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30th BEAM Pro Training & Examination Energy Use (EU) for New Buildings
Ir Dr T T CHOW Green Building Faculty
Panel Chair of Energy Use, Technical Review Committee, and Elected Director of
BEAM Society Limited
09 November 2015
• Overall Objectives of Assessing Energy Aspects
• BEAM Plus V1.2 Energy Use Criteria for New Buildings
• Original Route
• Alternative Route – Passive Design
Presentation Overview
2
Space
Conditioning
20%
Cooking
22%
Hot water
20%
Refrigeration
11%
Lighting
7%
Others
20%
3
• Buildings have huge impact on energy and emissions
• Buildings account for 58% of overall energy consumption in 2008
• Buildings account for 90% (91%) of electricity consumption in 2008 (2009)
• Where are the potential for energy savings?
Residential
19%
Commercial
39%
Industrial 10%
Transport 32%
Space
Conditioning
24%
Cooking
13%
Hot water and
refrigeration
10%
Office Equipment
5%
Lighting
10%
Others
38%
• Our buildings provide huge potential in energy savings.
HKSAR EMSD Energy End-Use Data 2010
The Situation in Hong Kong
0
10000
20000
30000
40000
50000
60000
70000
Existing Buildings in Hong Kong
• Existing buildings dominate the stock of Hong Kong for years to come
4
Nu
mb
er o
f b
uild
ings
2020 – 80.6% Existing 7.6% New 6.1% Rehabilitation 5.6% Replacement
2030 – 62.4% Existing 16.4% New 11.5% Rehabilitation 9.8% Replacement
Replacement
Rehabilitation
New
Existing
2050 58,000 buildings
2050 – 36% Existing 28% New 20% Rehabilitation 16% Replacement
Source: HK Govt, Buildings Dept HK Govt, Rating and Valuation Dept HK Govt, Census and Statistics Dept Hk Govt, Hong Kong 2030, planning and vision strategy
2020 2010 2030 2040 2050
Current Stock of Buildings
• Residential buildings make up the greater part of the floor area composition
• Industrial Buildings are older and may be in more need of retrofitting
• However, commercial buildings use the most energy
Residential
18%
Commercial
38%Industrial 9%
Transport
35%
0
5
10
15
20
25
30
35
Offices Commercial Residential Industrial
5
Floor Area for Various Building Sectors (Total =156,481,000 m2)
Private Office
6%
Retail + Restaurant +
Others
6%
Government,
Institution &
Community
6%
Industrial
11%
Public Residential
32%
Private Residential
39%
Buildings Age
Floor Area
HK3030 Campaign –
• HKGBC initiative
• vision for a low carbon, sustainable built environment in Hong Kong
• by reducing the absolute electricity consumption of buildings in Hong Kong by 30 percent of the 2005 level by the year 2030.
Energy Saving Plan for Hong Kong 2015~2025+
Energy Saving Plan for Hong Kong 2015~2025+
6
BEAM Plus Energy Use Overall Objectives:
•Minimum energy performance
•Reduction of CO2 emissions
•Energy benchmarking
•Energy efficient system / equipment
•Renewable energy
•Energy conservation
•Energy management
•Energy efficient building layout
•Alternative Route – Passive design
Energy Use Aspects
7
ANNUAL ENERGY USE / REDUCTION OF CO2 EMISSIONS
•PASSIVE DESIGN – orientation, massing, façade treatment, building plan, to optimize lighting, cooling and solar gain etc.
• CONSUMPTION & DEMAND – benchmarks for annual consumption (kWh/m2/yr), maximum demand (VA/m2/yr) with reference to base case on Energy Budget approach
• By Energy Simulation
• Buildings including commercial premises, hotels, residential properties, schools & other building types can be benchmarked on a performance based using thermal simulation.
