Surveys published ventilation rates, primarily of single housing units. Finds helium is the most commonly used tracer gas and that average annual ventilation rate of most occupied houses is between O.5 and 1.5 air changes per. hour. Summarises important recommendations and gives bibliography of 230references.
Reports field monitoring program by the Lawrence Berkeley Laboratory to assess the potential impact of reduced ventilation of indoor air quality. Three houses, designed to be energy-efficient, were monitored using a mobile laboratory. Parameters measured included infiltration rate, CO2, CO, NO2, NO, O3, SO2, HCNO, total aldehydes and particulates.
Presents model of indoor pollution that assumes a linear relation between indoor pollutant levels and the air change rate. Discusses effect of heating system and cooking on pollutant levels and ventilation rate. The model predicts that when air change rate is reduced 4-fold, heating systems pollutant contributions can still rise up to 3-fold despite the saving in energy from reducing ventilation. Suggests precautions are necessary when tightening building envelope. Recommends that pilot lights be eliminated and effective kitchen ventilation systems installed.
Points out that conservation measures such as storm windows which seal a building protect occupants from outdoor air pollution but amplify effects of pollution generated indoors. Considers which effect is greater. Develops a model relating indoor air pollutant concentrations to outdoor concentrations and to v, the air exchange rate, which is consistent with reported behaviour of common pollutants. Model predicts that indoor concentrations follow outdoor concentrations but maxima and minima lag behind, and are not as pronounced as theiroutdoor counterparts.
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.
Reports the results of three programmes of measurements of ventilation carried out in one-family houses, which in most cases were of the 'council house' type. The first programme measured ventilation rates using tracer gasin two houses room by room. Wind speed and direction were recorded but no general relation between ventilation and wind was found. The second measured ventilation rate in individual rooms in a house under six different wind conditions. The third measured ventilation rates in three identical homes.
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.
Discusses the effect of wind on air change rates in buildings. Reports series of model tests conducted in a water flume and a wind tunnel. A plexiglass box with holes in it was filled with gas, either nitrogen or carbon dioxide, and placed in a controlled air flow. The concentration of gas was plotted in a semi-logarithmic form. Gives typical examples of these graphs.Discusses feasibilty of estimating rate of air change by a hyperbolic function, but finds that more tests are needed forpractical recommendations.
Reports measurements of air infiltration made on two mobile homes, identical except that one was treated with sheathing board and the other caulked. Carbon monoxide was used as a tracer gas and wind speed and direction, solar radiation, andoutside and inside dry and wet bulb temperatures were recorded. Finds considerable scatter in the data and analyses the reasons for this. These include the considerable sensitivity of infiltration rate to wind and instrument drift.
Presents results of a survey of natural infiltration rates in 2 identical modern homes-one gas fuelled and one electric-over aperiod of a year. Infiltration rates were determined by releasing tracer gas, usually ethane, into the main return duct and measuring concentration every half hour. Discusses results and dependence of infiltration rates on wind speed and direction. Gives preliminary result that wind probably exerts agreater effect on infiltration than any other variable.
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