Ventilation systems perform a number of tasks. They must remove contamination/pollution, they act as heat/cold transporters and they must create a satisfactory room climate without causing draughts. States that users must be aware of the limitations of ventilation systems and that ventilation systems are not able to carry out all tasks completely satisfactorily. Compares the efficiencies of displacement and mixing systems and gives guide values for temperature differences between room air and supply air for office and industrial applications.
This paper describes tracer gas measuring techniques that have been used to characterize ventilation and air infiltration in buildings, with an emphasis on recent developments and applications in large industrial and commercial structures. Fundamentals and applications are presented for both single andmultiple tracer gas methods. In addition to techniques suitable for detailed characterization of building airflows, procedures and equipment appropriate to surveying large numbers of buildings are also discussed.
Ventilation rates were measured in nine office buildings using an automated tracer gas measuring system. The buildings range in size from a two-storey federal building with a floor area of about 20,000 ft2 (1900 m2) to a 26-storey office building with a floor area of 700,000 ft2 (65,000 m2). The ventilation rates were measured for about 100 hours in each building over a range of weather conditions. The results are presented and examined for variation with time and weather. In most cases, the ventilation rate of a building is similar for hot and cold weather.
Air infiltration and ventilation rate measurements were made during all seasons of the year in eight federal office buildings using an automatic air infiltration system designed at the National Bureau of Standards. The eight federal office buildings were located in Anchorage, Alaska; Ann Arbor, Michigan; Columbia, South Carolina; Fayetteville, Arkansas; Huron, South Dakota; Norfolk, Virginia; Pittsfield, Massachusetts; and Springfield, Massachusetts.
Air qulaity measurements along with airflow rate measurements of air conditioning system were conducted in an office building occupied by workers with clerical activities. Contaminamts measured were CO2, SPM (suspended particulate matters) NOx and airborne bacteria. Indoor CO2 and SPM levels were found to be quite high, 1,600 ppm (CO2) and 0.25mg/ m3 (SPM), respectively, at their maximum and exceeded Japanese Standards The cause of the high concentration was found to be air leakage in the outdoor air intake duct. The air leakage rate was estimated applying mass-balance model of CO2.
In order to reconsider the ventilation requirment in office environment and air environmental indices to determine it, field measurements were carried out. The amounts of outdoor air taken into air conditioning system were controlled in three levels and the concentrations of various indoor airpollutants were measured. It was found conclusively that 30 cubic meters per hour per person of intentionally introduced outdoor air was appropriate for ventilation requirement for offices and carbon dioxide was also appropriate as an index.
Effectiveness of ventilation as a major means of controlling indoor air quality was evaluated by correlating concentrations of gaseous (CO and CO2) and particulate (total) pollutants with two ventilation parameters. Pollutants are differently af
Large, multicelled and naturally ventilated buildings pose many problems for the measurement of overall infiltration rates using tracer gases. In this paper, a simple technique proposed earlier is explored further by reference toa computer model study as well as by field measurements in two in two naturally ventilated office buildings. Results show that using this technique, the overall infiltration rates of large, multicelled and naturally ventilated buildings can be obtained to a good approximation.
Provides the text of the 68 papers presented at the symposium, arranged under the following headings - Plenary session, Advanced developments in ventilation, Control of toxic and explosive contaminants, Advances in tracer gas use, Ventilation for residential and modern office buildings, Advances in local exhaust technology, Ventilation for control of carcin- ogens and biohazards, Ventilation measurement and control, Sources emission rates, Filters, Air recirculation and energy conservation.
Indoor air pollution is particularly noticeable today, resulting from the improvement of ventilation in building envelopes in order to economise in heat energy, and the consequent reduction of fresh air entry, leading to poorer air quality. The article describes the effect of tobacco smoke on the indoor climate of residential and office buildings and its effects on health, particularly its effect on non- smokers, or the passive effects of smoke.