Energy Use Aspects
8
EFFICIENT SYSTEM & EQUIPMENT
• Embodied Energy of Building Structures
• Ventilation / lighting systems in carpark – energy consumption and system control
• Lift, Electrical services – EMSD’s COP
• Positioning of units and installation requirement for decentralised A/Cs
• Lighting for public areas – control gear loss, circuit efficacy, control system
• Efficient appliances – Energy efficiency label
RENEWABLE ENERGY SYSTEMS
• Solar, wind & biomass
Energy Use Aspects
9
ENERGY MANAGEMENT
• Testing and Commissioning
• Operations and Maintenance – Manual, management plan, training and facilities
• Metering and Monitoring
• Energy Management – Audit, Objectives and Targets, Budget, Energy Charges
Energy Use Aspects
10
11
EU NB
No. of Prerequisites 1
No. of Credits 42
No. of Bonus 2
Credit Summary for NB Version 1.2 Original Route : EU P1 Minimum Energy Performance EU 1 Annual Energy Use – Reduction of CO2 Emission (15) EU 2 Peak Electricity Demand Reduction (3) EU 3 Embodied Energy in Building Structure Elements (1+1B) EU 4 Ventilation System in Car Parks (2) EU 5 Lighting System in Car Parks (2) EU 6 Renewable Energy Systems (5) EU 7 Air Conditioning Units (1) EU 8 Clothes Drying Facilities (1) EU 9 Energy Efficient Appliances (2) EU 10 Testing and Commissioning (4+1B) EU 11 Operation and Maintenance (3) EU 12 Metering and Monitoring (1) EU 13 Energy Efficient Building Layout (2)
BEAM Plus – EU Energy Use in New Buildings
EU Selective Approach
Building Passive Design
Spatial Planning
Natural Ventilation
HVAC System
EU 2 Peak Electricity Demand Reduction
EU 13 Energy Efficient Building Layout
Lighting System
Vertical Transportation
Route 1: Current BEAM Plus Approach
Route 2: Combine EU 1, 2 & 13
Building Fabric
Daylight Prescriptive
Performance based
Operable Window Area
Cross Ventilation Design
Building Active System
EU 1 Reduction of CO2 Emission
Or
Or
0
10
20
30
40
50
Cre
dit
s
20 credits
EU Original and Alternative Routes
EU Selective Approach
Building Passive Design
Spatial Planning
Natural Ventilation
HVAC System
EU 2 Peak Electricity Demand Reduction
EU 13 Energy Efficient Building Layout
Lighting System
Vertical Transportation
Route 1: Current BEAM Plus Approach
Route 2: Combine EU 1, 2 & 13
Building Fabric
Daylight Prescriptive
Performance based
Operable Window Area
Cross Ventilation Design
Building Active System
EU 1 Reduction of CO2 Emission
Or
Or
0
5
10
15
20
25
30
35
40
45
Cre
dit
s
20 credits
EU 1 Selective Path – Route 1
14
NB/EB EUP1 Minimum Energy Performance – the Prerequisite (zero credit)
After 21 Sep 2012, one mandatory code of practice - Energy
Efficiency for Building Services Installations 2012
Before that,
4 codes of practice: Air-conditioning Code, Lighting Code,
Electrical Code, Lift and Escalator Code
plus in addition, Performance-based Building Energy Code 2007.
15
EU1 Reduction of CO2 Emissions
- 1 to 15 credits for reduction of CO2 emissions or annual energy consumption by; [in terms of units of either CO2–kg or kWh per year; conversion factor depends on the type of fuel like electricity, town gas or natural gas]
(a) Commercial and Hotel Buildings,
3%, 5%, 7%, 9%, 11%, 14%, 17%, 20%, 23%, 26%, 29%, 33%, 37%, 41% &
45%.
(b) Educational Buildings,
3%, 4%, 5%, 6%, 7%, 9%, 11%, 13%, 15%, 17%, 19%, 21%, 24%, 27% & 30%.
(c) Residential Buildings,
3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 16%, 18% & 20%.
(d) Other Building Types,
1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, 16%, 18% & 20%.
Computer analysis making reference to the baseline model
Energy Use Aspects
16
Area Weighting method (AWM)
AWM shall be adopted for a complex building for EU and IEQ portions based on the development's construction floor area / normally occupied area. Application examples are the various mixed use buildings, e.g. retail + residential; retail + office; or mixed use of ventilation system; centralised + decentralised system.
