Effects of built-in balcony on thermal performance in residential buildings: A case study

Abstract

In this study, effects of built-in balcony on thermal performance in residential buildings were investigated numerically by means of open-ended structure approach. For this purpose, the parametric study has been carried out for various ratios of balcony depth/balcony height (L/H), closed barrier height/balcony height (h/H) and Rayleigh numbers (Ra) using a computer program in case of no wind for laminar flow. Analyses were conducted for Rayleigh numbers ranging from 10³ to 10⁶. The calculations were carried out for the ratios of L/H, namely, 0.0, 0.24 and 0.6, and the ratios of h/H, namely, 0.0, 0.18 and 0.35. The working fluid was assumed to be air (Pr = 0.71). According to the findings, for Ra ⩽ 10⁴, Nusselt number (Nu) decreases with the increasing ratio of L/H for the constant h/H = 0.35. However, for Ra ≥ 10⁵, Nu sharply decreases with the increasing ratio of L/H, while Nu again sharply increases after L/H ≅ 0.25 and almost remains constant after L/H ≅ 0.5. For the constant L/H = 0.54, Nu decreases with the increasing ratio of h/H for the whole Ra. It is suggested that the ratio of L/H should not be over 0.35 and the ratio of h/H should be at least 0.35.