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This paper describes an original investigation of a new flowmeter and a method of balancing of airflow circuits in low pressure ventilating systems. The flowmeter is simple and robust in its construction, imposes virtually no resistance to

This paper describes part of a research on the influence of environment on physiological reactions and thermal comfort. Experimental rooms and apparatus are described and the imperfections in some of the instrumental methods - especially in respect to the measurement of air change by tracer substances - are noted. A brief description of a method to measure air change is givenin which CO2 is used. The importance of limiting the rate of air change in rooms heated by fires - as a means to save heat - is stressed.

Indoor air quality sampling strategies and analytical techniques have changed significantly in the past ten years. The changes reflect both the shifts in study objectives and the development of new forms of instrumentation. Toillustrate these trends, this paper describes early field techniques for measuring indoor air quality using a heavily instrumented mobile laboratory that is suitable for measuring one building intensively for up to four weeks.The style of measurement now is complemented by large field survey projects using passive samplers as the dominant instrumentation.

Results are given of the effect of ventilation rate, duct length and particle concentration on ion concentration under laboratory conditions. The effect of electrostatic fields is discussed.

A major pathway for loss of conditioned air in east Tennessee homes with externally located HVAC systems is leakage in the ductwork. The effect on infiltration rates, as measured by Freon-12 tracer gas dilution, becomes marked if the central duct fan is operating. Duct fan on and duct fan off measurements of the rate of air exchange gave mean values of 0.41 and 0.78 ach respectively in a total of 31 homes.