Better daylighting to improve energy efficiency of existing buildings using building modelling case: Qazvin Construction Engineering Organization (QCEO), Iran

Abstract

With increasing concerns towards energy performance of existing buildings, as the biggest users of energy in the building industry, implementing appropriate green retrofit measures for lower energy consumption is crucial. Designing for better daylighting is one of the applicable strategies to achieve higher energy efficiency with low primary operation costs in parallel with low environmental effects. The main aim of researching in this field is to improve the designers’ ability to take more advantage of natural light and cut down the artificial energy consumption in their green projects. This paper, presents a study on daylight significance also, the possible design strategies to use natural light along with proper control of heat gains and glare, focusing on existing buildings. The application of this study is demonstrated in the building of “Qazvin Construction Engineering Organisation (QCEO)”, which is one of the most important office buildings in Iran. Daylight field measurements with Lux meter showed that using electrical lighting in QCEO, even during the days, is inevitable, due to the insufficient internal daylight level. Then, modifications of interior walls and ceiling color were tried with virtual modeling and simulations done with Dialux. The results revealed that there is a good opportunity of obtaining more daylit floor area and therefore, a great decrease in QCEO electricity usage for lighting, per annum. This paper concludes that implementing proper design strategies is able to decrease electricity usage for lighting in existing buildings.