Transcript Passive Design Part 1

SEMINAR ON PASSIVE & ACTIVE DESIGN
FOR E NERGY E FFICIENT B UILDINGS
3 October 2014
Holiday Inn Resort, Penang
Part 1 – Introduction & Overview of
Passive Design
By Ar Michael Ching Chee Hoong
h t t p : / / w w w . j k r. g o v. m y / b s e e p /
2
ENERGY USAGE IN BUILDING
Buildings are responsible for 1/3 of energy related GHG
emissions.
“Wasteful use of energy is
affecting our planet and our
environment. If we design, build
and manage our buildings so the
need for energy is reduced, only
then our effort will make a real
difference.”
3
SYNOPSIS
Passive design are features which
are intrinsic (or part of ) the building
form which contributes to good
environmental qualities such as
provides shelter or insulation
against the hot tropical sun or its
layout is such that it ensures quality
environment for occupant.
Active design features are M&E
systems which actively ‘intervene’
to ensure good or adequate
environmental
qualities
in
a
building. Active measures include
lifts, air conditioning, mechanical
ventilation , artificial lighting etc.
4
SYNOPSIS
PASSIVE DESIGN measures are key considerations in the design of
building for low energy and environmental performances. The importance
of Passive Design is underscored by its precedence over Active Design
measures in green and low energy building.
PASSIVE DESIGN measures (which are principally architectural in nature)
aims to embed features into a building which are intrinsically green and
low energy in nature. Active measures are design features which requires
‘active intervention’ of building systems (such as air conditioning,
mechanical ventilation, lighting systems etc) which will contribute to green
and/or low energy performances. Current pressing requirements for
green design and low energy in building which are increasingly driven by
mandatory building codes (e.g. recent revision to the UBBL incorporating
parts of MS1525) requires knowledge of Passive Design as in the skill set
of the design architect.
5
SYNOPSIS
Feature
Ensure thermal comfort
Adequate and comfortable
lighting
Ensure good air quality
Passive Design
Active Design
Building thermal
envelope;
Natural ventilation
Air Conditioning
System
Natural daylight
Artificial lighting
Natural ventilation
Mechanical
ventilation
Active design contributes to building energy.
Passive design aims to reduce building energy and maximise
comfort of the users.
We therefore need an understanding of Passive Design.
6
INTRODUCTION
THIS PRESENTATION introduces the topic of passive design in
the following progressive manner:
(1)Building Energy
(2)Low Energy Building
(3)Passive Design
(4)Building Energy Components
8
COMMERCIAL BUILDING ENERGY
Typical Energy Use (kWh)
Typical Office Building
9
COMMERCIAL BUILDING ENERGY
Kings Green Hotel,
Melaka (3 Star Hotel)
10 RESIDENTIAL BUILDING ENERGY
What About Residential Buildings?
How do we measure Residential Building Energy?
In CETDEM study of around 2005, at least 55% of energy use is
attributed to fuel for transport.
11 RESIDENTIAL BUILDING ENERGY
If we are only concerned with building energy, then we should only
focus on electricity use.
This is total Energy Use per family (middle income)
12 RESIDENTIAL BUILDING ENERGY
But in many Malaysian home, if designed properly, no AC units are
required.
13 COMMERCIAL BUILDING ENERGY -- CONCLUSION
In Commercial buildings, we can conclude that building
energy comprise the following:
1. Air conditioning
= 45% - 60%
2. Lighting
= 15% - 25%
3. Utilities
= 10% - 30%
4. General power outlets
= 10% - 30%
These are dependent
on building design.
This do not depend on
building design.
It is possible to design a building which lessen energy use of those
components listed above. These building components can be said to
be “intrinsic” to the building OR part of the building ‘character’.
14 RESIDENTIAL BUILDING ENERGY -- CONCLUSION
In Residential buildings, we can conclude that building
energy comprise the following (only for typical middle
class Malaysian family:
1. Air conditioning
= 0% - 40%
2. Lighting
= 8% - 20%
These are dependent
on building design.
3. Appliances (fridge, oven) etc = 10% - 30% This do not depend on
building design.
4. General power outlets
= 10% - 30%
For residential building a large part of building energy can be
attributed to ‘life-style’ which may be due to socio-economic, cultural
and even geographic location in nature.
If is even possible for a residential building to be designed without air
conditioning.
