.
In manufacturing, acceptable humidity
levels are clearly defined because
deviating from these levels can have
an adverse effect on productivity,
product quality and profitability
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HomEvap Direct
on
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HomEvap low energy
humidity for residential
or commercial
applications