Reports on the metabolic CO2 method for ventilation measurement which has been extended from mechanically ventilated rooms to naturally ventilated ones. The analysis, which under some circumstances is also relevant to tracer gas decay measurements, allows assessments of the individual incoming flows of air.
Reviews sources of indoor air pollution, factors which influence pollutant concentration, and health aspects. Reports on investigations into carbon monoxide concentrations in kitchens with geysers. Treats various factors including geyser type, state of maintenance, frequency of use, occupant type, cooking and ventilating behaviour, time and location of measurements etc.Reports nitrogen dioxide concentration measurements in kitchens and livingrooms relating to cooking and smoking.
Reports TNO-IMG research into ventilation of houses including the influence of cracks, open windows, weather conditions, occupants' behaviour, pollutants and guidelines. Lists conclusions such as an opened window renews the room air within half an hour. 40% of the occupants open windows for too long, 27%ventilate insufficiently, 25% of the dwellings are air tight, 75% leaky. Ventilation occurs partially through shafts (30%) and cracks (60%).Ventilation rates differ considerably between the rooms in a house.Ventilation ducts should have an exhaust function.
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.
Uses occupant-generated CO2 as an indicator of the actual ventilation rate in a San Francisco office building. Employs two techniques, a decay method and an integral method, and measurements are conducted simultaneously at several locations. The decay method compares favourably with the conventional measurement methods in both the all-outside-air and recirculation modes, whereas the integral method shows a considerable deviation from the other methods in the recirculation mode.
Gives a brief overview of:< 1. Measurement of air change rate using tracer gas.< 2. Measurement of air leakage using steady state and alternating pressure.< 3. Calculation methods (by hand and by computer) for predicting air exchange in a building.< Indicates where relevant research in these areas is being carried out, and outlines the role of the Air Infiltration Centre.
Briefly describes the need for air tight houses as an energy conservation measure, and for preventing moisture damage. Shows that very tight houses (0.5 ach/h) with mechanical ventilation function better than houses which have just fulfilled Swedish building requirements, or which have unsuitable ventilation systems. In some cases, condensation has formed on the inside of windows, and individual rooms sometimes receive insufficient ventilation. States that only in sufficiently airtight houses can ventilation be regulated to the required level and efficient heat recovery can function.
Reviews current methods of ventilation measurement in occupied buildings including tracer methods, pressurisation, and thermography. Gives criteria for good ventilation rate measurement techniques. Also explores new methods of measuring ventilation rates in occupied buildings. These include:< 1. Use of non-toxic tracers, including negative ions, CO2 and odour levels< 2. AC pressurisation< 3. The quantification of thermography< 4. Small-scale detection of local air velocities using hot-wire anemometry.
Describes a predictive model for air infiltration in residential structures. Uses wind speed and outdoor temperature data, along with selected building and site parameters to predict average infiltration. Presents long-term field validation results obtained in a portable test structure, together with long-term data from 3 unoccupied test houses at the Owens-Corning Technical Centre. Finds that the ratio between predicted and measured infiltration peaks near one in all comparisons. The estimated standard deviation of the ratios decreases with longer averaging times.
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