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.
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.
Characteristics of the ventilation in poultry buildings have been studied at the Hungarian Institute for Building Science. The pressure loss of the cross-building ventilation flow is determined for a section of a typical building and for two typical air inlet-outlet layouts. On the basis of velocity measurements the local hourly air change rates were determined in the cages and compared to the general air change rate in the building.
Shows that the leakage test in most buildings with mechanical ventilation may be performed with the ventilation system itself with only a slight reduction in the accuracy of the measurements. Using fans in the ventilation system, the pressure difference inside/outside may often reach a measurable value of 5-10 pa. If such a pressure difference is not obtained, the leakage exceeds allowable values and the building should be tightened. Before measuring, all of the supply air openings in outer core of the building should be closed and taped. All doors inside the apartment should be open.
Discusses and analyses the characteristics of methods of determining local air flows through the building envelope, methods of determining the air leakage and ways of determining air changes in rooms. Summarises in a table methods of determining local air flows. Of the air leakage methods, treats static and non-static methods. Considers three commonly used tracer gas methods for air change measuring methods.
Reports on continuous energy measurements carried out in 6 detached single-family, low-energy houses in Copenhagen. Describes a few typical construction details to illustrate solutions to the problem of cold bridges, and to demonstrate ways of obtaining airtight constructions. Measures air change rate using tracer gas decay method and pressurisation and suction tests. Works out total heat loss for a period when ventilation systems are sealed and the houses heated by electric resistance heaters.
Measures the air infiltration in individual rooms of a one-storey airtight house, using a special tracer gas measurement technique. Concludes that the overall ventilation rate was very low for the test house, although it had mechanical ventilation (exhaust fan). States that the best way of getting adequate ventilation is to install a ventilation system with built-in routes where fresh air can enter the building. This should either be balanced ventilation system or an exhaust fan system with special vents to the outside for supplying fresh air.
Assesses the quality of retrofit work carried out in 329 Swedish houses, which had received government energy-saving funds. Describes the selection of dwellings, the measurement methods employed (including thermography, pressure testing, tracer gas and heat flow) and the results.< In most houses, insulation work in attics and on external walls had been carried out satisfactorily. However, the houses were still not air tight and exhibited high ventilation figures (for pressure tests 8 air exchanges per hour at 50 Pa and for tracer gas tests 0.6 air exchanges per hour).
Provides a summary of Report IIIc of the overall research project `air change in buildings' undertaken by the EMPA, Switzerland, sponsored by the Swiss Federal Ministry for Environmental Protection. Describes a measurement programme undertaken in an unoccupied single family house built in 1979.
Provides a summary of Report IIIa of the overall research project `air change in buildings' undertaken by the EMPA, Switzerland, sponsored by the Swiss Federal Ministry for Environmental Protection. Describes an investigation ontwo identical insulated flats in the same block with the same orientation, one with folding shutters and the other with roller blinds. The occupants were instructed on how to close the blinds at night. Their normal living habits and ventilation preferences were not affected. Illustrates the flats and blinds diagrammatically and in photographs.