Environmental Controls I/IGEnvironmental Controls I/IGLecture 3

ClimateComfort Strategies

Bioclimatic Architecture

Typical exterior conditions as experienced over several years

ClimateClimate

Description of temperatures, humidity, precipitation, wind, and cloudiness

WeatherWeather

Regional climate and local weather affected by the…

ClimateClimate

… which creates seasonal effects which are further enhanced by the…

(1) Revolution of Earth around (1) Revolution of Earth around SunSun

…which changes the solar angles.

These angle changes and atmospheric conditions affect the…

(2) Declination of the Earth’s (2) Declination of the Earth’s axisaxis

L: p. 130 F 6.8a

…reaching the earth’s surface.

As radiation reaches the surface, convection air loops are formed. These currents are altered by the…

(3) Solar Radiation(3) Solar Radiation

(4) Rotation of the Earth(4) Rotation of the Earth… that forms air currents known as the “prevailing westerlies” and various sea currents.

These flow patterns in turn are altered by…

PrevailingWesterlies

…such as channels, mountains, hills, valleys, and canyons.

(5) Surface Characteristics(5) Surface Characteristics

Climate ZonesClimate ZonesNorth American climate zones were originally perceived as distinct and broad.

Olgyay Bioclimatic ChartOlgyay Bioclimatic ChartDeveloped to quantify shifts to comfort zone Adding moisture Adding ventilation Adjust MRT Adjust solar radiation

BioclimaticBioclimaticChartChart

86ºF/ 30% RH275 fpm wind7 grains H2O/# of air78.3ºF MRT

100ºF/ 10% RH28 grains H2O/# of air

48ºF/ 40% RH295 Btuh Radiation

AIA Climate Zones (1980)AIA Climate Zones (1980)

Psychrometric ProfilePsychrometric ProfileZone 4

Psychrometric ProfilePsychrometric ProfileZone 4

Comfort StrategiesComfort StrategiesApproaches to thermal comfort Technology based Bioclimatic based

Technology BasedTechnology BasedUses conventional mechanical systems as primary thermal comfort strategy

Pre 1900 Vernacular/low technology

1906 Air-conditioning1917 Curtain wall1934 Thermopane window1937 Fluorescent lighting1945 Mass production1951 Nuclear powered electricity

1972/1978 Energy crises~1985 Smart technology

Bioclimatics1995+ Technology + bioclimatics

Technology TimelineTechnology Timeline

Low Technology & Low Technology & VernacularVernacular

Conventional Technology Conventional Technology

Comfort VentilationComfort Ventilation

Evaporative CoolingEvaporative Cooling

High Thermal MassHigh Thermal Mass

High Thermal Mass with Night High Thermal Mass with Night VentilationVentilation

Internal GainsInternal Gains

HumidificationHumidification

Passive and Active SolarPassive and Active Solar

Strategy SelectionStrategy Selection86ºF/ 30% RHNatural VentilationEvaporative CoolingHigh Mass Cooling

100ºF/ 10% RHEvaporative CoolingHigh Mass Cooling w/ Night Ventilation

48ºF/ 40% RHPassive Solar (~1475 Btu/ft2-day)

Bioclimatic BasedBioclimatic BasedUses building form and climate opportunities as initial strategy

Bioclimatic ArchitectureBioclimatic ArchitectureClimate adaptive takes advantage of

local climate to enhance comfort

Climate rejecting relies primarily on

mechanical systems enhance thermal comfort

Climate Adaptive BuildingsClimate Adaptive Buildings Architectural form creates

microclimates Natural ventilation/daylight Seasonally dynamic Thermal mass

Climate Rejecting BuildingsClimate Rejecting Buildings Ignore local climate Primarily use HVAC Seasonally static Light weight material

Bioclimatic-Bioclimatic-ResidentialResidential

Small scale, low rise, personal user

Bioclimatic-CommercialBioclimatic-Commercial Large scale,

low, mid and high rise, public user

Bioclimatic-InstitutionalBioclimatic-Institutional High density, low

and mid rise, public and personal user