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A growing focus on occupant comfort, health and wellbeing has resulted in attempts to quantify indoor environmental quality (IEQ) and to determine the relative contributions of single IEQ aspects to an overall IEQ index. The recently developed IV20 tool assesses potential IEQ to label overall IEQ, and assign separate scores for the main indoor environment (IE) areas: thermal, visual, acoustic and air quality. In the absence of objective, universally applicable IEQ weights, this paper develops and executes a methodology asking regional experts with different backgrounds to make relative comparisons between related IE aspects. The authors hypothesize that wide-ranging subjective evaluations can be combined into useful relative weights (best operational solution based on the current status of IE literature). This paper presents results from an IE expert survey on relative IE aspect weights using simple percentile prioritization and the Analytic Hierarchy Process pairwise comparison. Results are compared to expert panel judgements to ensure validity. The advantages of this combined weight determination method are (1) that the expert survey ensures a broad spectrum of opinions and allows for input from different built environment disciplines, and (2) that the expert panel has tool-specific insight, methodology awareness and state of the art knowledge. [ABSTRACT FROM AUTHOR]

The purpose of night ventilation (NV) is to improve building energy and thermal comfort performance. The key to accurately predicting NV performance is selecting the appropriate convective heat transfer coefficient (CHTC) at different surfaces of the built environment. The current CHTC correlations used in building energy simulation tools are limited and prevent accurate modeling of NV strategies. The building thermal mass activation is also an important factor to influence the efficiency of NV. A series of dynamic full-scale experiments with ten thermal mass distribution schemes, four air change rates per hour (ACH), and two inlet air temperatures was conducted to derive the CHTCs at test room surfaces during NV in case of mixing ventilation. The results show that the existing correlations did not accurately predict the CHTC for most cases. Therefore, the new surface-averaged CHTC correlations with inlet temperature as reference were developed for different thermal mass distribution schemes and ACH. Installing the thermal mass on one surface can significantly enhance its CHTC and affect the CHTC at other surfaces. The mean CHTC of the test room was independent of the inlet air temperature but increased together with ACH and thermal mass level of interior surfaces. Finally, the presence and locations of tables had limited influence on the CHTC at interior surfaces but reduced the mean CHTC. • The heat transfer of night ventilation was investigated by dynamic experiment • The existing correlations did not predict the convective heat transfer coefficient well. • Thermal mass on surfaces greatly affected the convective heat transfer coefficient. • The display of furniture influenced its air distribution and the heat transfer coefficient. • New convective heat transfer coefficient correlations were developed. [ABSTRACT FROM AUTHOR]