Validation of a novel luminance based sensor system for visual environment monitoring and control

In the drive to reduce building energy consumption and carbon emissions, building controls are becoming ever more sophisticated, i.e. they must ensure that buildings respond well to external conditions in order to achieve comfortable internal environments with minimal energy expenditure. While indoor environmental quality (IEQ) aspects such as thermal comfort and indoor air quality can be reasonably well monitored and controlled with existing systems, standard building environment sensors cannot currently measure visual comfort parameters, opening up exciting opportunities for sensor development. This paper presents the prototype development of a novel, compact and low cost visual environment sensor, which uses an image-based approach to provide detailed data about the visual environment. These data may in the future feed into control systems, where they can be integrated with other environment parameters and thus inform a holistic IEQ control strategy. The potential applications of such a system include improvements of building control and in-vehicle comfort levels, monitoring of space use and occupant behaviour as well as large scale building performance research - all linked to improving building energy efficiency and/or occupant safety and well-being. In the paper we present data regarding the performance of five prototype systems in comparison with sophisticated, but cumbersome, research apparatus and explore sensor design issues, such as portability, user acceptability and compatibility/integration with existing state-of-the-art building technology.