2. Indoor Air Quality (IAQ) Introduction Poor indoor air
quality (IAQ) can be a significant health, environmental &
economic problem, and has become a public health & liability
issue for employers & building managers. Indoor Air Quality
(IAQ) The totality of attributes of indoor air that affect a
persons health & wellbeing. IAQ Evaluation determine how well
indoor air satisfies thermal & respiratory requirements of
occupants, prevents unhealthy accumulation of pollutants, &
allows for a sense of wellbeing. It also affects the personnel
costs of any business, since research findings show an association
with occupant productivity.
3. Indoor Air Quality (IAQ) Building Related
Illness-Diagnosable illness whose symptoms can be identified and
whose cause can be directly attributed to airborne building
pollutants (e.g., hypersensitivity pneumonitis or Legionnaires
disease) Sick Building Syndrome(SBS) Symptoms include eye, nose and
throat irritation, headache, allergies, fatigue 20% or more of
occupants experience same symptoms No medically diagnosable
symptoms Complaints persist for more than two weeks Symptoms often
lessen after person leaves building
4. Indoor Air Quality (IAQ) Sector of population differ
markedly in their sensitivities to pollutants. Asthmatic are
sensitive to variety of pollutants. Major indoor air
pollutants(those of indoor origin) typically completely different
from outdoor air pollutants.
5. Indoor Air Quality (IAQ) It is important to be clear on what
you or others may mean when discussing IAQ. 1. Engineer ( building
ventilation rate) 2. Architect ( the occupants perception of the
building) 3. Microbiologist (level of spores from plants, moulds
etcetera) 4. Hygienist or toxicologist (the exposures to specific
pollutants)
6. Indoor Air Quality (IAQ) Indoor air Any enclosed space where
people spend 1 hour/day or more The air in Non-industrial buildings
such as dwellings, offices, schools & hospitals. Exclude
industrial buildings Exposure limits 40 hours/week
7. Indoor Air Quality (IAQ) IAQ is the totality of attributes
of indoor air that affect a persons health & wellbeing.
Attributes can mean Pollutant level Air temperature Humidity Air
velocity Odors etc. Health (WHO) State of complete physical, mental
& social wellbeing & not merely the absence of disease or
infirmity
8. Indoor Air Quality (IAQ) Regulation To indoor air is limited
as compared to outdoor air quality & industrial workplace air.
National Health & Medical Research Council (NHMRC) &
National Occupational Health & Safety Commission ( NOHSC) To
improve air quality Improved ventilation codes Voluntary reduction
of pollutant emissions Improved public education
9. Indoor Air Quality (IAQ) Responsibility For IAQ
Responsibility for IAQ falls to environmental or health agencies in
many developed countries. For example, in US Environmental
Protection Agency carries out extensive research &
industry/community activities.
10. Indoor Air Quality (IAQ) Building Related illness & SBS
Building Related Illness-Diagnosable illness whose symptoms can be
identified and whose cause can be be directly attributed to
airborne building pollutants (e.g., hypersensitivity pneumonitis or
Legionnaires disease) Sick Building Syndrome(Tight Building
Syndrome) Used to describe situations in which building occupants
experience acute health and /or comfort effects that appear to be
linked to the time spent in a particular building. No specific
illness can be identified. Complaints may be localized in a
particular room zone or widespread throughout the building.
11. Indoor Air Quality (IAQ) Common Health Effects of Indoor
Contaminants Eye, nose and throat irritation Coughing and sneezing
Headaches Fatigue Irritability Allergies, sinus congestion
Dizziness Difficulty in concentrating
12. Indoor Air Quality (IAQ) Sick Building Syndrome Symptoms
include eye, nose and throat irritation, headache, allergies,
fatigue 20% or more of occupants experience same symptoms No
medically diagnosable symptoms Complaints persist for more than two
weeks Symptoms often lessen after person leaves building Clinically
defined illness or disease o E.g. Asthma, Legionnaires Disease,
Hypersensitivity Pneumonitis
13. Indoor Air Quality (IAQ) Why is There an Increase in IAQ
problems? More time indoors More chemical pollutants in buildings
Tighter buildings and reduced ventilation Deferred maintenance
Potential Causes Ventilation rate, ventilation system, airborne
chemical pollution, micro-organisms & particulates,
temperature, humidity, lighting, personal & organizational
factors.
