Solar Shading for Low Energy Use and Daylight Quality in Offices: Simulations, Measurements and Design Tools.
Författare
Summary, in English
This thesis investigates the impact of solar shading devices on energy use and daylight quality in office rooms. The impact on energy use is analysed through computer simulations with the dynamic energy simulation program Derob-LTH while the impact on daylight quality is investigated through measurements in full-scale experimental office rooms and simulations with the program Radiance. This thesis also includes a literature review of research on solar shading as well as design tools to incorporate shading devices at an early stage in the design of buildings.
This thesis indicates that, in cold countries, shading devices may provide more annual energy savings than any solar-protective (reflective, tinted) glazing and that the optimum glazing transmittance is orientation- and climate-dependent. For example, high annual energy savings are obtained on the south facade with higher transmittance glazings (compared with the east and west facade) because the potential for passive solar gain utilisation in the winter is high in comparison with the annual cooling demand. Exterior shading devices like awnings and overhangs may reduce the cooling demand dramatically but they are not suitable as daylight (glare) control devices. Devices like screens and venetian blinds are preferable because they cover the entire window area, which prevents sunlight patches in the room and the direct view of the bright sky. Screens and venetian blinds also reduce daylight in the room to levels that are suitable for computer work. However, it is essential that the screen be of a diffusing type since screens with a strong (specular) transmittance component result in poor daylight quality. The study on daylight quality also indicated that a screen transmittance of around 15 % may be optimum for a standard (3.5 by 6.0 m2) south-oriented office room with a window covering around 25 % of the facade area (12 % of the floor area).
This thesis indicates that, in cold countries, shading devices may provide more annual energy savings than any solar-protective (reflective, tinted) glazing and that the optimum glazing transmittance is orientation- and climate-dependent. For example, high annual energy savings are obtained on the south facade with higher transmittance glazings (compared with the east and west facade) because the potential for passive solar gain utilisation in the winter is high in comparison with the annual cooling demand. Exterior shading devices like awnings and overhangs may reduce the cooling demand dramatically but they are not suitable as daylight (glare) control devices. Devices like screens and venetian blinds are preferable because they cover the entire window area, which prevents sunlight patches in the room and the direct view of the bright sky. Screens and venetian blinds also reduce daylight in the room to levels that are suitable for computer work. However, it is essential that the screen be of a diffusing type since screens with a strong (specular) transmittance component result in poor daylight quality. The study on daylight quality also indicated that a screen transmittance of around 15 % may be optimum for a standard (3.5 by 6.0 m2) south-oriented office room with a window covering around 25 % of the facade area (12 % of the floor area).
Avdelning/ar
Publiceringsår
2001
Språk
Engelska
Publikation/Tidskrift/Serie
Rapport TABK
Dokumenttyp
Doktorsavhandling
Förlag
LTH, Lund University
Ämne
- Building Technologies
Nyckelord
- Byggnadsteknik
- Building construction
- screens
- venetian blinds
- awnings
- design tools
- measurements
- computer simulations
- solar-protective glass
- heating
- cooling
- visual comfort
- daylighting
- energy use
- Shading devices
- solar protection
- Architecture
- interior design
- Arkitektur
- inredningsarkitektur
- Energy research
- Energiforskning
Status
Published
Handledare
- [unknown] [unknown]
ISBN/ISSN/Övrigt
- ISSN: 1103-4467
- ISRN: LUTADL/TABK--1023-SE
Försvarsdatum
17 december 2001
Försvarstid
09:15
Försvarsplats
Arkitektskola (Sölvegatan 24, Lund), Sal B
Opponent
- Marc Fontoynont