Y. Kodama， Shuji Funo， S. Hokoi， N. Yamamoto， T. Uno， T. Takemasa： Surabaya EcoーHouse An Experiment in Passive Design in a Tropical Climate.Part1 Outline of the Project and Design of the Experimental Building， Sustaining the Future EnergyーEcologyーArchitecture， Proceedings of the PLEA'99 Conference Brisbane (ed. Steven S Szokolay)， September 22ー24
Surabaya Eco-House
An Experiment on Passive
Design in Tropical Climate Part 1
Evaluation and Simulation of
the Effects on Heat Performance
Dr. Y. Kodama (Professor, Kobe Design
University)
Dr. S. Funo (Assoc. Professor, Kyoto
University),
Dr. K. Takemasa (Assoc. Professor, Hiroshima
Prefectural Junior College of Health and Welfare)
Dr. S. Hokoi (Professor, Kyoto University),
N. Yamamoto (Graduate Student, Kyoto
University: Research Fellow, Instieute of Technology 10th Novemger),
T. Uno(Graduate Student, Kyoto University)
1.
Background and objective of Surabaya Eco-House
Entrusted
by the Ministry of Construction, the Infrastructure Development Institute Japan
conducted an experiment on energy- and resource-saving collective housing
jointly with the Institute of Technology Sepuluh Nopember (ITS), the Republic
of Indonesia, for the purpose of making contribution to improvement of living
environment and energy conservation in developing countries.*1
In order to build a
sustainable and recycling-based society, it is essential to improve performance
of buildings themselves in the light of regional climate and to create
favorable indoor environment with less dependence on energy-consuming
technologies. This requirement must be
fulfilled at an early date in developing countries, where energy consumption is
expected to rise sharply.
The latest project is a case
study designed to build future energy- and resource-saving collective housing
in developing countries featured by tropical climate with high temperature and
humidity.
2.
Eco-house Passive Design
Architectural and mechanical
methods are available for creation of favorable indoor environment. The former, called passive design, is a
designing and systematic method to utilize natural energy, such as sunshine,
changes in temperature, winds and terrestrial heat, while considering regional
climatic conditions. The latter is a
method relying on air-conditioning equipment.
Dependence on air-conditioning
is growing in developing countries under tropical climate. Itﾕs important to develop and apply passive design, particularly
passive cooling technology, not only in view of global environmental problems
and possible energy exhaustion but also with a view to building a
resident-participating community with consideration given to regional
characteristics (Fig. 1).
3.
From Rumah Susun Sombo as a model for post-KIP period to Surabaya Eco-house.
KIP (Kampung Improvement
Program) which started in the late 1960's is supposed as one of the most
significant programs for housing improvement in Indonesia. The main purpose of
KIP was to provide infrastructure to achieve better sanitary conditions in the
Kampungs. As KIP, by the latter half of 1980's, obtained sufficient results in
Surabaya, it came up with the further task to find a solution to high-density
residential district i.e. establishing new housing model..
One of the successful
solutions was the construction of the Rumah Susun Sombo (called as "Rusun
Sombo" in short) which was designed by Prof. Silas from ITS and Surabaya
city planning board (Fig. 2). This project is based on the principle so-called
"On Sight Development". Therefore special attention was paid to
former residents of "Kampung Sombo" who were to move into the Rusun Sombo
after its completion, so that residents would not be forced to move out as a
result of the improvement itself. For instance, its wide double-loaded corridor
with open-air edge plays quite an important role for maintaining resident's way
of living, because normally, for people living in kampungs, open-air space is
indispensable in respect of providing places where variety of activities take
place.
While designing Surabaya
Eco-house, it was decided that we would adopt Rusun Sombo as a basic model and
combine it with the ideas of passive design for further improvement. This is
because, in our point of view, providing a model with regards to the existing
local way of living is quite important for the building to be accepted by the
residents.
4.
Characteristics of the Surabaya Eco-house
As
mentioned above, Surabaya Eco-house is designed as a prototype collective
housing model that is appropriate for the local conditions in Surabaya. The
research group under Prof. Silas from ITS has been working on collective
housing based on social and environmental conditions of Indonesia in
cooperation with the group led by Assoc. Professor Funo at Kyoto University.
On the basis of the results of
the long-term research, the project is intended to build collective housing
which incorporates passive cooling technologies conforming to regional natural
conditions and to promote use locally produced building materials. It should be regarded as a prototype of the
Indonesian-type of collective housing in a sustainable society.
(1)
Skeleton-Infill-Type Construction
The
fundamental structure of a building (skeleton) is of concrete construction with
long-term durability, and partitions and exterior (Infill) are subject to needs
of residents for their participation in deciding-making process.
(2) Floor
plan fit for regional lifestyles
With importance attached to regional
lifestyles, common corridor of collective housing are wider in comparison with
conventional collective housing, giving a feeling of spaciousness. In the meantime, maximum privacy is ensured
in parts for exclusive use (Fig. 3).
(3)
Passive Cooling Technology
3-1)
Commonly Shared Open Space Arrangements, Ventilation and Natural Lighting
The
commonly shared free and open air space has been utilized to secure horizontal
and vertical ventilation channels.
Windows have been installed on the top roof to facilitate ventilation
and heat discharge, and to get natural lighting. And a 3-story high void space has been built
at the center of the building (Fig. 4).
