RENAISSANCE

INTRODUCTION

A NEW STYLE OF FORTIFICATION WITH EARTH WORKS BASTIONS AND ARTILLARY RESISTANT WALL DEVELOPED.

VAST OPEN SPACES WERE LEFT AT THE CENTRE OF TOWNS FOR COMMUNITY ACTIVITIES.

GREAT EMPHASIS ON ELEVATION TREATMENT OF BUILDING ROADS CAN BE SEEN.

TRADES BROUGHT THE CONCENTRATION OF THE PEOPLE TO TOWNS SITUATED OF THE MAIN CROSS ROADS.

OWNERS OF THE LANDS SHIFTED TO THE MERCHANTS AND THE POWER OF THE FEUDAL LORDS DIMINISHED.

PRINTING PRESS WAS INVENTED AND WAYS WERE DEVISED TO IMPROVE THE SIMPLE HAND MACHINES.

GUN POWDER WAS INVEVENTED IN THE 15TH C; AND NEW TECHNIQUES OF WARFARE WERE INTRODUCED, WHICH CHANGE THE WAR STRATEGIES AND OLD FORTIFICATIONS WERE FOUND INADEQUATE.

THE CONTRAST BETWEEN THE RICH MERCHANTS AND THE POOR INCREASED AND HENCE, THE INSECURITY OF LIFE OF THE POOR ALSO INCREASED.

AS A RESULT RELIGION AGAIN BECAME VERY IMPORTANT AND THE DISPLAY AND EXHIBITIONISM WERE MANIFESTED IN THE CONSTRUCTION OF FORMAL AND MONUMENTAL BUILDINGS DRAWING UPON THE CLASSICAL HERITAGE OF ROME.

MAINLY TWO TYPES OF MANIFESTATION ARE NOTICED IN THIS PERIOD:

1.NEW TOWNS WERE FOUND IN WHICH THE CENTRAL AND THE MOST DOMINATING BUILDINGS WERE THOSE OF THE NOBLES,I.E,THE COURTS OF THE KINGS.

FOR EXAMPLE: VERSALILLES IN FRANCE, CANBERRA IN AUSTRALIA AND WASHINGTON D.C. IN U.S.A. MAJOR PARTS OF LONDON IN U.K. WAS DESIGNED BY CHRISTOPHER WREN.

CITY OF KARLSRUHE

A-PALACE
B-GARDENS
C-TOWNS
IN THE OLD MEDIEVAL TOWNS THAT EXISTED, DEVELOPMENT WAS DONE IN THE DESIGNING OF THE PUBLIC CONGREGATION PLACES LIKE SQUARES, PIAZZAS (PLAZAS).


FOR EXAMPLE: THE PIAZZA OF ST. MARKS, VIENCE.

PIAZZA OF ST. PETERS.

PIAZZA DEL POPOLO, ROME.

PLACE DES VICTORES, PARIS.

ST.PETERS PLAZA

THE DESIGN SHIFTED FROM THE ENCLOSED ARCHITECTURAL TO AN EXTENSION AND EXPANSION OF OPEN SPACES.

SEVERAL EXISTING SQUARES WERE CONNECTED BY THE TREE LINED AVENUES AS IN PARIS.

ST.MARKS PIAZZA AND ITS DEVELOPMENT




VERSAILLES IN FRANCE:

S. LOUIS XII ORDERED LE NORTE TO DESIGN THE GARDENS OF VERSAILLES.

THE SPACES CREATED WERE OF UNPARALLED PROPORTION AND A SCALE OF INCOMPREHENSIBLE SIZE.

ALL ROADS LEAD TO THE CENTRE OF TOWN I.E, TOWARDS THE PALACE, PLAZAS WERE OPEN AND LESS CONFINED OF THE COUNTRYSIDE.



DESIGN SHIFTED FROM WALL IN ARCHITECTURAL FORMS TO AN EMPHASIZED BY COLONNADES AND ENTRANCE LINED BY AVENUES.

STAR SHAPED FORTIFICATION AND A CENTRAL CORE IS IDEAL CITY.

RENAISSANCE DESIGNERS FROZE THE STREETS WHICH RADIATED FROM THE CENTRE.

SUCH DESIGN EMERGED AROUND THE MIDDLE OF THE 15TH. C; FROM THE IMAGINATION OF ALBERT.

THE BAROQUE CITY:

THE AXIAL SYSTEM PLANNING WHICH WAS INTRODUCED BY LORENZO BERNINI DURING THE RENAISSANCE PERIOD WAS DEVELOPED DURING THIS TIME.

