indoor environmental qualityepsmg.jkr.gov.my/images/3/30/indoor_environmental_quality.pdfahu room...
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Indoor Environmental
QualityBy Ir. Ang Choo Hong, JSD, KSD, PPT
Ketua Penolong Pengarah Kanan,
Cawangan Kerja Kesihatan, JKR.
Presented at
Seminar Perlaksanaan Pembangunan Mapan,
Anjuran Jabatan Kerja Raya
10-11, Julai 2007,Bangi
What is Air-conditioning?
1. Temperature
2. Humidity
3. Air-change or ventilation
4. Removal of contaminants
(numerous test methods are available from
ASHRAE on the above)
What is IAQ? (ref: EPA, USA)
Indoor air quality (IAQ) refers to the quality of the
air inside buildings as represented by
concentrations of pollutants and thermal
(temperature and relative humidity) conditions
that affect the health, comfort, and performance
of occupants. Other factors affecting occupants,
such as light and noise, are important indoor
environmental quality considerations but not
cover here. (source:IAQ Building Evaluation and Assessment
Tool, Environment Protection Agency, USA)
IAQ and Air-Conditioning
By the definitions of air-conditioning and IAQ, it is obvious that they deal very much with the same subject. Both deal with pollution (contamination), temperature, humidity and ventilation. In fact, IAQ is a re-representation of air-conditioning.
COP of IAQ, DOSH Malaysia : IAQ and HVAC are closely related.
If there is a difference, than the difference is: air-conditioning emphasizes more on the engineering aspects (design, installation, operation, control and maintenance) of getting the quality air (of right temperature, humidity, ventilation and cleanliness) whilst IAQ emphasizes more on the outcome or air quality per se.
What is IEQ?
NIOSH, (USA) investigators have found that air quality may be caused by a number of factors, encompassing much more than air contamination. Other factors such as comfort, noise, lighting, ergonomic stressors (poorly designed work stations and tasks) and job related psychosocial stressors can individually and in combination contribute to complaints. Hence, IEQ more accurately describes the scope of the problem (referring to Sick Building Syndrome).
(Ref: Building Air Quality: A Guide for Building Owners and Managers available from Superintendent of Documents, U.S. Government Printing Office. P.O. Box 371954, Pittsburgh, PA 15250-7954 ($24.00 per copy; stock number 055-000-00390)
Hence,
IEQ = IAQ (or Air-conditioning)
+ noise
+ light
+ ergonomic stressors
+ psychosocial
stressors
IAQ or Air-conditioning Practice
in JKR
The normal maintenance of air-cond. in
JKR includes regular filter change and
cleaning, coil cleaning, water treatment, to
ensure that users get clean, well-ventilated
and cool air.
IAQ or Air-conditioning Practice
in JKR
Apart from that, JKR (Woksyop Persekutuan) had also embarked on the following, aimed at improving IAQ:
1 Robotic Duct-cleaning
Pejabat am dan pejabat perancang, JKR Woksyop Persekutuan -1995
Makhamah Tinggi Jenayah -1998
Istana Negara Balai Rongseri -2000
Jabatan Kajicuaca -2004
IAQ or Air-conditioning Practice
in JKR
2. Bioactive Coil Treatment (to keep cooling coils
clean, efficient, free of fungi and bacteria)
Makhamah Tinggi Jenayah -1998
Pejabat Pengurus Perkhidmatan, JKR Woksyop
Persekutuan -1998
3. UV Light Installation (to keep cooling coils
clean and efficient, free of fungi and bacteria)
Makhamah Persekutuan -1998
How to measure IAQ?
Chemical: CO, CO2, formaldehyde, ETS
Physical: temp, air velocity, humidity
Biological: mites, virus, spores
Radiation: radon
DOSH Guidelines
CO2 : max C1000 ppm
CO : max 10 ppm
Formaldehyde : 0.1 ppm
Respirable Particles : 0.15 mg/m3
Total VOC : 3 ppm
Source of Contamination
Sources outside buidling:
–Contaminated Outdoor air
–Emission from nearby sources
–Soil gas
–Moisture or standing water
Equipment
–HVAC (location)
–Non HVAC
Source of Contamination
Human Activities–Personal
–Housekeeping
–Maintenance
Building Components and furnishing– Locations that produce or collect dust
and fibre
–Unsanitary conditions and water damage
–Chemical released
HVAC
Overcooling problem
Humidity problem – mold formation
Air filtration
Ventilation
Outside air supply
Types of Symptoms and
Complaints
Headachefatigueshortness of breathsinus congestioncoughsneezingeye, nose, and throat irritationskin irritationdizzinessnausea
NOISEArea N.C. Level Range
Lab./ Waiting Area / Corridor 30 - 40
Outpatients treatment / Casualty 30 - 35
Operation Theatre 25 - 30
Recovery / Anaesthetic rooms 25 - 30
Sluice / Scrub / Sterilizers 35 - 45
Toilets / Bathrooms 40 - 50
General Wards 30 - 35
Private wards 25 - 35
Conference Rooms 30 - 40
General Office Room 35 - 45
Engineering Workshop 60 - 70
Kitchens 50 - 60
Outside Main Plant Room 60 - 70
Strategi Memperbaiki IAQ• 1. Operasi Penyaman udara
– Control valve malfunction
– Chiller plant malfunction
– Fresh air intake
• 2. Penyelenggaraan Sistem Penyaman
Udara
– Penapis udara (HEPA)
– Cooling fins
– Pulley
– Condensate tray
– AHU room cleanliness
– Servicing of FCU
• 6. Kebocoran paip
• 7. Duct Sweating
• 8. Avoid sealing
• 9. Early occupancy
• 10. Renovation
• 11. Duct-cleaning?
• Guidelines for Environmental Infection Control
• in Health-Care Facilities
• extracted from pg 34
• Duct cleaning in health-care facilities has benefits in terms of system performance, but its usefulness for infection control has not been conclusively determined. Duct cleaning typically involves using specialized tools to dislodge dirt and a high-powered vacuum cleaner to clean out debris.263 Some duct-cleaning services also apply chemical biocides or sealants to the inside surfaces of ducts to minimize fungal growth and prevent the release of particulate matter. The U.S. Environmental Protection Agency
• (EPA), however, has concerns with the use of sanitizers and/or disinfectants to treat the surfaces of ductwork, because the label indications for most of these products may not specifically include the use of the product in HVAC systems.264 Further, EPA has not evaluated the potency of disinfectants in such applications, nor has the agency examined the potential attendant health and safety risks. The EPA recommends that companies use only those chemical biocides that are registered for use in HVAC systems.264. Although infrequent cleaning of the exhaust ducts in AII areas has been documented as a cause of diminishing negative pressure and a decrease in the air exchange rates,214 no data indicate that duct cleaning, beyond what is recommended for optimal performance, improves indoor air quality or reduces the risk of infection. Exhaust return systems should be cleaned as part of routine system maintenance. Duct cleaning has not been shown to prevent any health problems,265 and EPA studies indicate that airborne particulate levels do not increase as a result of dirty air ducts, nor do they diminish after cleaning, presumably because much of the dirt inside air ducts adheres to duct surfaces and does not enter the conditioned space.265 Additional research is needed to determine if air-duct contamination can significantly increase the airborne infection risk in general areas of health-care facilities.
• The above strategies deal mainly with
HVAC. How about sources of
contamination? Pathway ? And
occupants?
• Carpet
• Adhesives used in office furniture
• Manufactured wood products
• Cleaning agents
• Insecticides
• Fibre partition walls, upholstery products
• Copy machines, printers, computers, toners
• Plastic wrappings, plastic materials
• Paint