Good indoor air quality (IAQ) is required for a healthy indoor work environment. Poor indoor air quality can cause a variety of short-term and long-term health problems. Health problems commonly associated with poor IAQ include allergic reactions, respiratory problems, eye irritation, sinusitis, bronchitis and pneumonia. IAQ problems occur in buildings that are served by a mechanical ventilating and air conditioning (MVAC) system including air-cooled split unit. IAQ problems can be due to indoor air pollutants or to inadequate ventilation. There are many sources of indoor air pollutants and among the common ones are environmental tobacco smoke (ETS) emitted due to burning of tobacco products; various chemical substances such as formaldehyde emitted from furnishings; volatile organic compounds emitted from the use and application of solvents; and ozone emitted from photocopiers and laser printers. It should be noted here that ETS has been recognized as a human carcinogen by the International Agency from Research on cancer (IARC) in 2002 and exposure to it will increase the risk of coronary heart disease.

a. Objectives of Indoor Air Quality (IAQ)Assessment

Objectives of conducting assessment of IAQ are:

• To identify the sources of the indoor air contaminants either within the place of work or from the outsideair;
• Toevaluatetheexposureoftheoccupantstotheindooraircontaminantseither from indoor or outdoorsources;
• To determine the air temperature, relative humidity and air movement at the place ofwork;
• Todeterminetheadequacyofmechanicalventilationattheplaceofwork;
• To conclude on the compliance to the recommended standard on indoor air quality; and
• Torecommendnecessaryactionstobetakentoimprovetheindoorairqualityat the place of work.

b. Sampling Techniques

There are basically TWO types of assessment methods:

• Real-time measurements;and
• Integrated sampling with subsequent laboratoryanalysis.

c. Parameters to Indicate Indoor Air Quality (IAQ)Status

Theparameterstoindicatewhetheranindoorenvironmentiscomfortableandhealthyor otherwise can be summarised asfollows:

• Chemical contaminants, such as carbon dioxide, carbon monoxide,formaldehyde and environmental tobacco smoke(ETS);
• Physical conditions, such air temperature, air velocity andhumidity;
• Biological agents, such as mites, virus, and spores;and
• Radiation such asradon.

d. Indoor Air Quality (IAQ) InvestigationProcess

Investigation of indoor air quality problem It shall be the responsibility of the building owner or building management to investigate concerns about indoor air quality when:

• Complaints arereceived;
• Theoccupancyinthespaceexceedstherecommendednumberofoccupancyin the original design;or
• Renovations are made that involve significant changes to the ventilationsystem

e.g. a room without supply or return air.

Task 1: Perform Indoor Air Quality (IAQ) InvestigationProcess

Perform the IAQ investigation process as shown in Figure 3.1. Go through and complete the following documents available in the Industry Code of Practice on Indoor Air Quality 2010.

• Appendix 3-A: Checklist for Walkthrough Inspection;and
• Appendix 3-B: Questionnaire for BuildingOccupants.

Task 2: Perform Carbon dioxide (CO₂), Temperature and Humidity IAQ Measurement

Equipment:

• TSI VelociCAL9565p
• TSI980

3.7 Results

Assuming the air data collection below as a refference from your organization.

Table 1: Carbon dioxide (CO2), Temperature and Humidity IAQ

T Time	9:00 AM	12.00 PM
Temperature	72.8F (20.67C)	71.7F (22.05C)
CO2	811 ppm	949 ppm
% RH	67.7 %	60.2%

Based on Table 1:

2. Compare the measurement with relevant standards or guidelines
4. Discuss the result
6. Conclusion (10 mark)

• Explain the health effects due to poorIAQ. (10 marks)
• Explainindetail,IAQsamplingstrategy. (10marks)