|
|
| • |
Design
Tools: |
| |
 |
| The design of the passive solar systems was carried
out with the help of a number of design tools. |
|
| |
A module of the ESP
simulation model known as ESP-AIR was used to evaluate the air flow patterns.
The output presented the air flow patterns within the buildings for different
wind speeds and directions. The air velocity within the occupied space
was then used to calculate the comfort index according to the Fanger
or Gagge theory. |
|
| |
The dynamic thermal model
CASAMO-CLIM was used to evaluate the comfort conditions in the buildings
and calculate the cooling loads when a mechanical system was used from
internal gains, solar gains, building envelope, air change rate, building
inertia, etc. Hourly simulations for a typical apartment and the reception building
were made for a design day every month. |
|
| • |
Results for Reception
Building: |
| |
|
| The reception building has a large volume and high occupancy.
The annual cooling load if the building has no shading or night ventilation
amounted to 2770 kWh (see Figure 29) with a peak power consumption of
2.8 kW. In July or August (which have similar climates and are critical
from the cooling point-of-view) use of shading devices will reduce the
cooling load by 77% (see Figure 30). The greatest contribution to this
is made by the clerestory shading. Night ventilation at 5 ACH would save
another 5%. Night ventilation at 20 ACH would save 12%. |
|
| |
With night-time ventilation and shading
but no mechanical cooling, the temperature in the reception hall varies
from 23 o C to 27 o C (see Figure 31). The comfort diagram shows that,
provided the air velocity is maintained at a sufficiently high level,
the hall will be comfortable. The required air velocity can be achieved
by cross ventilation and it may be enhanced locally by use of a ceiling fan. |
|
| • |
Results for Typical Apartment |
| |
|
| The annual cooling load for a typical apartment with
no shading or night ventilation was found to be 950 kWh (...). The peak
cooling power requirement in July or August was at 2 pm and amounted
to 0.72 kW. |
|
| |
As with the reception building, July
and August are regarded to be the most critical months for cooling
in the apartments. Therefore the effectiveness of various cooling strategies
was evaluated for these months. It was found that shading reduced cooling
loads by 25% (...). Night ventilation can save another 32%. Peak cooling
loads can be reduced by 20% -mainly by solar protection. Even with ratios
of glazing area to floor area as low as 9%, shading is a very effective
way of reducing cooling loads. With shading and night ventilation the
high cooling loads occur in the daytime when the apartments are empty.
It can be deduced, therefore, that the absence of a mechanical cooling
system does not matter. With the temperature range found in the apartment,
good ventilation (either natural or mechanically-assisted) will give
comfortable conditions without a mechanical cooling system. |
|
 |
|
 |
Figure 30. Cooling loads
for reception building in
July |
|
Figure 31. Hourly temperatures
in reception hall in July |
|
