Simulation of energy use, human thermal comfort and office work performance in buildings with moderately drifting operative temperatures

Abstract

Annual primary energy use in a central module of an office building consisting of two offices separated with a corridor was estimated by means of dynamic computer simulations. The simulations were conducted for conventional all-air VAV ventilation system and Thermo Active Building System (TABS) supplemented with CAV ventilation. Simulations comprised moderate, hot-dry and hot-humid climate. Heavy and light wall construction and two orientations of the building (east-west and north-south) were considered. Besides the energy use, also capability of examined systems to keep a certain level of thermal comfort was examined. The results showed that with the moderate climate, the TABS decreased the primary energy use by about 16% as compared with the VAV. With hothumid climate, the portion of the primary energy saved by TABS was ca. 50% even with the supply air dehumidification taken into account. The TABS working in a moderate climate kept the Predicted Percentage of Dissatisfied (PPD) <10% during 60% to 80% of the working hours per year. Optimization of the TABS's control strategy (circulation pump dead-band, water supply temperature) resulted in significant reduction of the annual working hours with PPD>10%; 1.4% in comparison to 17.5% hours/year. The highest estimated loss of occupants' productivity related to their thermal sensation hasn't exceeded 1% in whole year average.

Field evaluation of performance of radiant heating/cooling ceiling panel system

“…In addition, most studies employed test chambers and computer modeling [1,3,6,[10][11][12][13][14][15][16]. However, the performance of an in-situ system is usually not the same as that tested in a laboratory or calculated using computer models because it is exposed to a dynamic environment.…”

Indoor environmental quality: review of parameters and assessment models

“…An analysis carried out by Yao and Zhu (2012) using the building simulation software DeST (Designer's Simulation Toolkit) showed that thermotropic double-glazed windows compared with double glazed and tinted double-glazed windows reduced 70% and 53% of highly uncomfortable indoor thermal environmental condition, respectively, that in turn reduces electricity requirement for cooling. Kolarika et al (2011) estimated that the change of the building orientation from east-west to north-south affected the primary energy use by less than 10%. Yoshino et al (2004Yoshino et al ( , 2006 proved that thermal insulation and air tightness were the effective ways to pursue energy conservation for space heating.…”

A sensitivity analysis of the design parameters for thermal comfort of thermally activated building system

“…It provides better thermal comfort at a relatively lower initial and operating cost. TABS is reported to reduce primary energy consumption by approximately 50% in hot and dry climatic conditions [4]. It also reduces the peak energy demand by 60 to 70% [5].…”

“…Though there are a few studies on thermal comfort in such buildings, a few assumptions in these studies reduce the accuracy. For example, Kolarik et al [4], Hauser et al [17] and Ma et al [18] have assumed uniform indoor temperature while studying the influence of the thermal mass of the building with TABS.…”