ASHRAE Journal - September 2019 - 79

COLUMN PRODUCTIVITY-CIBSE

growth and fabric degradation.
In addition, current guidelines are necessarily simplified to apply to most cases for healthy adult populations.
There is a paucity of established guidance for specific
parts of the populations that may be more sensitive,
such as children, pregnant women, the elderly, or people with existing medical conditions.
This complexity is illustrated by allergies, asthma
and sensitivities, an area where our understanding of causes and effects is still relatively limited. In
some cases, individuals who exhibit strong responses
to exposure to a particular substance may be seen
as "canaries in the coal mine" as they exhibit a more
immediate, obvious and acute reaction to something
that affects us all but to lesser degrees. Others, such
as food allergies, produce reactions that are specific
to the individuals, whether due to medical conditions
or other factors such as medication or drug use, while
the rest of the population does not risk harmful effects
from exposure.
In other cases, individuals are convinced that exposure
to a particular factor is causing them harm, and they
suffer from very real symptoms, but the science does not
support a causal link to the factor being blamed; this is
the case for example with "electro-sensitivity," or perceived hypersensitivity to electromagnetic fields (EMFs),
where metaanalyses and double-blind experiments do
not support a link between such symptoms and short- or
long-term exposure to EMFs.3,4
Some evidence suggests there may be broader causes,
such as personal circumstances or the acceptance (or
not) of new technologies, particularly when these technologies are perceived as imposed without personal
control. This means that built environment professionals sometimes need to show an understanding of the
distress of individuals, while being able to support their
design proposals with the best available knowledge at
the time.

Innovative Solutions for Indoor Air Quality

There is much R&D regarding how to deliver the
most appropriate environments. Some features being
researched, such as indoor planting (flora) and the use
of traditional building materials, have been in use for a
number of years and the main uncertainty is about the
claims being made. There is much more uncertainty and
risk of unintended consequences with new products, or

Effects of Internal CO2 Levels on
Performance-CIBSE and ASHRAE Reviews
Recent research reviews by CIBSE8 and ASHRAE9
have reached similar conclusions on what should be the
right limits to internal CO2 levels, and the associated
potential for improvements to cognitive performance:
CO2 does seem to have an effect on its own, other than
simply being a proxy for ventilation effectiveness, but the
evidence is still somewhat inconsistent and most statistically significant effects are shown as occurring at CO2
levels well above the CIBSE recommended range (itself
based on BS EN 15251, with similar or higher levels recommended in its replacement BS EN 16798:1-2019).

even with well-intentioned phaseouts and substitutions:
for example, some concerns have been expressed that
the use of low-VOC paints may lead to increased risks
of bacteria and mould growth, or to the use of biocides,
which themselves have adverse effects.5 The following
approach is recommended when examining potential
new solutions:
* Are the product's claimed benefits based on realworld experiments? If so, how were the multiple parameters of a real-world environment controlled for? In the
case of laboratory studies, how representative are they of
real-life situations?
* Are the effects expected and proven in the longterm?
* The proposed solution may have proven positive
impacts on specific target pollutants, but have possible
reactions with other components in the air been considered?
* What is the required extent of application of the
system or product (such as in exposed area per room
volume), and is this realistic?
* If a pollutant is claimed to be "removed," by which
process is this? In the case of absorption (or other "fixation" process), is it proven over time, taking account of
possible re-release? In the case of decomposition, what
are the by-products and their effects?
* Are the claims based on independent research?
* Is data available from existing case studies?
The following examples illustrate the importance of
these questions. Indoor planting is a large R&D topic
in itself and is, therefore, not discussed here; there are
recent articles in the CIBSE Journal and a planned CIBSE
publication on this.
S E P T E M B E R 2 0 19

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ASHRAE Journal - September 2019

Table of Contents for the Digital Edition of ASHRAE Journal - September 2019

Contents
ASHRAE Journal - September 2019 - Intro
ASHRAE Journal - September 2019 - Cover1
ASHRAE Journal - September 2019 - Cover2
ASHRAE Journal - September 2019 - 1
ASHRAE Journal - September 2019 - Contents
ASHRAE Journal - September 2019 - 3
ASHRAE Journal - September 2019 - 4
ASHRAE Journal - September 2019 - 5
ASHRAE Journal - September 2019 - 6
ASHRAE Journal - September 2019 - 7
ASHRAE Journal - September 2019 - 8
ASHRAE Journal - September 2019 - 9
ASHRAE Journal - September 2019 - 10
ASHRAE Journal - September 2019 - 11
ASHRAE Journal - September 2019 - 12
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ASHRAE Journal - September 2019 - 14
ASHRAE Journal - September 2019 - 15
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ASHRAE Journal - September 2019 - 31
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ASHRAE Journal - September 2019 - 37
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ASHRAE Journal - September 2019 - Cover3
ASHRAE Journal - September 2019 - Cover4
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