17
• Credit EU2 – Peak Electricity Demand Reduction
(a) Commercial and Hotel Buildings: 1 to 3 credits for a reduction in the peak electricity demand by 15%, 23% and 30% respectively.
(b) Educational and Residential Buildings: 1 to 3 credits for a reduction in the peak
electricity demand by 8%, 12% and 15% respectively.
(c) Other Building Types: 1 to 3 credits for a reduction in the peak electricity
demand by 8%, 12% and 15% respectively.
The number of credits to be awarded will be determined with reference to the percentage reduction of the monthly peak electricity demand for the month with the highest electricity demand throughout the year of the assessed building relative to the respective benchmark (zero-credit) criteria evaluated from the Baseline Building model.
The assessment shall be included within the assessment of annual energy use via a single simulation run of the building project.
Energy Use - New Buildings:
18
Reference/Baseline Building Model
- BEAM Plus Manual Appendix 8 gives the default values and
assumptions for design parameters of the reference building, such
as for the residential building type
- Envelop: meeting OTTV regulation as the minimum; referring to
Appendix 8.2 when coming across the residential building or other
building type
- Air-conditioning system: identical zoning to the design building;
system and equipment to follow table on page A-4, in which the
floor area refers to the air-conditioned space.
Public Housing Private Housing Industrial, commercial, and other building types <14,000sqm
Industrial, commercial, and other building types >14,000sqm
Cooling Generation
Unitary air-conditioner, non-split-type
Unitary air-conditioner, split-type
Unitary air-conditioner, split-type
Chiller*
Terminal type N/A N/A N/A VAV Heat Rejection Air-cooled Air-cooled Air-cooled Water-cooled
19
All the major building systems shall be included in the energy consumption assessment (in principle: overall energy consumption or energy bills should be reflected and hence all those carrying impact on the credit achievable should be included) These shall include (but not be limited to) the following: ‐ HVAC system; ‐ Lighting system; ‐ Lift and escalator; ‐ Hot water system; ‐ Any other systems that may have an impact on the % reduction
Whole / Total Building Energy Simulation
20
Supporting information should be provided to justify the following input parameters adopted in the simulation:
A. For Building Envelope - Building orientation and position, window-to-wall ratio (floor plan/drawing)
- Glazing properties including: U-value, shading coefficient (product catalogue and design specification)
- OTTV calculation shall be provided for commercial building (calculations)
B. For Lighting - Lighting power density for each functional areas with supporting information (design specification / product catalogue)
- Schematic drawings for reference
For residential development, the provision of LED lamp in tenant area is not considered as a saving measure, as building owner has no control over the system; lighting power density should also be modeled the same
Whole / Total Building Energy Simulation
21
• Credit EU1 - Reduction of CO2 Emissions
The number of credits to be awarded will be determined with respect to % reduction of CO2 emissions or annual energy consumption of the assessed building relative to the respective benchmark (zero-credit) criteria evaluated from the Baseline Building model.
Energy Use - New Buildings:
Methodology of energy simulation shall make reference to the latest Building Energy Code (BEC 2012) or Appendix G of ASHRAE 90.1-2007 or equivalent. APPLICABLE SOFTWARE Acceptable simulation software is listed in the Appendix II of Performance-based Building Energy Code 2007 Edition.
22
Table A1 Commonly used building energy simulation programs (PBEC 2007)
Simulation software
No single software suits all building and/or system dynamic simulation purposes Check for appropriateness for contemporary system and component modeling, e.g. Green roof?
Exceptional calculation method
23
• Exceptional calculation method can be used with reference to ASHRAE approach; in particular simulation results of HVAC and lighting energy consumption must be from the same simulation software (and can be referred by reading the computer printout where available).
• Section G2.5 of ASHRAE 90.1 2007 stipulates that when no simulation program can adequately model a design, material, or device, the rating authority may approve an exceptional calculation method to demonstrate above-standard performance.
• Applications for approval of an exceptional method must include documentation of the calculations performed and theoretical and/ or empirical information supporting the accuracy of the method.
