155 مبادرة #تواصل_تطوير المحاضرة ال 155 من المبادرة أ. د. / أحمد عبدالحميد أستشاري واستاذ إصلاح وتصميم المباني الاثرية بعنوان " Envelope Design in Hot Climate التصميم البيئي في الأجواء الحارة " وذلك يوم الإثنين 04 ابريل 2022 التاسعة والنصف مساء توقيت القاهرة العاشرة والنصف مساء توقيت مكة المكرمة و الحضور عبر تطبيق زووم https://us02web.zoom.us/meeting/register/tZUrf-2rrj8rEtIBL31QooIwoarmnQ60GHKY علما ان هناك بث مباشر للمحاضرة على القنوات الخاصة بجمعية المهندسين المصريين ونأمل أن نوفق في تقديم ما ينفع المهندس ومهمة الهندسة في عالمنا العربي والله الموفق للتواصل مع إدارة المبادرة عبر قناة التليجرام https://t.me/EEAKSA ومتابعة المبادرة والبث المباشر عبر نوافذنا المختلفة رابط اللينكدان والمكتبة الالكترونية https://www.linkedin.com/company/eeaksa-egyptian-engineers-association/ رابط قناة التويتر https://twitter.com/eeaksa رابط قناة الفيسبوك https://www.facebook.com/EEAKSA رابط قناة اليوتيوب https://www.youtube.com/user/EEAchannal رابط التسجيل العام للمحاضرات https://forms.gle/vVmw7L187tiATRPw9 ملحوظة : توجد شهادات حضور مجانية لمن يسجل فى رابط التقيم اخر المحاضرة.

2. 1

3. Contents
2
1. Introduction to Sustainability and Green Technology
2. Building Sustainability
3. Sustainability and the Building Envelope
4. Sustainable Design of the Building Envelope
5. Concluding Remarks

4. Introduction
to
Sustainability
and Green
Technology
3

5. What is Sustainability?
4
Sustainability is the capacity to endure. For humans,
sustainability is the long-term maintenance of
responsibility, which has environmental, economical,
and social dimensions, and encompasses the
concept of resource use.
In ecology, sustainability describes how biological
systems remain diverse and productive over time, a
necessary precondition for the well-being of humans
and other organisms.

6. What is
Sustainability?
(Continued)
• Sustainability represents the optimum
interaction between the three spheres
of sustainability
• The environment
• Society
• The economy

7. Sustainable Engineering
6
Sustainable engineering is the process of using
energy and resources at a rate that does not
compromise the natural environment, or the ability
of future generations to meet their own needs.
Sustainability recognizes the need for us to move
away from using resources in an inefficient and
wasteful way
GO GREEN &HELP THE PLANET

8. Areas of
Sustainable
Demands
The following are areas in which
sustainability is demanded:
– Energy use
– Climate protection
– Health
– Food
– Economic innovations
– Urban development

9. Building
Sustainability
8

10. What is a Green Building?
• A green building, also known as a
sustainable building, is a structure that is
designed, built, renovated, operated, or
reused in an ecological and resource-
efficient manner.
• Green buildings are designed to meet
certain objectives such as protecting
occupant health, improving employee
productivity, using energy, water, and other
resources more efficiently, and reducing the
overall impact to the environment.
9

11. Radiant Floor
Heating
Summer
Sun
PV Powered
Exhaust Fan
Winter
Sun
Natural
Ventilation
Rainwater
Collection
Natural
Ventilation
Natural
Daylight
Natural
Daylight
Passive
Solar
Photovoltaics
23kw Array
Example of a Green
Building
10

12. Elements of
Green
Buildings
1. Selection of an environmentally
sustained site
2. Efficient use of water resources
3. Conservation of energy, usage of
renewable resources and protection the
environment
4. Conservation of building materials,
reduction of waste and sensible usage of
resources
5. Protection and enhancement of indoor
environmental quality

13. Why Build Green?
12
The built environment has a vast impact on the natural
environment, human health, and the economy. By adopting green
building strategies, we can maximize both economic and
environmental performance.
Green construction methods can be integrated into buildings at any
stage, from design and construction, to renovation and
deconstruction.
However, the most significant benefits can be obtained if the design
and construction team takes an integrated approach from the
earliest stages of a building project

14. Environmental
Benefits
• Enhance and protect biodiversity and
ecosystems
• Improve air and water quality
• Reduce waste streams
• Conserve and restore natural resources

15. Economic
Benefits
• Reduce operating costs
• Create, expand, and shape markets for
green product and services
• Improve occupant productivity
• Optimize life-cycle economic
performance