KING LOUIS XIV ORDERED TOP REMOVE HIS PALACE FROM THE CONGESTED PARIS TO THE OPEN HUNTING GROUND OF VERSAILLES AND ORDERED TO HAVE THE AVENUES TO RADIATE OUT THIS MAGNIFICIENT PALACE.

AFTER NAPOLEON III ROSE TO POWER IN 1853, THE CITIES WERE CONGESTED WITH SLUMS AND THE CONDITION OF PARIS WAS DETERIORATING.

MECHANICAL TRAFFIC WAS TO BE INTRODUCED ON THE ROADS AND IT WAS URGENT NECESSITY TO CHECK THE HAPHAZARD GROWTH OF PARIS.

GEORGE EUGNE HAUSMANN CAME UP WITH NOVEL PLAN OF HAVING STRAIGHT AVENUES, JOINING THE IMPORTANT PLACES; BOULEVARDS WERE MADE AND SOME FORM OF BUILDING BYE-LAWS LIKE HEIGHT RESTRICTIONS WERE INTRODUCED.

THE MAIN FEATURE OF BAROQUE PLANNING WERE AS FOLLOWS:
1. AVENUES,
2. FOUNTAINS,
3. AXIS AND
4. GEOMETRY.

EXAMPLE: THE SHONE BRUNN PALACE AT GERMANY WHERE THE SIDES OF THE TREES WERE ALSO CHOPPED OFF ALONG THE ROAD TO ACHIEVE THE ‘AXIS’ OF THE DESIGN.

CONCLUSION:

THUS WE SEE THAT IN THE MEDIEVAL PERIOD, THE MAIN EMPHASIS WERE GIVEN TO THE ‘MASS’ OF THE BUILDINGS, IN THE RENAISSANCE PERIOD THE IMPORTANCE WAS GIVEN TO THE ‘SPACE’ AND IN THE BAROQUE PERIOD, THE IMPORTANCE WAS LAID UPON BOTH ‘MASS’ AND ‘SPACE’.

MEDIEVAL TOWN PLANNING

INTRODUCTION


The time span between fall of the Roman empire till the start of renaissance is termed as DARK AGES as no great construction or development was carried out during this period.
Economy was rooted in agriculture and the feudal system was the new order.
Merchants & craftsmen formed guilds to strengthen their social & economic position.
Wars among the rival feudal lords were frequent.

PLANNING

1.Early medieval town was dominated by church or monastry & castle of lords.
2.For protective measures, towns were sited in irregular terrain, occupying hill tops or islands. Towns assumed informal & irregular character.
3.Church plaza became a market place.
4.Roads generally radiated from church plaza& market plaza to gates with secondary lateral roadways connecting them.
5.Castle was surrounded by wall & moat as a protective elements.
Irregular pattern in planning was devised to confuse enemies; as enemies unfamiliar with town.
Open spaces, streets, plazas developed as an integral part of site.
Streets were used for pedestrian while wheels were restricted to main roads.

CITIES IN TWELTH & THERTINTH CENTURY
The city of middle ages grew within the confines of the
walls.
While the population was small, there was space in the
town, but when it increased the buildings were packed
more closely and the open spaces filled.

Result was intolerable congestion, lack of hygiene and
pestilence.

CITY OF NAARDEN

1.CARCASSONNE

It contains market square,
castle & church of St.Nazzair.
Irregular pattern for streets is seen.




2. NOERDLINGEN

A Cathedral
B Moat

It shows the radial & lateral pattern of irregular road ways with the church plaza as the principal focal point of the town.

3.CITY MOUNT ST. MICHEL

It was the picturesque town.
It was church larger than the palace that dominated the medieval town of
St. Michel .
The town was enclosed within a protective wall . The artisan were sensitive
to the form & material of the building erected. Under their guidance
and care was exercised in the placement of, and relation between , structure of
the town which gave the picturesque town.


4.MONTPAZIER

During the 13th & 14th centauries colonial cities were founded by young empires to protect their trade and provide military security.
They were platted for allocation of sites to shelters and the regular plan is a distinct contrast to the informal.

The Medieval dwelling –

The medieval dwelling was conceived as an individual
fortress.
The average dwelling was two stories in height. The work- room and storage
Were on the first or basement. Sometimes kitchen was also located here. Living , dining
& sleeping took place on the second floor.
Masonry was the usual construction , although wood frame filled with
Wattle & clay & roofed with thatch for comparison, a small manor house is shown.

It contains a ‘ hall’ & cooking were perforated on this floor. A dormitory or solar was located in the tower above the chapel.
A drain pipe was imbedded in the wall for disposal of waste. The window had no glass and were protected with shutters.
Manor houses were extended in size and formed the nucleus of villages in many cases.

