The impact of temperature gradient on energy consumption of displacement ventilation system in the tropics

Abstract

The objective of this study was to investigate the energy consumption at different temperature gradients in a Field Environment Chamber, 11.1 m (L) × 7.5 m (W) × 2.6 m (H), served by displacement ventilation system in Singapore. Sixteen identical workstations were arranged equally into two rows and positioned at the centre of the chamber to simulate a typical office layout. Each workstation consists of a computer and a chair of upholstered with backrest. Subjects were exposed to 3 levels of vertical air temperature gradients (nominally 1, 3 & 5 K/m) between 0.1 and 1.1 m height and 3 room air temperatures of 20, 23 & 26oC at 0.6m height. During the experiment, relative humidity at 0.6m height and outside air provision were kept constant at 50% and 10 l/s/p respectively. Subjects were performing sedentary normal office work during the experiment. The duration of each session of the experiment is 3 hours. Heat sources inside the chamber were subjects and computers. The results show that at the same room air temperature and humidity level, DV system with greater temperature gradient in the tropics has higher energy saving potential.