3-2)
Double-Roofing
To
effectively break sunlight heat, the roof has been designed as
double-layered-roof with heat-insulating and air layers. The heat-insulating
materials have been developed of local products, coconut fiber. The air-layer is placed on the outer-side of
the heat-insulator, intending quick spontaneous discharge of sunlight heat
(Fig. 5).
3-3)
Windows and Outer-walls for Insulating Sunlight Heat
A
bigger roof and deeper eaves have been built to cut the sunlight and wooden
outer-walls system not to absorb sunlight heat. (The outer-walls system will be
introduced in a future plan.)
3-4)
Ventilation Channels in Private Sections
To
facilitate cross ventilation in the private unit, an arrangement of openings
and operating system have been designed. Two openings have been installed on
the outer-wall, and a vent window onto commonly shared open space. The
operating system has been designed to allow ventilation not only during daytime
but also at night
(Fig. 6).
3-5)
Cold Storage by Night Ventilation
Concrete
floor slab with big thermal capacity is utilized as a cooling system. Cool air
is led into rooms by the night ventilation to store the coldness in the
concrete floor. This provides a coolant for the next daytime.
3-6)
Radiant Cooling System by Circulating-Water
A polyethirene pipe is buried
in the concrete floor slab to circulate well water for radiant cooling
effect. The well water is kept in an
underground tank beneath the ground floor and is circulated by a solar-driven
pump. The circulated water is re-used for flushing toilets or sprinkling (Fig.
7).
5.
Personal Computer Simulation
The simulation software we
used is " Solar Designer Ver.4.1". This software is based on the
program called "Passwork" which was developed by Building Research
Institute, Ministry of Construction, Japan. This software can calculate the
indoor temperature of a certain room that is basically closed by walls and
slabs. *2 Influence from rooms
surrounding the target room both horizontally and vertically is also taken into
account by adding its approximate value to the thickness of the walls and slabs
of the target room. *3 Below is the procedures for executing simulation quoted
from the manual whose original explanation is in Japanese.
a.
Input data on physical settings of the building
1. Openings/
data on dimensions, orientation and location (Fig. 8-1)
2.
Specification of openings/ data on heat transmission coefficient, solar-radiant
transmission coefficient
3.
Shadings/ data on dimensions, locations
4.
Slabs/ data on thickness of concrete and insulation parts, finishing,
solar-radiant absorption coefficient, thermal conductivity
5.
Walls/ data on thickness of concrete and insulation parts, finishing,
solar-radiant absorption coefficient
6.
Ceiling/ data on thickness of concrete and insulation parts, finishing,
solar-radiant absorption coefficient
7. Air
conditioning, louver, number of air changing, indoor produced heat
b.
Setting climate pattern
8.
Loading registered climate patterns
9.
Input and change climate patterns/ latitude, longitude, temperature, albedo and
so forth.
c.
Calculation and estimation of the performance
11.
Calculation
12.
Final result with the graphs indicating temperatures of chosen elements (Fig.
8-2)
6.
Monitoring equipment and measurement points
There are mainly three kinds
of equipment that were used in monitoring. The first one is temperature and
humidity data collector called "Ondotori"(Pic. 1).
"Ondotori" has a special sensor that can measure temperature and
humidity of the air at the same time. The second one is the temperature data
collector called "Data Collector"(Pic. 2). This equipment has
so-called "T type thermocouple" for a wider use. The sensor can
measure almost any kinds of temperature including air, surface and even water.
The last thing is the solarimeter with which we can measure the amount of solar
radiation by recording an integrating voltage(Pic. 3-1, 2). The recording
interval for all above-mentioned equipment was set 10 minutes.
There is another equipment
used in the monitoring called Assmann thermometer. Assmann thermometer can
measure dry-bulb and wet-bulb temperature, so that the relative humidity can be
figured out with the conversion table. The data was compared with those from
"Ondotori" and "Data Collector" to confirm if the error
range would be acceptable.
Measurement points are
indicated in Fig. 9 (In Fig. 9 , "OT" means Ondotori, "DC"
for Data Collector and "KD" for Solarimeter). There are mainly four
parts to be measured, namely Double Roofing, Open Common Space, rooms and water
tank. On each floor, there are two rooms to be measured with intensive data
collection on "northeastern room".
This is because of Surabaya's geographical location in the south
latitude. Normally rooms located on the northern side have severe condition in
terms of thermal environment. In the northeastern room, Globe temperature is
also measured(Pic. 4). If the normal and Globe temperature do make difference,
it could be concluded that Circulating-Water Radiant Cooling System has been
successful.
Footnote
*1
This project was implemented in cooperation with Department of Architecture,
Faculty of Technic and Civil Engineering, ITS. Those who made special
contribution to this project from ITS are Prof. J. Silas, Ir. Dipl. Ing Sri
Nastiti NE and Irvansjah ST.
*2
Practically there are two ways of approximation. One is to consider whole building as one box;
another is to consider each room respectively.
*3 The guideline for conversion is still being discussed.
Acknowledgements
We
would like to express our special gratitude here by mentioning two companies'
contribution, which was indispensable to our project. Mitsubishi donated
devices for radiant cooling including polypropylene pipe especially for this
project. Solar cells that generate electricity for radiant cooling are donated
by Sharp Cooperation. We greatly appreciate assistance provided by both
companies.