CIVILIZATIONs

AEGEAN AND MINOAN CIVILIZATION


The Aegean and the Minoan civilizations were the prelude to the Greek civilization.
This civilization flourished on the islands of Crete. The development of this civilization on the island was known as Minoan civilization after king Minos.
The development of the mainland is termed as Helladic or also Mycenaen Civilization known after the city of Mycenae.
The mainland of Greece always required strong defensive boundary.

The palace of the king served as the center of community life in Aegean culture.
On the island of Crete the town sites offered natural protection.
Ancient cities like Knossus were not surrounded by walls due to the natural boundary of seas.
On the main land of Greece, cities needed the protection of ramparts.
The cities of Tiryns and Mycenae were heavily fortified.

The Aegean cities were irregular in form. Meandering streets followed the irregular topography of the sites.
The streets were narrow lanes paved with stone.
There was a developed system of water supply, sanitation and drainage for palaces and many of the houses.
Most dwellings were one storied in height and densely built.
The town did not appear to be congested.
In the cities of Aegean culture, the palace of the king used to be an integral part of the town life.
Broad steps lead to an open court which was probably a place for assembly and entertainment.

DWELLINGS OF THE AEGEAN CIVILIZATION:
The houses comprised a few small rooms called the Megaron.
These rooms opened into a small light court.
At times there was an opening in the roof for the collection of rain water in a cistern.
The houses of the lower class was confined to the Megaron and a vestibule whereas the houses for upper class and the palaces were equipped with the drains.
One storey construction was done in mud bricks and stone foundation.

GREEK CIVILIZATION

The Classical Greek Civilization includes the civilization on the mainland of Greece, Aegean archipelago of islands and the west coast of Anatolia.
The Aegean civilization fell roughly around 1200 B.C. and the Greek civilization took 500 years to get formulated.
Greece was invaded from the north by the Dorians. Those who went to Anatolia were the Ionians.
These two principalities formulated the distinct character of the Greek Civilization.

Greek Civilization can be broadly classified as :
Hellenic
Hellenistic
The people on the main land of Greece mixed with the Aegean people which gave rise to a noble class.
This class rose in power and exercised an influence on the common people
The influence of king reduced and thus the palace citadel disappeared.

Temples dedicated to god replaced the palaces on the acropolis.
The emergence of merchant class gave rise to redistribution of the estates of nobles among the common people.
With this concept of the law that were determined by the people, Athens became a democratic state.

THE CITY OF ATHENS

During the early years of democracy, the Greek city had wandering unpaved lanes.
There was no drainage and sanitation.
Water was carried from the local wells and waste was disposed off in the streets.
There were no palaces, but temples were present alongwith a few public buildings.
The common assembly place was called as the pnyx.

The pnyx was an open air podium where the citizens met to consider the affairs of the state.
The agora was the market place and the center of urban activity. It was irregular in form.
There was very less difference between the houses of the rich and the poor people. The rooms were grouped about an interior court.
Most towns were surrounded by protective walls.

COLUMNS OF GREEK ARCHITECTURE.
An order consisted of an upright columns and the horizontal entablatures or the part supported.
The orders that developed in the Greek period were:
Doric order
Ionic order
Corinthian order.


The Greek architecture comprised of many features that included the columns of various orders.

The columns in the form of sculptures of women were also an important feature of the Greek architecture.
These were seen at Erecthion and were called as Caryatid porches.


Theory of Hippodamus:
Hippodamus was an architect from the city of Miletus and was credited the origination of the “grid-iron” pattern of streets.
The grid-iron system, according to Hippodamus, established a rational arrangement of buildings and circulation.
For the city plan, the individual dwelling was considered as a module.
The blocks were shaped to provide appropriate orientations for the dwellings within them.
The functional uses of the buildings and the public space were recognized in the arrangement of streets.
This facilitated the easy movement of people and vehicles.
The rigid geometry of the Hippodamus street system was superimposed upon the uneven topography of the sites.
This resulted in the development of steps to negotiate with the steep slope.
This was accepted as the movement was on foot.


PUBLIC SPACE:
The public spaces consisted of the Agora or the market place,, assembly halls called as the Ecclesiasteron, Council hall called as the Bouleuterion and the Council chamber called as the Prytaneum.

