2021年1月23日发(作者：bask)




中英文资料翻译


外文文献：


Evaluating Water Conservation Measures For Green Building In
Taiwan
Green Building evaluation is a new system in which water conservation is prioritized as
one of its seven categories for saving water resources through building equipment design in
Taiwan. This paper introduces the Green Building program and proposes a water conservation
index with quantitative methodology and case study. This evaluation index involves
standardized scientific quantification and can be used in the pre-design stage to obtain the
expected result. The measure of evaluation index is also based on the essential research
in Taiwan and is a practical and applicable approach.
Keywords: Green Building; Evaluation system; Water conservation; Building equipment


1. Introduction
The environment was an issue of deep global concern throughout the latter half of the 20th
century.
Fresh
water
shortages
and
pollution
are
becoming
one
of
the
most
critical
global
problems.
Many
organizations
and
conferences
concerning
water
resource
policy
and
issues
have reached the consensus that water shortages may cause war in the 21st century[1],if not a
better solution .Actually, Taiwan is already experiencing significant discord over water supply.
Building new dams is no longer an acceptable solution to the current water shortage problems,
because of the consequent environmental problems. Previous studies have concluded
that water savings are necessary not only for water conservation but also for reducing energy
consumption [2,3].



Taiwan
is
located
in
the
Asian
monsoon
area
and
has
an
abundant
supply
of
rainwater.
Annual precipitation averages around 2500mm. However, water shortages have recently been



a critical problem during the dry season. The crucial, central issue is the uneven distribution of
torrential rain, steep hillsides, and short rivers. Furthermore, the heavy demand for domestic
water use in municipal areas,
and the difficulties in building new reservoirs are also
critical
factors.
Government
departments
are
endeavoring
to
spread
publicly
the
concept
of
water-conservation.
While
industry
and
commerce
have
made
excellent
progress
in
water
conservation, progress among the public has been extremely slow.






Due
to
this
global
trend,
the
Architecture
and
Building
Research
Institute
(ABRI),
Ministry of Interior in Taiwan, proposed the “Green Building” concept and built the evaluation
system.
In
order
to
save
water
resources
through
building
equipment
design,
this
system
prioritizes water conservation as one of its seven categories. This paper focuses on the water
conservation measures for Green Building in Taiwan and a quantitative procedure for proving
water-saving efficiency. The purpose of this work is not only aimed at saving water resources,
but also at reducing the environmental
impact on the earth.
2. Water conservation index




The water conservation index is the ratio of the actual quantity of water consumed in a
building
to
the
average
water-
consumption
in
general.
The
index
is
also
called,
“the
water
saving
rate”.
Evaluations
of
the
water- consumption
quantity
include
the
evaluation
to
the
water-saving efficiency within kitchens, bathrooms and all water taps, as well as the recycling
of rain and the secondhand intermediate water.
2.1. Goal of using the water conservation index
Although
Taiwan
has
plenty
of
rain,
due
to
its
large
population,
the
average
rainfall
for
distribution to each individual is poor compared to the world average as shown in Fig. ,
Taiwan
is
reversely
a
country
short
of
water.
Yet,
the
recen
t
improvements
in
citizens’
standards of living have led to a big increase in the amount of water needed in cities, as shown
in Fig. 2, which, accompanied by the difficulty of obtaining new water resources, makes the
water shortage problem even worse. Due to the improper water facilities designs in the past,
the
low
water
fee,
and
the
usual
practical
behavior
of
people
when
using
water,
Taiwanese



people
have
tended
to
use
a
large
quantity
of
tap
water.
In
1990,the
average
water-consumption quantity in Taiwan was 350l per person per day, whereas in Germany it is
about 145l per person per day, and in Singapore about 150l per person per day. These statistics
reveal the need for Taiwanese people to save water.




The promotion
of better-designed
facilities which facilitate water-saving will become
a
new trend among the public and designers, because of concerns for environmental protection.
The water conservation index was also designed to encourage utilization of the rain, recycling
of water used in everyday life and use of water-saving equipment to reduce the expenditure of
water and thus save water resources.
2.2. Methodology for efficient use of water resources




Some construction considerations and building system designs for effective use of water
resources are described below.
2.2.1. Use water- conservation equipment



