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Effectiveness of External Window Attachments Based on Daylight Utilization and Cooling Load Reduction for Small Office Buildings in Hot Humid Climates
Abstract
This study explored the effectiveness of
selected external shading devices and glazing
treatments used to minimize the total annual energy
consumption in small office buildings in hot humid
climates. The external shading devices included a
permanent horizontal overhang and a light shelf.
The selected types of glazing included clear,
reflective, tinted, low-emissivity coating, and
heat-mirror glass.
One concern about using external window
attachments is that while reducing the solar heat
gains, they also reduce the amount of the daylight
needed to supplement interior lighting. Therefore the
objective of this study was to explore which strategy
would give a balance between solar heat gain
reduction and daylight utilization and result in the
most energy savings in the building.
Computer simulations using an hourly energy
calculation model were conducted to predict the
building's total energy consumption using each
strategy. The economics of each strategy were
analyzed with lifecycle costing techniques using the
present value technique. Results show that properly
designed overhangs that shade clear glazing are
slightly more cost-effective than specialized low-e
glazing systems. These results are unique for hot
humid climates where winter heating is not an issue.
On the contrary, when used in cold climates,
external shading devices tend to increase the building's energy consumption.
Citation
Soebarto, V. I.; Degelman, L. O. (1994). Effectiveness of External Window Attachments Based on Daylight Utilization and Cooling Load Reduction for Small Office Buildings in Hot Humid Climates. Energy Systems Laboratory (http://esl.tamu.edu); Texas A&M University (http://www.tamu.edu). Available electronically from https : / /hdl .handle .net /1969 .1 /6634.