physical experiments and computer simulation for such
unit in deliveringthe interior daylight illuminance to
various points in a test room under real tropical skies.
E
XPERIMENTAL
S
ETUP
Full scale experiments were conducted in an outdoor
test room that was constructed to facilitate researches on
daylighting. The room was located on the roof deck of
the seven-story building of the School of Bioresearches
and Technology, King Mongkut’s University of
Technology Thonburi (KMUTT), Bang Khun Tien
Campus. The room itself is at latitude 13.57°N and
longitude 100.44°E.Figure 1 illustrates a pictorial view of
the test room.
Fig. 1. The outdoor test room.
The room was a rectangular shape with interior
dimensions of length 9 m and width 3 m (see Fig. 2).
The room height was 3 m measured from the floor to the
ceiling. The interior surface reflectance of the walls and
the ceiling were 0.80 and that of the floor was 0.3,
respectively.
A single pane glazed window was situated on south
wall of the room. The window was 6mm clear glass and
was 2.80 m. wide and 1.3 m high. Its sill was 0.85 m.
above the floor. A clerestory with 0.5 m height was
situated above the view window.
Fig. 2. Configuration of the test room and the daylight measurement in
the test room.
Measurements on interior daylight in the room were
made at five points located on a line perpendicular to the
window wall across the center of the room on the work
plane level (0.75m above floor). The points were
positioned along the line at 0.5m, 1.5m, 3.5m, 5.5m and
7.5m depths of the room (
D
) (see Fig. 2 again). A data
logging system was used to acquire all measured data
from the sensors every five minutes.
With the room, the experiments were performed for
an anidolic concentrator formed with an external
parabolic reflector and equipped with clerestory above
the south window of the room. The configuration and
dimension of the concentrator unit is shown in Fig. 3(c).
The parabolic reflector was made of stainless steel sheet
with surface reflectance of 0.9.In the study, the
simulation was also made for experimental comparison.
Figure 3(a) and 3(b) shows additional two cases: (a)
window with no exterior shading device and (b) window
with overhang the simulations were made for the
comparison.
(a) No shading (b) Overhang (c)Anidolic concentrator
Fig. 3. Three study cases of daylighting from a side-window
(Dimensions in centimeters).
As well, during the experiments, exterior daylight
illuminances were measured and recorded by a
meteorological station. The station was located on the
roof deck of the same building where the scale model was
located. At the station, daylight and solar irradiance of
global, diffuse horizontal and beam normal components
have been measured. Vertical illuminances and
irradiances in the four cardinal directions (North, East,
South and West) have also been measured using a pair of
an illuminance sensor and a pyranometer in each
direction. The clock times of the data loggers at the
station and at the experimental room were synchronized.
Figure 2 shows a photograph of the station. No tall
building or structure offers obstruction.
Fig. 4. A daylight measurement station at Bang KhunTien campus.
C
ALCULATION OF
D
AYLIGHT FROM
A
NIDOLIC
C
ONCENTRATOR
A lighting software was used to calculate the interior
daylight illuminance and distribution from anidolic
daylighting system in the space. It was used to simulate a
same size of the room model and same position of light
2013 International Conference on Alternative Energy in Developing Countries and Emerging Economies
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