Examines various definitions of ventilation efficiency. When using tracer gas techniques the definition of a ventilation system's efficiency can be based on the slope of the tracer gas curve, or the ratio between concentrations, or the area under the curve. Examines the consequences of these definitions for a simple theoretical model. Presents experimental measurements on a test room which show that sometimes very low ventilation efficiency can occur.
Reports investigation of the limiting conditions that produce frosting on air-to-air heat exchangers. Also determines the adequacy of provisions for the prevention of frosting and ice buildup. Four types of heat exchanger were investigated as part of a more general investigation of the operating characteristics of air-to-air heat exchangers. Also reports investigation for various types of energy recovery systems of the cross leakage or contamination of the fresh air by the exhaust air.
Surveys instrumentation for measuring pressures from about 0.001 to 50mm. of mercury (0.13 to 6650 N/sq.m.) described in publications during the years 1960-1968. U-tube micromanometers and diaphragm - capacitance gages are treated in considerable detail. Also describes gas column manometers; elastic element micromanometer with optical, inductance, resistance wire, strain gage, and vacuum tube transducers; piston gages; vane gages and centrifugal micromanometers. Discusses measurement of dynamic pressure, atmospheric pressure oscillations, low vapour pressure, and calibration techniques.
Ventilation efficiency involves two aspects, to preserve thermal comfort, draughts should be avoided and yet one tries to obtain the best "sweeping out" which corresponds with a maximum exhaust of contaminants from the occupied zone for a given flow rate.< Reports study of 75 tests of ventilation efficiency made in a climatic roomrepresenting a heated living room. Thermal comfort was tested by measuring the air velocity both in the ventilation jet and in the occupied zone.
This research report explores the possibilities for energy saving in municipal office buildings. It is based on a study carried out for one London borough in mid-1980`s taking one specific building complex, comprising two adjoining buildings, as an example. The energy-saving measures covered include reduction of air-change rates by draught- proofing windows doors and skylights, and the report indicates the scale of potential savings along with the capital costs.
The report was prepared, at the request of the Environmental Protection Agency by the Committee on Indoor Pollutants. It outlines the scope of the problems regarding indoor pollutants and discusses their sources, their effects on human health and welfare, the technologies available for their control or abatement, and concerns about the effects of energy-conservation strategies on indoor concentrations of pollutants. It approaches the subject of indoor pollution from three viewpoints: 1. Physical factors, such as indoor pollutant sources and concentrations. 2.
Reviews the important variables which need to be known when analyzing wind loads on low buildings. These include reference height, roof angle, end zones, internal pressures and openings, surrounding terrain and buildings.
Comments on the aesthetic aspects of window renovation and replacement and describes common forms of deterioration giving detailed suggestions for repair and for the improvement of air tightness and sound insulation.
Lists sources of radon and its isotopes in housing. Diagrams illustrate radon content as a function of air change rate. Estimates risk factors. Notes lack of coordinated national or international regulations. Relates number of lung cancer cases caused by radon to total recorded. States recommended maximum permissible concentrations.
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