Describes a simple device which pressurises an enclosed volume of air adjacent to individual components in the building fabric. The air flow through the crackage is measured and the interdependence of the flow rate and pressure is examined. Windows, floors, loft traps and suspended ceilings are examined. A simple relationship is found to be applicable to individual components but no universal relationship is found for a general range of components with superficially similar cracks.
Reviews air infiltration studies in New Zealand. Tighter houses have evolved over the years through changes in building methods and materials. Some of the tighter houses can have condensation problems. Investigates the airtightness of 40 houses together with the leakage resistances of a range of building components and bulk sheathing materials. A comparison with houses in other countries shows that comparatively tight houses can arise from simple construction methods not employing vapour barriers. Gives air infiltration rates as a function of windspeed for 4 of the 40 houses.
Discusses the problems associated with poor air quality in tight buildings. Considers how problem conditions can be identified and evaluated, and gives some possible solutions to improving air quality. These include turning the thermostat down slightly, increasing ventilation levels, and ensuring that themechanical ventilation system is working properly, or calling in a specialist to identify the problem.
Studies the airtightness of about 50 passive solar homes located through out the USA using low cost measurement techniques. Measures include pressurization tests to measure airtightness and tracer gas measurements to determine air infiltration rates. Pressure tests show a variation in airtightness of homes from 3-30 changes/hr at 50 Pa, with a median of 5-9 changes/hr.The air infiltration measurements cover a wide range from 0.05-3 changes/hr, with a median of 0.5 changes/hr. Finds that these passive solar homes are not significantly tighter than less energy-conscious houses.
Notes initial airtightness requirements in SBN 1980 and discusses various forms of ventilation. Discusses how tightness testing can reveal location and magnitude of leaks. Gives theoretical method of calculating air leakage flow and relates this to practical measurement. Considers different alternatives such as pressurising the building and combining tightness testing with thermography. Discusses 1980 building regulations and what buildings ought to be tested. Lists critical points of a building and measures which can contribute to good airtightness.
Measurements made in Finland have shown that the airtightness of many small houses is lower then the level of requirements specified in Sweden. States that the most important areas for sealing up external walls in concrete structures are the joints in the internal shell, the joints between concrete and timber structures, and the joints between door and window frames. All these areas can be made airtight by using appropriate materials and construction methods. In general, the air tightness of small concrete houseshas been found to be good and to comply with the specified requirements.
The air tightness of buildings is part of an investigation performed by the State Research Centre of Finland. Regulations are being developed in Finland for the maximum allowable leakage in buildings. These can be stated as 0.2 ach/hr for residences, 0.1 ach/hr for low apartment buildings, and 0.2 ach/hr for high rise buildings. Tightness can be measured using a suitable fan connected to a board in a window or door opening, or by thermography.
Measures air infiltration and tightness of Swedish houses using the tracer gas technique and the fan pressurisation technique. Uses a previously developed model correlating air tightness and infiltration to evaluate the performance of Swedish homes. Shows that it is difficult to achieve the recommended minimum ventilation rate according to the Swedish Building Code by relying on natural air infiltration. Most new homes do, however meet the Code's stringent air tightness requirements. A comparison with American houses show that Swedish homes are very tight.
Presents the latest results of air infiltration research in Finland. The aim is to increase the knowledge of the influences of air infiltration on energy consumption, ventilation and indoor climate. Briefly describes the principles of a calculation model for predicting the interconnection between airtightness and air change rate. Describes improvement of air tightness in Finnish buildings, with special attention to construction details. Discusses possibilities of draughtless and controlled fresh air intake through the building envelope.
Reviews new regulations and their consequences for external wall structures. Considers energy savings, air tightness requirements, U-values, air movement and zone division, heavy and light structures, building classification according to room temperature, incidental heat gains from insolation.
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