KeTTHA Low Energy Building (LEO)
16 BUILDING ENERGY BENCHMARKS
Energy Consumption
Malaysia has the HIGHEST per capita Energy Consumption
among ASEAN countries
17 BUILDING ENERGY BENCHMARKS
Why do we need Building Energy Benchmarks?
Building Energy Benchmarks are indicators of building performance
which is use as comparison between different building design (uniform
gauge for comparison).
Building performance benchmarks are important:
1.
Indication of building ‘environmental quality’ which may be demanded by
the market forces.
2.
Benchmarks on
which regulatory requirement on building energy
performance may be mandated, example:

BEI (Building Energy Intensity) defined by GBI for compliance scoring
in the GBI environmental rating system.

OTTV (Overall thermal transfer value) of building which is a form of
building energy performance benchmark which is now mandatory in
some states
18 BUILDING ENERGY BENCHMARKS
For Commercial Buildings the following benchmarks by GBI &
JKR-BSEEP:
Hotel BEI
per year
Resort BEI
per year
Retail
Malls BEI
per year
Industrial
BEI per
year
Data
Centre
(PUE)
1
150kWh/m²
200kWh/m²
245kWh/m²
240kWh/m²
180kWh/m²
1.9
2
140kWh/m²
190kWh/m²
230kWh/m²
225kWh/m²
150kWh/m²
1.8
3
130kWh/m²
175kWh/m²
212kWh/m²
210kWh/m²
140kWh/m²
1.7
4
120kWh/m²
160kWh/m²
196kWh/m²
195kWh/m²
130kWh/m²
1.6
5
110kWh/m²
150kWh/m²
181kWh/m²
180kWh/m²
120kWh/m²
1.5
6
100kWh/m²
135kWh/m²
165kWh/m²
160kWh/m²
110kWh/m²
1.4
7
90kWh/m²
120kWh/m²
148kWh/m²
145kWh/m²
100kWh/m²
1.3
8
-
-
-
-
90kWh/m²
Level
Office BEI
per year
Low Energy Building (LEO) is any building performance, level 6
and below!
19 BUILDING ENERGY BENCHMARKS
Energy Consumption - BEI
Cumulative percentile
100%
80%
60%
40%
20%
0%
50
100 150
200
250
300
350
400
Building Energy Index (kWh/m2/year)
Source : PTM
450
20 BUILDING ENERGY BENCHMARKS
For Residential Buildings NO BEI benchmarks, BUT building
energy performance based on OTTV is practiced by GBI & JKRBSEEP:
Levels
GBI RNC Version 3 OTTV landed
GBI RNC Version 3 OTTV High rise
1
50W/m²
50W/m²
2
46W/m²
46W/m²
3
42W/m²
42W/m²
4
38W/m²
38W/m²
5
34W/m²
6
30W/m²
21 BUILDING ENERGY BENCHMARKS
For Residential Buildings NO BEI benchmarks, BUT building
energy performance based on OTTV is practiced by GBI & JKRBSEEP:
Levels
GBI RNC Version 3 OTTV landed
GBI RNC Version 3 OTTV High rise
1
50W/m²
50W/m²
2
46W/m²
46W/m²
3
42W/m²
42W/m²
4
38W/m²
38W/m²
5
34W/m²
6
30W/m²
>75% of the Solar Gain by a typical Intermediate single storey terraced
house is through its Roof
>40% of the Solar Gain by a typical 5 storey block of flats is through its
Roof
23 BUILDING ENERGY COMPONENTS
Passive design features are features which are ‘intrinsic’ to the building
(i.e. is an integral part or character of the building). Examples are
orientation away from direct sun,
well insulated building,
windows to allow natural day-light
Naturally ventilated building etc.
24 BUILDING ENERGY COMPONENTS
Passive design features are features which are ‘intrinsic’ to the building
(i.e. is an integral part or character of the building). Examples are
orientation away from direct sun,
well insulated building,
windows to allow natural day-light
Naturally ventilated building etc.
