AN INVESTIGATION OF THERMAL COMFORT IN SINGAPORE �S PUBLIC HOUSING: FIELD STUDIES FROM 1987 TO 2018

Abstract

At least 80% of the Singapore population lives in public housing, also known as the Housing Development Board (HDB) flats. With these flats being naturally ventilated, achieving thermal comfort becomes a challenge, as the indoor thermal condition is largely influenced by the outdoor climate. When occupants face thermal discomfort in warm conditions, they turn to mechanical devices such as electric fans and air-conditioning and may eventually depend vastly on them for cooling. As a result, it would lead to higher demands for energy from non-renewable energy sources, increase local carbon emissions, and consequently aggravate the warming situation that the country is facing.

This study aims to investigate the thermal comfort history and thermal preference of Singapore public housing residents. It does so through an evaluation of four historical data points of years 1987, 2000 – 2001, 2005 and 2016 – 2018 respectively. The study first understands the residents’ level of acceptance of the thermal condition of their homes by analysing the thermal sensation and comfort responses. The indoor climatic measurements were analysed to understand their influence on the thermal comfort. Further, the thermal preference votes were examined to understand the residents’ preferred thermal environment of their homes. Thermal history was lastly analysed to understand its influence on the thermal comfort and preference.

The findings of the study reveal that there is a decline in thermal acceptability over the last two decades. It found that air temperature and air velocity among others, influence residents’ thermal comfort in the flats. It also found that occupants’ thermal history plays a significant influence on their thermal comfort and preference. People who are frequently exposed to air-conditioning tend to be less tolerant of extreme thermal environments, compared to others who are frequently exposed to natural ventilation and mechanical ventilation (fans). The residents in Singapore also prefer their homes to adopt the same mode of ventilation as what they are frequently used to. Besides they prefer to live in cooler than neutral environments. The results were collectively reviewed to provide recommendations for alleviating thermal discomfort in HDB flats without the use of air-conditioning.

Keywords: Housing and Development Board (HDB) Flat, Natural Ventilation, Thermal Comfort, Thermal Preference, Thermal History, Thermal Adaptation