CLIMATE AND HUMAN COMFORT
COURSE:AR6303
CLIMATE AND BUILT ENVIRONMENT
Ar.Gayathri Kalyanasundaram
ENERGY – WHAT IT IS?
• Everything that we can see, touch and
sometimes even think is associated with
energy.
• It is easier to describe its manifestations.
• Boiling, Moving, even thinking
THE ENERGY ISSUE
• The amount of energy expended cannot be
more than the amount of energy there was to
begin with.
• Basically, energy can change its
forms, but the total amount of
energy remains.
TYPES OF ENERGY
Energy can be divided into two types:
Renewable energy and
Nonrenewable energy.
Renewable energy includes Nonrenewable energy includes
• biomass energy, • oil,
• solar energy, • natural gas,
• wind energy, • coal and
• geothermal energy, heat • nuclear energy
produced by our earth
• hydro energy, and
• tidal energy.
Energy can be divided into two types:
Renewable energy and
Nonrenewable energy.
Renewable energy is Non-renewable energy is
energy generated from energy, taken from "finite
natural resources such as resources that will
sunlight, wind, rain, tides, eventually dwindle,
and geothermal heat, becoming too expensive
which are renewable or too environmentally
(naturally replenished). damaging to retrieve“.
What Is Energy EFFICIENCY?
A building or a system becomes energy efficient
when it makes GOOD use of energy.
i.e., Energy efficiency is a measure of how well a
system is using energy.
This is expressed as η (pronounced as eta)
η = Output / Input
The measure is a percentage value varying from
0% to 100%
Importance of Building Energy Efficiency
• Buildings are significant users of energy and building
energy efficiency is a high priority in many countries.
Efficient use of energy is important since global
energy resources is finite and power generation
using fossil fuels (such as coal and oil) has adverse
environmental effects.
• The potential for energy savings in the building sector
is large.
BUILDING ENERGY EFFICIENCY IN HISTORY
Indigenous and vernacular building at its best is
a direct expression of adaptation to climate
and to constraints of resources…
Climate and Material limitations have not
prevented building designers from evolving
solutions of great craft and elegance.
Lets review a few historic examples -
COURT YARDS OF CHETTINADU HOUSING
In Chettinad houses the axis runs
parallel to the courtyard so that there
is an uninterrupted passage of doors
from the main to the back door.
Stack effect of the Kerala Housing
The roofs in the Kerala
houses were also performing
the ventilation stack effect as
there was a ventilator
incorporated with the roof.
The haveli or balcony which is a wind inlet in the first floor of a merchant
house in Rajasthan.
Highly ornate pillars
and stone trellis work keeps
the sun out whilst
providing natural ventilation.
Vav well or stepped well in Gujarat which was a
drinking water source and also a meeting place during
summers in Gujarat
“The vavs or baolis (step-wells) of
Gujarat consist of two parts: a
vertical shaft from which water is
drawn and the surrounding inclined
subterranean passageways,
chambers and steps which provide
access to the well.
The galleries and chambers
surrounding the well became cool,
quiet retreats during the hot
summers”
These stepped wells are also a social
phenomenon with many gatherings
Step wells
The thinnai was the outdoor
living room with in-built seating
and with generally a sloped roof
on top designed entirely for day
use when the temperature got
unbearable inside with little air
movement.
It was also a place where
vendors brought in the goods
and sold it to the household, a
meeting space for friends and
the most comfortable place for
an afternoon nap.
CLIMATE CLASSIFICATION IN TROPICS
CLIMATIC ZONE – KOPPEN SourceInternational
CLASSIFICATION Borders: University of
Texas map library[1]-
India Political map 2001
Disputed Borders:
University of Texas map
library[2]-
China-India Borders-
Eastern Sector 1988 &
Western Sector 1988,
Kashmir Region 2004[3].
State and District
boundaries: Census of
India[4]-
2001 Census State Maps
Survey of India Maps.
Other sources:
US Army Map Service,
Survey of India Map Expl
orer
, Columbia University
Map specific sources:
india_climate_map.jpg
.Date2007
AuthorSaravask, based
on work by Planemad and
• The Köppen climate classification is one of the most
widely used climate classification systems.
• The system is based on the concept that native
vegetation is the best expression of climate.
• Thus, climate zone boundaries have been selected with
vegetation distribution in mind.
• It combines average annual and monthly temperatures
and precipitation, and the seasonality of precipitation.
Tropical semi-arid steppe climate
• This region is a famine prone zone with very unreliable rainfall which
varies between 40 to 75 cm annually. rainfall occurs in June to Sep
also occurs in the months of October and November. The coldest
month is December but even in this month the temperature remains
between 20°C and 24°C. The months of March to May are hot and
dry with mean monthly temperatures of around 32°C. The vegetation
mostly comprises grasses with a few scattered trees due to the
rainfall. Hence this area is not very well suited for permanent
agriculture.
Tropical wet and dry climate
• Winter and early summer are long dry periods with temperature
above 18°C. Summer is very hot and the temperatures in the interior
low level areas can go above 45°C during May. The rainy season is
from June to September and the annual rainfall is between 75 and
150 cm. Only Tamil Nadu receives rainfall during the winter months
of October to December.