Active design features are features which are building systems (usually
mechanical and electrical in nature) which actively contributes to or
enhances the performance of a building (‘performance’ may include
energy or environmental quality). Examples are:
Air conditioning system
Mechanical ventilation
Artificial lighting
Lifts & Escalators
Plug Load & etc
25 BUILDING ENERGY COMPONENTS
Services
Factors affecting kWh usage
Parameters in design
ACMV
Heat Transmission through walls/roof
Weather Data
Solar irradiance
OTTV, RTTV, Sun position & shading
calculation
Air Infiltration
Weather data
Human population/traffic
Time-based traffic
Lighting load
Human traffic, day light factor
Machine load
Occupancy Pattern
Utility
Human traffic
Occupancy Pattern
Day Lighting
Sun Position, glare control
Power/ Plug
Load
Human Traffic
Occupancy Pattern
Utility
Usage Pattern
Lighting
26
MS1525 AND PASSIVE DESIGN
Code of Practice on
Energy Efficiency and
Use of Renewable Energy
for Non-Residential
Buildings
Now 3rd edition 2014
incorporated into UBBL in
certain states, hence
becomes part of a By-law
27
MS1525 AND PASSIVE DESIGN
MS1525 has the following Parts
0. Introduction
1. Scope
2. Normative Reference
3. Terms and Definitions
4. Architectural
and
design strategy
passive
5. Building Envelope
6. Lighting
7. Electric power and distribution
8. Energy
management
control system
and
28
MS1525 AND PASSIVE DESIGN
MS1525 Section 4 – Architectural and
passive design strategy
1. Site planning & orientation
2. Daylighting
3. Façade design
4. Natural ventilation
5. Thermal insulation
6. Strategic landscaping and
7. Renewable
solar)
energy
(principally
29
MS1525 AND PASSIVE DESIGN
MS1525 Section 5 – Building
Envelope contains the following:
1. Concept of Overall Building
Thermal Transfer (OTTV)
2. Sun path and building orientation
3. Shadings
insolation
to
mitigate
4. Daylighting
5. Roofs thermal performance
6. Roofs with skylights
7. Air leakage
solar
30 PASSIVE DESIGN FEATURES
Passive design features are can be listed as the following design
measures:
1. To Orientation - Building Orientation (sun path)
2. To Shade - Building thermal envelope (OTTV) & Roof thermal
envelope (RTTV)
3. To Insulate - Building thermal envelope (OTTV) & Roof thermal
envelope (RTTV)
4. To Daylit - Natural day lighting by windows, daylighting system such
as light tube, light shelf etc.
5. To Ventilate - Naturally ventilated building by cross and stack
ventilation
31 PASSIVE DESIGN FEATURES
Passive design features are can be listed as the following design
measures:
1. To Orientation - Building Orientation (sun path)
2. To Shade - Building thermal envelope (OTTV) & Roof thermal
envelope (RTTV)
3. To Insulate - Building thermal envelope (OTTV) & Roof thermal
envelope (RTTV)
4. To Daylit - Natural day lighting by windows, daylighting system such
as light tube, light shelf etc.
5. To Ventilate - Naturally ventilated building by cross and stack
ventilation
Building Envelope
Qin
Tin
(22°C)
20 March 2014
33 CASE STUDY TO QUANTIFY THE BLDG ENERGY
Building design features which contributes to building cooling energy
can be illustrated as follows:
Heat gain & solar heat
gain thro’ roof (RTTV)
Lighting
heat gain
Fresh Air
Intake
Electric
Motor
heat gain
People
heat gain Electric
Appliance
heat gain
Heat gain thro’ windows
Heat gain
thro’ walls
Air Infiltration (doors/
windows/ cracks)
20 March 2014
34 CASE STUDY TO QUANTIFY THE BLDG ENERGY
Case study attempts to find out how much is the contribution of various
building components
The Model:
20 March 2014
35 CASE STUDY TO QUANTIFY THE BLDG ENERGY
Building Cooling Energy
20 March 2014
36 CASE STUDY TO QUANTIFY BLDG ENERGY
Some Conclusion

Building façade contributes to about 15% of cooling energy

Roof contribution is proportional to the ratio of roof space to total
built-up

Air intake or how ‘leaky’ a building is contributes up to a whopping
25% to building cooling energy.

Electrical equipment inside building contributes a major 30%. This
component unfortunately is usually not influence by building
designers but by the M&E engineer. However building designed
with minimal or less dependency on electrical equipment will be
have significant effect on building energy.

People or occupant only contribute from 15%-20% of bldg energy.
Understanding above and building usage pattern can assist
designers in building low energy building.
