INDOOR AIR QUALITY

(IAQ)

For Bedok Safety Group (26th May 2011)

By Eric Ng

Absolute Instrument Systems (Pte.) Ltd.

www.aisys.com.sg

Presentation Topics

Why should you be concerned about Indoor Air

Quality?

How to do an IAQ audit?

What parameters are monitored?

Why should you be concerned about

IAQ?

Why should you be concerned about

IAQ? – Sample Questionnaire

Do you have to put on extra clothing for comfort? Regularly / Sometimes / Never

Does the office air feel stuffy?

Does the office air have an unpleasant odour?

Visible mould.

Dusty air vent.

Stuffy nose: daily/2-3 times weekly/Less

Dry throat: daily/2-3 times weekly/Less

Cough: daily/2-3 times weekly/Less

Skin rash/itchiness: daily/2-3 times weekly/Less

Eye irritation: daily/2-3 times weekly/Less

When do you experience relief from these complaints?

After I leave my workstation / After I leave the building / Never – SS 554:2009 Code of practice for Indoor air quality for air-conditioned buildings.

Why should you be concerned about

IAQ?

Ensure comfortable, healthy work environment

Sick Building Syndrome

Building-Related Illness

Productivity concerns

Liability concerns

Singapore Standard SS 554:2009 Code of practice for Indoor air quality for air-conditioned buildings – recommends an IAQ audit be carried out once every three years.

What is Acceptable IAQ

“Air in an occupied space toward which a

substantial majority (80%) of occupants express no

dissatisfaction and in which there are not likely to

be known contaminants at concentrations leading to

exposures that pose a significant health risk.”

– SS 554:2009 Code of practice for Indoor air quality for air-conditioned buildings.

IAQ, Work Performance and Health

Sick Building Syndrome (SBS)

Eye, Nose, Throat Irritations, Coughing, Wheezing, Stuffy or runny nose, Respiratory Infections, Skin Rash, Headaches, Dizziness, Nausea, Fatigue, Difficulty in concentrating.

Conditions required for SBS

Workers experiences these symptoms

And no specific illness can be identified

And symptoms vanish or dissipate shortly after worker leave building.

Causes of poor IAQ

Air-Conditioning and Mechanical Ventilation

(ACMV) systems that are poorly designed,

maintained or operated.

Presence of Sources of indoor air contaminants.

Indoor air contaminants Common sources

Carbon Dioxide Exhaled air, Complete combustion

Carbon Monoxide Vehicles, Cooking, Smoking

Formaldehyde/ TVOC Wooden furniture, cleaning agent, adhesive,

glues, sealants, paints, lacquers, upholstery,

perfumes, disinfectants, paper products.

Ozone Photocopiers, laser printer, ozone generator

Mould Wet or moist carpets, high humidity environment

Bacteria Building occupants, decomposed food, pest

IAQ Audit – a four step protocol

Step 1 – Walk-through inspection

Step 2 – Conduct air sampling and obtain

feedback from building occupants

Step 3 – Data analysis

Step 4 – Building remedial action.

Recommended IAQ parameters

Chemical parameters

Carbon Dioxide – 700ppm above outdoor

Carbon monoxide – 9 ppm

Formaldehyde – 0.1 ppm

TVOC – 3 ppm

Respirable suspended particles – 50 microgram/m3

Thermal comfort parameters

Operative temperature – 24 to 26 ˚C

Relative humidity - <65% for new buildings, <70% for

existing buildings.

Air movement – 0.10 to 0.30 m/s

Recommended IAQ parameters

Recommended IAQ parameters

Biological parameters

Total viable bacterial count – 500 cfu/m3

Total viable mould count – 500 cfu/m3

– SS 554:2009 Code of practice for Indoor air quality for air-conditioned buildings.

IAQ monitor: EVM7

Available Sensors

Relative Humidity

Temperature

CO2 (NDIR)

02

CO

H2S

NO

NO2

HCN

EtO

CL2

SO2

Particulates

Photoionization Detector ppm

Photoionization Detector ppb

IAQ monitor: EVM7

Thank you