Iskandar Makhmudov (Jeju National University) SET2009 - 8th International Conference on Sustainable Energy Technologies, Aachen, Germany.

1. SET2009 - 8th International Conference on Sustainable Energy Technologies, .Aachen, Germany.
August 31st to 3rd September 2009
Page 1 of 4
Performance analysis of a schoolroom model
for solar applications
Iskandar Makhmudov1, Hyunjoo Han2, Young Il Jeon2,
Sang Hoon Lim3, Wongee Chun1
1
Department of Nuclear & Energy Engineering Department, Jeju National
University, Jeju, 690-756, Korea
2
Division of Architecture, Dongguk University, Seoul, 100-715, Korea
3
New & Renewable Energy Research Division, Korea Institute of Energy
Research, Taejeon, 305-343, Korea
ABSTRACT: The thermal and indoor daylighting behaviour of a schoolroom was
investigated by using a numerical model whose reliability was experimentally
examined. The schoolroom model, constructed using the modern simulation tool,
has a number of south-oriented windows under which black iron plates are installed
to induce thermosyphoning with arrays of upper and lower vents. A hallway is
considered to cause 0.35 air changes per hour for zones by natural ventilation. For
thermal analysis, simulations were carried out using the standard weather
conditions and physical properties of real materials. Perfect thermal insulation was
assumed for the ceiling, floor and walls between adjoining schoolrooms. Results
showed that the simulation model of the present work, although simple, is accurate
enough to predict the building’s thermal performance. Especially, in the early
stages of designing, the results could be effectively applied to assess various
aspects of design parameters in real cases without undue difficulties.
Keywords: Thermal analysis, Simulation, Daylighting, Schoolroom
1. INTRODUCTION windows. The configuration of schoolroom
design, which contains certain distinctive
Passive solar heating technologies can characteristics in trapping and utilization of
offer a wide range of benefits for buildings solar energy, was proposed by the Ministry
and our deteriorating environment by of Education in Korea (once considered as
reducing energy consumption and carbon the standard passive solar schoolroom). The
emissions. Considering the geographical configuration adopts the two-zone system
location of Korea, passive solar schemes with black iron plates for quick absorption
could be efficiently (and economically) and release of solar energy. The thermal
applied to public and residential buildings performance of the schoolroom during
for space heating and daylighting. winter time will be presented in this study.
This paper reports the design, simulation
and in-site measurement results of a
prototype schoolroom with some passive
solar features other than large south-facing

2. SET2009 - 8th International Conference on Sustainable Energy Technologies. Aachen, Germany
31st August to 3rd September 2009
Page 2 of 4
2. MODEL SCHOOLROOM
The configuration of the schoolroom
model (Fig.1) consists of two parts (zones):
a schoolroom with 7.5m (length) x 9m
(width) x 3.3m (height) and hallway with
2.7m x 9m x 3.3m. The schoolroom has
large south facing windows whereas the
hallway locates relatively small windows on
the north side of the wall. The walls, ceiling
and floor of the schoolroom are made of
concrete and heavily insulated.
Figure 2: Schematic view of the
schoolroom south-facing area.
Thermosyphoning could be induced by
Figure 1: Schematic view of the
opening the upper and lower vents which
schoolroom model.
allows continuous flow of hot air into the
schoolroom during heating periods. In
The south-facing area of the schoolroom
summer, overhang prevents the indoor
is comprised of two sections (Fig.2). The
temperature from overheating and cross-
upper half consists of two layers of operable
ventilation is induced by opening the
windows for direct gains, while the lower
windows in the opposite (north) side of the
half is characterized by a non-operable
schoolroom.
glazing followed by a black iron plate for
Weather conditions were taken from the
quick absorption and emission of solar
weather database [1] of the U.S. Department
energy. The black iron plate is covered with
of Energy for Seoul, Korea. The interzonal
3mm single glass layer for protection from
air flow between the schoolroom and
environment impacts. As the sun’s rays pass
hallway is assumed to be 0.35 air changes
through the outer glazing and hit the surface
per hour. This accounts for the occasional
of black plate, this immediately raises its
opening of the door during intermissions.
temperature and in turn heats the air trapped
Most of the heat flow between the zones is
within glazing and the iron plate.
through the partition wall that separates the
schoolroom and hallway. Each schoolroom
is occupied with 50 students. Classes are
held from 9 a.m. to 5 p.m.

