krypton

Reports on tracer gas to ascertain feasibility of use of isotope techniques and how quickly fresh air is distributed in a room under set conditions. Describes the use of 85 Kr isotope.

The primary aim of the project is to describe and document a measurement method suitable for checking whether minimum requirements for ventilation efficiency are fulfilled after a ventilation system has been regulated. The project concentrates on occupied areas with mechanical ventilation such as dwellings,offices and schools. Excludes industrial buildings since special conditions such as ventilation rates, polluting processes and local extraction apply to these. Defines ventilation efficiency, describes equipment and measurement with CO2, N2O, SF6, Kr85.

Assesses the role of natural ventilation in modern hospitals. Considers optimum standards of air change rates for winter and summer conditions and reviews factors within the hospital context that are likely to affect the achievement of natural ventilation. Notes an air change rate of 1.5/hr. is usually assumed for heat loss calculation. Finds cross ventilation is unlikely to be achieved and designs should be based on single sided ventilation. Reports tracer gas measurements of natural ventilation in Southland Hospital, Shoreham by Sea.

Reports tests of the effect of various air treatment devices on the radon daughter concentrations within a room. Test were carried out using an electrostatic precipitator, a humidifier and a dehumidifier. The ventilation rate of the room was measured using Krypton 85 as a tracer gas.< Finds that the use of a humidifier, dehumidifier or carbon filter gave no significant alteration to the radon concentrations in the room, but that the electrostatic precipitator reduced the concentration considerably and was equally effective when operated with or without the carbon filter.

Describes use of a radioactive tracer for measuring ventilation rates. Finds krypton 85 is the most suitable gas although xenon 133 and argon 41 have been used. Mentions various studies using radioactive tracers made in both France and England. Suggests commercial sources for krypton 85.

Discusses the principles involved in measuring air change rates using tracers and gives the theory. Outlines the preparation of the tracer and the test procedure in stables. Finds that satisfactory results can be obtained when the concentration of krypton-85 is only one tenth of the maximum allowable. Lists the advantages of the method.

Reviews qualities desirable in a tracer gas for the measurement of ventilation rates in buildings. Reports experiments in which radioactive argon was used to measure the ventilation rate in a room. Results obtained agreed with simultaneous measurements using hydrogen as tracer. Suggests use of method for measuring ventilation rates in large buildings and use of krypton gas as an alternative to argon.

Discusses use of tracer gases for the measurement of natural ventilation rates States advantages of using radio isotopes are increased speed and sensitivity. Gives expressions for calculating air change rates using radio isotopes from thedecrease in signal. Suggests use of krypton 85 or Xenon 133 as tracers. Discusses errors in the method. Reports study of air quality in a naturally ventilated building in Yakutsk. Air change rates, temperatures and concentrations of carbon monoxide were measured in kitchens with gas stoves.