2013-09-11 _ climate themes and factors

1ARCHITECTURE AND CLIMATELuca Finocchiaro

Climate analysis Principle, examples and case studies

2ARCHITECTURE AND CLIMATE

AAR4832+AAR4532 // Climate and built forms

• Climate – as a source for making architecture• Built forms – as tools for environmental control


Environmental control – compass termitesInternal temperature is constantly within 1 degree of 31Celsius, day and night, summer and winter, while the external temperature varies between 3 C to 42 C. This is achieved by building a wedge shaped tower mound of 3 Metres height which always points North. As the tower heats up, air inside rises drawing fresh cool air from below. Also the wind blowing across the top of the mound helps to suck in fresh air through the nest. And the termites regulate the flow of air through their nests, by blocking and unblocking the channels.


Biological models inspiring thermal models for environmental control.

Biomimicry process _ learning from nature


1230Sacrobosco

humans historically tended to habit environments with favourable climatic conditions

2010G-Econ project

1150Macrobius


Climate rejecting buildings Climate adapted buildings

Vs.

Aggressive compact shapes neglecting any sort of dialogue with

the external environment.

Sensitive forms whose aiming at maximizing the use of external

resources.


Modifying the natural environment to approach optimum condition of liveability. The shelter should filter, absorb or repel environmental elements according to their beneficial or adverse contributions to man’s comfort.

Source: Victor Olgyay, Design with climate.

The shelter The shelter


Temperature Relative humidityVariables affecting thermal comfort are the most important for bioclimatic architectural design.


Psychrometric chart as basic scientific tool for cioCLIMAtic design


Classifications of climates

Köppen-Geiger climates chart (1936) based on monthly Temperature and precipitations values and spontaneous vegetation (expression of climatic factors action).


Koppen-Geiger


Climatic zones _ bioclimatic architectural design.Koppen Geiger climates classification

Cool Warm humidTemperate Hot arid


Victor Olgyay (1963). Vernacular architecture diversity & similarities

Cool Warm humidTemperate Hot arid

Source: V. Olgyay, Design with climate


Climatic design archetypes

Cold Temperate Hot dry Warm humid


Cold climatesChallenge _ extremely cold temperatures and high relative humidity values in winter. Main concerns: lack of heat or heat losses.


Cold climates – Vancouver

Passive solar heating

Green roofs


Climatic design archetypes _ cold climates

Minimizing heat losses through insulated (u-values walls - 0.12 W/m2 and low glass/ratio) and extremely airtight envelopes in order to avoid thermal losses through ventilation (infiltration<0,5 ach).


Norman Foster, London City hall

Compact shapes minimizing the contact surface with the exterior are preferable


Norman Foster, the Gherkin


Norman Foster, the Gherkin

Thermal mass might be helpful when not continuously heated


Climatic design archetypes _ cold climates

light weight construction are faster to warm up

22ARCHITECTURE AND CLIMATE Glazed balcony

Wohnhaus Hottigerau, Kathan-Schranz, Strolz architects, 1996.

Cold climates - Innsbruck, Tyrol

• Equator facing windows are necessary tools for solar heating (their use is often coupled with thermal mass)


Academie Mont-cenis, Jourda and Perraudin architects

Cold climates – Herne, Germany

Greenhouse


hot-dry climatesChallenges _ overheating problems with dry air, usually characterized by large diurnal temperature variation. Potential _ Evaporative cooling.


Climatic design archetypes _ hot-dry climates

Ostuni _ White paints act as selective surface and high emittance


hot dry climates _ Riyadh (Saudi Arabia)

Wind towers Patios Thermal mass


hot dry climates _ Riyadh (Saudi Arabia)

Thermal massLarge diurnal range (up to 20K) suggest the use of large thermal mass in the walls but also in roof with big thermal capacity.


hot dry climates _ El Cairo Qa’a with durqa’a

Outdoor climate is often hostile. Internal patios permit the creation of a more perfect microclimate in substitution to the exterior one (cooler air thanks to thermal stratification effects, often coupled with vegetation and fountains for evaporative cooling).

29ARCHITECTURE AND CLIMATELouis Kahn, Parlament of Dahka

hot dry climates _ Dahka


HenningLarsen / Minestry of foreign affairs Riyadh


Warm-humid climates_ not that hot but aggravated by high humidity values _ evaporation potential.


warm humid climate _ Hong Kong

Ventilation Solar shading


Climatic design archetypes _ warm-humid climates Typical house: elevated

house to catch the wind and using lightweight

construction. Warm-humid climates are

located around the equator where the roof

receive high radiationbecause the sun is in the

zenith (this can be avoided: using a reflective roof surface or skin, having

an attic, ensuring adequate ventilation of

the attic, resistive insulation on the ceiling)

Small windows in east and west to avoid penetration

of heat gains from low-angle sun.

Cooling effect _ cross ventilation strategies.


warm humid climate _ Japan

Ventilation + Solar shading


Wind _ passive systems

GLENN MURCUTT, MARIKA ALDERTON HOUSE, Australia, 1991-1994

• small diurnal variation _ massive walls are thus not worth.