16. Social Benefits
• Enhance occupant comfort and health
• Heighten aesthetic qualities
• Minimize strain on local infrastructure
• Improve overall quality of life

17. Elements of
Green
Buildings
• Siting
• Energy efficiency
• Material efficiency
• Water efficiency
• Occupant health and safety
• Building operation and maintenance

18. Siting
• Start by selecting a site well suited to
take advantage of mass transit.
• Protect and retain existing landscaping
and natural features. Select plants that
have low water and pesticide needs,
and generate minimum plant
trimmings. Use compost and
mulches. This will save water and time.
• Recycled content paving materials,
furnishings, and mulches help close
the recycling loop.

19. Energy
Efficiency
• Most buildings can reach high energy
efficiency levels using the following
strategies contribute to this goal.
• Passive design strategies can dramatically
affect building energy performance. These
measures include building shape and
orientation, passive solar design, and the
use of natural lighting.
• Develop strategies to provide natural
lighting. Studies have shown that it has a
positive impact on productivity and well
being.

20. ….Energy
Efficiency
• Install high-efficiency lighting systems with
advanced lighting controls. Include motion
sensors tied to dimmable lighting
controls. Task lighting reduces general
overhead light levels.
• Use a properly sized and energy-efficient
heat/cooling system in conjunction with a
thermally efficient building shell. Maximize
light colors for roofing and wall finish
materials; install high R-value wall and
ceiling insulation; and use minimal glass on
east and west exposures.
• Minimize the electric loads from lighting,
equipment, and appliances.

21. …Energy
Efficiency
• Consider alternative energy sources
such as photovoltaics and fuel cells
that are now available in new products
and applications. Renewable energy
sources provide a great symbol of
emerging technologies for the future.
• Computer modeling is an extremely
useful tool in optimizing design of
electrical and mechanical systems and
the building shell.

22. Material
Efficiency
• Select sustainable construction
materials and products by evaluating
several characteristics such as reused
and recycled content, zero or low off
gassing of harmful air emissions, zero
or low toxicity, sustainably harvested
materials, high recyclability, durability,
longevity, and local production.
• Such products promote resource
conservation and efficiency. Using
recycled-content products also helps
develop markets for recycled materials
that are being diverted from
California's landfills, as mandated by
the Integrated Waste Management
Act.

23. …Material
Efficiency
• Use dimensional planning and other
material efficiency strategies. These
strategies reduce the amount of
building materials needed and cut
construction costs.
• For example, design rooms on 4-
foot multiples to conform to
standard-sized wallboard and
plywood sheets.
• Reuse and recycle construction and
demolition materials. For example,
using inert demolition materials as a
base course for a parking lot keeps
materials out of landfills and costs
less.

24. …Material
Efficiency
• Require plans for managing materials
through deconstruction, demolition,
and construction
• Design with adequate space to
facilitate recycling collection and to
incorporate a solid waste management
program that prevents waste
generation

25. Achieving
Material
Sustainability
• Use local, natural, and sustainable
materials
• Energy efficiency
• Use recyclable and reusable materials
• Minimize the use of chemical
treatments
• Take care to store the construction
materials to reduce the waste and
damage
• Protect on site dust, air and water
pollution
• Minimize waste going to landfill
• Identify waste or demolition products
that can be recycled or reused

26. Examples of
Green
Materials
• Earth-rammed/mud/adobe residential
buildings
• Aerated cellular concrete (ACC)
/Aerated Autoclaved Concrete (AAC)
precast concrete panels.
• Recycled brick/concrete
• Cob ( earth + straw)
• Wood

27. Rammed-Earth
Buildings
• Rammed-earth or
Adobe or mud buildings
is a good example of
green sustainable
energy-efficient
buildings in hot climate
26

28. Civano community in Tucson, Arizona, is an early (1990s) example of a
New Urbanist walkable, green home development with clear energy
efficiency and water conservation.
27

29. Rammed-Earth
Construction
• Rammed-earth is a technique for
building walls using raw
materials of earth, chalk, lime
and gravel. It is an ancient
building construction method
that has seen a revival in recent
years as people seek more
sustainable building materials
and natural building methods.
• Rammed-earth walls are simple
to construct, noncombustible,
thermally massive and durable.
• Compressive strength up to 4
MPa
28

30. Adobe
Construction
• The construction of the entire
wall begins with a temporary
wood formwork to act as a
mold for the desired shape
and dimensions of each wall
section. Damp material is
poured in to a depth of 10-25
cm and then compacted to
around 50% of original height.
Hand ramming pole or
powered tampers are used.

