Transcript Document

2S ARCHITECTURAL GLASS SEMINAR
Balancing Window Heat Gains against Daylighting in Tropical Climates
29th October 200 Renaissance Hotel Kuala Lumpur
Ar Chan Seong Aun
M Arch (Distinction), B Arch (Hons), B Bdg Sc (VUW, NZ), APAM, AIPDM, TAM
CONTENT
1. GREEN BUILDING INDEX
2. ENERGY EFFICIENT ARCHITECTURE
3. DAYLIGHTING ESSENTIALS
4. HEAT GAINS THROUGH WINDOWS
5. OPTIMIZING THE BUILDING ENVELOPE
1
GREEN BUILDING INDEX
What are the LOCAL issues for Malaysia?
•
HYPER URBANIZATION - Urban Population expected to
grow by between 40% to 50% by 2030 from 70% to 80% of
Total Population. The way we plan our Cities will be a Key
component of a sustainable future
•
Malaysia will become a Net Importer of Energy by 2015.
How we design our buildings will reflect how much energy
they require to run.
•
Malaysia has the HIGHEST per capita Energy Consumption
among ASEAN countries
•
No control over import of energy inefficient equipment as
there are no proper standards – WTO requirement
What are the major issues?
What are the major issues?
Malaysia as Net Energy Importer
SOURCE : PTM
Why Have GREEN or SUSTAINABLE Buildings?
• Save energy and resources, recycle materials and
minimise the emission of toxic substances throughout
its life cycle,
• Harmonise with the local climate, traditions, culture
and the surrounding environment, and
• Able to sustain and improve the quality of human life
whilst maintaining the capacity of the ecosystem at
local and global levels
Why Have GREEN BUILDING INDEX?
• Allows for easy public evaluation of what are
REAL green buildings,
• Serves as key design principles for Architects
and Engineers to design green buildings, and
• Performance parameters are set for better
TOTAL BUILDING PERFORMANCE
BUDGET 2010 : GREEN BUILDING INCENTIVES
•On Promoting Construction of Green Buildings
•To expand the use of green technology, the Government launched the Green
Building Index (GBI) on 21 May 2009. GBI is a green rating index on
environmentally friendly buildings. Green buildings save utility costs and
preserve the quality of the environment. To promote green technology, the
Government proposes that:
•First: Building owners obtaining GBI Certificates from 24 October 2009 until 31
December 2014 be given income tax exemption equivalent to the additional
capital expenditure in obtaining such Certificates; and
•Second: Buyers purchasing buildings with GBI Certificates from developers be
given stamp duty exemption on instruments of transfer of ownership. The
exemption amount is equivalent to the additional cost incurred in
•obtaining the GBI Certificates. This exemption is given to buyers who execute
sales and purchase agreements from 24 October 2009 until 31 December 2014.
2
ENERGY EFFICIENT
ARCHITECTURE
How Energy Efficient are Malaysian Buildings?
Cumulative percentile
100%
80%
BEI of office
buildings in
Malaysia
60%
40%
Source: PTM
20%
0%
0
50
100 150
200 250
300
350 400
Building Energy Index (kWh/m2 year)
450
Normal buildings
(Kuala Lumpur)
Electricity consumption kWh/m²/year
Malaysian Office Buildings
Energy Indexes
300
Solar energy
Electricity consumption
250
LEO building
(Putrajaya)
200
150
100
50
ZEO building
(Bangi)
0
-50
-100
Normal
buildings
LEO
Building
ZEO
Building
0-energy
(Zero Energy Office)
Where is the most Energy Used?
Novozymes Office Building Energy Load
Equipment
24%
Air Conditioning
Lighting
Equipment
Lighting
12%
Air Conditioning
64%
Green Building Index (Non-Residential)
innovatn
7%
water
10%
energy
35%
matls
11%
site
16%
IEQ
21%
MS1525 the Cornerstone of Malaysian Energy Efficiency
MS 1525:2007
•
All buildings exceeding 4,000
m2 of air conditioned space
shall be provided with an
EMS system and
•
OTTV shall not exceed 50
W/m2
•
RTTV shall not exceed 25
W/m2
Optimizing Window functions
HEAT GAIN vs DAYLIGHT
VIEW vs PRIVACY
FRESH AIR vs HUMIDITY
Temperature and Humidity
( Subang Weather Data)
Why do we need to air condition our Offices?
Relative Humidity 80%
The Comfort Zone
3
DAYLIGHTING ESSENTIALS
AFTER AIR CONDITIONING LIGHTING ENERGY
CONSUMPTIONB IS THE NEXT MOST IMPORTANT
FOR COMMERCIAL BUILDINGS.
Energy Index
150.0
worst
130.0
base
mewc
90.0
70.0
50.0
30.0
10.0
Fresh Air
Gain
Dehumid
Fresh Air
Dehumid
Ppl Latent
Gain
Ppl Gain
Ext
Conduction
Gain
Solar Gain
Small
Power Gain
Lighting
Gain
Chiller
Energy
Lighting
-30.0
Small
Power
-10.0
Fan Energy
kWh/m2/year
110.0
WINDOWS & DAYLIGHTING IN BUILDINGS
• Daylight in Building
offset electrical
lighting load
• Electrical lights
produces more heat
than Diffused Daylight
• Zone electrical
lighting system
correctly
DAYLIGHTING ESSENTIALS
1. Bring the light in high, above the view plane
2. Diffuse sunlight inside the space. Don’t allow beam
sunlight to strike work surfaces.
