A CASE STUDY APPROACH IN UNDERSTANDING THE RELATIONSHIP BETWEEN CO2 AND TVOCS IN THE EXTENT OF AFFECTING BUILDING OCCUPANT �S PRODUCTIVITY LEVEL

Abstract

Indoor Air Quality (IAQ) bears a close relationship with building occupant’s health, comfort and productivity. While various IAQ parameters are being identified as the contributor to Sick Building Syndrome (SBS), little was known on their respective impact of worker’s productivity. This study seeks to examine the IAQ in office building, in particular to the relationship between Carbon Dioxide (CO2) and Total Volatile Organic Compounds (TVOCs) in affecting occupant’s productivity level.

In this research, IAQ audits using case study approach was done on an office building. Objective measurement was carried out with 8 parameters at the occupant’s breathing zone: Temperature, Relative Humidity, Dew point, Carbon Dioxide, Carbon Monoxide, Air Velocity, Total Volatile Organic Compounds and Dust particles. Spot measurements were taken at 8 sampling locations in the office to compare against the recommended IAQ guidelines. Subjective measurement such as survey and interview were conducted to identify the perceived productivity and satisfaction on IAQ.

The experimental result showed that CO2 level had exceeded the acceptable indoor threshold in the office but no significant effect was observed for occupant’s alert level. The concentration of TVOCs was kept within the limit but showed a rising trend at areas with photocopiers and use of cleaning agents. Although the objective result indicated acceptable TVOCs level, the perceived IAQ by occupants was considerably unsatisfactory. The perceived productivity seemed to be influenced by the IAQ which did not meet with most respondent’s expectation. The elevated CO2 level appears to indirectly affect occupant’s perceived productivity. TVOCs concentration, on the other hand, might reduce occupant’s productivity even at low-level due to its complex combination.

Inadequate ventilation in the office could lead to poor IAQ and thus creating an environment that lower worker’s productivity. Recommendations have been provided to improve the overall indoor air quality performance in the office.