1. 1. Presentation BY: M. UMER
2. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 22. Indoor Air Quality (IAQ) Ventilation Engineering Controls Modify ventilation system Modify pressure relationships Filters Ion generators Humidification systems
23. 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. 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. 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