window

A multitude of design strategies are available to achieve energy-efficient windows. Opportunities for improving window performance fall into six groups: site, exterior appendages, frame, glazing interior accessories, and building interior. Design strategies within these groups can improve one or more of the six energy functions of windows : solar heating, daylighting, shading, insulation, air tightness and ventilation. Gives 33 strategies for energy saving. Includes information on weatherstripping windbreaks, shutters, multiple glazing and many others.

Reports measurements of natural ventilation and leakage rates in two test rooms in a university building. Describes rooms and instrumentation. Gives results of pressurization tests with windows closed but not sealed, sealed, and weatherstripped. Gives results of measurements of ventilation rate using N2O as a tracer gas. Discusses the analysis of results and experimental errors. Compares measured rates with ventilation rates calculated using crackand ASHRAE methods.

Reports laboratory tests of sound transmission loss, thermal transmittance and rate of air leakage conducted on full-scale specimens of typical residential exterior wall constructions, either unbroken or penetrated by a door or window. A total of 109 acoustical tests and 48 thermal tests are reported. The resultant data are compared with literature data on similar constructions. Some correlation was found between sound transmission loss and air leakage.

Gives results of a survey carried out in December 1978 on heating and ventilating of dwellings. 2000 men and women were questioned throughout the federal republic. Gives range of dwellings, desired and actual room temperatures, types of windows, frequency and duration-of window opening and the existence of draughts.< Concludes inter alia that heat loss through ventilation is greater than commonly assumed. In particular this heat loss is through leaky windows and ventilated bedrooms.

Treats importance of keeping uncontrolled ventilation to a minimum in buildings equipped with balanced ventilation. Provides theoretical and experimental description of leakage of air past windows. Includes comparison between standards of different countries. Discusses effect on building ventilation of variations of wind and outdoor temperature. Considers in conclusion measurement of air flows between rooms in a building. Describes development of tracer gas method based on computer-assisted evaluation.

Considers windows as part of system of air controlling features of buildings to enhance air movement through living zone to cool occupants. Discusses how air is moved by pressure differences set up as wind strikes a building. Treats how location and type of window determines the pattern of air entering a building. Size of window opening determines speed. Location and type of window directs the air as the nozzle of a hose directs water.Considers how overhangs, landscaping screens, trees, and shrubs can also be used in control of air movement.

Reports tests of air leakage of windows, made in a wind tunnel. Six different windows were tested, five were of the same design with different manufacturers and materials;two steel, one wood, one aluminium and one cast iron. Gives expression for the airflow through a window. Discusses pressure distribution on buildings and stack effect.

Discusses the problems of sealing double glazing to reduce condensation between the panes. Describes sealed glazing unit and sealants used. Discusses causes of failures. Reports tests for seal leakage made by lowering air pressure surrounding theunit and observing glass deflection. Windows were also tested by weathering in the laboratory and by exposure to actual weather conditions. Discusses results and finds extreme difficulty in providing and maintaining an effective sealing system.

Considers the rate of natural ventilation required in a room to maintain a healthy concentration of oxygen given the efficient sealing of windows against draughts. Includes a nomogram toassist the calculation of a rate of air introduction according to the height of the building, wind loads, and type of window construction.

Reports on a project to assess the air infiltration performance of new residential windows and compare field test results with anticipated performance. Supporting tests and techniques included air leakage tests of windows in the factory, leakage testing of the window/wall installation crack and infrared thermography of test conditions. Tests were also run to determine performance of new windows during cold weather, the possible change in performance over time, the performance of fixed sash and of old and retrofit windows. Presents results of pilot study.