States that the reduction in energy losses due to reduced air infiltration is often overestimated because the effect of open windows is not taken into account.< Shows that the habits of airing are rather similar in some European countries. The proportion of windows open or ajar is inversely proportional to the indoor- outdoor air temeperature difference over a large interval of this temperature difference.< The proportionality constant seems to take a value that is independent of the building construction or the heating system of the residential building.
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.
Investigations in Denmark show that there are as many as 75 different compounds in indoor air in tight houses including toluene, xylene, and radon. The dust in homes contains a large number of allergically active ingredients, the most important being the dust mite, which occurs in bed clothes.< States that good air quality is therefore difficult to maintain with natural ventilation in new tight houses. If the hygienic demands of this decade increase the need for ventilation, mechanical ventilation seems to stand a good chance.
In dwellings and similar spaces with limited volume, dilution of indoor air contaminants may be insufficient. The concentration of contaminants in the inside air depends partly on the rate of emission into the room, partly on the ventilation and the concentration of impurities in the outside air. Sulphur dioxide, hydrocarbons, ozone and lead compounds occur in higher concentrations in the outside air, whereas nitrogen oxides, carbon monoxide, benzpyrene (from tobacco smoke), formaldehyde and dust have higher concentrations indoors.
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.
Reports on a comparative study of residential infiltration as predicted by computer model and as measured in the Mobile Infiltration Test Unit (MITU) as well as in selected test houses, both occupied and unoccupied. Sensitivity analyses were also conducted on each parameter contained in the model against data obtained from MITU.
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.
Describes a technique developed for measuring air flows between internal spaces of houses. Involves using a portable gas chromatograph to monitor the concentrations of three tracer gases released in three distinct zones within the building envelope. Using the results of each measurement, which takes approximately two hours, the ventilation rate of each zone can be calculated along with the interconnecting air flow. Presents the tracer gas equations involved, and includes an account of the experimental method and the practical difficulties encountered.
Discusses the use of a regenerative, air-to-air, rotary heat exchanger as part of a controlled ventilation system in a modern tightly built house. Describes analytical studies and the construction of a prototype. A four-month trial ina test-house indicated that the unit would be capable of recovering 5000 Kw/hof waste energy if operations were extended over the full heating system.
Gives measurements of the ventilation as well as the temperature efficiency of mechanical supply and exhaust systems (balanced systems). The ventilation efficiency is a measure of the performance of providing air in the occupied zone and is also an indicator of the air quality. The temperature efficiency is a measure of the system's capability of supplying heat in the occupied zone. Monitors ventilation efficiencies by adopting tracer decay techniques and the temperature efficiencies by measuring the stationary temperatures.
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