ARCH 2006 Climate 42°C (107°F)Likely death 41°C (105.8°F) Sweating stops. Coma sets in. May damage the brain. 40°C (104°F)Heat stroke Hyperthermia (inevitable body heating) occurs. Evaporative cooling - sweat. (for short periods at the rate of upto 4 litres/hr) Vasodilation (skin surface dilates). Increase in heat transportation to the surface. Rise in skin temperature and dissipation of radiant and convective heat. 37°C (98.6°F)Normal, healthy condition Vasoconstriction. Lower skin- temperature, goose-pimples (erection of hairs) Shivering (increase in muscular metabolism) 35°C (95°F) Hypothermia (inevitable lowering of deep-body temperature) 25°C (77°F)Likely death Climate and Site and Human Comfort

ARCH 2006 Climate Six Major Factors Determine Thermal Comfort Environmental 1.Air temperature (dry bulb temperature or DBT) 2.Humidity (relative humidity RH) 3.Air movement (velocity v in m/s) 4.Radiation (Mean radiant temperature MRT) Individual 5.Activity 6.Clothing Thermal Comfort

ARCH 2006 Climate Typical Metabolic Heat Generation for Various Activities Activity Btu/(h.ft²) Resting Sleeping Seated, quiet Walking (on level surface) 2.9 ft/s (2 mph) 4.4 ft/s (3 mph) 5.9 ft/s (4 mph) Office Activites Writing Typing Filing, standing Walking about Lifting/ packing Driving Car Miscellaneous Activities Cooking Housecleaning Pick and Shovel work Leisure Activities Dancing, social Calisthenics/ exercise Tennis, singles Basketball

ARCH 2006 Climate Bioclimatic Terms Saturation humidity line Absolute humidity (AH) is the vapor content of air, given in grams of water vapor per kg of air, i.e. g/kg. Air at a given temperature and pressure can support only a certain amount of moisture and no more. This is referred to as the saturation humidity(SH). If this is plotted on a graph against the dry bulb (air) temperature (DBT), we get what is called the saturation humidity line.

ARCH 2006 Climate Relative humidity line Relative humidity (RH) is an expression of the moisture content of a given atmosphere as a percentage of the saturation humidity at the same temperature: RH = 100 x AH/SH (%)

ARCH 2006 Climate Wet bulb temperature lines: Wet bulb temperature (WBT) is measured by a hygrometer (or psychrometer). This consists of two thermometers, one measuring the DBT, the other having its bulb enclosed in a wet wick. 'Web bulb depression' is noted as the difference in the temperatures between the wet wick thermometer and the DBT. The difference happens as the wet wick thermometer is cooled down by the evaporation on the wick. The amount of evaporation is a direct indication of the moisture carrying capacity of the atmospheric air at that temperature and that lowers the WBT. When the air is saturated, there is no evaporation, thus the DBT and WBT readings are identical, the depression is zero. In this way, the 'status point' is determined at the intersection of the vertical DBT line and the sloping WBT line of the psychrometric chart.

ARCH 2006 Climate

"THE COMFORT ZONE" The Bioclimatic Comfort Chart - Victor Olgyay Design With Climate 1963 Bioclimatic Chart

ARCH 2006 Climate Bioclimatic Chart

ARCH 2006 Climate Bioclimatic Chart For Dallas, TX

ARCH 2006 Climate

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Siting of trees relative to a house is critical to ensure that during summer sun is blocked by vegetation while during the winter sun can still penetrate into the building. (After Borer and Harris, 1998).

ARCH 2006 Climate Light Transmission Reduction by Trees

ARCH 2006 Climate Recommended Form and Orientation for Cool Regions Minimize the surface area of buildings (compact form) to reduce exposure to low temperatures. Strategies Maximize absorption of solar radiation Reduce radiant, conductive, and evaporative heat loss Provide wind protection

ARCH 2006 Climate Recommended Form and Orientation for Temperate Regions Building Form Elongated along east-west axis to maximize south facing walls Strategies Minimize east and west exposures which are generally warmer in summer and cooler in winter than southern exposures Balance Solar heat gain with shade protection on a seasonal basis Encourage air movement in hot weather, protect against wind in cold weather

ARCH 2006 Climate Recommended Form and Orientation for Hot-Arid Regions Building Forms should enclose courtyard spaces Strategies Reduce solar and conductive heat gain Promote cooling by evaporation using water features Provide solar shading for windows and outdoor spaces

ARCH 2006 Climate Recommended Form and Orientation for Hot-Humid Regions Building Form Elongated along east-west Axis to minimize east and west exposures Strategies Reduce Solar Heat Gain Utilize Wind to Promote Cooling by Evaporation Provide Solar Shading for Windows and Outdoor Spaces

ARCH 2006 Climate Vegetation and Temperature /Humidity changes

ARCH 2006 Climate Air Movement Air movement is affected by global and local factors. Seasonal air pressure Earth’s rotation Variations in heating and cooling of the land Topography

ARCH 2006 Climate

mda.state.mn.us Shelter belt/Windbreak

ARCH 2006 Climate Windbreak Effects on Airflow Berm Deflecting Airflow

ARCH 2006 Climate Shelter belts of trees should be planted at a distance of 1 to 3 x house height from the building to maximize wind drag. In addition fences in front of the building can assist this further (After Borer and Harris 1998)

ARCH 2006 Climate

Microclimate Analysis

ARCH 2006 Climate