Cooling load reduction effect and its mechanism in between-glass cavity and venetian blind operation during the summer season
- 487 Downloads
The proper operation of venetian blinds in between-glass cavity airspaces is one of the most commonly used passive control techniques and can significantly reduce the cooling load and energy use in buildings. This study investigated the cooling load reduction effect of the blind integrated with the cavity operation. A full heat balance analysis was performed using EnergyPlus to provide a detailed understanding of the heat transfer mechanism that takes place around the blind and between-glass cavity. A sensitivity analysis was also carried out to evaluate the effects of different slat angles and blind operation hours. The results show that integration of the blind and between-glass cavity operations can significantly reduce the cooling load in buildings. The cooling load reduction effect of the cavity operation (by approximately 50%) was greater than that of the blind operation (by 5% to 40%, depending on slat angle and operating hours). It was found that the interzone heat transfers between the cavity and the room space and convection heat fluxes from each surface mainly contribute to the total cooling load reduction. In addition, the double-sided blind had a greater potential to reduce the cooling load compared with a conventional single-sided blind due to its greater capability of reflecting direct solar radiation and preventing diffuse solar radiation from penetrating the room space. The results of the study show that the largest reduction of cooling load can be achieved by the cavity operation, followed by the blind operation and the proper selection of operating hours for the blinds.
Keywordsvenetian blinds between-glass cavity operation cooling load heat balance method energy simulation
Unable to display preview. Download preview PDF.
- Alzoubi HH, Al-Zoubi AH (2010). Assessment of building facade performance in terms of daylighting and the associated energy consumption in architectural spaces: Vertical and horizontal shading devices for southern exposure facades. Energy Conversion and Management, 51: 1592–1599.CrossRefGoogle Scholar
- ASHRAE (2007). ASHRAE Standard 90.2, Energy-Efficient Design of Low-Rise Residential Buildings. Atlanta, USA: American Society of Heating, Refrigerating and Air-Conditioning Engineers.Google Scholar
- ASHRAE (2009a). ASHRAE Fundamentals Handbook, Chapter 19 Energy Estimating and Modeling Methods. Atlanta, USA: American Society of Heating, Refrigerating and Air-Conditioning Engineers.Google Scholar
- ASHRAE (2009b). ASHRAE Fundamentals Handbook, Chapter 16 Ventilation and Infiltration. Atlanta, USA: American Society of Heating, Refrigerating and Air-Conditioning Engineers.Google Scholar
- ISO Standard (2001). ISO Standard 15099, Thermal Performance of Windows, Doors and Shading Devices—Detailed Calculations. International Organization for Standardization.Google Scholar
- Korea Energy Management Corporation (2011). Efficient Energy Usage Standard.Google Scholar
- Simmler H, Fischer U, Winkelmann F (1996). Solar-thermal window blind model for DOE-2. Simulation Research Group Internal Report, Lawrence Berkeley National Laboratory.Google Scholar