3. SET2009 - 8th International Conference on Sustainable Energy Technologies. Aachen, Germany
31st August to 3rd September 2009
Page 3 of 4
3. RESULTS AND DISCUSSION complexity of the schoolroom model in the
present analysis.
Thermal analysis was done by To measure the effect of solar lighting for
ECOTECT and its results were compared the schoolroom, photometric analysis was
with previous simulation results of also carried out (Tab. 2). Nine photosensors
SUNCODE (Tab. 1). In general, ECOTECT were placed on the western wall (where a
values [2, 3, 4] fluctuated from 6.0 C to 9.6 chalkboard is situated) horizontally and
C and SUNCODE values showed a range vertically at a regular interval of 45cm. The
of 5.9 - 8.2 C. The highest values were illuminance values shown in Table 2 are
observed at 1 p.m. in both cases. those recorded at 12:30 p.m. under an
overcast sky condition in Seoul (37.5° N and
Table 1: Temperature comparison between 126.9° E). Simulations were also carried out
SUNCODE and ECOTECT(C). for daylighting using RADIANCE whose
___________________________________ accuracy has long been established by many
Hour ECOTECT SUNCODE Temp. Diff. previous studies.
___________________________________
00 6.2 6.3 0.1 Table 2: Illuminance value compared at
01 6.2 6.4 0.2 different locations between the measured
02 6.2 6.3 0.1 and simulation (lux).
03 6.2 6.2 0.0 __________________________________
04 6.2 6.1 0.1 Sensor Simulation Measured
05 6.2 6.1 0.1 __________________________________
06 6.2 6.0 0.2 1 421.6 421
07 6.3 5.9 0.4 2 470.9 414
08 6.4 5.9 0.5 3 468.0 434
09 9.3 6.4 2.9 4 323.5 343
10 9.4 6.5 2.9 5 350.0 350
11 9.4 7.2 2.2 6 360.3 359
12 9.4 8.0 1.4 7 254.6 254
13 9.6 8.2 1.4 8 274.1 265
14 9.4 8.0 1.4 9 271.8 271
15 9.2 8.0 1.2 _________________________________
16 9.2 8.1 1.1
17 9.0 7.8 1.2 From this table, we could see two agrees
18 6.2 7.5 1.3 quite well despite measurement
19 6.1 7.1 1.0 uncertainties and other unknown factors that
20 6.1 7.0 0.9 could have influenced otherwise.
21 6.0 6.8 0.8
22 6.0 6.5 0.5
23 6.0 6.3 0.3 5. CONCLUSION
___________________________________
In the present study, the typical passive
Temperatures varied proportionate to the schoolroom model was investigated for its
intensity of solar radiation, which changes indoor thermal and daylighting performance
throughout the day. A maximum using different computational tools. For
temperature difference of 2.9 C was thermal analysis, ECOTECT was brought in
observed in two cases which deems whose results were compared with those of
relatively reasonable considering the SUNCODE. Meanwhile, its indoor
daylighting performance was examined

4. SET2009 - 8th International Conference on Sustainable Energy Technologies. Aachen, Germany
31st August to 3rd September 2009
Page 4 of 4
using RADIANCE and then compared with
some measured values. It is felt that the
procedures taken for thermal and lighting
analyses in the present study could be
further extended for other types of solar
buildings (systems) to elicit the most
feasible design in reality for maximum
efficiency in utilizing the sun’s energy.
ACKNOWLEDGEMENT
This work was supported by the grant
(No. 2009-0075776) from the Korea Science
& Engineering Foundation.
REFERENCES
[1]Weather database of the U.S. Department
of Energy: http://apps1.eere.energy.gov/
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A performance study on Direct Gain
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[3]Norbert Lechner, 2000. Heating, Cooling,
Lighting: Design Methods for Architects
(2nd edition).
[4] H. Han, A comparative study on the
thermal performance of passive solar
schoolroom, MS Thesis, Chungnam Nat’l
University, Korea, 1991.
[5]G. Makaka, E.L.Meyer, M. McPherson,
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[7]C. Reinhart, A. Fitz, 2006. Findings from
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