This paper considers the building's envelope in the design phase. Energy related decisions during the design phase have great influence on the life cycle cost of the building. Since sunlight and climate are changing factors, the envelope is equipped with mobile and adaptable components (shading devices, movable insulation, opening window schedules ...) which can react to climatic conditions. Architects use computer aided design tools to describe a building and its envelope.
The application of a continuous thermal insulation on the external face of building walls ameliorates the thermal performance of external walls and alleviates problems related to thermal bridges. However a further improvement of this insulation system may be achieved by using ventilated walls, which consist of an open ended cavity placed between an insulating board {directly applied on the external side of outer walls) and an external cladding.
Each year in Canada, building fires cause hundreds of deaths, thousands of injuries and billions of dollars’ worth of property damage. Canada has the second highest fire death rate among 15 industrialized countries. In Canada in 1988, about 72% of fire deaths and 40 percent of fire property losses occurred in small buildings, such as one- and two-family homes, apartment buildings and hotels/ motels. The 1989 fire statistics for Alberta indicate that about 70% of fire deaths and 51 percent of fire property losses occurred in small buildings.3 What can we learn from these numbers?
Existing commercial buildings are surveyed and categorized based on the construction characteristics of their envelope. The envelope heat gain and the resulting cooling load demand are analysed with the aid of energy simulation tool DOE-2. l D. The concept of the overall thermal transfer value (OTTV) is applied to study the association of the envelope designs with the cooling requirement, and a modified approach in asessing the effective envelope heat gains under a sub-tropical climate is proposed.
Recent research suggests that fine-particulate air pollution increases the incidence of lung disease and premature death. In this paper, single fibre filter theory was used to predict the theoretical particulate collection efficiency of air permeable walls (dynamic insulation). The relationship between particle diameter and filtration efficiency for dynamic insulation, as a function of flow rate, is examined and compared to that for a conventional filter.
A pressure-equalized rainscreen (PER) wall is a multiple-line-of-defence approach to rain penetration control. This Update defines pressure equalization and discusses the various elements that must be incorporated in a PER wall to minimize rain penetration due to air pressure differentials.
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