Traces the relationship between ventilation needs and methods and the growth of civilization. Describes the development of ventilation methods and assessment of air quality, especially since the Industrial Revolution. Questions whether currently accepted ventilation criteria are still valid, andsuggests that ventilation is only one of several means of ameliorating the internal environment.
Mechanical ventilation systems usually provide a fixed quantity of "fresh" air to a building space based upon the maximum number of people expected to occupy that particular space. When the use of a building space is below its design maximum, the amount of outside air brought into that space can be reduced, thus generally also reducing energy consumption through lower heating and cooling loads. One method of determining the necessary ventilation rate for aparticular space is to utilize an air quality detector (eg CO2 or O2) sensitive to building occupancy and activity load.
Describes the monitoring of indoor air quality in a San Francisco office building where occupants had registered eye, nose and throat irritation complaints. Data was taken under two different ventilation rates. Carbon dioxide concentrations increased as the ventilation rate decreased, odour perceptibility increased slightly at the lowest ventilation rate, and other pollutants generally showed very low concentrations, which increased when ventilation was reduced.
Describes sources of radon in buildings. Summarizes data on observed indoor radon concentrations in houses in New York, Salzburg Austria, and Florida. LBL studies in energy efficient buildings in Maryland, Minnesota, and New Mexico show that tight houses have higher radon concentrations then conventional houses. The data reported is based on "grab samples" taken on mild days (low wind and small indoor and outdoor temperature differences) with all doors and windows closed, resulting in a "worst case" estimate.
Investigates what minimum fresh air supply per person is required to prevent unacceptable odour annoyance due to stale smells in offices and comparable buildings. The experiment is carried out in different buildings in rooms of varying size and occupancy density, with mechanical or natural ventilation. Determines the air supply to the room, the CO2 concentration, the number of lighted cigarettes, the odour concentration and the extent of odour annoyance to occupants.
Briefly reviews sources and types of air contaminants common in tight houses. Covers four indoor pollutants - carbon-monoxide and nitrogen dioxide from gas stoves, particleboard plywood and urea-formaldehyde from insulation, and radon from various building materials.Suggests ways of lowering pollutant levels without compromising energy conservation considerations.
Describes work sponsored by the Electric Power Research Institute (EPRI) to investigate indoor air quality in 10 single-family houses and 2 office buildings in Boston. The point was to compare indoor and outdoor pollutant levels, and find reasons for the differences. Found particulate levels were higher indoors, and houses with gas facilities showed higher concentrations of carbon monoxide and nitrogen oxides.
Numerically predicts air quality and thermal comfort in 2-dimensional ventilated air spaces of several geometries when conditions on the various room surfaces are taken to be either adiabatic or constant temperature.
Investigations in Denmark show that there are as many as 75 different compounds in indoor air in tight houses including toluene, xylene, and radon. The dust in homes contains a large number of allergically active ingredients, the most important being the dust mite, which occurs in bed clothes.< States that good air quality is therefore difficult to maintain with natural ventilation in new tight houses. If the hygienic demands of this decade increase the need for ventilation, mechanical ventilation seems to stand a good chance.
In dwellings and similar spaces with limited volume, dilution of indoor air contaminants may be insufficient. The concentration of contaminants in the inside air depends partly on the rate of emission into the room, partly on the ventilation and the concentration of impurities in the outside air. Sulphur dioxide, hydrocarbons, ozone and lead compounds occur in higher concentrations in the outside air, whereas nitrogen oxides, carbon monoxide, benzpyrene (from tobacco smoke), formaldehyde and dust have higher concentrations indoors.
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