Discusses the symptoms and compaints of the occupants of unhealthy buildings. Compares the availability and sensitivity of building sensors to human sensitivity for the full fange of indoor air contaminants. Refers to the difficulty of assessing pollution using occupant questionnaires. A simple equation for determining contaminant concentration is presented and ventilation standards are discussed.
The Department of Building Technology, the Technological Institute of Copenhagen, have for several years been developing equipment for continuous measurement of air infiltration. It enables continuous measurement of air change rate in up to ten rooms, the constant concentration method with tracer gas is used, and the results are recorded on a computer diskette during measurement. Analysis of possible measuring errors show that the method is accurate and to within plus or minus 5%. Shows the results of measurement of air infiltration in 10 relatively airtight dwellings.
After a brief treatment of the ideas and aspects that play a role in ventilation, gives a general outline of chosen investigation methods, with a concise review of apparatus and calculation models used. Presents a review of the ventilation investigations carried out by IMG-TNO during the last 10 years in factories, labs, hospitals, auction halls etc.
Continues on from a previous paper, which gives a theoretical framework for using moments of concentration histories as a means of assessing air quality. Gives a more detailed presentation of the test conditions and the results from each test, together with plots of concentration v.time graphs.
Describes international research activities in the field of air infiltration, based on a recent research survey. Projects include research on indoor air quality and comfort, comparison of procedures for calculating air change rates in buildings, compiling data on air flow and pressure distributions around buildings, and measurement techniques. At the end, concentrates on Swiss projects.
Notes concern in recent years about complaints by occupants concerning the air quality in internal rooms. It is usually necessary to carry out an analysis of the air conditions to discover the underlying cause of the complaints. Gives advice on analysis methods. Treats selection of the appropriate measurement method, and timing and location of the measurements. Demonstrates the measurement techniques by examples.
To experimentally determine the repeatability of pressurization test results, pressure tests a home about 80 times in one year. Studies the effect of weather conditions on test results, along with changes in the results over time. For local wind speeds less than 2.5 m/s the 50 Pa leakage rate has a standard deviation of about 2% of the mean over short time periods. For stronger winds, errors as large as 15% compared to calm weather test results occur. Finds a seasonal variation of 25% in the leakiness of the house.
A rational method is presented to determine the locations within a building where the highest average concentrations of contaminants may occur. Using this procedure, the number of sampling points necessary for indoor air quality (IAQ) evaluation of a building is reduced to a minimum. Thus the time and cost necessary for building evaluation and analysis can be decreased. Experimental measurements made in a research house are presented to validate the method.
A comprehensive theoretical framework is presented, based on the use of moments of concentration histories ie multiplying concentration readings by time of reading and then integrating with regard to time. The concept can be used to characterize either the diffusion of the supplied air or a contaminant released within the room. Results are presentd from about 50 measurements demonstrating the usefulness and practical applicability of the approach for assessing air quality in ventilated buildings. Different experimental procedures have been explored and are discussed.
Describes the general methodology for ventilation measurements by tracer gas, using decay, constant concentration and constant emission methods. Defines ventilation efficiency and the ways in which it can be experimentally determined. Gives the results of a series of lab measurements to determine the accuracy of the decay method under different conditions, and the efficiency of some mechanical ventilation systems.
Login