A research of household tap-water consumption revealed that the proportion of the water
used in flushing toilets and in bathing, amounts to approximately 50% of the total household
water
consumption,
as
given
in
Table
1.
Many
construction
designers
have
tended
to
use
luxurious
water
facilities
in
housing,
and
much
water
has
thus
been
wasted.
The
use
of
water-saving equipment
to
replace such facilities is
certain
to
save a large amount of water.
For example, the amounts of water used in taking a shower and having a bath is quite different.
A
single
shower
uses
around
70l
of
water,
whereas
a
bath
uses
around
150l.
Furthermore,
current construction designs for housing in Taiwan tend to put two sets of bathtubs and toilets,
and quite a few families have their own massage bathtubs. Such a situation can be improved
only by removing the tubs and replacing them with shower nozzles, so that more water can be
possibly saved. The commonly used
water- saving devices in
Taiwan now include new-style
water taps, water-saving toilets, two- sectioned water closets, water-saving shower nozzles, and
auto-sensor
flushing
device
systems,
etc.
Water-saving
devices
can
be
used
not
only
for
housing, but also in other kinds of buildings. Public buildings, in particular, should take the
lead in using water-saving devices.



2.2.2. Set up a rain-storage water supply device




The
rain- storage
water
supply
device
stores
rain
using
natural
landforms
or
man-made
devices, and then uses simple water-cleaning procedures to make it available for use in houses.
Rain can be used not only as a substitute water supply, but also for re control. Its use also helps
to decrease the peak-time water load in cities. The annual average rainfall in Taiwan is about
2500 mm, almost triple better than the global average. However, due to geographic limitations,
we could not build enough water storage devices, such as dams, to save all the rain. It is quite
a pity that annually about 80% of the rain in Taiwan is wasted and flows directly into the sea,
without
being
saved
and
stored.
The
rain-storage
water
supply
system
is
used
with
a
water-gathering system, water-disposal system, water-storage system and water-supply system.
First, the water-gathering system gathers the rain. Then, the water flows to the water-disposal
system through pipes, before being sent to the water-storage system. Finally, it is sent to the
users’equipment
through
another
set
of
pipes.
Using
the
drain
on
the
roof
of
a
building,
leading to the underground water-storage trough, is considered an effective means of gathering
rain. The water, after simple water-disposal processes, can be used for chores such as house
cleaning, washing floors, air-conditioning or watering plants.
2.2.3. Establishing the intermediate water system




Intermediate
water
is
that
gathered
from
the
rain
in
cities,
and
includes
the
recycled
waste-water
which
has
already
been
disposed
of
and
can
be
used
repeatedly
only
within
a
certain range, but not for drinking or human contact. Flushing the toilet consumes 35% of all
water.
If
everyone
were
to
use
intermediate
water
to
flush
toilets,
much
water
could
be
efficiently saved. Large- scale intermediate water system devices are suggested to be built up
regularly with in a big area. Each intermediate water system device can gather, dispose and
recycle
a
certain
quantity
of
waste-water
from
nearby
government
buildings,
schools,
residences,
hotels,
and
other
buildings.
The
obtained
water
can
be
used
for
flushing
toilets,
washing cars, watering plants and cleaning the street, or for garden use and to supplement the
water
of
rivers
or
lakes.
A
small-scale
intermediate
water
system
gathers
waste-water
from
everyday
use,
and
then,
through
appropriate
water-disposal
procedures,
improves
the
water
quality to a certain level, so that finally it can be repeatedly used for non- drinking water. There



are extensive ways to use the intermediate water. It can be used for sanitary purposes, public
fountains, watering devices in gardens and washing streets. In order to recycle highly polluted
waste-water,
a
higher
cost
is
needed
for
setting
up
the
associated
water-disposal
devices,
which
are
more
expensive
and
have
less
economic
benefits
than
the
rain-utilization
system.
Except for the intermediate water-system set within a single building, if we build them within
large-scale communities or major construction development programs, then it is sure to save
more water resources efficiently and positively for the whole country as well as improve the
environmental situation.
4. Method for assessing the recycling of rain
Systems for recycling rain and intermediate water are not yet economic beneficial, because
of
the
low
water
fee
and
the
high
cost
of
water-disposal
equipment.
However,
systems
for
recycling rain are considered more easily adoptable than those for recycling intermediate water.
Herein, a method for assessing the recycling of rain is introduced to calculate the ratio (C) of
the water-consumption quantity of the recycled rainwater to the total water-consumption.
4.1. Calculation basis of recycling rainwater
The
designer
of
a
system
for
recycling
rainwater
must
first
determine
the
quantity
of
rainwater and the demand, which will determine the rainwater collection device area and the
storage
tank
volume.
Rainwater
quantity
can
actually
be
determined
by
a
simple
equation
involving precipitation and collection device area. However, precipitation does not fall evenly
spread over all days and locations. In particular, rain is usually concentrated in certain seasons
and
locations.
Consequently,
the
critical
point
of
the
evaluation
is
to
estimate
and
assess
meteorological
precipitation.
Meteorological
records normally include
yearly, monthly, daily
and hourly precipitation. Yearly and monthly precipitation is suitable for rough estimates and
initial assessment. However, such approximation creates problems in determining the area of
the rainwater collection device and the volume of the storage tank. Thus, daily precipitation
has been most commonly considered. Hourly precipitation could theoretically support a more
accurate assessment. However, owing to the increasing number of parameters and calculation
data increases, the complexity of the process and the calculation time, result in inefficiencies.
Herein, daily precipitation is adopted



