Describes measurements made to compare ventilation rates in six Belgian houses with both natural and mechanical ventilation systems using O2 and N2O as tracer gases. Ventilation rates were correlated with wind speed. Air leakage across individual components of the house was measured and from this the distribution of leakage areas calculated.
Suggests many ways of reducing outdoor air admitted to a building. Notes importance of measuring minimum air flow to ensure adequate ventilation. Suggests measuring the concentration of CO2 in indoor atmosphere and using the results to control incoming ventilation. Describes simple and inexpensive implementation of the technique.
Describes measurements of airtightness and ventilation in prefabricated 'modulent' houses, 25 single-storey with habitable lofts and 8 single-storey, all with mechanical extract systems. Measurements used pressure method and tracer gas in houses with different airtightness, types of window, windproofing and facing materials. Possibility of presetting ventilation terminals and fans to achieve recommended airflows was investigated. Treatsrelationship between wind, temperature and airtightness. Notes number of shortcomings in ventilation system discovered during investigation.
Points out that difficulty in calculating fortuitous ventilation in buildings caused by infiltration means that energy demand of a building contributed by it is scarcely ever known. Provides equations describing infiltration due to pressure differences, which in turn are caused by wind conditions, inside/ outdoor temperature differences and possible influence of mechanical ventilation systems. Describes computer program developed in Finland to calculate air infiltration. Demonstrates infiltration rates in houses.
Claims procedures for design of ventilation and air flow systems are energy wasteful. Cause lies in their methods and technical bases and influence of other factors entering into final systems choice (particularly economics). Discusses outside air requirements. Concludes ventilation rate can be lowered 45% to 50% if higher humidities are used. Proposes new standards based on fact that ventilation rate is independent of air space per person. Analyses air distribution systems and sub-systems in terms of minimum energy requirements.
Outlines necessary ventilation rates for an occupied room. Discusses natural ventilation of a room through openings in the ceiling. Discusses natural draught ventilation for single family houses, combined natural draught and mechanical ventilation, mechanical fresh air ventilation based on a central duct, fortuitous ventilation caused by air infiltration and leakage. Compares natural and mechanical ventilation. Considers supplyair systems for single family houses, warm air heating and possibilities for heat recovery.
Login