States that with double and triple glazed windows the air flow through the joints reduces the transmission heat flux. This has the effect of lowering the heat load and in particular the annual heat energy demand. The same phenomenon occurs when the windows are covered with shutters at night. Provides calculation equations.
Waste air windows protected by intermediate louvres show the share of absorption in the transmission coefficient to be dependent upon the air throughput through the window. To calculate it, a general solution is given. Practical calculation is simplified by graphs established for two common louvre designs in two, three and four-pane windows.
Presents the results of tests on the air leakage characteristics of a number of different energy conservation products applied to a double hung window. Gives air leakage characteristics under simulated in-situ conditions atvarious wind speeds for the different products. Results show that interior shutters perform best, followed by interior storm windows, a reflective shade, quilts and standard window shades. Within a group, products involving perimeter sealing give the best air leakage characteristics.
Assesses energy saving as a function of window air tightness, and transforms value into a corresponding U-value. Uses a single-cell infiltration model, and shows that using the U-value is a convenient way of comparing different energy saving methods. As an example, computes the U-value for the windows in a detached single-family house in an urban area and for Gothenburg weather conditions.
Presents preliminary results of a demonstration program on energy retrofits of low-cost housing in the Lombardy Region, with particular reference to retrofit of windows. Energy analysis shows that window retrofits can be very cost-effective, particularly when applied in conjunction with ordinary maintenance operations.
Traces the development in the UK of performance based standards for windows from the original British Standard Draft for Development 4 issued in 1971, through the UEAtc MOAT No1 isued in 1974, to the recent BS No 6375 Part 1 1983. The original three attributes of wind resistance, air permeability andwatertightness have been gradually developed. Test methodology has been refined, and for weathertightness levels of performance have been identified to reflect various categories of use.
Tests of airtightness and raintightness of windows have been carried out continuously at the Swedish National Testing Institute since 1977. As many factors such as size, material, method of opening and type of weatherstrip employed can all vary among windows tested, it is not easy to draw conclusions about the influence of any one factor. Test results for each window are also strongly influenced by the workmanship and quality of the individual window.
Decribes how the 19 floor 76m high Arts Tower at Sheffield University is having its energy use characteristics investigated. Illustrates a typical floor plan. Describes and illustrates a component pressure testing rig todetermine the infiltration coefficients of the vertically sliding windows. Treats the criteria determining the rig design and the air flow measurement procedure. Treats tests on windows where the sealant did and did not appear defective, the overall values of window coefficients, testing of a weatherstripped window, the payback period for weatherstripping the windows.
A large number of air-conditioned office blocks constructed in recent years in the FRG have been equipped with waste-air ventilated windows. Based on experience now available from planning, laboratory tests and practical operation, describes the different design principles and their technical characteristics. Bases the evaluation on window designs which have been used in 11 office buildings totalling 10000sq.m useful floor area.
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