20 March 2014
SEMINAR ON PASSIVE & ACTIVE DESIGN
FOR E NERGY E FFICIENT B UILDINGS
3 October 2014
Holiday Inn Resort, Penang
Part 2 – Building Thermal Envelope
By Ar Michael Ching Chee Hoong
h t t p : / / w w w . j k r. g o v. m y / b s e e p /
38 INTRODUCTION
THIS PRESENTATION introduces the topic of Building Thermal
Envelope in the following progressive manner:
(1) Basic concepts in Building Thermal Envelope, MS1525
(2) OTTV and Roof U-Value
(3) Site Planning and Orientation
(4) Shading
(5) Insulation
(6) Daylight
(7) Natural Ventilation
Heat gain & solar heat
gain thro’ roof (RTTV)
Lighting
heat gain
Fresh Air
Intake
Electric
Motor
heat gain
People
heat gain Electric
Appliance
heat gain
Heat gain thro’ windows
Heat gain
thro’ walls
Air Infiltration (doors/
windows/ cracks)
40 BASIC CONCEPTS - BUILDING THERMAL ENVELOPE
Building thermal envelope is based on the idea of Energy Input / Output
to a system (in this case solar energy into building):
Qin
Tin
(22°C)
Tout (30°C)
41 BASIC CONCEPTS - BUILDING THERMAL ENVELOPE
Building thermal envelope contributes up to 15% of building cooling
energy which make up about 50% of total building energy.
43 THE CONCEPT OF OTTV
MS1525:2007 CLAUSE 5.2
OTTV applies to building envelope
MS1525:2007 CLAUSE 5.5
Roof U-value refers to the thermal
transmittance of the roof construction
MS1525:2007 CLAUSE 5.6
RTTV applies to roof with skylights
44 THE CONCEPT OF OTTV
MS1525:2007 Clause 5.2
A design criterion for building envelope known as the
Overall Thermal Transfer Value (OTTV) has been
adopted. The OTTV aims at achieving the design of
building envelope to reduce heat gain through the
building envelope and hence reduce the cooling load
of the air-conditioning system.
The OTTV…should not exceed 50 W / m2
45 THE CONCEPT OF OTTV
Assumptions
The concept of OTTV is based on the assumption
that the envelope of the building is completely
enclosed.
In the OTTV formulation, the following items are
not considered:
1.
internal shading devices eg curtains
2.
solar reflection or shading from adjacent
buildings
green walls
3.
`
46 THE OTTV FORMULA
MS1525:2007 Clause 5.2.2 says
The formula for the OTTV of any given wall orientation is as follows:
OTTVi  15 α (1  WWR) Uw  6 (WWR) Uf  (194 x CF x WWR x SC)
OTTV =
Heat
Conduction
through
Walls
0.2% to 5%
+
Heat
Conduction
through
Windows
10% to 20%
+
Solar Heat
Gain
through
Windows
70% to 85%
47 THE OTTV FORMULA
MS1525:2007 Clause 5.2.2 says
The formula for the OTTV of any given wall orientation is as follows:
OTTVi  15 α (1  WWR) Uw  6 (WWR) Uf  (194 x CF x WWR x SC)
OTTV =
Heat
Conduction
through
Walls
0.2% to 5%
48 THE OTTV FORMULA
MS1525:2007 Clause 5.2.2 says
The formula for the OTTV of any given wall orientation is as follows:
OTTVi  15 α (1  WWR) Uw  6 (WWR) Uf  (194 x CF x WWR x SC)
OTTV =
Heat
Conduction
through
Walls
0.2% to 5%
+
Heat
Conduction
through
Windows
10% to 20%
49 THE OTTV FORMULA
MS1525:2007 Clause 5.2.2 says
The formula for the OTTV of any given wall orientation is as follows:
OTTVi  15 α (1  WWR) Uw  6 (WWR) Uf  (194 x CF x WWR x SC)
OTTV =
Heat
Conduction
through
Walls
0.2% to 5%
+
Heat
Conduction
through
Windows
10% to 20%
+
Solar Heat
Gain
through
Windows
70% to 85%
50 THE OTTV FORMULA
OTTVi  15 α (1  WWR) Uw  6 (WWR) Uf  (194 x CF x WWR x SC)
α (alpha) = solar adsorbsion value of wall surface
WWR = window to wall ratio
Uw = U value ofwall
Uf = U value of fenestration (windows) W/m² K
CF = Correction Factor (due to orientation)
SC= Shielding Coefficient of windows.