24
EU1 Reduction of CO2 Emission
Appendix 8.3: “TOWN Gas 0.592 kg CO2 per
unit of town gas consumed” changed to
“3.141 kg CO2 per unit of town gas
consumed”.
(Technical Circular of 28 Nov 2013; based on
EPD/EMSD published data)
25
Reporting Building Energy Analysis - Simulation report shall be prepared and certified by suitable qualified person.
- Applicant shall verify / demonstrate the energy simulation software used in compliance with relevant standard, e.g.
Building Energy Code or requirement stated in the BEAM Plus Manual;
- Narrative description for energy saving / conservation measures adopted in the development shall be provided;
- Any adopted Optimized Energy Performance shall supplement with supporting information;
- Information used should be consistent throughout the assessment;
- Detailed breakdowns of the Annual Energy Consumption for different systems ( HVAC / lighting / lift, etc.) and different functional areas of the development (e.g. club house, residential, retail) shall be provided for both baseline and design cases.
26
Reporting Energy Analysis
For EU2 the applicant is to report the followings: - Year round analysis for Peak Electricity Demand
- Load schedule during the period of peak electricity demand
- Substantiation on the offset resulted by renewable energy, if
any.
27
• A comprehensive and coherent CO2
emission reduction plan
0
20
40
60
80
100
120
140
160
180
200
Ave
rage
Building Ene
rgy Cod
es
ASHRAE
Plann
ing and
Des
ign
Ene
rgy Efficien
cy
On-
site ren
ewab
les
Biomas
s or offs
iteCarbon
Neutral?
Off-set remaining energy through local
renewables green tariffs, carbon credits
or other emission reduction projects
kg C
O2e
/m2 /
yr
Ons
ite R
E
Act
ive
syst
ems
Pas
sive
Des
ign
Hon
g K
ong
Bui
ldin
g E
nerg
y
Cod
es
Ave
rage
Gra
de A
offi
ce b
uild
ing
in H
ong
Kon
g
Energy efficient
design
Best
practices Baseline
Baseline
kWh/
m2 /
yr
0
100
200
300
AS
HR
AE
Sta
ndar
d 90
.1-
2007
20-30%
EMSD Building Energy Codes
Energy Efficiency
On-site Generation
& Others
Passive Design
Reduction of CO2 Emission Framework
80
130
180
230
280
Typical B
uild
ing
ASHRAE 9
0.1-
2004
Day
light
ing
Act
ive
Ligh
ting
Dou
ble S
kin F
açad
e
Hyb
rid V
entila
tion
CO
2 se
nsor
Chille
d Ceilin
g and
UFA
C
GSHP
CHP +
River
Ene
rgy
Efficien
t App
l.
Ren
ewab
les
10 to
40%
Red
uctio
n
Energy conservation and Efficiency
kgC
O2e
/m2 /
yr
>50
% R
educ
tion
Bui
ldin
g E
nerg
y C
ode
Ligh
ting
Pro
visi
on
采光系统
Act
ive
Day
light
Sys
tem
主动式自然采光系统
Hyb
rid V
ent.
复合通风系统
/ 自然通风
Gro
und
Sou
rce
HP
地源热泵系统
CH
P +
Riv
. Coo
l.
