Correlates hourly infiltration in 3 adjacent unoccupied test houses to determine the relative contribution of wind and stack effects. The database, obtained using tracer gas techniques over 2000 hourly readings in each house, is sorted to a single 45 degree sector. Different weather sealing techniques give mean infiltration rates of 0.19, 0.45, and 0.59 ach for the 3 houses. Addition of independent wind and temperature induced pressures correlate only part of the weather induced data variability leaving a residual RMS scatter of about 0.004 ach.
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.
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.
Discusses an energy saving project managed by a Swedish contractor ABV and sponsored by the SCBR. The project concerns about 500 flats in buildings that are 25-40 yrs old. Uses and applies experiences from theoretical and experimental work of testing air permeability and calculation of ventilation and infiltration. Describes development of some new techniques for measuring infiltration/ventilation. The work has also resulted in a new measuring unit for recording and treating temperature values.
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.
Measures air exchange across open cold store doors using an anemometer and by tracer decay methods. Anemometer results show that an empirical factor of 0.68 should be applied to the predictive equation by Tamm. Observes a further reduction in air change rate (about 47% reduction) due to imperfect mixing of the air. Air curtains reduce infiltration by about 75-80% and plastic curtains by approx. 93%. Forklift traffic and internal circulation fans also affect air change rate.
Describes a programme undertaken by the AIC to validate mathematical models of air infiltration. Uses experimental data to assess the reliability and full range of applicability of air infiltration models, and to identify key parameters that
Explains possibilities of saving energy in the area of ventilation. Summarises fundamental theories for calculating air flow through building leaks, ventilators and fan systems which are put in their total context - wind, temperature, air leakage, intentional ventilation, building technology, energy requirements. Treats factors which influence ventilation requirements. Compares results from field studies of actual air change rates with the requirements of Swedish Building Standard 1980.
Uses a two-region model to predict infiltration, to take into account non-ideal mixing of tracer gas in a building. Considers versions of this model:< 1. Fluid flows between the 2 regions and the environment in any manner provided steady state and mass balance are maintained.< 2. There is limited interchange between the regions< 3 Air flows into the first region and out of the second with (unbalanced) interchange between the two.< 4. The second region is a "dead-water" zone, which is not directly connected with the outside.<5.
Gives a series of short articles on air quality, air infiltration, and the ventilation needs of low energy buildings. These are -< 1. Sandberg M. Quantifying the pollution. Defines the quality of ventilation< 2. Warren P. Predicting infiltration rates. Explains BRE's method of predicting air infiltration in houses< 3. Getting close to zero. Describes the low energy EKONO office complex< 4. Sherman M. Grimsrud D. Which ventilation system? Shows that the choice of the economically optimum ventilation system depends on the tightness of the building.
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