Temperate climates _ Rome Challenges _ characterized by a seasonal variation between under heated and overheated periods.


temperate climates _ Rome

Solar shading, greenhouses, ventilated roof, patios, Trombe wall


temperate climates _ La Coruna, Spain

• Characterized by seasonal differences• Under-heating problems in wintertime suggest the use of low u-value envelopes (<0,7

W/m2) coupled with equator facing windows for passive solar heating. • The same window can generate overheating problems in summertime. Shading

device are thus required in summer time in combination with the use of natural ventilation strategies.

• Day-Night temperature differences might suggest the use of heavy weight construction systems.

Filters (shutters, in-between spaces, shading, …)


Filters _ Coderch, residential block in Barceloneta, Barcelona


Filters _ Coderch, shaded balconies


Climatic factors


bioclimatic architecture

is a regionalist approach to architectural design based on the understanding of the local climate and the exploitation of naturally

available resources.


Ken Yeang _ Bioclimatic skyscrapers

Spiralling gardens, that are used for shading, cooling and filtering air. Plants improve airquality by removing particulate matter, carbon dioxide and volatile organic compoundsand by humidifying air. // variable deep air zones at the facades of buildings, in the form oflarge open-to-the-sky naturally ventilated atriums with louvered-coverings, or recessedbalconies, or large sky courts.


Green buildings today aim not only at containing their operational energy demand but at also reducing their environmental

impact in a life cycle perspective.

Norwegian buildings are responsible for: • 40% national energy use • 20% of waste• 40% material use• 14 % of CO2 emissions

Countries by CO2 emissions


AC

TIVE

PASS

IVE

AIR WATER

EARTHFIRE

Mircoeolic

Natural ventilation

Geothermal

Thermal massGreen roofs

PV

solar heating

Thermal, humidification,

Waves movement

Rain harvesting,

solar thermal, humidification

hybr

id Hybrid passive downdraught

cooling+

49ARCHITECTURE AND CLIMATE Luca Finocchiaro

SUN


Solar radiation potential _ Source: NASAthe entire climate is driven by the energy input from the sun, determining variations of atmospheric temperature and relative humidity values.


Annually-averaged air temperature (1961-90)

Source: Robert A. Rohde for Global Warming Art.


The sun It is fundamental to understand the movement of the sun and the

quantity of radiation coming all along the year.The earth moves around the sun on a slightly elliptical orbit (Earth axis is

titled by 23.5°to the plane of the sun orbit).


The sun

Sun position can be determined by: Altitude (0 - horizon; 90 - zenit)Azimuth (0 North, 90 E, 180 S, 270 W)


Sun path diagrams _ stereographic

2D representations of the movement of the sun all along the year

175°Azimuth

°Altitude


Variability according to the latitude

Source: S. Szokolay, Introduction to architectural science.


Sun path diagrams _ orthographic

Orthogonal representation on a cylindrical surface (0º - N, 180º S, etc. )

175°

35°°Altitude

175°Azimuth


Solar radiation

Only 20% circa of the solar radiation emitted by the sun reach the earth surface

100%

40% - 1353 W/m2

Source: V.Olgyay, Deisgn with climate

Average = 164 Watts per square meter over a 24 hour day. So the entire planet receives 84 Terrawatts of Power (our current worldwide consumption is about 12Terrawatts)


Irradiation on the earth surface vary with:

1 – angle of incidence2 – depletion due to the atmosphere

(distance in relation to the angle)3 – duration of sunshine and daylight also

in relation to the topography.

Solar radiation



Solar radiationIrradiation on a surface can be measured in: - Irradiance W/m2

- Irradiation over a time period Wh/m2 (area inside the rectangle in the figure)

Source: S. Szokolay,Introduction to architectural science.


Radiation striking a surface – ex. vertical wall - is the sum of: • Direct radiation from the sun • Diffused radiation from the sky vault• Reflected from the surrounding terrain• Coming from the heated ground and nearby objects• Exchange from building to sky vault

Solar radiation / Greenhouse effect



Maximum irradiance at the earth’s surface is around 1000 W/m2 and the annual horizontal irradiation varies from about 400KWh/m2y near

the poles to a value in excess of 2500 KWh/m2y in the Sahara desert or north western Australia.


Sol-Air approach / optimal orientation

Underheated periods _ Maximization of solar radiation, the building should be positioned in order to receive as much radiation as possible.

Overheated periods _ Minimization of not desired solar radiation. Solar shading protection.

Optimal orientation on a yearly basis depends on the surface which receives relatively the most radiation impact during the underheated season and the least in the overheated times.


Solar radiation analysis

South facing facade

North facing facade

The quantity of radiation is expressed in KWh/m2

Solar radiation - Energy received at normal incidence in relation to the solar altitude (1 m2 of surface all along the year)

>> Possibility of animating the graphic showing the variation of radiation from 0 to 360 degrees.

