An investigation of thermal environment of an existing UFAD system in a high-rise office building in the tropics.

The current case study was conducted to identify the causes of environmental health issues in the office space associated with the existing Underfloor Air Distribution (UFAD) system in a high-rise office building in the tropics. The causes of the indoor environmental quality degradation are the key to resolve the environmental health issues. Thus, the parameters such as the indoor air temperature, relative humidity (RH), relative air velocity, carbon monoxide (CO), carbon dioxide (CO2 ), formaldehyde, total volatile organic compound (TVOC) and particulate matter (PM10 ) were evaluated in five office spaces. The results showed that the diffusers were not effective in creating air mixing at the occupied space. The RH has exceeded the threshold limit of 70%. The CO2 concentration has exceeded 1000 ppm, and the formaldehyde has exceeded 0.1 ppm. These indicate the poor design and maintenance of the building that lead to the degradation of indoor environmental quality. Long exposure to the poor indoor environmental quality will cause permanent health damages. The Indoor Air Quality (IAQ) management plan must be established and implemented in the ongoing basis to ensure the health of the occupants are safeguarded. As part of the plan, the practice to conduct an IAQ assessment once every 3 years is recommended to ensure the health and well-being of the occupants are safeguarded.