High level circular use of post-consumer insulating glass units will contribute to lower the environmental and social impact of insulation glass industry. The application of various circular strategies for insulating glass units (IGU’s) is rising. The product age will give an indication of the remaining life-time of an IGU, but a method which includes screening a technical quality is needed to check if an IGU is indeed suitable for re-use on a high level of circularity. In this study the argon concentration is suggested as discriminative quality. Energy efficient double glazing applied in windows of buildings situated in The Netherlands were studied. Product codes were noted and unraveled. Measurements were performed using the Sparklike Laser Portable, a non-invasive argon measuring device, which generates argon concentration, glass thickness and cavity width values. In addition, measurements were performed with a Glass Check thickness meter. The resulting data were analyzed. Measuring errors were explored and used to setup a testing procedure. Threshold values of the product age and argon concentration were selected for different circular strategies. In conclusion, a screening method using the product age and argon concentration to determine the circular use potential of insulating glass units is proposed.
MULTIFILE
The adaptivity of façades is increasingly recognized as an important functional feature to be integrated with the state-of–the-art building technology. The aim is thereby to control its reversible system states in real-time to adapt to current indoor and outdoor conditions. Concepts reported elsewhere integrate two or more functions related to structural integrity, ventilation, heating and cooling, solar protection, as well as energy generation and storage. Although advantages are perceived obvious, the number of realized case studies remains limited. Triggered by this observation, the authors of this contribution report research findings from a literature study and interviews with stakeholders in the field, including contractors, building consultants and architects. The three key-findings suggest that (1) the functions daylighting and energy generation/storage are most commonly integrated into façades or façade components characterized as being adaptive, (2) interviewees are divided on the implementation potential of most of the designs/concepts and (3) the aesthetics of the design, (investment) costs, durability and required maintenance are critical for a widespread market uptake. Herewith, this paper contributes new knowledge to the discussion related to finding the right level of system integration in building technology.
MULTIFILE
Thermal comfort is determined by the combined effect of the six thermal comfort parameters: temperature, air moisture content, thermal radiation, air relative velocity, personal activity and clothing level as formulated by Fanger through his double heat balance equations. In conventional air conditioning systems, air temperature is the parameter that is normally controlled whilst others are assumed to have values within the specified ranges at the design stage. In Fanger’s double heat balance equation, thermal radiation factor appears as the mean radiant temperature (MRT), however, its impact on thermal comfort is often ignored. This paper discusses the impacts of the thermal radiation field which takes the forms of mean radiant temperature and radiation asymmetry on thermal comfort, building energy consumption and air-conditioning control. Several conditions and applications in which the effects of mean radiant temperature and radiation asymmetry cannot be ignored are discussed. Several misinterpretations that arise from the formula relating mean radiant temperature and the operative temperature are highlighted, coupled with a discussion on the lack of reliable and affordable devices that measure this parameter. The usefulness of the concept of the operative temperature as a measure of combined effect of mean radiant and air temperatures on occupant’s thermal comfort is critically questioned, especially in relation to the control strategy based on this derived parameter. Examples of systems which deliver comfort using thermal radiation are presented. Finally, the paper presents various options that need to be considered in the efforts to mitigate the impacts of the thermal radiant field on the occupants’ thermal comfort and building energy consumption.
