A thermal performance parametric study of window type, orientation, size and shadowing effect

Abstract

Windows are one of the elements that greatly influence the performance of buildings, both in terms of thermal comfort and energy consumption for heating or cooling. It is therefore important to find an optimal design that balances their orientation, dimension and shadowing. This paper presents a methodology for the parametric study of a window optimal dimension, based on the thermal performance of a reference room located in the climate region of Coimbra, Portugal. First, the parameters of opening type, orientation, and size are evaluated. During a second stage, the impact of using overhangs is assessed, with one of the most common window types in Portugal. The thermal assessment is carried out by calculating the degree-hours of discomfort using dynamic simulation. Results show that for this location, triple glazing has better performance than single and double glazing, especially for the north orientation. The worst opening orientation is northeast and northwest, independent of the window type. It is observable that optimum window dimension does not imply equal space cooling and heating needs. Results also demonstrate that overhangs do not significantly improve the room's thermal performance but allow windows to have a wider interval of admissible sizes without compromising performance.

The impact of thermal transmittance variation on building design in the Mediterranean region

“…On the other hand, regardless the climate conditions, the optimal W W R may be doubled for the simultaneous effect of an improvement of the envelope features and of an enhancement of the installed lighting electric power. Amaral et al [9] performed a parametric study of a reference room where the window size, orientation, and shadowing are analyzed for three types of glazing in Coimbra, Portugal. The authors concluded that lower U -values of the windows contributes to have smaller windows facing south, west, and east orientations and larger windows facing north; being the south orientation the one which contributes higher to the space thermal performance.…”

“…These indexes, when correlated with the energy consumptions, can be useful to draw guidelines that point out the way for better building performances [9][10][11][12][13][14][15], thus helping designers to explore alternative forms and designs. In the specific case of Mediterranean climates, it is interesting to understand which are the most adequate thermal transmittance values of the buildings' elements that decrease the heating demands without excessively raising the cooling needs.…”

Experimental Investigations of the Indoor Thermal Performance of Open Door System (ODOORS) House Prototype in Tropical Climate

“…A number of researchers have studied effect of various housing design parameters on the thermal performance. These parameters included orientation of building, typology of housing, insulations, effect of various microclimates, window types and sizes, effect of shadowing and so forth [15][16][17][18][19]. Most of the research apply virtual simulation model and generative method, which could generate large set of synthetic dataset while some are using scaled models to place in wind tunnels with controlled environment [11,19].…”

The potential impact of low thermal transmittance construction on the European design guidelines of residential buildings

“…The author determined that these factors have a high effect on the U -value, particularly 1 for roofs and walls facing West and East orientations. Amaral et al [9] found that double and triple 2 glazing windows facing North contribute positively to the zone thermal comfort, due to the diffuse 3 solar radiation gains being greater than the losses by thermal transmittance, in Coimbra (Portugal).…”