INDOOR AIR QUALITY. Ir Al-Khairi Mohd Daud. Pakar Keselamatan dan Persekitaran

Transcription

1 INDOOR AIR QUALITY Ir Al-Khairi Mohd Daud Pakar Keselamatan dan Persekitaran

2 SCOPE Background Definition of IAQ Related factor contribute to IAQ Indoor environmental quality Importance of IAQ for working Environment IAQ Fundamentals and Control Measures

3 WHY IAQ IS BECOMING A CONCERN? Changed from natural ventilation to tight buildings concept. Rely on ACMV to provide general ventilation but may suffer from insufficient IAQ as a result of energy conservation measures to reduce operational cost Changing on building materials. Synthetics had largely replaced the natural construction/finishing materials, e.g. wood/stone Modern finishing and construction materials emit VOCs (volatile organic compounds) into building environment Additional sources are volatile agents from cleaning and graphics materials, pesticides, hydraulic elevator fluid, and personal care products

4 INDOOR AIR QUALITY A term which refers to the air quality within and around buildings and structures, especially as it relates to the health and comfort of building occupants. IAQ can be affected by gases (including carbon monoxide, radon, volatile organic compounds), particulates, microbial contaminants (mold, bacteria) or any mass or energy stressor that can induce adverse health conditions.

5 POOR INDOOR AIR QUALITY INDICATOR Too hot, too cold Too dry, too much humidity Stuffiness or lack of air circulation Objectionable odors Present organism and bacteria Present toxic chemical substance Present spore, molds and others

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7 IAQ HAZARDS Factor Can Contribute to Airborne Pollution Particulates respiratory problem Biological Agent Hazardous Chemical Substance ETS, Dust Spores, Molds, Bacteria, Parasites Formaldehyde, asbestos, Volatile organic compound, Pesticides, Lead, CO, CO2

8 INDOOR ENVIRONMENTAL QUALITY ENVIRONMENTAL Lighting Temperature Indoor Air Quality PHYSICAL Workstation design Posture Repetitive Work Manual Handling Users PSYCHOSOCIAL Job Design Work Practices Work Organisation

9 IAQ PROBLEMS Increasing health problems / death Reducing productivity due to discomfort or increase absenteeism Accelerating deterioration of furnishings and equipment Straining relations between employers and employees Creating negative publicity that could put services at a competitive disadvantage Opening for potential liability problems

10 Health Effects Related to IAQ Building-Related Illness (BRI) Sick Building Syndrome (SBS) Multiple Chemical Sensitivity (MCS)

11 SICK BUILDING SYNDROME (SBS) A phenomenon that occur when more than 20% of the occupants of a building complain about air quality or have definite symptoms (ILO Encyclopaedia) There is no obvious cause and where medical tests reveal no particular abnormalities. The symptoms appear when individuals are in the building but disappear when they leave the building

12 BUILDING RELATED ILLNESSES Less often, but often more serious, and are accompanied by very definite clinical signs & clear laboratory findings Examples of BRI hypersensitivity pneumonitis, humidifier fever, Legionnaire s disease, and Pontiac fever

13 MULTIPLE CHEMICAL SENSITIVITY (MCS) A subset of the population may be particularly sensitive to low levels of a broad range of chemicals at levels common in today's working environments. This condition is known as Multiple Chemical Sensitivity Symptoms may be similar to those of SBS and often attributed to trace amount of chemicals (especially those with perceptible odor)

14 Disease Types, Agents of Infection, and Reservoirs Type of Disease Agent Disease Reservoir(s) Contagious disease influenza viruses influenza infected people measles virus measles infected people Mycobacterium tuberculosis infected people tuberculosis Virulent Histoplasma histoplasmosis wet soil enriched environmental capsulatum with bird droppings infections Coccidioides coccidioidomycosis dry soil (deserts) immitis Legionella Pontiac fever hot water systems, pneumophila cooling towers, etc. Opportunistic Legionella Legionnaires disease hot water systems, environmental pneumophila cooling towers, etc. infections based Mycobacterium atypical tuberculosis natural water avium reservoirs Cryptococcus cryptococcosis dry bird droppings neoformans Aspergillus aspergillosis self-heating plantfumigatus organic matter

