Towards nearly zero energy building concept – visual comfort and energy efficiency assessments in a classroom

Abstract

PurposeThis paper aims to raise awareness on how a simple action by the occupant can significantly influence building energy efficiency, cost and CO2 emissions to the environment. Classrooms in schools are the primary energy consumers (45.4%) due to the use of artificial lighting, despite Malaysia's tropical climate being ideal for daylight exploitation. This paper focuses on assessing the workplane daylight distribution quality and quantity in baseline and existing conditions of a typical pre-school classroom in Kuala Lumpur as a model-based exploration strategy towards nearly Zero Energy Buildings.Design/methodology/approachThe adopted method is based on the calculation of average daylight factor (DF), daylight illuminance level (IL) and uniformity ratio (UR) parameters affected by the internal fixed drapes through computational and in situ measurements according to the requirements of the law and respective standards comprising the MS1525:2019, GBI and BREEAM.FindingsThe results show how user behaviour can turn a well-daylit area (Net Lettable Area>90%) into a poor-daylit area (NLA<5%) by sacrificing natural daylight. All the parameters' values were significantly decreased from 10% (UR) up to 88% (ADF). Full dependency on artificial lighting has imposed a total of RM18858.90 and CO2 emissions of 25,362 kg for all pre-schools' classrooms in the country per day.Social implicationsThe paper develops the occupants' awareness on their contribution to climate change and global warming through the information and transparency provided.Originality/valueThe evidence indicates that a simple action by the occupant can significantly influence visual comfort, EE, cost and CO2 emissions to the environment.