THE AGORA:
Located in the center of the town plan.
E-W and N-S streets lead to the Agora.
Occupied about 5% of the city area.
The Agora had dimensions approx. one fifth of the width and breadth of the town itself.
Geometrical plan. Square or rectangular open space surrounded by colonnades, porticoes.
It does not allow movement of people across the open space.
Streets terminated at the Agora and did not cross it.
The open space was reserved was used for the pedestrian movement and circulation.
There were olive groves outside the walls of the city.
There were provisions of building laws regarding the restriction of buildings from encroaching on the streets .
Prohibition of projection of upper floors beyond the first floor wall.

DWELLINGS:
There were shops adjacent to the dwellings of the merchants.The houses were enclosed about a central hearth.
Streets were paved and sanitation was improved by providing underground drains.
Facility for the disposition of sewage was not provided.


CITY OF OLYNTHUS:
Irregular layout of streets.
The city contained Agora and an assembly space.
The dwellings were small and irregular in form.
At places, the Hippodamian plan can be seen with main streets laid -in a north-south direction about 300 feet apart and connected by east-west street of narrow width some 129 feet apart.
The city in later period had paved street and underground drains.
Some houses were two storied in height.

THE CITY OF PRIENE:

Grid- iron pattern of street system.
Agora is at the center of the town, surrounded by temples shrines, public buildings and shops.
Recreation and entertainment facilities are provided in gymnasia, stadia and theatre.

THE CITY OF MILETUS:
This city too shows the grid-iron system of roads.
The market place had freedom for pedestrian movement, streets generally by-passed terminating the open space.
Services to the shops from exterior street.
Agora was treated as the series of exterior rooms.
It was rectilinear in form but the spaces were not symmetrical.
Shrines and public spaces were located about the agora.
The bouleuterion, the ecclesiasteron and prytaneum were located about the agora.

THE HELLENISTIC CITY:
The era after Alexander the Great is termed as the Hellenistic era.
Public buildings like the Odeion, the treasury, the library and the prison were added to the agora.
Baths and stadia were built for entertainment.
Gardens and parks were introduced
Villas were built.

REINFORCED CAVITY WALL

INTRODUCTION :



A WALL CONSTRUCTED IN TWO LEAVES OR SKINS WITH A SPACE OR CAVITY BETWEEN THEM IS CALLED A CAVITY WALL.
USED AS AN EXTERNAL WALL.
THE MAIN PURPOSE OF CONSTRUCTING A CAVITY WALL IS TO PREVENT THE PENETRATION OF RAIN TO THE INTERNAL SURFACE OF THE WALL.
IT MAY OR MAY NOT BE REINFORCED.

ACCORDING TO BUILDING REGULATION RULES :

THE CAVITY SHALL NOT BE LESS THAN 50 MM NOR MORE THAN 75 MM IN WIDTH AT ANY LEVEL.

EACH LEAF SHALL NOT BE LESS THAN 100 MM IN THICKNESS AT ANY LEVEL.

FOR A NOMINAL 255 MM WIDE CAVITY WALL OF ANY LENGTH THE MAX. HT. IS 3.6 M & FOR LENGTH NOT EXCEEDING 9 M , THE MAX. HT. IS 9 M.

INNER LEAF CAN NOT BE LESS THAN 75 MM THK. IF THE WALL FORMS PART OF APRIVATE DWELLING HOUSE OF ONE STOREY OR IS THE UPPER STOREY OF SUCH A DWELLING HAVING ONLY TWO STOREYS.

A GAUGE MORTER NOT WEAKER THAN 1:2:9 SHOULD BE USED.

ADVANTAGES :

IT IS ABLE TO WITHSTAND A DRIVING RAIN IN ALL SITUATIONS FROM PENETRATING TO THE INNER WALL SURFACE.

NO NEED FOR EXTERNAL RENDERING

GIVES GOOD THERMAL INSULATION,KEEPING THE BUILDING WARM IN WINTER & COOL IN SUMMER.

ENABLES THE USE OF CHEAPER & ALTERNATIVE MATERIALS FOR THE INNER CONSTRUCTION.

POSSESSES HIGHER SOUND INSULATION VALUE THAN A STANDARD BRICK WALL.

DISADVANTAGES :

REQUIRES HIGH STANDARD OF DESIGN & WORKMANSHIP TO PRODUCE A SOUNDLY CONSTRUCTED WALL; THIS WILL REQUIRE GOOD SUPERVISION DURING CONSTRUCTION.

SLIGHTLY COSTLIER THAN A STANDARD 1 BRICK THK. WALL.

IT IS NEEDED TO INCLUDE A VERTICAL D.P.C. TO ALL OPENINGS.