15 NIOSH Study IAQ Complaints 50% from building ventilation deficiencies Lack of outside air Poor air distribution Uncomfortable temperatures & humidities Sources of contaminants in system 30 % from indoor air contaminants Formaldehyde, solvent vapors, dusts, smoke, elevated CO 2 Microbiological agents 10 % from outdoor source Motor vehicle exhaust, smoke, construction dusts Pollen, fungi, molds 10 % unknown source

16 IAQ STANDARD IAQ standards may differ widely from one organisation to another. For some pollutants, there are no established IAQ standards IAQ standards are set at 3-10 times below the ACGIH (TLV), based on: health effects of pollutants possibility of continuous (24 hr) exposure exposure to the public including susceptible pregnant women, aging adults, and infants For example, carbon monoxide: TLV = 25 ppm IAQ standard = 9 ppm (US National Ambient Air Quality Standards)

17 IAQ STANDARD Carbon Dioxide The best indicator to determine the efficiency of ACMV system. - Acceptable range = 350ppm to 750ppm (ASHRAE Standard, 62 1, 2004) - Maximum limit = 1000ppm (US-EPA Guidelines) If CO2 level are above 1000ppm, it is a valid presumption that the outdoor air ventilation rate is too low Carbon Monoxide Sources: Garage, Outdoor Air, Combustion Product Standard 8Hrs = 9ppm ( National Ambient Air Quality Standards)

18 IAQ STANDARD Total Volatile Organic Compound Sources: From new building furniture and material 8Hrs Exposure = 0.5mg/m³ Formaldehyde Sources: Press wood product, furniture and furnishings 8Hrs Exposure = 0.05ppm Particulate Matter (PM10) Source:smoke, dust, deteriorating material, outdoor air Standards for 8Hrs = 50 g/m³ Particulate Matter (PM2.5) Source: Combustion Product, incense, cooking, oudoor air Standards for 8Hs = 15 g/m³ (USAEPA Guidelines)

19 IAQ STANDARD Relative Humidity: %RH Temperature : ºC Oxygen Supply: % Air Movement : 0.15 m / s Adequate Fresh Air Intakes: 20 cubic feet/minute (cfm) outdoor air intake per person For smoking lounge: 60 cfm per person

20 Common IAQ Issues

21 Total fungal counts Adopted from WHO/ Health Canada 50 CFU/m3 of a single species, further investigation Up to 150 CFU/m3 of mixture of species, reflective of the outdoor species, acceptable Up to 500 CFU/m3 of Cladosporium or other tree and leaf fungi, acceptable. > than this value, poor filters

22 NEA SINGAPORE GUIDELINES Parameters Limit Unit Carbon dioxide 1000 ppm Carbon monoxide 9 ppm Chemical Formaldehyde 0.1 ppm Ozone 0.05 ppm Volatile organic compound 3 ppm Biological Total bacteria counts 500 cfu/m 3 Total fungal counts 500 cfu/m 3 Suspended particulate matter 150 ug/m 3 Physical Air temperature ºC Relative humidity 70 % Air movement 0.25 m/s

23 Malaysian Code of Practice on IAQ Indoor Pollutant 8-hr time-weighted average concentration ppm mg/m 3 Respirable particulates 0.15 Carbon dioxide C1000 Carbon monoxide 10 Formaldehyde 0.1 Total volatile organic compound 3 C means ceiling limit, not to be exceeded at any time.