51 THE OTTV FORMULA
OTTVi  15 α (1  WWR) Uw  6 (WWR) Uf  (194 x CF x WWR x SC)
1) Window to Wall ratio
2) Wall & Window Properties (including color)
3) Shading Devices
52 BUILDING ENERGY BENCHMARKS
53 THE CONCEPT OF ROOF U-VALUE
Common roof insulation materials
– Mass Insulation
– mass, thickness and
thermal resistance slow
down heat transfer
– Reflective Insulation
– reflect radiant heat
– low thermal emissivity
54 THE ROOF U-VALUE FORMULA
U-values are worked out from the Thermal
Resistance of the respective materials making up
the Roof, similar to that for Walls.
U-value is the heat transmission value of the
composite roof in W/m2K, and is inversely
proportional to R,
ie,
U = 1 / Rtotal
The higher the R, the lower the U, the better.`
55 THE ROOF U-VALUE FORMULA
MS1525:2007 Clause 5.5.1
Table 9. Maximum U-value for roof (W/m²K)
Roof Weight
Group
Light
(Under 50
kg/m²)
Heavy
(Above 50
kg/m²)
Maximum U-Value (W/m²K)
0.4
0.6
56 ROOF CONSTRUCTION AND THERMAL VALUES
Metal Deck Roof with Insulation
Component (outside to inside)
Thickness
Conducitvity
Resistance
mm
w/(m.K)
T/C
Outside Solar absorption
0.700
Outside Surface Resistance
0.055
Metal Deck (Aluminum)
0.5
221
0.000
Fiberglass
100
0.035
2.857
Air space
100
0.195
Asbestos Free Ceiling Board
12
0.108
0.111
Inside Surface Resistance
0.148
Total Thermal resistance
4.266
U-value (W/m2K)
0.234
57 ROOF CONSTRUCTION AND THERMAL VALUES
1. Cement sand screed.
2. Bitumen /felt
3. Reinforced concrete
4. Cement sand plaster
Reinforced Concrete RooF Slab
Component (outside to inside)
Outside Solar absorption
Outside Surface Resistance
Cement sand screed
Polystyrene Foam
Bitumen Felt Layer
Reinforced Concrete slab
Cement sand plaster
Inside Surface Resistance
Total Thermal resistance
U-value (W/m2K)
Thickness
mm
25
20
5
100
12
Conducitvity
w/(m.K)
0.533
0.035
0.5
1.442
0.533
Resistance
T/C
0.700
0.055
0.047
0.571
0.010
0.069
0.023
0.148
0.923
1.083
58 INSULATION TO LIGHTWEIGHT ROOF
0.8
ROOF U-VALUE (W/m2K)
0.7
0.6
MS 1525
0.5
lightweight roof
< 0.4 W/m2K
0.4
0.3
0.2
0.1
0.0
0
50
100
150
200
250
INSULATION THICKNESS (mm)
300
350
59 INSULATION TO HEAVYWEIGHT ROOF
ROOF U-VALUE (W/m2K)
3.0
2.5
2.0
1.5
MS 1525
1.0
heavyweight roof
< 0.6 W/m2K
0.5
0.0
0
50
100
150
200
250
300
350
INSULATION THICKNESS (mm)
G Reimann
61 SITE PLANNING AND ORIENTATION
MS1525 Clause 4.3
Generally, the best
orientation for buildings
is with the long
directional axis facing
North-South, thus
minimizing East-West
orientation.
62 SITE PLANNING AND ORIENTATION
MS1525:2007 Clause 4.3
The micro-climate, shading,
radiant temperature, wind
direction, precipitation etc
should be analysed for the
locality.
64 SHADING DEVICES - HORIZONTAL
The reasons for shading is to shield windows from the direct solar
radiation which is a major cause of solar heat gain (up to 70-85%)
Shading can be horizontal / vertical.
Vertical shading device.
65 SHADING DEVICES - HORIZONTAL
66 SHADING DEVICES - HORIZONTAL
MS1525:2007 Table 5
If R1 falls between increments, adopt the next larger ratio.
If R1 is below 0.30, SC2 = 1.
If R1 is > 2.00, SC2 values shall be the same as R1 between 1.30 and 2.00
67 SHADING DEVICES - HORIZONTAL
68 SHADING DEVICES - VERTICAL
Vertical shading device.
