English

Explains why house external shell and ventilation system must be treated as integral elements of a total system. Explains, using an analogous water system, why air leakage through shell is greater using push-pull ventilation than when using extract ventilation and why houses should be airtight.

Reports the investigation of the natural ventilation of three test houses. Describes the houses which were of standard design. Natural ventilation rates were measured using sulphur hexafluoride as a tracer gas. An energy audit was also performed using a fan to pressurize and depressurize the house and an infrared scanner to detect the leakage paths. The tracer gas measurements were converted to a format similar to thepressurization results by using a previously developed model. Gives results in the form of graphs.

Calculations of water vapour flow through walls and ceilings are frequently based on the permeability of building materials and implicitly assume that most of the vapour transport takes place by diffusion. Finds that this model is generally inval

Describes experiment to determine the effect of an evergreen windbreak on residential heat losses attributable to air infiltration. Eight-meter tall pines were arranged as an experimental windbreak to shelter a townhouse for nine weeks Air infiltration was measured continuously using SF6 as a tracer gas to compare air change rates before and after the windbreak. A dimensionless parameter was derived to distinguish between wind-and temperature-produced air infiltration and to determine the effects of wind direction.

Describes tests made on fifty different weatherstrips. Tests were made in the laboratory of airtightness, rigidity, ageing, load tests, freeze tests and wear tests. Strips mounted in windows were tested for ageing and resistance to driving rain. Gives test methods and results and discusses the characteristics of eight main types of strip.

Documents and compares the air infiltration levels experienced in five Twin Rivers townhouses before and after retrofit. The retrofits sealed and caulked window frames, sealed cracks along the attic floor/party wall Junction and reduced leakage from basement to attic. Weather data and air infiltration rates were analysed using multiple regression, polar plotting, stemleaf plotting and comparisons of infiltration rates with inside to outside temperature differences. Gives results in graphs and tables.

States that porosity is the most important single parameter describing shelterbelts but is very difficult to measure or define. Describes a method for categorizing wind breaks in terms of porosity using only measured minimum leeward-wind velocity. Gives theoretical expressions for the flow through a porous shelterbelt. Describes experiment to measure wind velocities around shelterbelts of low, medium and high porosity. Shows that wind measurements could be made any height without affecting relative reduction in velocity.

Reviews current status of research in North and South America relevant to the prediction of tall building behaviour in response to wind. Four main headings are considered a)meteorological research-wind structure and climate, b) full- scale investigations of wind action on tall buildings, c) development of wind tunnel techniques for building aerodynamics, d) simplified theoretical models of wind effects on tall buildings.

Outlines the principles of infrared thermography and describes the equipment. Reports investigation at the National Swedish Institute for Material Testing into the use of thermography. Finds that the method should primarily be used as a relative method for plotting of building faults on external walls and for qualitative judging of their nature. It is not suitable for quantitative determination of the heat resistance of walls.Gives typical thermograms prepared using a test wall to which artificial defects were added.

Reports study of the ways in which different ventilation levels affect people part 1 of the study took place in Gavle. Air change rates, the amounts of radon and its derivatives were measured. Finds that ventilation installations are often poorly adjusted giving a wide variation between flats in the levels of air change. Amounts of radon and daughters were also higher than expected, due mainly to the poor ventilation. Concludes that lowering ventilation to present recommended level of 0.5 changesper hour cannot be recommended without further investigation.