Owing to the large
size of the Complex building, a substantial amount of energy is needed and to
optimize energy use with minimal waste was a significant issue in designing the
A study revealed
that the conventional air-conditioning systems used in general office building are those that
consume the most energy in uncomfortably and exceedingly hot and humid climates. Each time the
system is switched on and off, a massive amount of energy is lost. When the system
is turned off, the outside heat and humidity flows into building and accumulate
in the floors, walls, ceiling, furniture as well as in other office equipment. Consequently,
considerable energy is required for the air to be cooled and dehumidified when
the system is switched on again.
The Government Complex demonstrates
how to decrease the use of energy. The selected “Close Building” structure was considered suitable for the environment and tropical
climate of Thailand. On addition, a highly insulated building envelope has been employed
to withstand heat and humidity and allow a minimal infiltration of outside air
into the building. At
the same time, it helps to reduce heat accumulation by preventing cold air
escaping from the building. The highly insulated building envelope reduces the energy consumed
by the air-conditioning
system, following the Cold Box concept, and turns the building into a 24 hour
accumulative cooling mass.
The multi-layer roof
consists of high reflectance value materials, a steel structure and six-inch-thick
layer reduces heat transfer from the roof to the building with the maximum heat
transfer being 10 times lower than is achieved by using concrete tiles with
aluminium foil. The
roof is also designed for solar cell installation.
The inclined wall
is a unique feature of the Government Complex. By learning
outwards, the sunlight-exposed surfaces on the wall are minimized and heat transfer into
the building is eight times lower than that of a perpendicular wall.
Special Building Envelope
The insulated building envelope helps reduce heat transfer to the inside of the Complex. The overall thermal transfer value is 10 watts per square metre while the roof thermal transfer value is 5 watts per square metre.
A comparative study of the rate of thermal transfer through brick walls in general and the walls of the Complex revealed that changing temperature, by as much as twofold higher, had the least impact on the Complex walls whilst drastically heating brick walls.
Flow Window System
This system helps
reduce the diffusion of heat that enters the building by using double-isolated
windows, in the middle of which there is air flow space for air to ventilate. As the outside
air passes through the outer glazing at a temperature of 28°C, the excess heat
beneath the glazing will be expelled from the building. This results in
a lower temperature of air entering the building and, at the same time, lessens
infiltration of the indoor air so the building envelope can maintain a cool
atmosphere within the building in the same manner as a Cold Box.
Cooling Water-based System for Heat Reduction
This system helps reduce heat more
efficiently because it minimizes the amount of water used and requires less
water from the air conditioning system is discharged into the pond and then
circulates around the Ratthaprasasanabhakti Building while radiating heat into
the air. The
earth ground of the pond, 28°C on average, also absorbs the heat. In this manner,
the water temperature is lowered to a level that is appropriate for chilled
Thermal Storage is
a system that retains coolness in the form of chilled water. In this system,
chilled water is produced during the night when the cost of electricity is
lower than daytime, and kept in a chilled water tank. It is released
later during the day to cool the building in addition to the air-conditioning
system; this helps to save a great deal of energy.
A chilled water
tank is placed underneath each building. The total capacity of chilled water (7.5°C) is 22,500 cubic
metres, equivalent to a 3,000 refrigeration ton chiller operating for 10 hours.
To produce chilled
water for the air-conditioning
system through the Co-Generation System and cold air distribution not only substantially
saves energy but also generates shared benefits among sectors as follows:
Complex can directly gain benefits from the stable and sustainable energy
distribution system within the premises where electricity is produced on site. Furthermore,
since PTT Public Company Limited and the Metropolitan Electricity Authority are
the professional operators that handle the management and maintenance of the
system, this creates an opportunity for a new kind of business which is
promising and yields benefit to the nation. Investment in
electricity production on site highly worthwhile as this helps reduce energy
loss in the line transmission process.
Building users can
work in a comfortably cool place at all times even after working hours thanks
to the cost-efficient
24 hour air-conditioning
our nation benefits from utilizing natural gas via this policy regarding the
use of domestically produced energy and minimizing gas imports. Moreover,
natural gas is a clean and environmentally friendly energy source. The Co-Generation
System increases efficiency of the use of natural gas up to 80 percent
Concrete Ceiling, Terrazzo Floor, Double Door
for Thermal Storage
ceilings and terrazzo floors have been decorated to retain coolness within the
building while double doors are used as entrances and exits to filter out heat
that flows in when opening and closing the doors.