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25 IAQ FUNDAMENTAL REQUIREMENTS AND CONTROLS

26 Elements of IAQ Design and construct Indoor contaminants Commissioning Ineffective Filtering / Cleaning Ventilation system Moisture Outdoor Environment

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28 1. IAQ DURING DESIGN AND CONSTRUCTION Basic design decision Site selection Building orientation Location of outdoor air intakes How the building to be cooled down, heated and ventilated Building performance

29 Control of Construction Contaminants Contain Construction Area Maintain office area at positive pressure relative to the containment room Seal containment room sufficiently Flow additional supply air to this area during the construction activities A large exhaust machine to keep the containment area under Significant Negative Pressure Block RETURN air path in this area

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31 Control of Construction Contaminants Temporary Exhaust through a window or opening in the outside wall: Exhaust indoor air outside the building. Do not BLOW FRESH AIR into the construction area Block the RETURN air Seal the construction room sufficiently to insure ADEQUATE NEGATIVE PRESSURE is maintained at all times If necessary, block the supply air, so that the construction area is served by transfer air from surrounding spaces in the building

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33 2. Lack of commissioning Commissioning of system to meet the design standard Cleaning of duct works and pipes Sealing of entrance to hot air path

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36 3. Moisture in Air Assembly Moisture leaks Roof leaks Rain penetration through leaky windows Envelope design and construction defect Poor building pressure control

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39 Controlling the Molds Control water accumulation and leaks Promptly remove excess water Thoroughly dry wet materials Rectify numerous sources of moisture that promote mold growth

40 4. Poor Outdoor Air Quality Hospital are supposed to be located in clean and quite environment Source of outdoor contaminants Motor vehicles from motorways Activities from adjacent buildings

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43 Controlling Outdoor Air Sources Proper design layout of rooftop No chance for cooling tower mists entering outdoor air intake or openings Screened air intake to keep bird nest away Aware of possible nearby contamination with changing direction of prevailing winds Consider all potential wind directions Prudent roof maintenance strategies - may need to close outdoor air during repairs No-idling protocol for loading dock and inside car park Manage pressure differential for major sources (car park) Keep dirt out of building

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45 5. Moisture and Dirt in ventilation system Moulds and dirt accumulated in ventilation system Due to Inadequate levels of particle filtration Poor filter management Problem with cooling coils condensate or other moisture source

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48 6. Indoor Contaminants source Contaminants released from normal building materials and furnishing (new) Materials and substances brought into building during operation

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50 Controlling Common Indoor Sources Develop a Housekeeping Plan IAQ methods and training are critical Cleaning agents are sources of pollution and should be handled and used properly Vacuuming with high efficiency filters Feather dusters can be inefficient Review CSDS of cleaning chemicals and pesticides used Exhaust fan for stationary sources Exhaust hood for major sources

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52 7. Contaminants from Indoor Equipment and activities Improper equipment operation Inadequate exhaust ventilation Poor choice of materials used in these activities

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54 Controlling Common Indoor Sources Develop a Painting Protocol Ventilate with more outside air during and soon after painting Develop Pesticide Protocol Minimize the use of pesticides Develop a Smoking Policy Ban Smoking Restrict smoking to outside building or at smoking lounge

55 8. Inadequate ventilation rates Lack of compliance with applicable codes and standards Installation and maintenance problems Space use change without assessment of the need for updated ventilation rates. Poor air distribution leading certain section poorly ventilated

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58 CONTROL MEASURES Elimination/relocation of air contaminant source, & appropriate location of air supply/exhaust openings of mechanical ventilation system; Substitution of building material or office chemicals with less harmful substance; Improving ventilation; Installation of air cleaning devices; Administrative controls; Maintenance

59 9. Ineffective filtration and air cleaning Treatment of air filtration Effective air cleaning and maintenance management

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63 Controlling Pollutant Pathways Seal all cavities in walls, ceilings or floors around pipe. Pollutants travel through wire casings Keep common pathways (elevators and stairways) clean and free of pollutant sources Correctly plan the flow path of pollutants HVAC systems transport pollutants as well

64 TAKE AWAY Indoor air quality problems are related to energy conservation measures Poor IAQ can cause health issues for occupants IAQ complaints are primary a result of inappropriate building ventilation Critical elements of a IAQ Program include O&M plans for the HVAC system

65 THANK YOU