31. Autoclaved Aerated
Concrete
• Aerated Cellular concrete (ACC) also
known as Autoclaved Aerated Concrete
(AAC) is a lightweight precast concrete
made of cemnetitious paste of cement
and fine sand with a multitude of
micro/macroscopic discrete air cells
uniformly distributed throughout the
mixture to create a lightweight concrete.
• ACC is cured under elevated pressure
inside special kilns called autoclaves
30

32. AAC/ACC Products
31

33. AAC Masonry
AAC is a lightweight masonry product (25-
30 pcf) with superior insulation
characteristics, UL rated for fire safety,
susceptibility to pest, strength and
environmental impact
AAC sustainable homes protects the
environment by reducing energy
requirements and employing recycled
material
This is a promising step towards green and
sustainable masonry buildings
32

34. Building with
LEED?
• The Leadership in Energy and
Environmental Design Green Building
Rating System (LEED) is a voluntary,
market-based rating system for
defining what elements make a
building 'green' and to quantify how
'green' a building is in comparison to
another building.
• LEED is based on accepted energy and
environmental principles and strikes a
balance between known effective
practices and emerging concepts. It
encourages a whole building approach
over a building's life cycle that guides a
collaborative and integrated design
and construction process

35. LEED
Objectives
LEED was developed to define "green
building" by establishing a common
standard of measurement; promote
integrated, whole-building design
practices, raise awareness of green
building benefits and transform the
building market.

36. How does
LEED Work?
• LEED provides a menu of green
building measures in five
environmental categories:
• ◦ Sustainable Sites
• ◦ Water Efficiency
• ◦ Energy and Atmosphere
• ◦ Materials and Resources
• ◦ Indoor Environmental Quality

37. LEED
Certification
• After a building has been completed
and the project team has submitted
the project documentation along with
the appropriate fee, the Council will
certify the project as LEED Certified,
Silver, Gold or Platinum based on the
total number of points earned on a
menu of green building measures.

38. LEED Points
• LEED is flexible enough to apply to all
project types including healthcare
facilities, schools, homes and even
entire neighborhoods.
• Within each of the LEED credit
categories, projects must satisfy
prerequisites and earn points. The
number of points the project earns
determines its level of LEED
certification.

39. LEED Main
Credit
Categories
• Sustainable sites credits encourage
strategies that minimize the impact on
ecosystems and water resources.
• Water efficiency credits promote
smarter use of water, inside and out, to
reduce potable water consumption.
• Energy & atmosphere credits
promote better building energy
performance through innovative
strategies.
• Materials & resources credits
encourage using sustainable building
materials and reducing waste.
• Indoor environmental quality credits
promote better indoor air quality and
access to daylight and views.

40. Points for
Certification
• At least 26 points are required for LEED
certification. Silver, gold, and platinum
levels are also available.
• Credit Category Points Available
• Sustainable Sites 14
• Water Efficiency, Energy and
Atmosphere 17
• Materials and Resources 13
• Indoor Environmental Quality 17
• Total Core Points 64
• Innovation and Design Process 5

41. LEED
Certification
Levels
• Certified 26 – 32 Points
• Silver 33- 38 Points
• Gold 39 - 51 Points
• Platinum 52 - 69 Points

42. The Center for Neighborhood Technology, Chicago, Illinois, designed by Farr Associates,
a LEED Platinum certified project, shows some of the elements that make up a green
building project. Energy use is estimated to be 50% less than a standard building.
Native garden
includes rain
garden and
rain barrels
Bike
parking
Thermal ice
storage system
Additional
windows
for more
day lighting
Reflective
ENERGY STAR®
rooftop covering
Efficient cooling
system
Limited Parking
(15 spaces for
60 employees)
Permeable
parking lot
Skylights
Designated car-
share, car-pool and
hybrid parking
Proximity to
public transit
Additional green
& open space
41

43. Sustainability
and the
Building
Envelope
42

44. Significance
• For sustainable design ,
construction and of a facility,
there is an especially important
interface between the indoor
and the outdoor environments,
that of the building envelope.
• The building envelope, by
definition, is enclosure,
barrier and separator of the
outdoor environment and the
desired indoor environment 43

45. … Significance
Therefore, the building envelope
plays an important part in recent
increased commitment to
environmental stewardship and
conservation, and results in an
optimum balance of cost,
environmental, social and human
benefits while meeting the mission
and the function of the building.
44

