climate responsive design

7/27/2019 Climate Responsive Design

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Climate Responsive Design


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Passive Home Training Module for Architects and Planners

Why Climate Responsive

Buildings account for 40% of the final energyconsumption

More than 60% of the energy used in the building is forheating/cooling and lighting.

Hence it can be reduced by better design using passivetechniques.

Correct design and construction can contribute todramatically decrease energy consumption and CO2emissions

Example: at average, each Passive house consumes 80% less energy

for heating than standard house; this translates into annual avoided CO2

emissions of 2.4 tonnes/year for one house


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Passive Systems

A Passive System provides indoor environments with heat, cold, ventilation

or light by using and controlling the natural energy flows which surround abuilding, such as solar radiation and wind

There is a range of passive systems and measures, suitable for different

climates

Examples of Passive Systems in traditional architecture:

Painting exterior walls white to keep houses cool in summer

Building thick, heavy walls, namely on brick and mud, both for insulation and

regulation of indoor temperature

Controlling daylight and solar gains by appropriate windows use

Promoting a microclimate near the house by use of water and vegetation


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Passive Systems

White washed houses and narrow streets in the Santa Cruz district of Seville, Spain. Just two of the

many different strategies employed by traditional architecture to keep houses cool in summer.


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Passive Design

The term Passive Design has come to indicate buildings which integrate

low energy active components such as pumps and fans, with PassiveSystems

The energy consumed by the active component remains significantly lower

than the energy content of the natural energy flow which the component

controls

In many cases the energy demand of the active system is so low that it can

be met economically and feasibly by a renewable energy source such as a

PV panel


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Thermal Comfort

Discussions on low energy buildings should not neglect that buildings must

provide comfortable environments in which to work, relax and play Comfort models describe quantitatively (based on large surveys of people)

in what range of conditions people will feel thermally comfortable inbuildings

Choosing too narrow a range of thermal conditions can lead tounnecessary consumption of energy

Comfort models evaluation may be based on a variety of parametersdepending on people, such as metabolic rate and clothing, but also onindoor (and outdoor) conditions, such as air temperature and humidity,radiant temperature, air velocity, thermal asymmetries


7/29Passive Home Training Module for Architects and Planners

CLIMATE

India has different climatic conditions ranging from extremely hot conditions to

severely cold conditions.

Energy availability is scarce and people have to protect themselves from these

extremities of the climate in a natural way.

Traditional architecture exhibits variety of building design suited to the respective

climatic conditions.

The month wise climatic data available for 233 stations spread over the whole country has been analysed by the CBRI, Roorkee.

The various climatic zones thus determined have been delineated on the map of the

country.

The various stations have been categorised under one or the other climatic zone if

their climate conformed for six or more months, otherwise it is placed under the

composite. zone



FACTORS AFFECTING CLIMATE



Solar radiation

Solar radiation is

the radiant energy

received from the

sun.

It is the intensity of

sunrays falling per

unit time per unit

area and is usually

expressed in Watts

per square metre(W/m2).



Solar radiation



Temperature

The temperature of air in a shaded (but well ventilated) enclosure is

known as the ambient temperature; it is generally expressed indegree Celsius (C).

Temperature at a given site depends on wind as well as local factors

such as shading, presence of water body, sunny condition, etc.



Air humidity

Air humidity, which represents the amount of moisture present in the

air, is usually expressed in terms of relative humidity.

Relative humidity is defined as the ratio of the mass ofwater vapour

in a certain volume of moist air at a given temperature, to the mass

of water vapour in the same volume of saturated air at the same

temperature; it is normally expressed as a percentage.



Precipitation

Precipitation includes water in all its forms rain, snow, hail or dew. It

is usually measured in millimeters (mm) by using a rain gauge.



Wind

Wind is the movement of air due to a difference in atmospheric

pressure, caused by differential heating of land and water mass onthe earths surface by solar radiation and rotation of earth.

Wind speed can be measured by an anemometer and is usually

expressed in metres per second (m/s).



