C. Aghemo, A. Pellegrino, V. R.M. Lo Verso

Politecnico di Torino, Dipartimento di Energetica, Faculty ofArchitecture chiara. aghemo@polito. it

Introduction

The use of daylight in non-residential buildings has become an important strategy to improve environmental quality and energy efficiency by minimising artificial lighting consumption, heating and cooling loads. Daylighting design and building design should be inseparably linked to each other, in one only creative process aimed at generating appropriate architectural and technical solutions while reducing building energy consumption1. Nevertheless, daylighting strategies are seldom considered in the earliest stages of a building design: this is often due to the lack of simple tools able to accurately predict the performances of daylighting systems exposed to lighting conditions varying continuously in distribution and intensity, according to seasons, day’s hours and specific climate conditions.

As an alternative to a software based-on approach2,3, an efficient prediction tool for daylighting design is represented by the use of scale models under an artificial sky and sun, purposely designed facilities which enable reproducing daylighting conditions by means of artificial lamps and luminaires.

Scale models are often used by designers to analyse design solutions in a three­dimensional physical representations, hence belonging to design culture and assuring a good adherence with real situations, since even complex spaces can be reproduced; furthermore, the simulation ofopaque and transparent materials’ optical properties is easier in most conditions, thanks to the possibility of using real materials.

Using scale models under an artificial sky and sun makes it possible to simulate the dynamic behaviour of daylight to allow the comparison of the environmental performances of different daylighting systems: it is actually possible to maintain constancy and repeatability of luminance distribution of the sky vault and the apparent movement of the sun, assessing a daylighting system with reference to same daylighting conditions4,5,6.