Describes a completely automated constant concentration tracer gas technique for measurement of air infiltration. The equipment consists of five components: 1 a controller, 2 a tracer gas analyzer, 3 an injection and sampling unit, 4 special mixing fans and 5 apparatus for the calibration of the tracer gas flow. The system is controlled by a microcomputer.
This paper presents the measurement technique and results of 23 one-week measurements of air change rate in occupied dwellings. The measurements conducted show that the occupants exert a very considerable influence on the total air change rate. The air change rate for occupied dwellings is, on average, 3-4 times greater than the rate in sealed dwellings (with air-escape valves, doors, windows and ventilation system closed). The measurements also reveal a trend towards a higher air change rate in mechanically ventilated dwellings than in naturally ventilated dwellings.
A steady state multi-cell calculation model has been developed in order to predict the interconnection between airtightness and ventilation rates. The model has been tested with measured leakage data of a detached house.
This paper discusses the measurement of air infiltration rates and reports on measurements relating indoor and outdoor aerosol size distributions in the 0.01 to 1 micron size range.
A tracer gas technique has been used for evaluation and characterization of air flow pattern of contaminants penetrating into buildings. As a tracer, sulfur hexafluoride (SF6) was used and detected by a gas chromatograph equipped with an electron capture detector. SF6 was released at suspected points of contaminants origin at a constant flow rate and was detected quantitatively in the room or laboratory of concern.
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.
An automated 10-point air sampling network which uses an electron capture detector gas chromatograph to continuously measure changes in sulfur hexafluoride tracer concentration in a residential environment will be described. The injection of the tracer is controlled by a microprocessor which decides to inject sulfur hexafluoride tracer to return its concentration to a preprogrammed set point. Infiltration rates from fan induced pressurization will be compared to the infiltration rates as reported from the replacement of sulfur hexafluoride tracer.
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
For optimum building design it is of importance to investigate the comfort and the energy conservation obtained with different types of ventilation systems and levels of airtightness of buildings. This could be achieved by aid of computer models based on full-scale and model measurements. In order to obtain experimental data as input data to such a computer model, an experimental, detached one-family house has been built near to Gothenburg on the Swedish west coast.
Ventilation efficiency was measured with freon gas in 3 large industrial buildings under normal working conditions. Size of building varied from 3000 to 10000 m2 and room height from 5-19 m. The ventilation systems were of 3 types: 1. Overhead fresh air supply network with conventional air inlets, 2. Fresh air supply direct to occupied zones by a low impulse system, and 3. Overhead fresh air supply distributed by the Dirivent system. Describes techniques of tracer gas measurements. Illustrates some results in graphs.
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