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

30% of all commercial buildings have IAQ

problems - WHO

Most are minor irritation

What is IEQ?

IEQ, IAQ and Air-conditioning

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

In terms of scope of work:

80% IAQ or Air-conditioning

20% others

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

JKR Guide

Temperature 22-24 C (73-75F)

Humidity : 55 +- 5%

Air Change: 12 -20 per hour

Biological

FCU

No guides

200FCU

30 FCU/m3 (non-operating)

1000 cfu/m2 swab samples

What are the main causes of IAQ

Problem?

Source of contamination

HVAC

Pathways

Occupants

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

Other sources

–Accidents

–Special use areas

–Repair activities

HVAC

Overcooling problem

Humidity problem – mold formation

Air filtration

Ventilation

Outside air supply

Pollution Pathway

Stack effect and wind

Pressure difference

Occupants

High risk people

Sick Building Syndrome (SBS)

Building-Related Illness (BRI)

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

Sources of Noise

M&E Plant Room

AHU Room

Air suppy – MV and Air-cond

Lift

How to treat noise

Location is of prime importance

Insulation?

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

• 3. Mechanical Ventilating Fans –pastikan

berfungsi, dan berfungsi betul.

• 4. Lubang, tingkap, pintu

• 5. Air Panas

• 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

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.