zero carbon building
TRANSCRIPT
Zero Carbon Building
Christopher TO
Construction Industry Council
Construction Industry Council
• Set up under the Construction Industry Council Ordinance (Cap.587)
• Functions of the CIC are stipulated in Sections 5&6 of the
Construction Industry Council Ordinance (Cap.587)
2
Enhance
Cohesiveness
Functions
of CIC
Enhance
Cohesiveness
Advance Skills
Through Training
Elevate the
Quality and
Competitiveness
Promote Good
Practices
Reflect Needs
and Aspirations
Introduction
Promoting the ongoing development and
improvement of industry
Encouraging research activities and the use of
innovative techniques and to establish or
promote the establishment of standards for the
construction industry
Promoting good practices in the construction
industry in relation to…, environmental
protection,…
Background
• Hong Kong Government has recently targeted for
Carbon Reductions (50% to 60% Carbon Intensity
Reduction by 2020 compared to 2005 baseline)
• Buildings consume 90% electricity and are responsible
for 60% Greenhouse gases (GHG) emissions in HK –
Construction industry has a significant role to play in
GHG emission reduction
Objectives
Serving as an exhibition and education centre
- To showcase the state-of-the-art eco-building design and
technologies to the construction industry internationally
and locally as well as to raise community awareness of
sustainable living in Hong Kong
- To promote the green living and working and the human
behavioural changes which can contribute to the GHG
emission reduction
8 Sheung Yuet Road
Kowloon Bay
Kowloon East
D-01
CafeEco-Plaza
Urban Native Woodland:
Biodiversity in urban area
ZCB
Commercial
Area
Shop
Eco-Terrace
Outdoor Exhibition Areas
Landscape Master Plan
D-01
Hopefully, in 2 years’ time…
Basement / Ground Floor Plan
Ground Floor Plan
Ground Floor Plan
Ground Floor Plan
Ground Floor Plan
Mezzanine Floor Plan
Mezzanine Floor Plan
Programme
• Inception Oct 2010
• Commencement of Study and Design Apr 2011
• Commencement of construction July 2011
• Project completion Jun 2012
• Official opening Jun 2012
• Public opening Sep 2012
Significance of ZCB
• 1st zero-carbon building in HK
• 1st building with grid feed-in in HK
• 1st native urban woodland in HK
• One of the 1st BEAM Plus Platinum new building projects
• 1st large scale use of biodiesel made from waste cooking oil for electricity generation
• One of the few ZCBs in the world that account for carbon emissions during the operation stage as well as the embodied carbon of the construction process and the major structural materials
Key Features
• Carbon neutral
• Energy positive
• Climate positive
• Experimenting
• Evaluating
• Evolving
• Educating
Key Design Features
Outdoors
High Greenery Coverage
Urban Native Woodland
Eco-paver and Grasscrete as
Pervious Surfaces
Air Tree
Passive Design
Climate-responsive Built Form and
Orientation
Ultra-Low Overall Thermal Transfer
Value (OTTV)
High Performance Glazing System
Wind Catchers and Light Pipes
Earth Cooling Tube
Active Systems
High-Volume-Low-Speed Fans
High Temperature Cooling System
Smart Controls / Building
Management System
Microclimate Monitoring Stations
Zero Carbon Renewable
Technologies
Bio-fuel Tri-generation Plant
Photovoltaic
Low Embodied Carbon Materials
Low Embodied Carbon
Construction
Others
Water Use Management
Thematic Showcases for Eco-workplace
and Sustainable Living
Design Strategy – Climate Positive
Greenery + Cool Materials
Key Design Feature
High Greenery Coverage
• About 50% for greenery coverage of the site,
including vertical greening
• Tree ratio at about 200 trees per hectare
• Existing mature trees within the site in good
conditions are preserved.
• The high degree of greenery serves as “carbon
sink” to absorb carbon dioxide as well as “heat
sink” to cool summer prevailing winds and
reduce the heat island effect.
Key Design Feature
Urban Native Woodland
• Over 150 native trees, with over 40 different species
in the woodland
• Native woodland area of about 2,000m2 (over 20% of
the site)
• Diversity of native species enhances biodiversity to
provide food and shelter to attract native wildlife into
the city.
Key Design Feature
Eco-Paver and Grasscrete
• Act as pervious surfaces which allow water
permeation and act as cool materials to help
reduce heat island effect
• Eco-paver has a top layer with titanium dioxide
which has the added value for air pollutant
removal
Key Design Feature
Air Tree
• A covered walkway system
cladded with sustainable timber
providing shade, cooling air
breeze and a framework for
climbing plants
• Cooling breeze is accentuated
by ceiling fans
• Reduction of uncovered
impervious surface and
associated heat island effect
Key Design Feature
Climate-responsive Built Form & Orientation
• Optimize beneficial use of wind, sun and daylight
• Reduce the demand for mechanical heating/cooling
and artificial lighting
• Main façade facing SE to capture prevailing summer
breeze
• Tapered built form to draw stronger airflow across
the building and to reduce exposure solar heat gain
from the south façade and increase daylight from
the north façade
• Elongated built form to reduce façade areas towards
the East and West
Key Design Feature
Ultra-Low OTTV
• The lower the overall thermal transfer value (OTTV),
the smaller the solar heat gain through building
fabric and the cooling load for air conditioning
• OTTV of ZCB at 11W/m2, about 80% lower than
statutory requirement at time of completion
• Due to optimized window-to-wall radio, deep
overhang over the south façade, external shading
fins, minimized east and west facades/windows,
high performance glass wall system, and shaded
and insulated roof
Key Design Feature
High Performance Glazing System
• To lower cooling load and reliance on artificial
lighting
• U value is kept as low as 1.6 W/m2 based on the
Insulated Glazed Unit construction with low-e coating
• Low Shading Coefficient (SC) at 0.33 and relatively
high Visual Light Transmittance (VLT) at 0.54
Key Design Feature
Wind Catchers & Light Pipes
• On top of the design for cross ventilated and
daylight layout, wind catchers and light pipes are
provided on the rooftop to enhance natural
ventilation and daylighting for areas furthest
away from windows
Key Design Feature
Earth Cooling Tube
• Provided near the building for
pre-cooling of fresh air by
making use of the cooler
thermal mass of the earth
• Reduce cooling load and
energy use due to the passive
pre-cooling of the incoming air
• The temperature difference
between the air and the earth
mass in the summer at about
5ºC maximum.
