window

Describes study and operating principles of device allowing a window (or more usually a light-weight cladding unit) to be placed in variable temperature conditions simulating actual summer and winter conditions, in order to determine the airtightness of the window under these conditions. Describes testing of three plastic window frames in the device and supplies the measured values of the airtightness before, during and after the tests, and the corresponding curves.

The airtightness of windows is an important feature in deciding habitability. in additional to the conventional, the window sashes featuring improved soundproofing and insulation performance have appeared. Summarizes the results of measurements of the air-tightness of these sashes made using carbon dioxide as a tracer gas, as well as double sliding and single sliding windows using actual size samples. Explains experimental apparatus and measuring method.

The significance of air tightness on building performance and the factors affecting the air leakage performance of the building enclosure are discussed. the ability of the ASTM standard air leakage test method to check the quality of design and manufacture of factory-assembled walls, windows and doors as well as the inability of the method to provide the building designer with quantitative air leakage data for calculating heating and cooling loads and designing smoke control means is also discussed.

Part of an extensive research programme being carried out also in Denmark, Finland and Sweden. Describes 75 window tests and gives diagrams of air flow and rain penetration apparatus. Proposes tentative evaluation curves for air penetration of windows of a stringent kind suitable for a severe climate. For air pressure of 30-40 mm of water, an 'acceptable' air flow is about 30 m.m. per hour per test window, with 'good' at about 20 and 'excellent' about 11. The curves are shown graphically.

Points out that increased levels of thermal insulation in dwellings make ventilation heat loss an increasingly significant proportion of total dwelling heat loss and of great significance for sizing heating installations and selecting their control equipment. Treats attempts to reduce ventilation loss by specifying greater tightness of building structures, especially windows.

A study made to confirm the values given in german standard DIN 4701. considers theoretical natures of air permeability and the k-value as they concern windows. Finds that infiltration through windows without weather-stripping depends to such an extent on the quality of manufacture and fitting that essential differences between single-glazed, double-glazed and double windows scarcely exist. Finds no real difference between woodenand metal frames when new, but after normal wear and tear an average value of 3m(3)/h for each metre of gap at 1mm pressure difference is acceptable.

According to TGL standard 112-0319, the demand of heat required for ventilating a building essentially depends on the passage of air through its window and door joints. This varies to a great extent. The losses of thermal energy can be reduced substantially by tolerance specifications for joint dimensions. Such tolerances will result in permissible resistance coefficients for different types of windows. Depending on thehygienic requirements suitable selection is then possible within a narrow margin of error.

Gives general data about windows in the experimental dwellings and the transport of air through small openings. Describes method for calculating the rate of air infiltration through windows as a function of the pressure difference between both sides of the construction. Presents results for each type of window graphically in several ways. Gives figures for cracks between movable construction parts.

Reviews means of rain water penetration and how to apply one-stage weather proofing listing the disadvantages. Reviews research results obtained with two-stage weather proofing by adding an additional seal and summarises the pressure variations resulting from wind plus the design of horizontal and vertical joints between individual facade segments. Discusses the practical design of joint and sealant illustrating this for a few window types and adds that this design is also applicable for a complete curtain wall.

Describes retrofitting a wood-frame residence, having only limited insulation in the attic, to reduce its energy requirements for heating and cooling. The three retrofit stages comprised : reducing air leaks ; adding storm windows : andinstalling insulation in the floor, ceiling and walls. The housewas extensively insulated to evaluate energy savings and other performance factors. an economic model was used to evaluate the cost effectiveness of the retrofit options.