tracer gas

Experimental methods have been developed to determine rates of air renewal. Based essentially on the use of a tracer gas, these methods permit the determination of real values on the site of the building itself. The pressurisation method which e

Ventilation and infiltration rates were measured in eight office buildings using an automated tracer-gas measurement system. The buildings range in size from a two-story building with a floor area of about 2000 m2 to a 15-story office building.

Describes how multizone tracer gas analysis techniques can provide a complete description of office ventilation. Treats the concept of ventilation effectiveness to characterise internal air distribution. Discusses the measurement of whole building ventilation rates and ventilation effectiveness in mechanically ventilated office buildings.

Describes the measurement of infiltration in each of the seven rooms of a house over the period from November 1983 to January 1984 with occasional use of mechanical exhaust ventilation. Nitrous oxide was used as the tracer gas. External meteorological conditions were also recorded. The measurement principles are outlined and detailed results presented. Various mathematical models are assessed in comparison with the measured data.

A pilot test series has been performed to study the possibility of using carbon dioxide produced by the burners of a test furnace as a tracer gas to measure the fire gas leakage of door assemblies. The experiments show that a test method based on tracer gas techniques can be developed avoiding thedrawbacks of the proposed ISO test method DP 5925 Part 3 based on the use of an enclosure. The investigated method works well for leakage measurements in ambient and medium temperature ranges. A special test door suitable for theoretical estimation of leakage rates was used in the test.

A constant concentration tracer gas system was designed and constructed to continuously measure the air infiltration rate in as many as ten zones of a building. The portable, microcomputer controlled system injects a metered amount of tracer

One important factor in the spread of airborne infection must be the movement of the air itself i.e. the ventilation, although an exact correlation of it with the risk of infection has yet to be found. As part of an infection survey in a hospital ward we made a detailed study by physical methods of the movements of the air and of the transport of particles by this means. A description is given of the methods employed.

The problem of describing quantitatively the effective ventilation in a room when the air within the room is imperfectly mixed is discussed. It is suggested that the protection afforded by the ventilation to any given position against air

This paper describes the experimental techniques devised to measure the necessary parameters on installed heating systems. With these data the seasonal performance of a heating system can be computed. The effectiveness of various operating and system modifications can then be predicted. Thecalculated effects of some modifications are presented in a companion paper.

Air infiltration rates are important in determining greenhouse heating requirements. Design recommendations usually suggest one to two complete air exchanges per hour under calm conditions. Tests made in 10 commercial ranges showed no greenhouse in excess of one exchange per hour, with one as low as 0.34 per hour, and an average of 0.56. However, additional tests at CSU showed marked variation, depending upon greenhouse size and heating methods, as well as type of structure and outside wind velocity.