Key Design Feature High-Volume-Low-Speed Fans
• Patented blades design to enhance evaporation
for comfort
Key Design Feature
High-Temperature Cooling System
• Comprises chilled beams, underfloor displacement
cooling and desiccant dehumidification
• Higher supply air temperature allowing greater
extent of free-cooling (number of hours suitable for
free cooling increases from 200 hours to 600 hours
each year)
Key Design Feature
Smart Controls/ BMS
• The building monitors itself constantly, so that
the active and other building systems can be
evaluated and optimized for their operation and
environmental performance
Key Design Feature
Microclimate Monitoring Stations
• 4 micrcoclimate monitoring
stations are placed on and around
the building to evaluate how the
building performs and interacts
with its surroundings
• These monitoring stations offer
critical data to the Intelligent BMS
for optimization of building
environmental performance in
response to actual microclimatic
conditions.
Key Design Feature
Water Use Management
• 3 Eco-toilets making use of
waterless urinals, low-flow
sanitaryware and grey water
recycling
• 1 toilet is equipped with black
water recycling treatment
• Stormwater harvesting
• Artificial wetland with subsurface
flow to treat grey water/stormwater
by the roots of plants
Renewable
Active Systems
Energy Hierarchy
Energy Strategy
Reduction of Energy Demand
Passive Design
Active Systems
20% 25%
Renewable Energy Generation
Biodiesel Tri-
generation System
PV Panels
- multi-crystalline
- BIPV
- CIGS
Solar Water Heating
Renewable Energy
Bio-fuel Tri-generation Plant
• 1st large-scale use of bio-diesel as a renewable tri-
generation (a combined Cooling, Heating and Power
<CCHP> system)
• Waste-to-energy (bio-diesel produced from waste
cooking oil)
• Generate 143 MWh per year
• Capture 70% of the fuel energy (adsorption cooling /
desiccant dehumidification), compared to 40% for
conventional energy supply through grid electricity
where the bulk of fuel energy is rejected into the sea
or atmosphere.
CCHPPower + Cooling + Dehumidification
Renewable Energy
Photovoltaic
• Solar irradiance of the whole site with reference to
surrounding context and neighbouring buildings
has been studied to determine the best location
for the building to receive the solar energy
• Generate 87 MWh per year (over 60% of ZCB
consumption)
• 3 different types of PV are used:
– 1015m2 multi-crystalline on the inclined roof (about
80% of the roof)
– BIPV-thin film covering the viewing platform, and
– cylindrical CIGS thin film integrated in the air tree
Multi-Crystalline
BIPV
CIGS
Emissions during operation
50 years
Emissions during construction
Emissions embodied in materials
On-site renewable energy offset8,080 tonnes (161 tonnes per year)
150 tonnes
1,400 tonnes
Energy Plus
4,600 tonnes(92 tonnes per year)
Net energy output over operating energy consumption to offset
embodied carbon of major structural materials & construction
Total
6150
tonnes
8,080
tonnes
Carbon Strategy
Low Embodied Carbon Materials
• Regionally manufactured
materials
• Sustainable timber
• Reinforced concrete with steel
rebar with recycled content
and high percentage of
Pulverized Fly Ash
Consume less energy or emit less carbon in
their process of
extraction, manufacturing and transportation
Low Embodied Carbon Construction
• Balanced cut and fill for the site formation works
• Gabion wall construction making use of construction
debris salvaged from demolition
PerformanceConstruction Stage – CO2 Reduction
Reference CO2
Emission
Target CO2
Emission of
This ZCB
Reduction
Construction Process
2200 t
150 t
30%
Material Use 1400 t
PerformanceOperation Stage – CO2 Reduction and Energy Savings in Building
Typical Design Building CO2 Emission
140 t/yr
Building Energy Consumption
200 MWh/yr
Measures Taken in
Design to Reduce CO2
Building CO2
Reduction
(ton CO2/yr)
CO2
Reduction
(% of total
building)
Building Energy
Saving
(MWh/yr)
Energy
Saving
(% of total
building)
Envelope design 6 4 9 4
Ventilation design 10 6 14 6
Lighting design 33 20 47 20
Cooling design 27 16 38 16
Total Reduction 76 46 108 46
CCHP Generation 81 48 143 (generated) N/A
PV Generation 61 36 87 (generated) N/A
Energy Consumption: <100 kWh/sqm/yr
46% less than the baseline of HK’s Building Energy Code (BEC)
