Uses a multi-channel infra-red gas analyser to measure nitrous oxide tracer gas concentration at six points round a house. Combines concentrations to give overall house ventilation rates and to estimate the air exchange between individual rooms. The gas analyser is also used to measure air movement between the house and its roof (with 5 sampling points in the house and one in the roof). Results show that typically 20-30% of the air that enters a houseleaves via the roof space through gaps in the ceiling.
Compares the air change rates measured with SF6 and CO2 using the tracer gas decay technique and the fan extraction method over a wide variety of test chamber sizes and mixing systems. Shows that the conventional air handling orportable floor fans can provide adequate mixing for SF6 tracer gas decay measurements of infiltration. Warns that the mixing operation may become the dominant driving force of infiltration during calm climatic conditions. Finds that +-0.08 ach/h is a reasonable measure of experimental error at the 95%confidence level using SF6 as the tracer gas.
Reports on tracer gas to ascertain feasibility of use of isotope techniques and how quickly fresh air is distributed in a room under set conditions. Describes the use of 85 Kr isotope.
Reports on a measurement system developed by the Institute of Technology at Tastrup Denmark, involving a microcomputer- controlled system for registering air change rates using tracer gas (nitrous oxide) according to the constant concentration method. The system is designed for measuring and metering tracer gas in up to 10 separate rooms (using an infrared gas absorption detector). It operates through automatic data logging on a floppy disc and can run without supervision for extended periods (up to six days).
Gives a summary of the existing types of air infiltration measurement techniques and instrumentation using tracer gases. Describes automated air infiltration instrumentation used by researchers in the US, Canada, the UK, Denmark, Sweden and Switzerland. The equipment can operate in the decay mode, constant flow mode and the constant concentration mode.
Reviews a research project which has the objective of establishing:< 1. Expressions for ventilation efficiency< 2. Methods for measuring ventilation efficiency< 3. Rules for acheiving efficient ventilation.< Derives expressions for ventilati
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.
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.
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.
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.
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