Wind



Classification of Climates



Hot and Dry

lies in the western and the central part of India; Jaisalmer, Jodhpur

and Sholapur

flat with sandy or rocky ground conditions water level is very low.

Due to intense solar radiation (values as high as 800-950 W/m2),

the ground and the surroundings of this region are heated up very

quickly during day time. In summer, the maximum ambient temperatures are as high as 40

45 C during the day, and 2030 C at night. In winter, the values

are between 5 and 25 C during the day and 0 to 10 C at night. It

may be noted that the diurnal variation in temperature is quite high,

that is, more than 10 C

relative humidity is generally very low, ranging from 25 to 40 %

the annual precipitation being less than 500 mm



Warm and Humid

The warm and humid zone covers the coastal parts of the country.

Some cities that fall under this zone are Mumbai, Chennai andKolkata

In summer, temperatures can reach as high as 30 35 C during the

day, and 25 30 C at night.

In winter, the maximum temperature is between 25 to 30 C duringthe day and 20 to 25 C at night.

the relative humidity, which is generally very high, about 70 90 %

throughout the year

Precipitation is also high, being about 1200 mm per year, or even

more.

The wind is generally from one or two prevailing directions with

speeds ranging from extremely low to very high. Wind is desirable in

this climate, as it can cause sensible cooling of the body.



Moderate

Pune and Bangalore are examples of cities that fall under this

climatic zone. Areas having a moderate climate are generallylocated on hilly or high-plateau regions with fairly abundant

vegetation

The temperatures are neither too hot nor too cold. In summers, the

temperature reaches 30 34 C during the day and 17 24 C at

night. In winter, the maximum temperature is between 27 to 33 C

during the day and 16 to 18 C at night.

The relative humidity is low in winters and summers, varying from 20

55%, and going upto 55 90% during monsoons.

The total rainfall usually exceeds 1000 mm per year.


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Composite

The composite zone covers the central part of India. Some cities

that experience this type of climate are New Delhi, Kanpur andAllahabad.

The maximum daytime temperature in summers is in the range of 32

43 C, and night time values are from 27 to 32 C. In winter, the

values are between 10 to 25 C during the day and 4 to 10 C at

night.

The relative humidity is about 20 25 % in dry periods and 55 95

% in wet periods

Precipitation in this zone varies between 500 1300 mm per year.

This region receives strong winds during monsoons from the south-east and dry cold winds from the north-east. In summer, the winds

are hot and dusty


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Cold and Wet

Generally, the northern part of India experiences this type of climate.

Most cold and cloudy regions are situated at high altitudes.Ootacamund, Shimla, Shillong, Srinagar and Mahabaleshwar.

In summer, the maximum ambient temperature is in the range of 20

30 C during the day and 17 27 C at night, making summers

quite pleasant. In winter, the values range between 4 and 8 C

during the day and from -3 to 4 C at night, making it quite chilly.

The relative humidity is generally high and ranges from 70 80 %.

Annual total precipitation is about 1000 mm and is distributed evenly

throughout the year.

This region experiences cold winds in the winter season. Hence,protection from winds is essential in this type of climate.


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Cold and Dry

The cold and sunny type of climate is experienced in Leh (Ladakh).

The solar radiation is generally intense with a very low percentage

of diffuse radiation. In summer, the temperature reaches 17 24 C

during the day and 4 11 C at night.

In winter, the values range from -7 to 8 C during the day and -14 to

0 C at night. Winters thus, are extremely cold. The relative humidity is consistently low ranging from about 10 50

% and precipitation is generally less than 200 mm per year.

As this region experiences cold desert climatic conditions, the

design criteria are to resist heat loss by insulation and controlling

infiltration.


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IMPLICATIONS OF CLIMATE ON BUILDING

DESIGN


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Mahoney TablesTable-1 Data Input


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Mahoney TablesTable-1 Data Input


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Mahoney TablesTable-2 Diagnosis

M h T bl T bl 3 R d ti


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Mahoney TablesTable-3 Recommendations


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P i H T i i M d l f A hi d Pl

Mahoney TablesTable-4 Detailed Recommendations

climate responsive design

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