Discusses acceptable levels of CO2 contamination in occupied rooms. Describes measurements in a classroom over 3 days using an infra-red analyser with natural ventilation via the windows. Illustrates curves for CO2 concentrations in 8 graphs for closed windows. Notes that limiting value of 0.1% by volume CO2 (1000ppm) is reached in from 5 to 15 minutes. Repeated sudden ventilation by opening windows is not practicable. Evaluates air change rate. Concludes energy saving for ventilation in heavily populated rooms is only attainable by mechanical ventilation with heat recovery.
Reviews ventilation criteria for occupied buildings. Considers minimum ventilation for the control of carbon dioxide, odours, cigarette smoke, moisture and radon. Discusses future work to improve ventilation routes.
Steeply sloping ventilated roofs are preferred for single and two-family houses in West Germany. Notes lack of any scientifically substantiated notions concerning physical laws governing air exchange between ventilated zones and outside air. Describes air flow and heat transfer investigations in a 48 deg. sloping roof. Gives details of roof constructions. Illustrates roof space and distribution of thermocouples and arrangement for injecting tracer gas. Describes experimental procedure. Provides some measurement results. Compares theoretical bases with experimental results.
Treats drawbacks of current methods used in East Germany of calculating vapour barriers used to protect building elements from condensation. Notes building materials for which moisture absorbed in winter is sufficient to cause condensation damage before it has diffused in summer. Develops method based on calculation model of determining direct relation between any period of condensation and requisite vapour barriers. In addition amount of wateraccumulated during condensation period can also be determined.
Reports results of a project to assess energy conservation measures in a group of typical three-storey, naturally ventilated, blocks of flats, built in 1940 in Stockholm. The measures were:< 1) Improvement of boiler efficiency< 2) Weatherproofing of windows and doors< 3) Adjustment of the heating system and reduction of indoor temperature< 4) Additional insulation of attic floor<5) Additional insulation of external walls< Discusses the energy conservation effect and profitability of each measure.
Reports experimental measurements carried out in a boundary layer wind tunnel at the University of Western Ontario. Both external and internal pressures on two different models were measured with different porosities for the walls. Discusses results and concludes that mean internal pressures measured in thewind tunnel agree well with analytically predicted values that accurate evaluation of internal pressures is necessary to calculate building air infiltration.
Presents the results of a series of wind tunnel tests in which the surface pressure fields of low-rise buildings have been studied. These tests start with an examination of how the body shape influences the surface pressures for a range of isolated bodies. The test results then go on to describe how theparameters which describe an array of such model buildings influence the surface pressures.
This sixteen-page digest provides a guide to why condensation occurs in buildings and how to avoid it. Outlines causes of condensation problems in buildings.Gives 9 case studies. Discusses physical principles of moisture transfer. Describes vapour sources in buildings. Outlines ways of reducing thecondensation risk in buildings. Gives methods for predicting when condensation will occur.
Reports investigation of the air quality in a sound-insulated dwelling house. Measurements of ventilation rate and concentrations of CO, CO2, and NO2 were measured in a tight sound-insulated dining-kitchen, with and without the operation of a gas range, instantaneous hot-water heater and ventilation fan. Finds that natural ventilation was inadequate when the gas appliances were operating and recommends that an instantaneous gas hot-water heater should be provided with an exclusive air exhauster.
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