Red zones - overheated

Blue zones - underheated


Diary values in kWh/m2 - Diagram developed on the basis of the solar radiation collected by a 1 m2 surface all around the 360º.

• Blue – Underheated period

• Red – Overheated period

• Green – Annual average

• Yellow – best compromise

Optimal orientation

N.B. Optimal orientation is calculated assuming a homogeneous surface


Academie Mont-cenis, Jourda and Perraudin architects

Solar radiation passive use – greenhouses

Wohnhaus Hottigerau, Kathan-Schranz, Strolz architects, 1996.


Toyo Ito, Kaohsiung National Stadium

1MWP _ system

with its 14,155m2 roof it could potentially generate 1.14 gigawatt hours of electricity every year, enough to power up to 80% of the sorroundingneighbourhood.


Active house – active use _ PV


First Active house in Russia


21st JUN _ SHADING ANALYSIS 21st DEC _ SHADING ANALYSIS

jan feb mar apr may jun jul aug sep oct nov dec

Isolated context Urban context _ Kalvskinnet

Solar radiation – Saupstad / ARK6 course 2013


WIND


The wind

Differential heating of the earth surface causes pressure differences that become the main driving force of atmospheric phenomena (winds, clouds formations … ), providing a heat transfer mechanism from the equator towards the pole.

The movement of air masses and of moisture-bearing clouds are also influenced by the Coriolis force. At the equator a stationary air mass move with the earth’s rotation.

Global wind pattern


The windWind speed decreases at the ground level.

Climate weather files _ Air movements normally measured at 10m above the ground in open country (higher in built-up areas to avoid obstructions).

Wind rose (wind are classified per frequency in relation to the direction _ 12 bars, one per each month of the year)


Frequency HumidityTemperature

The wind chart gives the possibility of distinguishing among desired breezes and inconvenient winds for under heated and overheated periods, significantly helping bioclimatic design. (Distance from the centre indicates in this case the wind speed).

Wind selective analysis


Potential use for natural cooling strategies.

Wind _ Trondheim winter

Winter winds _ temperatures analysis

SE


Potential use for natural cooling strategies.

Wind _ Trondheim summer

Summer _ nightwinds for purge

ventilation

N


Wind _ speed/frequency/direction _ analysis


Wind _ passive systems

GLENN MURCUTT, MARIKA ALDERTON HOUSE, Australia, 1991-1994


Wind _ active systems

Wind turbines

Powerbridge _ Francesco Colarossi, Giovanna Saracino and Luisa Saracino

Microeolic, MIT


Cloudiness


Cloudiness

Cloudiness is based on a visual observation and is counted in % of sky hemisphere covered by clouds.

Cloudiness significantly affect the direct/diffused radiation ratio


Cloudiness

Direct radiation

Diffused radiation

Solar radiation - Diffused radiation, under certain condition – latitude, solar angle and sky vault conditions - can be as much as the direct.


Glasgow School of Art / North windows


PRECIPITATIONS


Precipitations

Total amount of rain, hail, snow or dew and is measured in mm per unit of time (ex. mm/day)


Total amount of rain, hail, snow or dew and is measured in mm per unit of time (ex. mm/day).

Precipitations


Coastal winds occur near the sea or other large bodies of water because of the water thermal capacity (creating a gradient of temperatures, thus a pressure difference).

Evaporative cooling effects _ water ponds or fountains in combination with wind or air movement.

Energy research centre, GelsenKirchen (DE), 1995Kiessler + Partner

Water _ passive systems


Water _ passive systems _ thermal mass

Thermal mass wall with milk-bottles. Arizona’s team for Solar Decathlon

Bottles made greenhouse


Tidal power system

Water _ active systems

harvesting energy from river waves _ GRO Architects _ modular docking stations


Earth


Earth _ passive systems _ Thermal mass

Domaine perraudinKsour – Adobe Granaries


Temperature hourly distribution


Ground source heat pumps harvest heat absorbed at the Earth's surfacefrom solar energy. The temperature in the ground below 6 metres isroughly equal to the mean annual air temperature at that latitude at thesurface.

Earth _ Trondheim


A geothermal heat pump or ground heat pump is a central heating and/or cooling system that pumps heat to or from the ground.It uses the earth as a heat source (in the winter) or a heat sink (in the summer).

Zollverein School _ SANAA

Earth _ hybrid system

Transsolar


References • Victor Olgyay. Design with Climate, bioclimatic approach to architectural

regionalism. Princeton University Press, Princeton, New Jersey, 1963.

• Steven V Szokolay. Introduction to architectural science, the basis of sustainable design. Architectural Press, USA 2010 (ISBN: 978-0-75068704-1)

• V. Brophy and J. O. Lewis, A green Vitruvius, principles and practice of sustainable architectural design. Earthscan, London 2011 (ISBN 978-1-84971-31—5)

• Rafael Serra and Helena Coch: Arquitectura y energia natural.

2013-09-11 _ climate themes and factors

Documents

thermal losses

built forms climate

external temperature

fresh air

thermal models

thermal comfort

external environment

flow of air