ABSTRACT
Natural ventilation is the exchange of air between a building exterior and interior through wind driven flow and improves human comfort through the removal of concentrated heat and humidity (ASHRAE 2005). This type of ventilation brings in outdoor air, when indoor temperatures are highest, increasing human comfort levels as air passes over the skin, creating a physiological effect by increasing convective and evaporative heat transfer from the skin’s surface. The behavioral characteristics of airflow in space are based on fundamental thermal principles: air tends to move in a straight
1 INTRODUCTION
Vernacular architecture is a designation for structures that exude centuries of experience built on the relationship between physical building constituents and the natural environment (Coch 1996). These structures are based on a fundamental zero-energy response to dynamic climatic conditions, using construction strategies such as orientation, degree of enclosure, and material systems to intensively shape adequate thermal zones for human inhabitation. In vernacular structures located in hot and dry temperate climates, thermal comfort is often achieved through natural ventilation (Khan et al. 2008). Through extensive periods of development, early populations advanced their specific knowledge base about the most effective use of construction resources in providing improved levels of comfort within the built environment. Today, much can be learned from study of these early settlements about passively maintaining thermal comfort while offsetting energy consumption. Before resorting to mechanical means, traditional solutions based upon ancient construction strategies can first be evaluated, and adapted to contemporary construction techniques (Fathy 1986). To curtail the misuse of energy attributed to steady state mechanical conditioning, this study examines provisions for thermal zoning evident within vernacular structures with particular focus on the energy-saving strategies established by these traditions. To analyze passive cooling potential
line due to its mass; its flow type changes from laminar to turbulent when encountering obstructions; its velocity increases when constricted; and it tends to move from high to low pressure areas around buildings (Lechner 2009).