热电冷三联供
, 江水冷却
Ren
ewab
les
新能源的利用
Ene
rgy
Effi
cien
t A
pplia
nces
省能源的装置
Dou
ble
Ski
n F
açad
e
主动式内呼吸通风幕墙
CO
2 S
enso
r
CO
2感应器
Existing commercial building stock in Hong Kong
Ligh
ting
prov
isio
n
Act
ive
dayl
ight
sys
tem
Enh
ance
d fa
cade
Nat
ural
Ven
tilat
ion
Dem
and
Con
trol
Sen
sor
Chi
lled
Bea
m +
UFA
D
Fre
e C
oolin
g
Tri-
gen
and
dist
rict c
oolin
g
Ene
rgy
Effi
cien
t App
lianc
es
Ren
ewab
le G
ener
atio
n
An Example of CO2 Reduction Strategy
28
29
Building Energy Simulation
30
Case Name Description
2 Proposed Single-skin Same system with baseline
3 DSF Double-skin Façade with Baseline HVAC System
4 Heat Recovery Double-skin Façade with Baseline HVAC System + Heat Recovery System
5 Evaporative Cooling Double-skin Façade with Baseline HVAC System + Heat Recovery System + Cooling Tower
Cooling
6 Daylighting Double-skin Façade with Baseline HVAC System + Heat Recovery System + Cooling Tower
Cooling + Daylighting
7 Free Cooling Double-skin Façade with Baseline HVAC System + Heat Recovery System + Cooling Tower
Cooling + Transition Season Ventilation
Overall Annual Energy Cost Saving: 21% [Comparing with Performance-based BEC]
Energy Study
BEAM Plus V1.2 – Passive Design Route
Credits Breakdown for Passive Design Description Credits
Spatial Planning/Building Orientation
Building Separation is 20% between target buildings to nearby buildings in accordance with APP 152
1
Building separation is 33% between target buildings to nearby buildings in accordance with APP 152 Alternatively Carrying out a performance assessment to show an improvement in ventilation performance assessment to show an improvement in ventilation performance for the proposed case compared to a site with a permeability of 33%
1
The total solar irradiation of all façades (kWh/m2) is less than 80% of baseline solar gain value of 395kWh/m2
1
Building Fabric
28.0 W/m2 < OTTV < 30.0 W/m2 1 26.0 W/m2 < OTTV < 28.0 W/m2 2 24.0 W/m2< OTTV < 26.0 W/m2 3 22.0 W/m2 < OTTV < 24.0 W/m2 4 20.0 W/m2 < OTTV < 22.0 W/m2 5
Natural Ventilation
Prescriptive
20% of habitable areas meet the ventilation requirements 1
40% of habitable areas meet the ventilation requirements 2
60% of habitable areas meet the ventilation requirements 3
80% of habitable areas meet the ventilation requirements 4
100% of habitable areas meet the ventilation requirements 5
Performance
20% of habitable areas that satisfies with AAWV requirement 1
40% of habitable areas that satisfies with AAWV requirement 2
60% of habitable areas that satisfies with AAWV requirement 3
80% of habitable areas that satisfies with AAWV requirement 4
100% of habitable areas that satisfies with AAWV requirement 5
Daylight 80% of room area that has glazing with VDF of 50% higher than the minimum requirement in APP 130
1
Total for Building Passive Design 14
HVAC System in Common Area 20% energy reduction compared to BEC 1 25% energy reduction compared to BEC 2
Artificial Lighting System in Common Area 20% energy reduction compared to BEC 1 25% energy reduction compared to BEC 2 30% energy reduction compared to BEC 3
Vertical Transportation System in Common Area 10% reduction of maximum allowable electrical power 1
Total for Building Active System 6
Total 20
Spatial Planning (Site Planning)
Requirement:
1 credit attained if the permeability of the site is in accordance with APP 152.
2 credits attained if the permeability of the site is 33% or more in both projection planes in accordance with APP 152
Alternatively the second credit can be achieved by:
Carrying out a performance assessment to show an improvement in ventilation performance for the proposed case compared to a site with a permeability of 33%
Reference:
Intention of the credit: Aims to improve access to ventilation for the neighbourhood, which in turn improves the natural ventilation potential, improves air quality and enhances the pedestrian environment – improving the architectural collateral of The City. APP 152, The Sustainable Building Design Guidelines, sets out as prescriptive method to assess this.
Design Strategy :
It is anticipated that this improvement will be achieved by:
•Increasing building separation
•Increasing building set back
•Implementing building staggering through the site
•Including large ‘holes’ in buildings
Spatial Planning (Site Planning)
Requirement:
1 credit attained if the average solar irradiation of all facades is
≤ 80% of baseline solar irradiation value of 395 kWhr/m2
Building Orientation
N
318 kWhrs/m2
42
5 k
Wh
rs/m
2
389 kWhrs/m2
44
8 k
Wh
rs/m
2
Intention of the credit:
Reducing the solar irradiation will reduce summer cooling loads and as such energy consumption. Different facade orientations will be exposed to different levels of solar irradiation through the cooling period The peak solar irradiation occurs towards the west. Residential developments are conditioned from April to October inclusive and have an average solar irradiation of 395 kWh/m2/(Apr-Oct). The method compares the solar irradiance received at a facade and sets a target improvement.