CAVITY BLOCK CONSTRUCTION
HOLLOW CONCRETE BLOCKS ARE USED FOR THE CONSTRUCTION.
DIFFERENT SIZES & TYPES OF BLOCKS ARE AVAILABLE.
THE TYPE OF BLOCK DEPENDS UPON WHERE IT IS TO BE USED.

DIFFERENT TYPES OF CAVITY BLOCKS

SAND-FACED PLASTER

PLASTERING
Plastering provides a finished surface that is firm and smooth.
The plaster acts as a sound and thermal insulation layer to some extent.
Plaster is a layer of cement-sand mortar applied over a masonry work which also acts as a damp-proof coat over the masonry.
Plastering enhances the appearing of the building.
Helps to provide a suitable base for colour wash.

SAND-FACED PLASTER
The first coat of cement plaster is carried out in cement mortar of proportion 1:4,I.e. one part of cement to four parts of clean,coarse and angular river sand by volume.
The thickness of first coat is 12mm.
The first coat is to be well watered for atleast 7 days.
The first coat is provided with zigzag lines so that the first coat adheres well with the second coat.
The second coat of sand-faced cement plaster is carried out in proportion 1:3 and the thickness of second coat is 8mm.
The second coat should be applied on the first coat before 7 days of completion of first coat.
Sand to be used in the mortar for the second coat is to be perfectly screened so that sand of uniform size appears on the surface.
Sponge is used on the second coat and it is applied when the second coat is wet and it is so worked that the density of sand grains appearing on the surface is equal and uniform.
After completion of the second coat, the surface is kept well-watered at least for 15 days.

DEFECTS IN PLASTERING
Blistering or plastered surface
Cracks
Flaking
Peeling
Popping rust-stains
Softness
Uneven surface


FOR MINIMISING DEFECTS IN PLASTERING WORK

The brick and plastering work should be carried out by skilled masons in the best workmanship manner.
Bond of brick should be properly maintained.
The surface to be plastered should be well-watered so that it may not absorb water from plaster.
Excessive trowelling should be avoided.
Fresh plaster surfaces should be protected from rain,dirt and excessive heat as sun.
Water free from salts should be used for brick work and plastering work.

SPECIALIZED RENDERING

Introduction:-
The words wall, walling, cladding, facings and wall facings are variously used relative to the usually vertical envelop of the buildings.
Cladding clothes the building in a protective clothing that is hung supported by or secured to the skeleton or structural frame as a jacket.
Cladding will be used to describe panels of concrete, GRC, GRP, glass & metal fixed to and generally hung from the frame, by supporting beams or inside light framing as a continuous outer skin to the frame.
More recently thin sheet metal panels, are used by themselves as a wall finish or with the frame and services exposed in what is referred as a hi-tech architecture.
In specialized external finishes the following techniques are generally used-
Aluminium cladding
Stone cladding
Heritage plaster

Aluminum cladding:-
In this aluminium metal panels are used in the form of separate flat or profiled panels supported by a metal carrier system which is fixed to the structure.
These panels are separated either by visible silicon joints or by visible members of their supporting frame.
The aluminium panel is a composite material composed to two strong sheets of .020" gauge aluminum and a polyethylene core. It is lightweight, rigid, and corrosion resistant. It is easily fabricated and can be used for a wide variety of applications.

Aluminum cladding:-
These panels are available in the following standard sizes-
SIZES 1220mmX2440mm, 1220mmX3050mm, 1220mmX3660mm.
THICKNESS
2mm, 3mm, 4mm, 6mm.
Special sizes are available as per order. In addition to this, larger widths of 1550mm & 1600 mm are available.




Joining of panels:

Fastening: Riveting & Bolting:
Aluminium blind rivet & stainless steel bolt/nuts are recommended to fasten Al panels.

Welding:
Aluminium panels edges can be joined by welding the core with the help of hot jet gun.




INSTALLATION DETAILS:









Characteristics:

Excellent flatness.
Minimum dead weight.
Consistency of paint finish.
Resistant to blow & breakage.
Weather ability or vibration damping.
Sound & heat insulation.
Ease of formability.
Ease of installation & maintenance.

Stone cladding:-

Stone facings are provided for a decorative finish to stimulate the effect of solidity and permanence traditionally associated with the masonry.
The types of stones used are limestone, Clipsham, Sandstones, Marble etc.
Facing slabs are fixed so that there is a cavity between the back of the slabs and the back ground wall or frame to allow fixings and tolerances. The type of fixings used to support and secure facing slabs in position are:
Loadbearing fixings
Restraint fixings
Combined loadbearing and restraint fixings.
Face fixings
Soffit fixings

Joints between stone slabs:-
Joints between stone facing slabs should be sealed as a barrier from rain water running off the face of the slabs.
Whenever water enters the cavity it will be trapped and will not evaporate and may cause conditions of persistent dampness. Open or Butt joints must be avoided.
For joints between limestone & sandstone- mortar of cement, lime, sand mix 1:1:6.
For joints between granite- mortar mix of 1:2:8.
Sealants may be also used such as 1 part polysulphide, 1 part polyurethane.