Basic principles of energy efficiency …
BASIC
CLIMATE
PRINCIPLE 1 - CLIMATE
Climate has a major effect on building performance and energy
consumption. Energy-conscious design requires an
understanding of the climate.
• Buildings will respond to the natural climatic environment
in two ways:
– Thermal response of the building structure (heat transfer and
thermal storage).
– Response of the building systems (such as HVAC and lighting
systems).
– To gain the maximum benefits from the local climate, building
design must "fit" its particular climate.
BASIC PRINCIPLE 2
– SITE PLANNING
• Site elements to be considered include:
– Topography - slopes, valleys, hills and their surface conditions.
– Vegetation - plant types, mass, texture.
– Built forms - surrounding buildings and structures.
– Water - cooling effects, ground water, acquifiers.
• Aspects of architectural planning which will affect thermal and energy
performance of buildings are:
• Site selection
• Layout
• Shape
• Spacing
• Orientation
• Mutual relationship
BASIC PRINCIPLE 3
– BUILDING ENVELOPE
• Building Envelope
Elements of the building envelope (= "protective skin"):
– Walls (exterior)
– Windows
– Roof
– Underground slab and foundation
Three factors determining the heat flow across the building
envelope:
– Temperature differential
– Area of the building exposed
– Heat transmission value of the exposed area
Use of Eco-friendly materials
Materials with low embodied
energy
• Materials that contain
recycled content or are
recyclable
• Local or rapidly renewable
material
• Non-toxic/Low Toxic
Materials
Fly ash, slag cement
BASIC PRINCIPLE 3 – BUILDING ENVELOPE
• The use of suitable thermal mass and thermal
insulation is important for controlling the heat
flow. Remember, the envelope components will
respond "dynamically" to changing ambient
conditions.
• Some people also consider the "embodied energy"
(include energy for producing and transporting) of
building materials when making the selection.
The roof of the Kabra
house in Jaipur
which recirculates
waste water through
the roof slab does
not require
conventional cooling
– it is a passive
cooled house
BASIC PRINCIPLE 4 – BUILDING SERVICE
SYSTEMS HVAC
Heating, ventilation and air-conditioning (HVAC) systems
are installed to provide for occupant comfort, health and safety. They
are usually the key energy users and their design is affected by
architecture features and occupant needs.
While being energy efficient, HVAC systems should have a degree of
flexibility to allow for future extensions and change.
To achieve optimum energy efficiency, designers should evaluate:
• Thermal comfort criteria
• Load calculation methods
• System characteristics
• Equipment and plant operation (part-load)
BASIC PRINCIPLES 4 – HVAC SYSTEMS
HVAC SYSTEMS
• Energy efficiency of many HVAC sub-systems include air systems,
water systems, central cooling and heating plants.
Energy efficient HVAC design now being used or studied include:
• Variable air volume (VAV) systems to reduce fan energy use.
• Outside air control by temperature/enthalpy level.
• Heat pump and heat recovery systems
• Building energy management and control systems.
• Natural ventilation and natural cooling strategies.
Thermal storage systems (such as ice thermal storage) are also being
studied to achieve energy cost saving. Although in principle they will
not increase energy efficiency, they are useful for demand-side
management.
BASIC PRINCIPLE 4 –BUILDING SERVICE
SYSTEMS-LIGHTING
Lighting systems
SYSTEMS
is another key energy user and additional cooling energy will be required to
remove the heat generated by luminaires.
Energy efficient lighting should ensure that:
– Illumination is not excessive.
– Switching is provided to turn off unnecessary light.
– Illumination is provided in an efficient manner.
– General design strategies for lighting design:
– Combination of general and task lighting.
– Electric lighting integrated with daylight.
– The use of energy efficient lamps and luminaires.
– Use light-coloured room surfaces.
• Other building services systems consuming energy include:
– Electrical installations
– Lifts and escalators
– Water supply systems
– Town gas supply system
BASIC PRINCIPLE 5 – PASSIVE COOLING
PASSIVE COOLING
• Passive systems - internal conditions are modified as a result
of the behaviour of the building form and fabric.
Strategies for passive heating and cooling:
Cold winters - maximise solar gain and reduce heat loss.
• Hot summers - minimise solar gain and maximize heat
removal.
• Correct orientation and use of windows.
• Appropriate amounts of thermal mass and insulation.
• Provision for ventilation (natural).
Ecological landscaping
• Based on knowledge of topography, drainage,
geology as well as flora and fauna of the
region
• Bo-biologue: passive design with trees
• •Protection of soil and vegetation
• Including water shed, waste and water
management
BASIC PRINCIPLE 6 - SUNCONTROL
SUN CONTROL
Strategies for shading and sun control:
External projection (overhangs and side fins).
• External systems integral with the window frame or attached
to the building face, such as lourves and screens.
• Specially treated window glass, such as heat absorbing and
reflecting glass.