Design Strategy:
• Favoring non west orientated facades;
• Design self shading into the building;
• Orientating the building to account for neighborhood shading and topography.
Building Orientation
Requirement:
1 credit if 28.0 W/m2 ≤ OTTV < 30.0W/m2
2 credit if 26.0 W/m2 ≤ OTTV < 28.0W/m2
3 credit if 24.0 W/m2 ≤ OTTV < 26.0W/m2
4 credit if 22.0 W/m2 ≤ OTTV < 24.0W/m2
5 credit if 20.0 W/m2 ≤ OTTV < 22.0W/m2
Building Fabric (Envelope)
Intention of the Credit:
Building envelopes in Hong Kong should be designed to minimize solar heat gain. This reduces summer cooling loads and associated energy consumption. For residential envelope heat transfer in Hong Kong, the impact of RTTV on credits achievable needs to be quantified, as such reference is still made to the Overall Thermal Transfer Value (OTTV). Buildings Department -Code of Practice for Overall Thermal Transfer Value in Buildings, 1995. Design Strategy: The Code of Practice considers:
1. Orientation 2. Window to wall ratio 3. Glazing specification (shading coefficient) 4. Solar shading 5. Wall build up (overall U-value, thermal mass and outer absorptivity)
Building Fabric (Envelope)
Natural Ventilation
Requirement:
Prescriptive Approach 1 credit if 20% of habitable areas meet the ventilation requirements. 2 credits if 40% of habitable areas meet the ventilation requirements. 3 credits if 60% of habitable areas meet the ventilation requirements. 4 credits if 80% of habitable areas meet the ventilation requirements. 5 credits if 100% of habitable areas meet the ventilation requirements.
Performance Approach
1 credit if 20% of habitable areas satisfy the Area-Weighted Average Wind Velocity (AAWV) requirement. 2 credits if 40% of habitable areas satisfy the AAWV requirement. 3 credits if 60% of habitable areas satisfy the AAWV requirement. 4 credits if 80% of habitable areas satisfy the AAWV requirement. 5 credits if 100% of habitable areas satisfy the AAWV requirement.
Intention of the Credit:
Natural ventilation reduces the dependency of mechanical cooling systems and reduces energy consumption. Ensure good provision for natural ventilation is included in buildings, as such this credit does not focus on wind directions or availability. These are covered in the site planning section. This credit simply optimizes the potential for natural ventilation. Design Strategy:
Good quality natural ventilation is not simply a case of opening a window. The following features should be considered:
• Size of openings must be sufficient to allow air to enter & exit;
• Cross ventilation is far more effective than single sided ventilation and should, where possible be included;
• Ensure that ventilation paths are not overly long;
• Ensure the ventilation path is clear of obstructions and the moving air is not required to turn many times;
• If re-entrants are included, ensure that they a not too small to allow ventilation air to enter
Natural Ventilation
How to achieve this credit: Prescriptive Approach
No more than one turn
allowed
Angle or turn, β, must be
less than 90o
a
b
Pass if total distance a+b < 12m
β
No more than one turn
allowed
Angle or turn, β, must be
less than 90o
a
b
Pass if total distance a+b < 12m
β
No more than one turn
allowed
Angle or turn, β, must be
less than 90o
a
b
Pass if total distance a+b < 12m
β
ab
c
Habitable area
Pass – windows lie in different
halves
Fail – windows lie in same half
Assessment box
Half way line
ab
c
Habitable area
Pass – windows lie in different
halves
Fail – windows lie in same half
Assessment box
Half way line
ab
c
Habitable area
Pass – windows lie in different
halves
Fail – windows lie in same half
Assessment box
Half way line
Cross ventilation window separation
•The total operable window size (i.e. physical opening not aerodynamic free area) in each habitable area should be double of that of the statutory requirement (i.e. operable window area to floor area not less than 1/8);
•When considering a single room the operable window size located at each wall should be at least 1/16 of the floor area;
