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close this bookNatural Energy and Vernacular Architecture: Principles and Examples with Reference to Hot Arid Climates (UNU, 1986, 172 pages)
close this folderPart 1. Man, natural environment, and architecture
close this folder2. Architectural thermodynamics and human comfort in hot climates
View the document(introductory text...)
View the documentTemperature
View the documentThermal conduction and resistance
View the documentRadiation
View the documentThermal convection
View the documentAtmospheric pressure
View the documentWater vapor
View the documentCooling by evaporation
View the documentThermal gain
View the documentThermal loss
View the documentDynamic thermal equilibrium
View the documentHeat-regulating mechanisms of the human body
View the documentMeasurement of conditions of human comfort

(introductory text...)

Thermal Conduction and Resistance
Thermal Convection
Atmospheric Pressure
Water vapor
Cooling by evaporation
Thermal gain
Thermal Loss
Dynamic thermal equilibrium
Heat-regulating mechanisms of the human body
Measurement of conditions of human comfort


The properties of matter and energy must be considered in order to fully understand climatic phenomena. Heat, radiation, pressure, humidity, and wind, among other factors, interact mutually to establish climate conditions near the Earth's surface.

In this environment of continuously changing pressure, wind movement, temperature, humidity, and cloud cover, an architect places a fixed building. Such a rigid structure is intended to provide a comfortable internal environment over a wide range of these external variables. Two factors facilitate this task: first, in temperate and subtropical zones, ordinary buildings offer fair protection from climatic extremes, and, second, the human body has a considerable margin of tolerance for these variables. However, special treatment is required, particularly in tropical zones.

When considering the architectural design of a building, as well as in town and regional planning, other elements should be considered. The continuous daily motion of the population, which has properties analogous to the humidity concepts of saturation, evaporation, and condensation, must be accommodated in houses, towns, and regions.

Any living organism continuously adapts itself to the flux of its environment. Once constructed, however, a man-made object can no longer adjust itself. This inflexibility of human creation is at once its weakness and its strength. A design can succeed in uniting the particular and permanent with the universal and continuously changing. Yet another design, by failing to sense the forces at work or to create a harmonious union, can isolate and alienate human life.

Before considering the application of scientific concepts to architectural design and town planning, it is useful to briefly examine some basic concepts of architectural thermodynamics and human comfort.