69 SHADING DEVICES - VERTICAL
70 SHADING DEVICES - VERTICAL
MS1525:2007 Table 6
If R2 falls between increments, adopt the next larger ratio.
If R2 is below 0.30, SC2 = 1.
If R2 > 2.00, SC2 values shall be the same as R2 is between 1.30 and 2.00.
71 SHADING DEVICES - VERTICAL
72 SHADING DEVICES - EGGCRATE
Eggcrate Shading Devices
MS1525:2007 Table 7
73 SHADING DEVICES - EGGCRATE
WHAT IS WRONG WITH THIS DIAGRAM?
75 THERMAL VALUES OF BUILDING MATERIALS
Heat flows when outside
temperature is higher then
inside temp. The thermal
property of material at
building envelope are
measured by its thermal
transmissivity
value.
The
inverse
of
transmissivity
is
resistivity. The thermal
property of building
material will be an
factor
in
building
energy.
76 THERMAL VALUES OF BUILDING MATERIALS
Normal Brick Wall
Normal Brick Wall External
Component (outside to inside) Thickness Conducitvity Resistance
mm
w/(m.K)
T/C
Outside Surface Resistance
0.044
0.036
External Plaster
20
0.55
Bricks
115
0.807
0.235
Internal Plaster
20
0.55
0.036
Inside Surface Resistance
0.120
Total Thermal resistance
0.472
U-value (W/m2K)
2.637
Conductivity of common brick walls:
(a) 115mm clay bricks, U=2.6 W/m² °K
(b) 230mm clay bricks, U=1.9 W/m² °K
(c) 115mm aerated bricks, U=2 W/m² °K
(d) 230mm aerated bricks, U=1.3 W/m² °K
Conductivity of cavity brick walls:
(a) 2x115mm clay bricks with , U=1.4 W/m² °K
77 ALPHA VALUE OF SURFACE
Alpha
value
of
surface
measures
the
impact
of
surface due to its absorption
of solar radiation. A ‘stronger’
color will have a higher alpha
value. Alpha value will directly
cause the temperature of a
surface to rise.
78 ALPHA VALUE OF SURFACE
SRI =
Roof Surface Temperature =
SRI =
Roof Surface Temperature =
86
49°C
27
70.7°C
79 GLAZING THERMAL VALUES
Glazing Properties
1. Visible light transmittance % of
visible light passing through
2. Visible reflectance; % of visible
light reflected
3. SHGC (Solar Heat Gain Coeff)
or SC (Shading Coeff); ratio of
solar incident heat to solar
heat transmitted.
80 GLAZING THERMAL VALUES
Glazing Properties
1. Visible light transmittance % of visible light passing through
2. Visible reflectance; % of visible light reflected
3. SHGC (Solar Heat Gain Coeff) or SC (Shading Coeff); ratio of
solar incident heat to solar heat transmitted.
4. U Value; heat transfer property due to outdoor/indoor temp.
difference – W/M² - °K
5. R-Value is resistance to heat transfer = 1/U.
6. UV Light Transmittance; % of UV lights passing through.
7. Spectral Selectivity: Ability to react selectively to different
wavelengths of light.
8. Glazing Colour: visible light filter affecting colour/tint of glaze.
9. Sound Transmission: ability to transmit sound.
81 GLAZING THERMAL VALUES
Types of Glass
There are three generic low solar heat gain glass types in used in Green
Building in the market today:
1. High Performance Float Glass; low U and SC Value
2. Tinted Glass
3. Low-E Glass
82 GLAZING THERMAL VALUES
Types of Low-E Glass
There are three generic low-e types in use in the market today:
1. High Solar Gain Low-E
2. Low Solar Gain (Solar IR Absorbing) Pyrolytic Low-E
3. Low Solar Gain (Solar IR Reflecting) Sputtered Silver Low-E
The 1st type of high solar gain low-e is not suitable for tropical climate use
because it is meant to allow solar radiation to be transmitted into the building
and then trapping it within the building to heat it up. This type of low-e glazing
is suitable for cold climates where heating is the predominant energy used in
a building.
The 2nd and 3rd type of low-e (Solar IR absorbing and reflecting) is perfect
for a tropical climate such as Malaysia’s because it stops the solar radiation
on the glazing itself by absorbing it or reflecting and reradiating it back
outside.