Natural Ventilation
How to achieve this credit: Prescriptive Approach
Natural ventilation – Re-entrant design
• External Plane – ExP defines the start of the re-entrant and equals 4.5m;
• Secondary Window Plane (SWP)
must not be less than 2.3m, below this size, air will stagnate and pollutants will not be removed from the re-entrant;
• Notional Plane (NP) of 1.5m width
from SWP to a secondary window;
W1
W1
L2
W3W2
NP
SWP
W1 = 4.5m
W2 ≥ 2.3m
L2 ≤ 4.5m
W3 ≥ 1.5m
ExP
Cross
ventilation path
W3L2
W3
W2
Natural Ventilation
How to achieve this credit: Prescriptive Approach
4.5m
Area of
room with
insufficient
ventilation
Room fails as not
all is covered by
single sided
ventilation
• The window will ventilate up to 4.5m from opening area, the area under question must be contained within this zone
• Two separated operable window panes must be located at same wall or different walls; and
• The total operable window size (i.e. physical opening not aerodynamic free area) in each habitable area must be 1/5 operable window of the floor area
If the internal partition is above this line, the upper part could be counted as single ventilated
Natural ventilation – Criteria for single sided ventilation
Natural Ventilation
How to achieve this credit: Performance Approach
Wind speed 3.0m/s
Choose 4 wind directions
Model realistic openings
Use CFD to predict air flow in the room
0.4m/s internal air speed is consider adequate for thermal
comfort
Calculate habitual rooms separately
Typical value at 50mPD for urban HK, this also gives a standard
comparison
Allows for variety of designs
Aerodynamic openings determine ventilation, not physical opening
Robust tool for detailed air flow predictions
Based on ASHRAE adaptive comfort model for HK’s climate and enables comfy 28oC internal temperatures
Different rooms can be benefit for a different wind direction
Natural Ventilation
Requirement:
1 credit if 80% of the habitable areas have glazing with a vertical daylight factor (VDF) 50% higher than the minimum requirement in APP 130.
Daylight
Intention of the Credit:
Daylight offsets the use and artificial lighting and improves occupant health and wellbeing. APP130 currently legislates for daylight design, BEAM plus is intended to improve performance beyond this. APP130 considers the potential access of a window to daylight and not the passage of daylight through the glass and across the room. Such assessment is considered in the IEQ section of this methodology.
Design Strategy:
• Orientating buildings to increase the view of the sky with respect to neighbors and topography.
• Massing the site to increase building separation.
• Positioning windows so as limit the self shading affect of the building.
Daylight
How to achieve this credit:
Daylight simulations: VDF ≥ 12% for 80% habitable area (8% in PNAP APP 130)
VDF ≥ 6% for 80% kitchen (4% in PNAP APP 130)
Input Parameters VDF calculation
Latitude of 22.33 °N
Longitude of 114.18 °E
Sky Condition CIE Overcast Sky
Ground Reflectance 30%
Surrounding Building Reflectance 30%
Daylight
Requirement:
Two pre-requisites must be achieved to gain the credits:
Compliance with the latest Building Energy Codes (BEC) by Prescriptive Option; and In the case where air-conditioning units are provided by the developer, units selected shall either be Grade 1 or 2 under the Government’s energy efficiency labeling scheme or room coolers. Three different categories fall under the section Active Building Systems,
HVAC systems in common areas: 1 credit for a 20% energy reduction compared to current BEC. 2 credits for a 25% energy reduction compared to current BEC. Artificial lighting system in common areas: 1 credit for a 20% energy reduction compared to current BEC. 2 credits for a 25% energy reduction compared to current BEC. 3 credits for a 30% energy reduction compared to current BEC. Vertical transportation in common areas: 1 credit for a 10% reduction from the maximum allowable electrical power rating.