Heritage plaster:-

Heritage plaster is the brand name given to a certain type of plaster.
It is a wall finish used to
give a textured finishes to
external and internal walls
Its available in the form of silica granules or flakes, to be mixed with a bonding agent.
It requires minimum 8 hours to dry, as 50% of the liquid is absorbed by the base, and 50% evaporates.
A silicon coat is applied as a top finish.
This plaster lasts for about 15-20 years ,as long as the smooth plaster base for it doesn’t crack.
It requires skilled labour, often provided by the manufacturers, to ensure product quality.

Advantages:-
This wall finish is durable, and lasts about 15-20 yrs, (given that the smooth plaster base behind it doesn't crack.) compared to cement paint, which needs to be reapplied externally every 3 yrs.
No further primer and paint is required over it
Various colors are available in heritage plaster.
Its weather resistant, easily washable and not prone to fungus, as cement paint is.

Disadvantages:-
Its quite expensive ( Rs.30-150 / kg of granules) compared to cement paint finish.
It requires skilled labour supplied by the manufacturer.
It has to be bought from authorized distributors.

Applications:-
Being weather resistant and durable, its preferred over cement paint for external walls.
It is often used to create interesting murals or designs with the large no. of colors and textures available.

CLIMATOLOGY

STUDY OF CLIMATOLOGY IS A STUDY OF ENERGY CONSERVATION AND DESIGN TO CREATE COMFORTABLE SHELTERS WITH RESPECT TO CLIMATE.

CLIMATE :
IT CAN BE DEFINED AS AN INTEGRATION IN TIME OF PHYSICAL STATES OF THE ATMOSPHERE,ENVIRONMENT, CHARACTERISTIC OF A CERTAIN GEOGRAPHICAL LOCATION.

WEATHER:
WEATHER IS THE MOMENTARY STATE OF ATMOSPHERIC ENVIRONMENT A CERTAIN LOCATION.
CLIMATE COULD BE DEFINED AS THE INTEGRATION IN TIME OF WEATHER CONDITIONS.

ATMOSPHERE
THE MIXTURE OF GASES ENVELOPING THE SURFACE OF THE EARTH HELD BY GRAVITATIONAL FORCE AND FRICTION IS THE ATMOSPHERE.
TOPOSPHERE 8-13 KM
STATOSPHERE 200 KM
INOSPHERE 300 KM
EXOSTSPHERE 1300 KM
OZONE LAYER

GLOBAL FACTORS


SOLAR RADIATION
EARTHS-SUN RELATIONSHIP
EARTHS THERMAL BALANCE
WINDS
OCEAN AND OCEAN CURRENTS
TOPOGRAPHY

SOLAR RADIATION

THE EARTH RECEIVES ALMOST ALL ITS ENERGY FROM THE SUN IN THE FORM OF RADIATION THUS,THE SUN IS THE DOMINATING INFLUENCE ON CLIMATES.
THE SPECTRUM OF THE SOLAR RADIATION EXTENDS FROM 290 TO 2300NM.

EARTH-SUN RELATIONSHIP

SEASON:TILT OF AXIS OF EARTH IS CONSTANT THUS THE CYCLIC CHANGES IN ATMOSPHERE ARE CALLED AS SEASONS.

EARTHS THERMAL BALANCE


THE RADIATION RECEIVED BY THE EARTH OR ABSORBED BY THE EARTH EACH YEAR IS BALANCED BY CORRESPONDING HEAT LOSS.WITHOUT THIS COOLING THE THERMAL BALANCE WOULD NOT BE MAINTAINED.
THE EARTHS SURFACE LOOSES HEAT.
A)BY EVAPORATION.
B)BY LONG WAVE RADIATION TO THE OUTER SPACE.
C)RISING OF HOT AIR.