in assessing rainwater systems used in buildings [4,7].
4.3. Case study and analysis
Following the above procedure, a primary school building with a rainwater use system is
taken
as
an
example
for
simulation
and
to
verify
the
assessment
results.
This
building
is
located in Taipei city, has a building area of 1260 m and a total floor area of 6960 m it is a
multi- discipline teaching building. Roofing is estimated to cover 80% of the building area, and
the rainwater collection area covers 1008 m .Rainwater is used as intermediate water for the
restrooms, and the utilization condition is set at 20 m per day, while
the out flow coefficient (Y) is 0.9. A typical meteorological precipitation in Taipei in 1992 was
adopted
as
a
database.
The
rainwater
storage
tank
was
set
to
an
initial
condition
before
the
simulation
procedure.
Herein,
four
tank
volumes
were
considered
in
the
simulations
of
rainwater
utilization
—
15,
25,
50,
100
m.
The
results
indicate
that
increased
storage
tank
volume reduces overflow and increases the utilization of rainwater. Given a 50 m storage tank,
the
quantity
of
rainwater
collection
closely
approaches
the
utilization
quantity
of
rainwater.
Consequently, this condition obtains a storage tank with a roughly adequate volume. When the
volume
of
the
storage
tank
is
100
m,
the
utilization
rate
is
almost
100%
and
the
overflow
quantity approaches zero. Despite this result being favorable with respect to utilization, such a
tank
may
occupy
much
space
and
negatively
impact
building
planning.
Consequently,
the
design concept must balance all these factors. The building in this case is six floors high, and
the roof area is small in comparison to the total floor area. The water consumption of the water
closet per year, but the maximum rainwater approaches 7280 m collection is 2136 m per year.
Thus,
significant
replenishment
from
tap
water
is
required.
This
result
also
leads
to
a
conclusion that high-rise buildings use rainwater systems less efficiently than other buildings.
Lower buildings (e.g. less than three floors) have highly efficient rainwater utilization and thus
little need for replenishment of water from the potable water system.
The
efficiency
of
rainwater
storage
tanks
is
assessed
from
the
utilization
rate
of
rainwater and the substitution rate of tap water. Differences in annual precipitation and rainfall
distribution
yield
different
results.
Figs.
5
and
6
illustrate
the
results
of
the
mentioned
calculation procedure, to analyze differences in rainwater utilization and efficiency assessment.



The simulation runs over a period often years, from 1985 to 1994, and includes storage tanks
with four different volumes. When the volume of the rainwater tank is
50 m, the utilization
rate of rainwater exceeds 80% with about 25% substitution with tap water. Using this approach
and
the
assessment
procedure,
the
volume
of
rainwater
storage
and
the
performance
of
rainwater use systems in building design, can be determined.
In the formula of the water conservation index, C is a special weighting for some water
recycling
equipment
that
intermediates
water
or
rain,
and
is
calculated
as
the
ratio
of
the
water-consumption
quantity
of
the
recycled
rainwater
to
the
total
water- consumption.
Therefore, this assessment procedure can also offer an approximate value of C for the water
conservation index.
5. Green building label and policy
“Green
Building” is
called “Environmental
Co
-
Habitual
Architecture” in Japan, “Ecological
Building”
or
“Sustainable
Building”
in
Europe
and
“Green
Build
ing
in
North
American
countries.
Many
fashionable
terms
such
as
“Green
consumption”,
“Green
living”,
“Green
illumination”
have
been
broadly
used.
In
Taiwan,
currently,
“Green”
has
been
used
as
a
symbol of environmental protection in the country. The Construction Research Department of
the
Ministry
of
the
Interior
of
the
Executive
Yuan
has
decided
to
adopt
the
term
“Green
Building” to signify ecological and environmental protection architecture in Taiwan.

5.1. Principles of evaluation
Green Building is a general and systematic method of design to peruse sustainable building.
This evaluation system is based on the following principles:
(1)
The
evaluation
index
should
accurately
reflect
environmental
protection
factors
such
as
material, water, land and climate.
(2) The evaluation index should involve standardized scientific quantification.
(3) The evaluation index should not include too many evaluation indexes; some similar quality
index should be combined.
(4) The evaluation index should be approachable and consistent with real experience.