The document discusses indoor air quality (IAQ) and its importance for health and productivity. Poor IAQ can cause issues like sick building syndrome. Maintaining good IAQ requires careful HVAC design, installation, and maintenance to filter pollutants from inside and outside sources. Continuous monitoring of factors like carbon dioxide and ventilation rates is needed to quickly address IAQ issues. Improving IAQ through measures like increased ventilation has been shown to substantially boost performance for both children in schools and adults in offices.

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What Price Indoor Air Quality
The World Health Organization describes the effect of indoor air pollutants on health as:
Sick building syndrome, which gives rise to eye, nose and throat irritation, dry mucous membrane
and dry skin, erythema (skin redness), mental fatigue, headaches, a high frequency of airway
infections and coughs, hoarseness and wheezing, itching and non-specific skin hypersensitivity, and
nausea and dizziness. Common symptoms characterized by nasal dryness or congestion, such as a
stuffy blocked nose or a runny nose, and also mental effects, such as difficulty in concentrating, can
arise.
Just because you may be suffering from some of these symptoms does not necessarily mean that
the environment in which you live and/or work has sick building syndrome, but one thing is for
certain, the climatic conditions across the GCC, coupled with indifferent construction and poor quality
maintenance does make it highly probable.
As Professor DJ Clements-Croome, School of Construction Management and Engineering, University
of Reading, Reading, Berkshire, United Kingdom has observed:
“Temperature, relative humidity, and air quality all affect the sensory system via thermo receptors
in the skin and the olfactory system (nasal passage). Air quality is mainly defined by the
contaminants in the air. However, the most persistent memory of any space is often its odour.
Strong, emotional, and past experiences are awakened by the olfactory sense. Odours can also
influence cognitive processes that affect creative task performance, as well as personal memories
and moods. Besides nitrogen and oxygen, the air contains particles and many chemicals that
affect the efficiency of the oxygenation process in the blood, and ultimately the air breathed
affects thinking and concentration.”
With people in the Middle East typically spending more than 90% of their time in an Air Conditioned
environment, the importance of indoor air quality (IAQ) is a matter of concern for governments,
which is why regulatory requirements were put in place by Abu Dhabi and Dubai several years ago,
although for some reason, enforcement has not yet been activated.
Compromises to IAQ.
The pollutants in the air in a room will typically come from two main sources:
● Infiltrations into the building from outside, such as dust and other particulate matter, gases
& fumes, (including volatile organic compounds), electrical particles such as negatively and
positively charged ions, biological agents and water vapour.
● Those generated from within the building, such as volatile organic compounds emitted from
building and furnishing materials, flakes of skin, carbon dioxide (CO2) and a variety of other
gases, particulates arising from poorly maintained electrical equipment including HVAC
systems and biological agents from mould growth.
It is clear that with so many sources of pollution able to adversely affect the well-being of occupants,
a building’s HVAC system needs to be not only of good design, but carefully installed, commissioned
and supported by quality maintenance, if the occupants are to be adequately protected.
Unfortunately even if this were true, there is still the issue of poorly constructed buildings to contend
with.
Environmental Services

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During the building design process, an HVAC engineer is required to make a number of assumptions
about a building, one of which is that it is actually built to, or close to the consultant’s
specification/drawings. Sadly however, we all know that this rarely happens in this part of the world,
with the inevitable consequence that the HVAC system design is compromised even before it is
installed.
Carbon Dioxide.
Carbon Dioxide (CO₂) is produced when people breathe. Each exhaled breath by an average adult
contains 35,000 to 50,000 parts per million (ppm) of CO₂ – 100 times higher than the average outdoor
concentration.
In recent years scientists and researchers have become ever-more aware of the growing significance
of CO₂ with respect to its effect upon the occupants of a building. According to the Canadian Centre
for Occupational Health & Safety, health effects can become acute at higher exposure levels, for
example, concentration levels of 7.5% lead to headaches, dizziness, restlessness, the feeling of an
inability to breathe, sweating, malaise, increased heart rate, increased blood pressure, and visual
distortion can become apparent.
Studies being carried out by the University of Reading in primary schools have shown that the CO₂
levels vary from 800 ppm to almost 5000 ppm. This finding is of particular concern because primary
schoolchildren spend several hours a day in the same room, and hence the build‐up of CO₂ is most
notable in the morning and in the afternoon. So far, the tests show that there is a relationship
between CO₂ levels and the effectiveness of some learning tasks.
Other relevant recent studies on schools include the work of Godwin & Batterman on IAQ in 64
Michigan primary and secondary schools, and Kim on respiratory symptoms, asthma, and allergen
levels in Korean and Swedish schools.
A detailed study by Pawel Wargocki from the International Centre for Indoor Environment and
Energy, Department of Civil Engineering, Technical University of Denmark, shows that improving IAQ
improves the performance of office work by adults and the performance of schoolwork by children.
By measuring the performance of individual tasks under controlled conditions, a relationship was
established between the performance of schoolwork and classroom ventilation. The relationship
suggests that doubling the fresh air supply rate to reduce the CO₂ level improves the performance
of schoolwork in terms of speed by about 8% and under certain circumstance up to 14% was observed.
The results of these experiments indicate that improving IAQ in classrooms by increasing the fresh
air supply rate can substantially improve the performance of a wide range of tasks characteristic of
schoolwork, from rule-based logical and mathematical tasks requiring concentration and logical
thinking to language-based tasks requiring concentration and comprehension.
The experiments also revealed that the magnitude of the effects on performance of schoolwork is
greater than for the performance of office work by adults, probably because children are more
susceptible to environmental conditions and because schoolwork is not quantified in monetary terms.
Even so, the economic benefits from improved productivity of office workers resulting from improved
IAQ considerably exceed the costs involved.
Another conclusion was that the risk of developing sick building syndrome is reduced and perceived
air quality is improved, when the ventilation rates are about 20 l/s per person. The work also indicated
that CO₂ concentrations below 800 ppm are preferable.
Dubai regulations specify a maximum indoor CO₂ concentration of 800 ppm.