3. Use only north and south vertical windows
4. Choose the glazing carefully.
•Continuous strip of narrow windows up high
•A few view windows. These have a low visible transmittance (0.2
– 0.3), to balance the luminance of the walls with the luminance
of the outdoor view. Every work place in the building should have
a visual connection to the outside
•Eggshell white color in the upper part of the room to bounce the
light across the room
•Mid-to-light colors in the lower part of the room
Effect of Window design on daylight distribution
Max daylight penetration = 2.5xWindow Height
PSALI Permanent Supp Artificial Lighting
PSALI
4
HEAT GAIN THROUGH WINDOWS
MS1525 key ref document
SECTION 5 : BUILDING ENVELOPE
TYPICAL BUILDING ENVELOPE HEAT GAINS
OTTV = 15a(1-WWR)Uw + 6(WWR)Uf + 194xCFxWWRxSC
Heat
Conduction
through
Walls
5% to 10%
OTTV < 50 W/m2
Heat
Conduction
through
Windows
Solar Heat
Gain
through
Windows
10% to 20%
75% to 85%
Let the MAXIMUM DAYLIGHT in
Block out the SOLAR HEAT GAIN
by maximizing the
SHADING COEFFICIENT
WINDOW EXTERNAL SHADING
WINDOW SHADING
• External Shading
Devices are more
effective than Internal
Blinds.
• Only need to block
out Direct Sunlight.
HORIZONTAL LOUVERS FOR N-S
FACING WINDOWS
VERTICAL LOUVERS FOR E-W
FACING WINDOWS
HORIZONTAL LOUVERS FOR N-S
FACING WINDOWS
VERTICAL LOUVERS FOR E-W
FACING WINDOWS
IMPROVING THE SHADING COFFECIENT OF
WINDOWS
Window SC = Glass SC x Shading Device SC
SC
= 0.6 x 0.8 = 0.48
a reduction of more than 50%
window
Projection
Window
Height
R1 = Projection / Window Height
Typical = 0.3m/1.2m = 0.25
SC = 0.8
TABLE 5
HORIZONTAL PROJECTION SHADING COFFICIENTS
0.9
0.8
0.7
Shading Coefficient
0.6
0.5
0.4
0.3
0.2
0.1
0
0.3 to 0.4
0.5 to 0.7
0.8 to 1.2
1.3 to 2.0
North/South
0.77
0.71
0.67
0.65
East
0.77
0.68
0.6
0.55
West
0.79
0.71
0.65
0.61
NE/SW
0.77
0.69
0.63
0.6
NW/SE
0.79
0.72
0.66
0.63
R1 (Projection / Window Height)
TABLE 6
VERTICAL PROJECTIONS SHADING COEFFICIENTS
1
0.9
0.8
Shading Coefficients
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0.3 to 0.4
0.5 to 0.7
0.8 to 0.12
North/South
0.82
0.77
0.73
0.7
East
0.87
0.82
0.78
0.75
West
0.86
0.81
0.77
0.74
NE/SW
0.83
0.77
0.72
0.69
NW/SE
0.84
0.79
0.74
0.71
R2 (Projection / Window Width)
1.3 to 2.0
5
OPTIMISING THE
BUILDING ENVELOPE
Let the MAXIMUM DAYLIGHT in
By having the highest VLT
Block out the SOLAR HEAT GAIN by
maximizing the
SHADING COEFFICIENT=Lowest SC
CHOOSE SPECTRALLY SELECTIVE GLAZING
ideal window transmittance
solar spectrum
0
500
visible
1000
1500
Wavelength,
2000
nm
2500
3000
WINDOW GLAZING
Spectrally Selective Glazing :
Lets in the lights, blocks out the heat
Tinted Glazing
Heat
Light
Sp. Sel. Glazing
Heat
Light
Typical Values, Double Glazing : Light 60% Transmission
Heat 30 % Transmission
OPTIMIZING VLT vs SC
Visible Light Transmittance
1
II
III
High VLT
Low SC
High VLT
High SC
IV
I
VLT
Low VLT
Low SC
0
Low VLT
High SC
0
1
SC
Shading Coefficient
OPTIMIZING VLT vs SC
Visible Light Transmittance
1
II
III
High VLT
Low SC
High VLT
High SC
IV
I
VLT
Low VLT
Low SC
0
Low VLT
High SC
0
1
SC
Shading Coefficient
Clear Glass VLT vs SC
CLEAR GLASS
1
0.9
VLT Visible Light Transmittance
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
SC Shading Coeff
0.8
0.9
1
TINTED GLASS
Tinted Glass VLT vs SC
1
0.9
VLT Visible Light Transmitance
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0
0.1
0.2
0.3
0.4
0.5
0.6
SC Shading Coeff
0.7
0.8
0.9
1
TINTED LAMINATED GLASS
TINTED LAMINATED GLASS
1
VLT VISIBLE LIGHT TRANSMITTANCE
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0
0.1
0.2
0.3
0.4
0.5
0.6
SC SHADING COEFF
0.7
0.8
0.9
1
REFSHINE-S 6mm
REFSHINE-S 6mm
1
0.9
0.8
0.7
VLT
0.6
0.5
0.4
0.3
0.2
0.1
0
0
0.1
0.2
0.3
0.4
0.5
SC
0.6
0.7
0.8
0.9
1
REFSHINE-S laminated
REFSHINE-S LAMINATED GLASS (6+INTERLAYER+FL3) SC vs VLT
1
VLT VISIBLE LIGHT TRANSMITTANCE
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0
0.1
0.2
0.3
0.4
0.5
0.6
SC SHADING COEFF
0.7
0.8
0.9
1
REFSHINE-S DGU
THE MORE YOU LEARN
THE LESS YOU KNOW
THANK YOU
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