46. Fundamental Principles for Sustainable
Building Envelope
45
energy use
Optimize
greener materials
Use
indoor environmental quality
Enhance
operation and maintenance principles
Optimize

47. Optimize energy use
• Heat gain/loss through the
building envelope is over 80%
of the total building loss.
• Windows and walls are most
significant and should have
higher thermal resistance.
46

48. • Walls with different thermal mass and
equal R values do not have the same
thermal response (say over 24 hours
period)
• Masonry walls, compared to lighter
walls, provide more uniform and
comfortable interior temperature
• Mass has a significant effect on
heating and cooling loads. Heavy
walls result in less fluctuation in
interior temperature and less demand
on h/c loads
•
47
Effect of Thermal Mass on
Energy Efficiency of the
Building Envelope

49. 48
Loadbearing Concrete
Masonry: An Energy
Efficient Building Envelope
Because of its thermal mass,
durability and elimination of
plastering and paint masonry
offers a green, sustainable
solution to building
construction.
Units can also be insulated to
improve thermal efficiency

50. Fare-Face Mortared CMU
Exterior Applications

51. Innovative CMU- Thermal Efficiency
• Insulated CMU
• AAC Blocks

52. Thermal Performance of
Insulated Loadbearing
Concrete Masonry- Toshka
Project in Egypt
51
Vertical Reinforcement
Utilities (pipe lines,cabels,..etc)
Horizontal Reinforcement
Thermal Insultaion
Block (b)

53. — Lower U value [ 0.2-1.2 ]
— Lower solar heat gain
coefficient SHGC [0 -1.0]
— High visible transmittance VT
[0.0-1.0]
— Lower air leakage AL [0.1-0.3]
— Higher surface condensation
resistance CR [1-100]
52
Characteristics of High
Rating Efficient Windows

54. Certain types of smart glass allow
users to control the amount of light
and thereby heat transmission.
When activated ( electric current)
the glass changes from transparent
to translucent, partially blocking
light while maintaining a clear view
through the glass.
53
Electrochromic Switchable
Smart Glass

55. Double skin facades offer several
advantages. They can act as buffer
zones between internal and external
conditions, reducing heat loss in
winter and heat gain in summer. In
combination with ventilation of the
space between the two facades, the
passive thermal effects can be used to
best advantage.
Natural ventilation can be drawn from the
buffer zone into the building by
opening windows in the inner façade.
The stack effect of thermal air currents
in tall buildings offers advantages over
lower buildings. This eliminates
potential security and safety problems
caused by having opening windows at
the top of tall buildings as well as wind
pressure
54
Characteristics of High
Rating Efficient Windows

56. Sustainable
Design of the
Building
Envelope
55

57. Building Envelope (Barrier) Requirements
• Durability
• Strength
• Rigidity
• Control of heat flow - insulation
• Control of air flow - air barrier
• Control of vapor flow - vapor barrier
• Control of rain penetration - screen wall
• Control of solar and other radiation
• Control of sound transmission
• Control of fire protection
• Aesthetically pleasing
• Economical requirements
56

58. Sustainable
Design
• Sustainable design should provide a
building with the following features:
• Durability
• Structurally sound - safety
• Functional-high performance
• Initial low cost
• Low maintenance cost-energy
efficient
• Aesthetically pleasing

59. Fundamental Principals for Sustainable
Building Envelope Design
58
Optimum
energy use
01
Use greener
materials
02
Enhance indoor
environmental
quality
03
Optimize
operation and
maintenance
practices
04

60. 59

61. Thermal
Response
• Thermal flow
• Effect of insulation
• Fenestration
• Effect of thermal mass
• Thermal bridging
• Thermal efficiency

62. Objective of
thermal
design
Objective: Control heat flow to:
1. Maintain comfortable indoor
conditions
2. Reduce heating/cooling loads, which
reduces operating costs
3. Control vapor
movement/condensation
4. Design to accommodate
contraction/expansion of building
materials and sealant joints
61

63. Heat Flow
Factors affecting
thermal energy flow:
• Solar radiation
• Air temperature
• Wind/air
movement
• Humidity
62

64. Thermal
Performance
• Factors affecting thermal performance:
• Air space
• Thermal mass
• Thermal resistance
• Fenestration

65. Insulation
• Thermal efficiency of insulation depends
on:
• Thermal resistance R
• Stability over time (R value dimensional
stability)
• Resistance to deterioration
• Securing attachments
• Insulation Improves the thermal
performances of building walls and roofs
by reducing both conductive heat flow
through the section and corrective heat
flow in air spaces. This results in more
comfortable indoor air temp and less
fluctuation Reduces cooling/heating loads

66. Effect of
Fenestration
on Building
Envelope
Thermal
Response
• Windows have the lowest insulation
value of any element of the building
envelope. They also permit radiant
energy to enter a space, as opposed to
conduction through the walls and roof.
Thermal radiation accounts for a large
portion of the energy in natural
sunlight.

