Automated passive measures: the next step in reducing the carbon footprint of our buildings

Abstract

Passive design is well acclaimed to be a key cornerstone for the design of green buildings, especially when relating to their energy performance and carbon footprint. However, due to the vagaries in the prevailing climate at a project site, passive measures are limited in their ability to ascertain an optimal use of natural resources available at the project site, while also working under certain circumstances against the provision of adequate indoor environmental conditions. The purpose of this project is to showcase the automation of passive measures by an automated daylighting and shading device for vertical glazed surfaces, which has the main objective of increasing daylight in a space while preventing direct sunlight from penetrating the space. During the year and throughout the day the solar azimuth and elevation is constantly changing which makes it of utmost importance for the device to be able to modulate and adapt to the changing solar azimuth and elevation angles. As the position of the sun changes throughout the day and over the course of the whole year; the blinds and shading equipment often have to be adjusted manually by the user at different times of the day. If this is not done, direct sunlight may enter the building and heat the space which results in a higher cooling load. Moreover, direct sunlight can cause glare problems. The proposed mechatronics system orients itself automatically based on the solar azimuth and elevation angles with respect to the particular orientation of the façade it is installed on. It also monitors the ambient light levels in the room and controls the artificial light accordingly. The system can be used in two modes; the overhang and the louver position, hence providing an all-in-one external shading device for glazed surfaces to deal with low, medium and high angle sun, and hence brings the much-needed flexibility to control heat gains through glazing. Research findings show that modulating the heat gains admitted through the glazing can have a significant influence on influencing the indoor thermal conditions, hence lending credit to the proposed system. It is also equipped with a WIFI module and a user interface to allow the user to control the system manually. The implementation and testing of the prototype provided conclusive results for the daylight monitoring, manual control and automatic control.