WINDS
THE AIR MOVEMENT ON THE SURFACE OF EARTH DUE TO DIFFERENCE IN PRESSURE WHICH IS CAUSED DUE TO CHANGE IN TEMPERATURE IS CALLED WINDS.
THE DIFFERENCE IN ATMOSPHERIC PRESSURE ARE INVERSELY PROPORTIONAL TO EACH OTHER.
THE ATMOSPHERIC MOVEMENT IS FROM HIGHER PRESSURE BELT TO LOWER PRESSURE.
TYPES OF WIND FLOWING OVER SURFACE OF EARTH ARE,
1.PLANETARY WINDS
2.MONSOON WINDS
3.CYCLONIC/ANTICYCLONIC WINDS

OCEAN CURRENTS
DEVELOPED DUE TO THE FOLLOWING REASONS:
UNDULATING SEA CORE/SEA BED
DIFFERENCE IN SALINITY OF WATER
UNEQUAL HEATING OF BODIES
SURFACE WINDS

TOPOGRAPHY
ON A LARGER SCALE INTERACTION OF TEMPERATURE PATTERNS ARE CREATED BY DIFFERENTIAL HEATING ON LAND,FOREST AND OCEAN.
THIS CAUSES CHANGE IN WEATHER.

VENTILATION
VENTILATION MAY BE DEFINED AS THE SYSTEM OF SUPPLYING OR REMOVING AIR BY NATURAL OR MECHANICAL MEANS TO OR FROM ANY ENCLOSED SPACE.
IN ORDER TO PRODUCE AND TO MAINTAIN EITHER HEALTHFUL,COMFORTABLE,OR THE NECESSARY AIR CONDITIONS WITHIN A STRUCTURE IT MAY BE NECESSARY TO INTRODUCE INTO AND REMOVE FROM THE SPACES OF THE BUILDING A DEFINITE AMOUNT OF AIR IN DEFINITE TIME.

NEED FOR VENTILATION
TO REMOVE HEAT AND MOISTURE GIVEN OFF BY THE OCCUPANTS.
TO PREVENT UNDUE CONCENTRATION OF BODY ODOURS,FUMES,VAPOURS,DUST,ETC.
TO PREVENT AN UNDUE CONCENTRATION OF BACTERIA-CARRYING PARTICLES.
TO PREVENT OXYGEN DEPLETION AS THE RESULT OF THE COMBUSTION OF FUELS AND OTHER MATERIALS.
TO PREVENT FLAMMABLE CONCENTRATION OF GAS,VAPOURS OR DUST.
TO PREVENT SMOKE AND FOG PRODUCTION.
TO CREATE AIR MOVEMENT AND THUS PREVENT EXCESSIVE HEAT FROM ALL SOURCES.

NATURAL VENTILATION
NATURAL VENTILATION DEPENDS ON AIR MOVEMENT INDUCED BY WIND AND TEMPERATURE DIFFERENCE.
SINCE THE RATE OF FLOW OF AIR THROUGH AN OPENING DEPENDS ON WIND VELOCITY,THE ADJUSTMENTS OF THE AREA OF THE OPENINGS TO MAINTAIN THE CONSTANCY OF AIR CHANGE BECOMES NECESSARY.
THE MAXIMUM AREA OF WINDOW OPENINGS SHOULD BE ONE-FIFTH OF THE FLOOR AREA.AS A MINIMUM IT SHOULD NOT BE LESS THAN ONE-TENTH OF THE FLOOR AREA.

WINDS-NATURAL VENTILATION

USE THE WIND FOR COOLING.
PRESERVE EACH BUILDINGS ACCESS TO COOLING BREEZES DURING OVERHEATED PERIOD.
ORIENT BUILDINGS TOWARDS COOLING BREEZES.
PROVIDE OPENINGS FOR VENTILATION THAT CAN BE SEPARATE THE HOUSE USED FOR VIEWS,SUNLIGHT,DAYLIGHT.
ADDITIONALLY,DURING PERIODS OF CALM,MICROCLIMATIC THERMAL WINDS CAUSED BY VALLEY EFFECTS,CITY EFFECTS OR WATER BODIES MAY OCCUR.

TYPES OF VENTILATION
OPEN OR MIXED VENTILATION SCHEME FOR YOUR BUILDING.
CLOSED SCHEME FOR THE OVERHEATED MONTHS,A MIXED SCHEME IS OFTEN APPROPRIATE FOR COOLER MONTHS.
MIXED SCHEME IS FOR AN INTERNALLY DOMINATED LOAD BUILDING.

OPEN BUILDINGS
NATURAL VENTILATION AND DEPEND ON THERMALLY OR WIND INDUCED INTERNAL AIR FLOW FOR COOLING.THIS COOLING STRATEGY WORKS ONLY IF THE INSIDE AIR TEMPERATURE IS HIGHER THAN THE OUTSIDE TEMPERATURE.
NATURAL VENTILATION CAN BE USED EVEN IN THE HOTTEST MONTH.
IN DRIER CLIMATES,COOLING CAN BE ACCOMPLISHED NEAR THE UPPER LIMIT OF THE COMFORT ZONE BY MOVING AIR AS WARM AS 87 DEGREE F.
THIS TEMPERATURE HAS TO BE SIGNIFICANTLY LOWER IN MORE HUMID CLIMATE.