67. Shading
• Solar control is one of the most important
measures to avoid indoor overheating and
discomfort in hot climates. It prevents direct
solar radiation from entering the building when
it is not desirable.
• Shading devices should be selected according
to the orientation of the windows.
• Shading is required to completely protect
windows all year-round. External shading
devices are more effective than internal ones
• internal shading devices are not
recommended as they trap heat on the interior
of the glass so it remains indoor, and they may
have a negative effect on natural light
conditions. A combination of exterior and
interior shading devices is recommended in
some cases to avoid glare from direct and
indirect solar radiation.
66

68. Climate
Analysis
• WUFI software
• https://wufi.de/en/software/what-is-wufi/
67

69. • Life-cycle raw material acquisition,
product manufacturing, packing
transportation, installation, use and
reuse/recycling/disposal should be
considered in choosing the material to
be use in the building envelope. In this
context, material durability and
longevity are key factors.

70. • The indoor environmental quality of a
building has a significant impact on
occupant health, comfort, and
productivity.
• Among other attributes, a sustainable
building envelope should maximize day
lighting, provide appropriate
ventilation and moisture control
(avoiding mil dew) and avoid the use of
materials that are high in volatile
Organic Component (VOC) emission

71. • Incorporating operation and
maintenance considerations into the
design of building envelope will
contribute to improved work
environment, higher productivity, and
reduced energy and resource costs.
• Designers should specify materials and
systems that simplify and reduce
maintenance cost (durable)

72. Examples of
Low
Maintenance:
Self-Cleaning
Glass
• SCG are coated with a thin transparent
layer of titanium dioxide. This coating
acts to clean the window in two stages,
using two distinct properties:
photocatalysis and hydrophilicity. In
sunlight photocatalysis causes the
coating to chemically break down
organic dirt adsorbed onto the window.
When the glass is wet by rain or other
washing water, hydrophilicity reduces
contact angles to very low values
causing the water to form a thin layer
rather than droplets and this layer
washes dirt away.

73. … Self-Cleaning Glass
Commercial example: Pilkington Active for low-
maintenance glass cleaning
72

74. Control of
Air
Movement
using Air
Barriers (AB)
• An air barrier is a system or network of
materials which prevent air movement
through a building enclosure.
• Requirements of AB:
• Air flow resistance,
• Continuity, and
• Sealing of seams, joints, edges, etc.

75. Another Example of Low
Maintenance: Use of High
Performance Sealants
1. Elasticity (movement capability)
2. Hardness
3. Substrate compatibility
4. Resistance to ultraviolet
5. Chalking
6. Dirt pickup
74

76. Green Roofs
A green roof or living roof is a roof of a
building that is partially or completely
covered with vegetation and growing
media, planted over a waterproofing
membrane. It may also include additional
layers such as root barrier and drainage
and irrigation systems.
75

77. Insulated Roofs
• Roof design and materials can reduce
the amount of air conditioning
required in hot climates by increasing
the amount of solar heat that is
reflected, rather than absorbed. This
is particularly true for low-rise
buildings since in this case the roof
constitutes a larger portion of the
total building envelope
• Green roofs reduce urban heat island
effect
76

78. Components of a Green Roof
77

79. Design
Considerations
for Green
Roofs
• Provide a drainage, aeration, water
storage barrier above the insulation
layer.
• Water leakage due to rain can cause
significant damage, mildew and poor
indoor air quality
• The extra weight of the vegetation and
the growing media should be included
in the calculation of dead load of the
roof.

80. Closing
Remarks
79
There is an urgent need for sustainable design of
building envelope in aggressive environments to
improve building performance and reduce
operating and maintenance costs. Developing a
rating system like LEED is a good start.
Building code should have provisions for
sustainable design including exterior wall
minimum thickness, high efficiency windows,
green roofs and solar panels on building roofs.
Sustainable building envelope design should be
included in undergraduate academic civil and
architectural engineering curricula to educate
future civil and architectural engineering students
on how to achieve sustainable building envelope.

81. Thank You
80

82. 81