Monday, January 30, 2017: 11:00 AM-12:00 PM
HVAC&R Systems and Equipment
Chair:
Ratnesh Tiwari, Ph.D., University of Maryland
This session examines performance aspects of three rather different radiation sensitive components/systems used on building envelopes. The first presentation looks at energy saving/thermal comfort trade-offs when different control strategies are used for a system that couples nocturnal radiative cooling panels with phase change ceiling panels in Denmark. The second compares the performance of transparent and opaque building integrated photoVoltaic/thermal collectors in two different locations in Canada. The last paper presents comprehensive measurements of roof solar reflectivity made on 30 different buildings in each of three different cities around the U.S. to get a better understanding of the field performance of high solar reflectivity roofing materials.
1 Field Measurements of Solar Reflectivity for In-Service Single Ply Roof Membranes (LV-17-C048)
High solar reflectivity roof membranes have been a focal point of energy saving efforts in building design. These efforts have been codified in the International Code Council (ICC) International Energy Conservation Code (IECC) and the American Society of Heating and Air-Conditioning Engineers (ASHAE) Standard 90.1 Energy Standard for Buildings Except Low-Rise Residential Buildings. In both of these texts prescriptive aged and or initial roof membrane solar reflectivity is specified. This paper reports the numerical findings of this study, examines causation for the differential levels solar reflectivity values discovered and proposes guidelines for roof membrane solar reflectivity used for design and modeling.
2 Parametric Analysis of the Control System of Solar Panels for Nocturnal Radiative Cooling Coupled with PCM Ceiling Panels (LV-17-C049)
As HVAC systems advance to meet the energy savings goals, their control system becomes increasingly complicated. In order to optimize the operation of a control system, the ideal combination of its parameters need to be realized, aiming at providing an acceptable indoor environment as defined by the standards and at the same time reducing the energy use as much as possible. In this simulation study, the coupling of solar panels with Phase Change Material (PCM) ceiling panels for cooling an office room was examined during the cooling season of Copenhagen (Denmark) by means of dynamic simulations.
3 Comparative Performance Evaluation of Transparent and Opaque BIPV/T Collectors: Roof and Façade Integration (LV-17-C050)
Building integrated photovoltaic/thermal (BIPV/T) system provides sustainable solution in design structure as part of the building envelop. A mathematical model was developed for transparent and opaque BIPV/T collector, (TBIPV/T) and (BIPV/T). Both models were implemented in TRNSYS to conduct comparative study. A single zone house was modeled in TRNSYS to conduct a case study to evaluate the performance of each collectors. Comparative studies were performed between both systems, each integrated into the façade and roof of the house for two locations in Canada.