83 GLAZING THERMAL VALUES
Single Glazing Low-E
These are hard coated metallic coatings on the surfaces of glazing that can
be exposed to the indoor climate. The metallic coating on the inside surface
reduces the emissivity of the glazing by 70% to 80%, thereby reducing the
heat that is radiated into the internal spaces, while allowing heat to be
radiated back outdoors. This glazing will provide better comfort conditions for
the building occupants due to its lower radiant heat and will indirectly allow
the airconditioning temperature to be raised to maintain comfortable
conditions. It is also important to note that adding low-e to single glazing only
lowers the SHGC effectively if it is on a tinted glass or the coating has a heat
absorbing layer. It is not difficult to find single glazing low-e products with a
LSG between 1.0 and 1.3.
Double Glazing Low-E
These are soft coated metallic coatings on the surfaces of glazing that cannot
be exposed. These coatings have to be protected in between the glazing.
These metallic coatings on the inside surface reduces the emissivity of the
glazing by 95% or more, thereby reducing the heat that is radiated to the
internal spaces.
84 GLAZING THERMAL VALUES
Case calculation
Reducing the amount of windows(glazing) on building façade).
85 GLAZING THERMAL VALUES
Case calculation
Reducing the Solar Heat Gain Capacity (U value) of glazing. .
87 DAYLIGHTING
MS1525:2007 Clause 4.4
Conventional and innovative
daylighting systems that
collect, transport, and
distribute light deep into
buildings that reduce the need
for artificial lighting are
recommended.
88 DAYLIGHTING – DAYLIGHT FACTOR
MS1525:2007 Clause 4.4
Conventional and innovative daylighting systems that
collect, transport and distribute light deep into buildings
and systems that reduce the need for artificial lighting are
recommended.
The simplest form of description of daylight distribution
is Daylight Factor, DF where
DF = (Internal Illuminance/External Illuminance) x 100%
Refer MS1525:2007 Table 1
89 DAYLIGHTING – DAYLIGHT FACTOR
MS1525:2007 Table 1
Zone
DF (%)
Distribution
Very bright
>6
Thermal and glare problems
Bright
3-6
Good (Not good, glare)
Average
1-3
Fair
(Good)
Dark
0-1
Poor
(Fair)
Based on Malaysian data, the average Daylight level
between 10am and 4pm is 30,000 lux.
Thus, a suggested DF of 1.5 = 450 lux (Fair);
a DF of 4.5 = 1,350 lux (Very very bright!)
90 DAYLIGHTING – LIGHT SHELVES
LIGHT SHELVES
with horizontal shading devices
91 DAYLIGHTING – LIGHT SHELVES
Light
shelf
ceiling
2m
4m
6m
92 DAYLIGHTING – LIGHT SHELVES
OUTSIDE
INSIDE
A. No lightshelf
and no louvres
OUTSIDE
INSIDE
B. External lightshelf
and no louvres
93 DAYLIGHTING – LIGHT SHELVES
OUTSIDE
INSIDE
C. With lightshelf
and louvres
OUTSIDE
INSIDE
D. Lightshelf tilted at 30o
and without louvres
94 DAYLIGHTING – LIGHT SHELVES
OUTSIDE
INSIDE
E. Lightshelf tiled at 30o
and with louvres
OUTSIDE
INSIDE
F. With outer and internal
lightshelves
95 DAYLIGHTING – LIGHT SHELVES
6
5.7m
4.9
4.8
5
5.0
3.9
3.7
4
Based on DF of
1.0%, ie approx
300 lux
3
2
1
0
A
Glare
risk
B
C
D
E
F
Preferred
96 DAYLIGHTING – LIGHT PIPES
98 NATURAL VENTILATION
MS1525:2007
Clause 4.6
Natural ventilation
is the use of the
natural forces of
wind and
buoyancy……to
ventilate internal
spaces and provide
thermal comfort
with reduced
energy.
99 NATURAL VENTILATION
100 CONCLUSION – FAÇADE DESIGN
MS1525:2007 Clause 4.5
The building envelope should be
designed to provide an
integrated solution for the
provision of minimizing heat
gain, daylight control, moisture
management systems, view and
passive & active solar energy
collection.
SEMINAR ON PASSIVE & ACTIVE DESIGN
FOR E NERGY E FFICIENT B UILDINGS
3 October 2014
Holiday Inn Resort, Penang
Thank you
h t t p : / / w w w . j k r. g o v. m y / b s e e p /