14. Indoor Air Quality (IAQ) Relationship of IAQ to
Productivity Costs for care health Sick leave Diminished
performance at work caused by adverse health Costs of investigation
occupant complaints Thermal comfort & lighting quality
15. Indoor Air Quality (IAQ) Fisk & Rosenfeld noticed
improved productivity by changing indoor environment. Potential
annual benefits were 10-30% reduction in acute respiratory
infections & reduced allergy & asthma Symptoms 20-50%
reduction in acute non-specific health symptoms 0.5-5% increase in
the performance of office work Annual cost savings &
productivity gains US$30-170 billion.
16. Indoor Air Quality (IAQ) Building Ventilation Purpose -
Remove or dilute airborne contaminants Supply air - mixture of
outside air and re-circulated air. Components o Air intakes,
dampers, filters o Heating & cooling units, coils, drain pans o
Ductwork o Supply vents o Exhaust vents o Plenum
17. Indoor Air Quality (IAQ) Regulations ASHRAE Outdoor Airflow
Requirements, 62.1- 2004 Vbz = RpPz+RaAz o Vbz = Breathing zone
outdoor airflow o Rp = Outdoor airflow rate required per person. o
Pz = zone population o Ra = Outdoor airflow rate required per unit
area. o Az = zone floor area
18. Indoor Air Quality (IAQ) A space within a building used by
occupants must be provided with means of ventilation with outdoor
air which will maintain adequate air quality. Mechanical
air-handling system in a building must control. Circulation of
objectionable odors & Accumulation of harmful contamination by
micro- organisms, pathogens & toxins. Contaminated must be
disposed of in a manner which doesnt unduly create a nuisance or
hazard in the building or other property.
19. Indoor Air Quality (IAQ) Poorly Located Air Intakes
Entrainment of vehicle exhaust from parking areas Entrainment of
bio-aerosols from debris on the ground Entrainment of exhaust from
adjacent roof vents, e.g. HVAC system, sewer Poor Filters or Poor
Filter Maintenance Excessive dust and dirt in the supplied air
Insects Mold spores
20. Indoor Air Quality (IAQ) Ductwork Leaks o Energy loss o Can
draw contaminants into ducts Duct liners o Can degrade; particles
enter supplied air
21. Indoor Air Quality (IAQ) Ventilation to Meet Occupant Needs
ASHRAE Standards Temperature Relative Humidity Minimum outdoor air
requirements CO2 levels below 1000 ppm. Outdoor air supplied at 15
cfm/person
22. Indoor Air Quality (IAQ) Ventilation Engineering Controls
Modify ventilation system Modify pressure relationships Filters Ion
generators Humidification systems
23. Indoor Air Quality (IAQ) Performance and maintenance of
ventilation system Changing of filters Checking correct
installation of filters Cleaning of condensate trays & cooling
coils Checking fan operation & operation of dampers that
influence airflow rates. Ventilation measurement may be necessary
After significant change in the building, HVAC system, or occupancy
or activity in the building. When control settings have been
re-adjusted When accurate records of the systems performance are
not available.
24. Indoor Air Quality (IAQ) Dilution is the solution When all
else fails, ventilate Relation between indoor & outdoor air.
Urban population spend 96% of each day, on average, in a rang of
enclosed environment such as home, the workplace, schools, shops
etc. Outdoor air is used to ventilate the office introduces outdoor
pollutants( carbon monoxide, VOCs such as benzene) Behavior of
occupants ( smoking, use of appliances) Indoor pollutants are
limited in their dispersion
25. Indoor Air Quality (IAQ) Major indoor air pollutants &
sources Indoor pollution sources that release gases or particles
into the air are the primary cause of indoor air quality problems.
Formaldehyde and VOCs from new building materials