CLOSED BUILDINGS

CLOSED BUILDINGS USE HIGH MASS WITHOUT SIMULTANEOUS VENTILATION.
THESE BUILDINGS MAY ALSO USE EVAPORATIVE COOLING ,DESICCANT COOLING,EARTHTUBE COOLING,ROOF PONDS,AND MECHANICAL REFRIGERATION.

MIXED BUILDINGS

MIXED BUILDINGS CAN BE CLOSED DURING VERY HOT HOURS,THEN OPENED FOR NIGHT VENTILATION TO REMOVE STORED HEAT.
THE SIGNIFICANT DIFFERENCE BETWEEN OPEN AND MIXED STRATEGIES IS THAT OPEN VENTILATION REMOVES HEAT AS IT IS GENERATED WHILE THE MIXED STRATEGIES REMOVES THE ENTIRE DAYS HEAT DURING A SHORT VENTILATION PERIOD.

PASSIVE VENTILATION
TWO BASIC WAYS----
CROSS VENTILATION-
DEPENDS ON THE FORCE OF THE WIND TO EXPEL HOT AIR FROM THE LEEWARD SIDE OF THE BUILDING TO BE REPLACED BY COOLER AIR FORCED IN THE WINDWARD SIDE.
STACK VENTILATION-
DEPENDS ON HOT AIR RISING TO EXPEL HOT AIR FROM OPENINGS HIGH IN A BUILDING.THIS HOT AIR IS THEN REPLACED BY COOLER AIR DRAWN IN THROUGH MUCH LOWER OPENINGS IN THE BUILDING ENVELOPE.THIS IS PARTICULARLY USEFUL IF YOU HAVE CALM WIND CONDITIONS DURING OVERHEATED MONTHS.IT CAN ALSO BE EFFECTIVE WITH EARTHTUBE COOLING.

VENTILATION AIR FLOW
1.FOR OPEN AND MIXED BUILDINGS-
SHOW THE AIR FLOW VENTILATION PATH.
ON SITE PLAN,FLOOR PLANS AND SECTIONS DRAW FLOW OF VENTILATION AIR AROUND AND THROUGH THE BUILDING FOR MONTHS IT NEEDS TO BE COOL.
WIND FLOWS FROM +VE PRESSURE TO –VE PRESSURE AREAS
HOT AIR RISES ,COOL AIR FALLS.

2.FOR CLOSED AND MIXED BUILDINGS-
SHOW THE RADIATION/AIRFLOW PATHS-
ON FLOOR PLANS AND SECTIONS INDICATE THE LOCATIONS OF THERMAL MASS.IN ORDER TO MASS COOLING STRATEGIES THE MASS MUST HAVE A LARGE AMOUNT OF SURFACE AREA AS COMPARED TO ITS VOLUME.
IF THE MASS WILL BE COOLED PRIMARILY BY RADIATION,DRAW THE PATH OF RADIANT TRANSFER FROM THERMAL MASS TO HEAT SINK AND SPECIFY THE TYPE OF HEAT SINK (NIGHT SKY,WATER BODY)
IF BUILDING RELIES ON NIGHT VENTILATION,WHERE THE MASS IS COOLED BY CONDUCTION/CONVECTION,DRAW THE PATH OF AIR CURRENTS OVER THE SURFACE OF MASS.

WINDCATCHERS AND TURBOVENTILATORS

WINDCATCHERS/WIND SCOOPS ARE USED TO TAKE COOL AIR INSIDE THE STRUCTURE.THESE ARE TALL STRUCTURE LIKE CHIMNEY FROM WHICH THE HOT AIR IS REMOVED.
TURBOVENTILATORS ARE ALSO USED WHICH ARE FIXED IN ROOF BECAUSE OF THE HOT AIR THESE TURBO-VENTILATORS ROTATES AND COOL AIR FIND ITS PATH THROUGH.
MANYTIMES CAVITY IS CREATED IN THE WALL WHERE COOL AIR IS ABSORBED AND WHILE PASSING ONTO THE HOT WALL IT ABSORBS THE HEAT AND ESCAPES AT THE ROOF LEVEL.
VENTILATORS PROVIDED AT ROOF LEVEL ALSO HELPS FOR NATURAL VENTILATION.