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The Challenges.
Addressing the problem of high levels of CO₂ in a building in itself does not provide a solution to the
wider issues of poor IAQ, but it is an important factor, particularly with respect to occupants’ mental
and cognitive functions. From a comfort perspective, issues such as temperature and humidity are,
for most people, the most important factors; if you feel comfortable, your body will be more relaxed,
which will enable you to perform better and if CO₂ levels are correct, that performance will be even
better still.
High levels of humidity, condensation and the subsequent presence of mould are an ever-present
problem. Apart from the unsightly appearance of mould, the real danger to health is from mould
spores and in particular mycotoxins. Mycotoxins are produced when two or more mould species are
present in close proximity, they are the mould’s defence mechanism, design to kill other mould
species. These are extremely dangerous to human health, often causing severe allergic reactions
and having a lasting effect in the body’s immune system; some mycotoxins are known to be
carcinogenic.
Other pollutants to be considered are:
● Volatile Organic Compounds (VOCs). These are an ever-present, typically leaching into the
building’s atmosphere from paints, adhesives, cleaning products, soft and hard furnishings,
clothing and electronic equipment. Damage to liver, kidney and the central nervous system are
known health risks when exposed to unacceptable levels.
● Particulates; and in this region, the most prevalent of which are sand particles. The most common
measurement is for particulates of less than 10 microns in size, but by far the most dangerous
are those particles that are less than 2.5 microns in size. These particles are raised into the
atmosphere from the desert by strong winds and are known to cause irreversible damage to the
lungs, they can also find their way into the blood stream.
To effectively mitigate all of these health risks, a multi-pronged approach is necessary as there is no
single action that can fix them all. Current regulations in the UAE and elsewhere call for IAQ
measurement to be taken once or twice a year, but the reality is that this is wholly inadequate if the
intent is to mitigate these health risks, what is required is continuous monitoring, so that there is a
constant stream of real-time data available to enable timely remedial action.
Even before continuous monitoring can be effective however, there is the challenge of fixing the
building. The low level of tradesmen skills, coupled with minimal quality oversight are two major
factors that contribute to a building not being constructed in accordance with the consultant’s
specifications, the other being the pursuit of profits above all other considerations. Trying to effect
a solution by just addressing shortcomings with the HVAC system is simply throwing good money
after bad. What is required is a holistic approach to the problem.
Type of Samples Maximum Acceptable
Formaldehyde < 0.08 ppm
Total Volatile Organic Compound (TVOC) < 300 micrograms/ m3
Particulates (<10 microns) < 150 micrograms/ m3
Ozone 0.06 ppm (120 micrograms/ m3)
Carbon Dioxide 800 ppm (1440 microgram/ m3)
Carbon Monoxide 9 ppm (10 micrograms/ m3)
Bacteria 500 CFU/ m³ (Algar plate)
Fungi 500 CFU/ m³ (Algar plate)
Current Dubai IAQ Maximums

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Practical Solutions.
The first step is to commission a survey of the building and the HVAC system. The focus must be on
identifying factors that impact on IAQ. The resultant report should provide a route map that enables
the client to take a structured approach to achieving an IAQ standard that ideally will exceed that
required by the local regulations.
The uncontrolled movement of air within a building not only compromises the design intent of the
HVAC system, it wastes energy and adds significantly to the level of pollutants in the building. Fixing
this must be the first priority.
Once this has been achieved, the installation of a continuous
IAQ monitoring system becomes a viable proposition. Ideally
such a system will be linked directly to the HVAC system, thereby
effecting control without human interference, the only problem
with this is that a typical BMS installation is unlikely to be able
to interpret the range of information being generated and even
less likely to have the sophisticated control algorithms necessary
to achieve the right outcome.
A control system such as the one developed by Tellus Environmental Services employs a number of
complimentary control elements to automatically modulate the volume of incoming air, accurately
control the moisture removal process and subsequent re-heating of distributed air, control the
re-circulation of exhausted air and manage energy recovery. The installation of this type of control
system in a building also has the added benefit of reducing the energy consumption of its AC system.
According to Pawel Wargocki from the International Centre for Indoor Environment and Energy,
Department of Civil Engineering, Technical University of Denmark, savings of between 5% and 27%
have been observed in commercial buildings where an approach similar to the one mentioned above
has been adopted.
To counter the effects of high levels of VOCs, special paints are available that, once applied to walls,
will neutralise VOCs. Highly effective filter systems will remove dangerous particulates and
non-chemical decontamination systems will remove biological agents before the conditioned air
enters the ductwork. Finally a mould remediation plan should be adopted, firstly to neutralise any
existing mould, secondly to remove affected material from the building and thirdly to protect against
further recurrence.
Conclusions.
● Good IAQ is a vital factor in maintaining the health and well-being of occupants in
buildings. The olfactory sense is very important psychologically, as well as physiologically.
The air we breathe ultimately affects the efficiency and effectiveness of our thinking and
day to day functions.
● From a commercial perspective, unhealthy buildings result in a loss of productivity, with
every work-hour lost typically costing as much as a kilowatt hour of energy, hence the
occupants’ well-being in monetary terms can be even more important than energy use.
● The education of our children is important, so why compromise it by allowing poor IAQ
to adversely affect their learning ability.
● The process of achieving good IAQ is a continual one throughout the design, construction,
commissioning, facilities management and renovation stages of a building’s life. The latest
building regulations will help to ensure that new buildings offer better IAQ, but it is the
existing building stock that really requires our undivided attention.