Three different types of methods for estimating ventilation rates in residences have been presented and the results of each method discussed. Field measurement experiences have helped to identify the potential errors of these methods. To date, the best correlations obtained have been between theconstant emission tracer methods involving perfluorocarbon and tracer gases. It is expected that a better understanding of the parameters that affect all of the techniques, specifically mixing volume, will lead to improved accuracy.
As part of a study to evaluate the effects of home weatherization on indoor air quality, a tracer gas method to determine infiltration rates was developed by modifying existing methods to meet several project constraints. A method was needed
An accurate determination of air renewal rate and connective exchanges between units was needed for study of the solar units of the experimental building LESO, in both an occupied and empty state. The CESAR compact equipment for tracer gas (nitrous oxide) measurement was developed. This unit uses a microcomputer to perform a simultaneous and periodical gas analysis in 10 locations. Three tracer gas methods can be used: decay, constant concentration, and continuous flow. The device and regulating program work well with low rates of concentration (100ppm of nitrous oxide).
Describes the general methodology for ventilation measurements by tracer gas, using decay, constant concentration and constant emission methods. Defines ventilation efficiency and the ways in which it can be experimentally determined. Gives the results of a series of lab measurements to determine the accuracy of the decay method under different conditions, and the efficiency of some mechanical ventilation systems.
Compares and contrasts different methods of ventilation measurement in large buildings. Conventional methods of using tracer gas to measure ventilation rates in large volumes are cumbersome and expensive. These constant concentration and decay measurements require artificial mixing, complex monitoring equipment and large installation costs. By using discrete injection and sampling units, long term samples of tracer gas be collected with the minimum of capital and installation costs. Samples collected represent the mean local equilibrium tracer gas concentrations.
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.
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