Describes some new theoretical and experimental techniques developed by British Gas to investigate the ventilation of buildings. These include:< 1. The multi-cell model "vent" for predicting ventilation rates< 2. "Autovent", the multi-cell constant concentration tracer gas technique used for measuring ventilation patterns in buildings.< 3. Pressurization techniques for measuring air leakage in buildings.< Gives a selection of results from applications of these techniques to show their scope.
Describes a field method for surveying residences for indoor air quality. The method requires 2 days of field testing for each residence - a day to perform a multipoint tracer gas study to characterize the ventilation efficiency of the various spaces in the house and to determine the overall air change rate; and a day to measure contaminant concentrations in locations selected according to the results of the tracer gas study and contaminant generation locations. Describes and discusses results obtained by this surveying procedure in 3 energy efficient residences.
Presents various measurement and inspection techniques for assessing the thermal performance of the exterior envelopes of buildings. Inspection techniques include the use of ground-based infra-red thermographic surveys, aerial infra-red surveys, tracer gas air infiltration measurements, pressurization tests for measuring the tightness of the building envelope, and spot radiometer surveys for detecting gross defects. Also considers heat flow meters, a portable calorimeter and a microprocessor-driven envelope testing unit. Provides recommended procedures for each technique.
Presents a review of the main methods used for the study of air movement. Includes sections on physical modelling (wind tunnel modelling etc), analogue (water and electrical) models of air movement, mathematical models and digital computer analogues, and full scale investigations including pressurization andtracer gas techniques.
Describes method which permits long term tracer gas measurements in several separate rooms simultaneously. The method employs a fully automated constant concentration system developed at the laboratory for building physics at the Swedish Institute for Materials Testing. Describes measurement principles andpractice.
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.
Investigates the reliability of the single-room infiltration model used in the computer program ENCORE. Compares calculated air change rates with tracer gas (N2O) measurements in 25 identical one and a half storey detached houses. Describes the infiltration model, the parameters and some results. Thecomparison shows good correlation at low wind speeds (< 3m/sec) but the model's values at higher wind speeds are too high.
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.
Gives a summary of the work in testing of different energy-saving retrofits performed in dwellings in Sweden. The report is based on work done at the Swedish National Testing Institute and the National Swedish Institute for Building Research carried out during the winter 1979-80. Thermography methods, pressure test method, tracer gas measurements and heat flow measurements wereused in 91 houses, which were retrofitted. Describes different test methods and discusses results of measurements.
Login