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Indoor Environmental Quality

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Presentation on theme: "Indoor Environmental Quality"— Presentation transcript:

1 Indoor Environmental Quality
By 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

2 30% of all commercial buildings have IAQ problems - WHO
Most are minor irritation

3 What is IEQ? IEQ, IAQ and Air-conditioning

4 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)

5 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)

6 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.

7 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 , Pittsburgh, PA ($24.00 per copy; stock number )

8 Hence, IEQ = IAQ (or Air-conditioning) + noise + light + ergonomic stressors + psychosocial stressors

9 In terms of scope of work:
80% IAQ or Air-conditioning 20% others

10 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.

11 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 Makhamah Tinggi Jenayah Istana Negara Balai Rongseri Jabatan Kajicuaca

12 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 3. UV Light Installation (to keep cooling coils clean and efficient, free of fungi and bacteria) Makhamah Persekutuan

13 How to measure IAQ? Chemical: CO, CO2, formaldehyde, ETS
Physical: temp, air velocity, humidity Biological: mites, virus, spores Radiation: radon

14 DOSH Guidelines CO2 : max C1000 ppm CO : max 10 ppm
Formaldehyde : 0.1 ppm Respirable Particles : 0.15 mg/m3 Total VOC : 3 ppm




18 JKR Guide Temperature 22-24 C (73-75F) Humidity : 55 +- 5%
Air Change: per hour

19 Biological FCU No guides 200FCU 30 FCU/m3 (non-operating)
1000 cfu/m2 swab samples

20 What are the main causes of IAQ Problem?
Source of contamination HVAC Pathways Occupants

21 Source of Contamination
Sources outside buidling: Contaminated Outdoor air Emission from nearby sources Soil gas Moisture or standing water Equipment HVAC (location) Non HVAC

22 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

23 Other sources Accidents Special use areas Repair activities

24 HVAC Overcooling problem Humidity problem – mold formation
Air filtration Ventilation Outside air supply

25 Pollution Pathway Stack effect and wind Pressure difference

26 Occupants High risk people Sick Building Syndrome (SBS)
Building-Related Illness (BRI)

27 Types of Symptoms and Complaints
Headache fatigue shortness of breath sinus congestion cough sneezing eye, nose, and throat irritation skin irritation dizziness nausea

28 NOISE Area N.C. Level Range Lab./ Waiting Area / Corridor 30 - 40
Outpatients treatment / Casualty Operation Theatre Recovery / Anaesthetic rooms Sluice / Scrub / Sterilizers Toilets / Bathrooms General Wards Private wards Conference Rooms General Office Room Engineering Workshop Kitchens Outside Main Plant Room

29 Sources of Noise M&E Plant Room AHU Room Air suppy – MV and Air-cond

30 How to treat noise Location is of prime importance Insulation?

31 Strategi Memperbaiki IAQ
1. Operasi Penyaman udara Control valve malfunction Chiller plant malfunction Fresh air intake

32 2. Penyelenggaraan Sistem Penyaman Udara
Penapis udara (HEPA) Cooling fins Pulley Condensate tray AHU room cleanliness Servicing of FCU

33 3. Mechanical Ventilating Fans –pastikan berfungsi, dan berfungsi betul.

34 4. Lubang, tingkap, pintu

35 5. Air Panas

36 6. Kebocoran paip 7. Duct Sweating 8. Avoid sealing 9. Early occupancy 10. Renovation 11. Duct-cleaning?

37 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 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.

38 The above strategies deal mainly with HVAC
The above strategies deal mainly with HVAC. How about sources of contamination? Pathway ? And occupants?

39 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

40 Conclusion IEQ is everyone’s concern Everyone can help improve IAQ/IEQ
IEQ is best addressed at design stage Engineers and Architects have an important role to play.

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