• Internal treatments either opaque or semi-opaque, such as
curtains and blinds.
BASIC PRINCIPLE 7 – DAY LIGHTING
DAYLIGHTING
• Daylight can be used to augment or replace electric
lighting. Efficient daylighting design should consider:
• Sky conditions
• Site environment
• Building space and form
• Glazing systems
• Artificial lighting systems
• Air-conditioning systems
BASIC PRINCIPLE 7 – DAY LIGHTING
DAYLIGHTING
The complex interaction between daylight, electric lights and HVAC should be
studied carefully in order to achieve a desirable solution.
Advanced window technologies have been developed to
change/switch the optical properties of window glass so as to
control the amount of daylight. There are also innovative
daylighting technologies now being investigated:
• Light pipe systems
• Light shelves
• Mirror systems
• Prismatic glazing
• Holographic diffracting systems
BASIC PRINCIPLE 8 – ACTIVE SYSTEMS
7. ACTIVE SYSTEMS
• Solar thermal systems (active solar) provide useful heat at a low
temperature. This technology is mature and can be applied to hot
water, space heating, swimming pool heating and space absorption
cooling.
• The system consists of solar collectors, a heat storage tank and water
distribution mains. An integrated collector storage system has also
been developed recently to eliminate the need for a separate storage
tank.
BASIC PRINCIPLE 8 – ACTIVE SYSTEMS
7. ACTIVE SYSTEMS
Photovoltaic (PV) systems convert sunlight into electricity using a
semi-conductor device.
The main advantages of PV systems include:
• Reasonable conversion efficiencies (6-18%).
• PV modules can be efficiently integrated in buildings, minimising
visual intrusion.
• Their modularity and static character.
• High reliability and long lifetime.
• Low maintenance cost.
Definitions
The ecological footprint is a measure of human
demand on the Earth's ecosystems
It compares human demand with planet Earth's
ecological capacity to regenerate.
It represents the amount of biologically
productive land and sea area needed to
regenerate the resources a human population
consumes and to absorb and render harmless
the corresponding waste.
• Using this assessment, it is possible to estimate how
much of the Earth (or how many planet Earths) it would
take to support humanity if everybody lived a given
lifestyle.
• For 2005, humanity's total ecological footprint was
estimated at 1.3 planet Earths - in other words, humanity
uses ecological services 1.3 times as fast as Earth can
renew them
• Every year, this number is recalculated - with a three
year lag due to the time it takes for the UN to collect and
publish all the underlying statistics.
Definitions
Sustainable architecture
is a general term that describes environmentally-conscious
design techniques in the field of architecture.
More importantly – It is about adaptable structures that can be
“recycled” many times over the course of its useful life
Sustainable architecture seeks to minimize the negative
environmental impact of buildings
– by enhancing efficiency
– and moderation in the use of materials, energy, and development
space.
Most simply, the idea of sustainability, or ecological design, is to ensure
that our actions and decisions today do not inhibit the opportunities of
future generations.
This term can be used to describe an energy and ecologically conscious
approach to the design of the built environment
K2 sustainable apartments in
Windsor, Victoria, Australia by
Hansen Yuncken (2006) features
passive solar design, recycled and
sustainable materials, photovoltaic
cells, wastewater treatment, rainwater
collection and solar hot water.
The passivehaus
standard combines a
variety of techniques and
technologies to achieve
ultra-low energy use.
Definitions
Green Architecture - Also known as sustainable
design, green architecture is simply a method
of design that minimizes the impact of
building on the environment.
The concepts about green architecture can
generally be organized into several areas of
application. These areas include
sustainability, materials, energy efficiency,
land use, and waste reduction.
• Earth Architecture
Buildings made with earth are economical,
energy-saving, environmentally-friendly, and
sustainable. Earth architecture includes
adobe, cob, straw, and compressed earth
blocks (CEBs).
Zero waste architecture
• A completely zero-carbon, zero-waste city from its very
beginning, with a solar power plant providing energy to
the construction process.
• Ex. Masdar City(project) - will rely on other renewable
energy sources, such as wind energy, geothermal power
and hydrogen power.
• Wastes will be reduced to zero:
– waste water will be reused,
– biological wastes will be used to create soil,
– and industrial wastes will be recycled and re-used.
– On top of that, cars will be banned, forcing people to use mass
public transport and Personal Rapid Transit.
Masdar City: zero-waste, zero-carbon planned city in Abu Dhabi
• Bio Climatic Architecture
– architecture that designs to
take advantage of climate and
environmental conditions.
– Bioclimatic architecture
concerns itself with climate (or
perception of climate) as a
major contextual generator,
and with benign environments
using minimal energy as its
target.
LECTURE REFERENCES
1. ENERGY-EFFICIENCT BUILDINGS, Edited by,
Walter F. Wagner, JR.,AIA
2. http://www.arch.hku.hk/~cmhui/teach/6535
6-Xc.htm
3. http://en.wikipedia.org/wiki/Non-
renewable_energy
4. http://en.wikipedia.org/wiki/Renewable_en
ergy
5. http://www.bionomicfuel.com/
