Treats importance of keeping uncontrolled ventilation to a minimum in buildings equipped with balanced ventilation. Provides theoretical and experimental description of leakage of air past windows. Includes comparison between standards of different countries. Discusses effect on building ventilation of variations of wind and outdoor temperature. Considers in conclusion measurement of air flows between rooms in a building. Describes development of tracer gas method based on computer-assisted evaluation.
Describes tests in Exeter University library of method of determining ventilation rate by measuring the amount that the atmospheric carbon dioxide concentration in an occupied space is raised above the outside ambient level. Compares rate obtained with that expected from the fan rating. Demonstrates that in addition to the ventilation rate, the average rate of production of carbon dioxide produced by the occupants could in principle have been estimated from the data.
Discusses actual ventilation rates in small houses and the requirements of Swedish building regulations. States that regulations do not take a total view of the energy balance in small houses, and pay no regard to the interplay between different forces.< Discusses a newly built 1.5 storey house as an example. Outlines problems in ensuring a low air change rate.
Describes the basic relation between pressure difference and air flow rate across an opening under steady state conditions. Taking the ventilation system into account, the pressure difference pattern across building enclosures andthe air leakage characteristics of exterior walls, interior separations and various service shafts must be understood, but at present little of this information has been available for actual buildings. Presents new data on the air leakage characteristics and natural ventilation rates for sound insulating houses.
Contains two papers reprinted from the Jnl. of Ind. Aerodynamics:-< 1) Wind-tunnel simulation of the adiabatic atmospheric boundary layer by roughess, barrier and mixing-device methods.< Discusses the philosophy of roughness, barrier and mixing-device simulation methods. Illustrates methods by measurements of simulations in the B.R.E.boundary layer wind tunnel.
Gives results of a survey carried out in December 1978 on heating and ventilating of dwellings. 2000 men and women were questioned throughout the federal republic. Gives range of dwellings, desired and actual room temperatures, types of windows, frequency and duration-of window opening and the existence of draughts.< Concludes inter alia that heat loss through ventilation is greater than commonly assumed. In particular this heat loss is through leaky windows and ventilated bedrooms.
Discusses mechanisms for radon liberation in dwellings. Mentions survey which found radon concentrations exceeding the maximum permissable concentration of 3 x 10^-12 curies in 13 of the 65 dwellings. Gives expressions for number of radon atoms in indoor air at time t and activity due to radon per unit volume. Discusses liberation of radon from walls and from soil and concludes that if the ventilation is poor or if there is a high emanation of radon, the indoor radon concentration may approach the maximum permissable level.
Reports study of emanation of radon from concrete blocks enriched with uranium ore, placed in an airtight enclosure. The radioactivity of air samples was determined using a high resolution silicon diode detector system.
Reports study of the exposure rate due to the gamma-ray natural background in some representative areas of Italy using a portable high-pressure ionization chamber. In some areas spectrometric measurements were made to distinguish between contributions to the total from cosmic rays and from natural radioactive series. The measurement areas were chosen to be representative of the main geological formations.
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