Air change rate is often reported as a single number, with no attention paid to different values of air change rate in different zones of a building. This may affect air quality evaluation as there may be undetected zones where air change rate is too small, resulting in localized pollutant concentrations. Describes a multi-point tracer gas technique used to quantify air change ratein different zones of various residential buildings. Defines and calculates zonal ventilation efficiency terms, and proposes a criterion for analysis of the results for indoor air quality evaluation.
Presents the underlying theoretical basis for measuring air flows in complex, multi-cellular buildings and by reviewing the existing experimental procedures which enables the carrying out of these measurements. Shows that inter-cell air flows can be determined only by generating N sets of tracer gas conservation equations, where N is the number of cells. Describes 3 systems being designed to carry out multi-cell ventilation measurements< 1. "grab sampling"< 2. multiple tracer measurements< 3. measuring averaged air change rates over long periods.
Describes a project aimed at developing a method of measuring air infiltration rates in large single cell enclosures and buildings, and of using the method to collect data on actual infiltration rates. Makes a brief survey of existing and novel methods of measuring air infiltration rates. Identifies 2 methods which merit further consideration - the use of methane as a tracer gas,measuring its concentration with an infrared laser technique; and the use of ethanol vapour as a tracer gas, measuring its concentration with a fuel cell detector.
States that a comprehensive sealing program should be considered in every residential energy conservation program. Covers the theory of air flow in a structure , how this theory is converted into a practical service, and theeffect on the house including humidity and air quality concerns. Describes the infiltrometer, a pressurization device used to detect air leakage, how to useit and how to interpret data.
Briefly overviews some of the available instrumentation and techniques that could be used by the home-owner, or professional auditor to evaluate energy use in houses. Includes descriptions of the "blower door" method for evaluating air leakage, and some tracer gas techniques for measuring air infiltration.
Describes a simple, inexpensive sampling technique for infiltration measurement using SF6 tracer gas. Uses pre-evacuated blood collecting test tubes with rubber stoppers for sampling. This is controlled by a micro-processor driven automatic sampler, which drives a hypodermic needle through the rubber stopper to fill the tube with an air sample. Analyzes samples using a gas chromatograph. Releases SF6 at ground level in a high-rise cold store and collects samples of air at different heights to see if stratification is present.
Explores the health implications, external and internal contributions, and the measurement of indoor air pollution including such subjects as sampling and analysis, calibration, time scale and interferences. Outlines the current status of prediction techniques, including areas such as one-compartment models, infiltration estimation, and empirical models. Summarizes the most common control methods. Examines, in detail, the application of modelling techniques to several typical indoor settings, for example, a restaurant, kitchen or a conference room with smokers.
Reports on an extension of the metabolic CO2 method for ventilation measurement to a naturally ventilated room having air flow connections with other internal spaces as well as the outside. Uses an infra-red gas analyser to monitor CO2 concentrations in the fresh air outside and also within theroom, the corridor and the ceiling space. An automatic unit switches the analyser between 6 sampling points. Comparison of the data with results from SF6 tracer gas decay methods gives close agreement.
Describes a technique for measuring air flows between internal zones of houses. Gives the theory of measuring one and two directional flows and describes the equipment used for practical measurements. Uses Freon 12, Freon 114 and BCF as tracer gases, and measures their concentrations using a gas chromatograph. Includes specimen results of one and two directional flows between a house and its roof. Discusses the possible applications of the method in houses.
Describes Schlegel's test chamber for measuring air and water infiltration around doors and windows. This can record infiltration at any point around the frame to high light the exact source of a leak. This is used to test the company's own draughtproofing and weathersealing products and is available to door and window manufacturers for development work.
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