Active Building Systems
51
EU3 Embodied Energy in Building Structure Elements
Objective:
Encourage the design of structural elements and choice of materials that results in lower embodied energy.
Requirement:
1 credit for demonstrating the embodied energy in the major elements of the building structure of the assessed building has been studied through a Life Cycle Assessment (LCA).
1 BONUS credit for demonstrating the major materials with low embodied energy are used in the project utilizing the LCA results.
www.emsd.gov.hk/emsd/eng/pee/lceac.shtml
(Building foundations, building core, walls, etc., excluding building services systems)
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NB EU6 /EB EU5 Renewable Energy Systems
• 1 to 5 credits where 0.5% to 2.5% or more of building energy consumption is obtained from renewable energy sources respectively.
• Alternatively, 1 to 5 credits where the minimum percentage of 20% to 100% of the building footprint is being covered/used by PV panels respectively and/or other renewable power facility generation equivalent renewable power output.
• Electricity consumption of tenant area could be excluded from the calculation.
• For EB, this has been changed from normal credits to Bonus credit (TC of 28 Nov 2013)
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• Credit EU 6 - Renewable Energy Systems
- 1 to 5 credits where 0.5% to 2.5% or more of building energy consumption is obtained from renewable energy sources; or
- 1 to 5 credits where 20% to 100% of the building footprint
is being covered/used by PV panels respectively and/or other renewable power facility generation equivalent renewable power output.
Energy Use Aspects
Energy Use - New Buildings:
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• Credit Eu 6 - Renewable Energy Systems
- A building (GFA = 40,000m2; 25 storey; 1,600m2 roof area/building footprint; Energy intensity index = 200 kWh/m2/yr) Energy consumption = 8,000,000 kWh/yr
- An area of 20% of building footprint = 1,600m2 x 20% = 320m2
- Maximum generation for PV panels is (125kWh/m2/yr x 320m2 ) = 40,000kWh/yr. (Each m2 of PV panels can produce approximately 125 kWh net of electricity)
- 0.5% of building energy consumption is obtained from renewable energy source from 20% of the building footprint
Energy Use - New Buildings:
Energy Use Aspects
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EU10 TESTING AND COMMISSIONING
1 credit for each (totally 5) of the following:
• a) Commissioning specifications,
• b) Commissioning plan,
• c) Commissioning,
• d) Commissioning report,
• e) Independent Commissioning Authority (bonus)
Provide technical details with adequate cost provision
Tenant areas may be excluded
During PA stage, specifications/tender documents as evidence to demonstrate compliance is considered acceptable.
Independent Commissioning Authority should not come from contract related companies of the building project. But developer is acceptable to act as the ICA.
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NB EU 13 ENERGY EFFICIENT BUILDING LAYOUT
• 1 credit for demonstrating the fulfillment of at least 3 items out of the following strategies;
• 2 credits for demonstrating the fulfillment of all of the following strategies:
For all building types excluding residential:
a) Consideration of built form and building orientation to enhance energy conservation;
b) Consideration of optimum spatial planning to enhance energy conservation;
c) Consideration of building permeability provisions of building features to enhance the use of natural ventilation;
d) Provision of fixed or movable horizontal/vertical external shading devices; and
e) Provision of movable external shading devices for major atrium facade windows or skylights.
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NB EU 13 ENERGY EFFICIENT BUILDING LAYOUT
For residential developments (assessed as per EU 1 – Alternative Route):
a) To demonstrate compliance, energy simulation must be provided to show that the average solar irradiance of all facades is lower than 395 kW/m2;
b) Compliance is demonstrated by showing that a site permeability of 20% can be achieved between assessed building and nearby buildings/ obstructions;
c) Demonstrate that 20% of the habitable space can utilize natural ventilation either by the prescriptive approach or the performance approach;
d) Demonstrate that the OTTV of habitable spaces is less than or equal to 30 W/m2; and
e) Demonstrate that the VDF (vertical daylight factor) of habitable spaces are 50% more than the baseline requirements.
香港九龍塘達之路 號賽馬會環保樓 樓
