AIVC - Air Infiltration and Ventilation Centre

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air quality

Ventilation requirements in relation to the emanation of Radon from building materials.

Radon is a radioactive gas which diffuses naturally from all mineral based building materials. States for most homes, concentration of radon is approximately inversely proportional to the ventilation, although this is not valid for very low or very high air change rates. Gives brief results of measurements of concentration of radon in dwellings. Outlines health risks from radon and daughters. Reviews norms laid down in some countries for specific situations. Discusses ways of reducing radon concentrations.

Hazards from products of combustion and oxygen depletion in occupied spaces.

Reviews hazards from excess carbon dioxide and carbon monoxide in poorly ventilated spaces. Discusses ventilation rates needed to keep concentrations below safe levels. Reviews toxicity studies of portable fuel-fired appliances and gives simple guidelines for the use of such equipment.

Health aspects related to indoor air quality.

Reports findings of a working group on health aspects related to indoor air quality. Identifies main air pollutants generated both outdoors and indoors. Considers adverse health effects of indoor pollutants. Concludes that ventilation rate is the important factor in the health concerns discussed. Finds a lack of valid health data on the indoor climate. Recommends further studies.

Indoor air pollution due to chipboard used as a construction material

Chipboard is a common building construction material which continuously emanates formaldehyde. Reports measurements of concentrations of formaldehyde in 24 rooms in 23 Danish dwellings where chipboard was used for walls, floors and ceilings. Gives results in table 1 of concentrations underdifferent combinations of temperature, humidity and ventilation rate. Finds average concentration of 0.62 mg/m3 and in some rooms concentration exceeded the German threshold limit for occupational exposure. Develops mathematical model for the room air concentration of formaldehyde.

Calculation of gas and particle concentrations in ventilated rooms with a non-steady rate of air pollution. Berechnung von Gas- und Partikelkonzentrationen in belufteten Raumen bei instationarem Schadstoffanfall.

Explains method for calculating time dependences and average values of gas and particle concentrations in ventilated rooms, which permits determination of air pollution propagation in a room by means of given target functions. Applies method forvarious ventilation rates. Provides calculated example of determination of gas concentration occurring in a room with a leaky gas container. Illustrates representative time functionfor different pollutants.

Radioactivity (radon and daughter products) as a potential factor in building ventilation.

Awareness has developed in the United States in the last five years that traces of radioactive radon gas and its daughter products are present in varying amounts in the indoor air. Reviews the existing literature in the subject giving a table showing reported radon concentration. Notes wide variation in results. mentions standards developed to protect uranium mines. Recommends research to quantify radon concentration data.

Ventilation requirements in houses and flats. Ventilationskrav i en-och flerfamilyshus.

Reports study of the ways in which different ventilation levels affect people part 1 of the study took place in Gavle. Air change rates, the amounts of radon and its derivatives were measured. Finds that ventilation installations are often poorly adjusted giving a wide variation between flats in the levels of air change. Amounts of radon and daughters were also higher than expected, due mainly to the poor ventilation. Concludes that lowering ventilation to present recommended level of 0.5 changesper hour cannot be recommended without further investigation.

Radon and ventilation - Radon och ventilation

Describes background to natural radiation in building materials and particular aspects of radium decay which produces radon. Notes human lung capacity to absorb airborne particles and associated health risks. Illustrates diagramatically different particle sizes retained in various sections of human respiratory system. Suggests methods to avoid exposure to decay products: avoid materials with high radium content and maintain low radon concentration through sufficient ventilation. Graph shows concentration of radon in relation to air change rate.

Ventilation requirements in rooms occupied by smokers: a review.

States that the need for fresh air to dilute cigarette smoke is the dominant criterion for ventilation design. Reviews the literature of the subject and concludes that the three main health factors are carbon monoxide, acrolein and particulate matter. Finds very wide differences in sensitivity between people. compares IHVE guide of 1970 with the british standard draft code of practice CP3 concludes that cigarette smoke shouldbe treated as a contaminant and not linked with body odour dilution.

Ventilation requirements

Discusses fresh air requirements and tolerable levels of contamination from various sources within a space. Explains the calculation of dilution rates. States that in summer the rates required will generally be higher than those derived from theinformation given because of the need to reduce temperatures in non-air-conditioned buildings and gives method for calculation of ventilation rate required.