Qi Jie Kwong

Perception of Thermal Comfort in the Enclosed Transitional Space of Tropical Buildings

The enclosed lift lobby distinguishes itself as a unique form of region categorised under building transitional spaces. This paper reports on an evaluation of thermal comfort conditions in a prominent transitional space in buildings which is the enclosed lift lobby of an educational institution in Malaysia, using field survey which included objective measurement and subjective assessment. The temperature set-point of air conditioner was increased and maintained at 26°C to investigate the human thermal perceptions in the enclosed region. Comparison was made on the percentage of thermal sensation, preference, acceptability and general comfort votes obtained from field survey. The outcomes clearly indicated that the human thermal perception in the enclosed lift lobby would be directly proportional to the level of human occupancy, and any sudden temperature change could lead to thermal discomfort of occupants. The respondents generally preferred to have cooler environment, rather than warmer one. Also, comfortable temperature can be obtained even with higher air conditioner thermostat settings. These findings may serve as a guide for building operators in the tropics to control the energy consumption of cooling equipment attached to the enclosed transitional spaces.

Evaluation of indoor thermal environment in a radiant-cooled-floor office building in Malaysia

This paper presents the findings of a thermal comfort survey conducted in a tropical green office building. The building was installed with a slab-integrated radiant cooling system, which operated concurrently with an integrated variable-air-volume system. Evaluation of indoor thermal environment was made, where both objective and subjective assessments were carried out. The air temperature, air velocity, relative humidity and surface temperatures were measured by using calibrated sensors. Based on the data collected from the field assessment, the thermal comforts indices with expectancy factor were calculated. The results showed that thermal comfort parameters were within the comfort range specified in a local guideline, except for the air velocity profile. Besides, discrepancy between the Predicted Mean Vote (PMV) with expectancy factor and Actual Mean Vote (AMV) was found, which showed that the former still overestimated the thermal sensation of occupants although an expectancy factor of 0.5 was used.

Assessment of energy saving potentials for protected spaces in commercial buildings

This paper presents the energy conservation improvement potentials of a protected space in a tropical building, which is subjected to various building services and safety requirements. Field measurement was conducted in this study, where the actual environmental conditions of a selected protected lobby and the major sources for space heat gain were systematically measured and studied. Besides, the energy consumption data of the building under study was also collected for energy management opportunities (EMOs) analysis. It was identified in the field assessments that the indoor thermal and visual comfort parameters were within acceptable levels. By following the recommended energy conservation schemes, it is possible to achieve a total reduction of approximately 16,000 kWh in building energy consumption annually, which provides a monetary saving of about 2,230 USD. For energy efficiency purpose, this study introduced a new method of reducing energy usage in the protected areas in buildings by taking the building safety requirements into consideration. Further savings are achievable by raising the thermostat settings during off-peak hours and replacement of the artificial lighting fixtures with the more energy efficient ones.