English

Infiltration models are used to simulate the rates of incoming and outgoing air flows for a building with known leakage under given weather and shielding conditions. 

A study was conducted in 40 homes in the areas of Oak Ridge and West Knoxville, in the summer and winter months, to quantify concentrations of COx, NOx, particulates, formaldehyde, and radon, as well as selected volatile organic compounds. 

Undertakes a comparison of full scale and model scale internal velocities of naturally ventilated rooms. The FSEC Passive Cooling Lab, an experimental building with a fixed roof supported by columns, whose floor plan and ceilings are reconfigurable, located at Cape Canaveral in Florida, is the building used in this study. The full scale tests were conducted during evening and early night to provide an almost thermally neutral atmosphere, during February and March 1982.

Reviews the literature on wind tunnel modelling of natural ventilation. Lists advantages of using wind tunnels. Discusses strategies for utilizing natural ventilation. Describes the mean windspeed coefficient method and the wind discharge coefficient method of estimating natural ventilation for design of buildings in hot climates, and gives their advantages and disadvantages. Gives criteria for constructing wind tunnel models.

Ventilation and air exchange in buildings and industrial plants can be induced by external winds and by buoyancy forces. The dependence of the air exchange and heat transfer on a large number of factors, including the detailed configuration of the building and surroundings makes an analytical or numerical analysis of practical design problems impractical, particularly when both the buoyancy and the wind-induced pressures are of the same order of magnitude.

The amount of air infiltration in a building, for given weather data, depends on the leakage and its distribution on the building envelope. In simulations of 17 designs of multiunit, multistorey buildings in Berlin, based on a typical meteorological year we obtained a wide range of infiltration values that varied according to the floor plan, the number and location of wall openings and cracks and the flow resistance relationship between the inside and the exterior of the building.

Air tightness results for 40 New Zealand timber frame houses of varying age and construction detail are given. The steady pressure method was used at 6-9 indoor-outdoor pressure differences in the range 10-150 Pa. The data is presented in four ways: 1. air changes per hour at 50 Pa, 2. the coefficient and exponent of a generalized leakage function, 3. the leakage rate per unit shell area at 50 Pa, and 4. the equivalent leakage area at 50 Pa. Houses in the 0-5 and 6-20 year age groups were not significantly different in terms of air tightness.

Dynamic insulation is a means of reducing building heat losses to near zero without the use of massive thermal insulation. It relies on recycling the heat conducted through the fabric or reducing the temperature gradient by means of a suitable heat transport fluid - usually air and sometimes water. Describes research and experience in Sweden and France. In Sweden, some 80,000 m2 of roofs (mostly of single storey sheeted structures) use the contraflow system of dynamic insulation and there have been a few experimental installations in the housing sector.

Presents the results of air leakage tests on the windows of the Arts Tower at Sheffield University. The results quoted show the ranges into which infiltration coefficients fall. Relates pay-back periods for weatherstripping to height above ground level. Tabulates mean values of leakage coefficient and flow exponent for defective and non-defective sealant and compares with values suggested in CIBS Guide.

Indoor air quality and air infiltration were measured in 16 low-energy Californian houses. Eleven houses had gas stoves: all had average infiltration rates of 0.5 h to the -1 or less, recent construction dates, low natural ventilation, and no mechanical ventilation.