helium

Ventilation rates in two test home were measured using helium as a tracer gas. Pressure differences across the exterior walls of the house were recorded using pressure taps. Gives results for air infiltration tests and the calculated air infiltration. Finds that during summer air infiltration rates varied approximately linearly with wind velocity. During the winter, the pattern and extent of air infiltration were influenced by both house stack action and furnace operation.

Reports investigation of air change rates in two residences using helium as a tracer gas. Gives results of measured air change rates, wind speed and direction and internal to external temperature difference. Uses statistical method to compare results from the two residences and concludes that temperature coefficients were statistically different but that wind coefficients were not. Finds high dependence of infiltration rates on indoor to outdoor temperature difference and that values for air leakage obtained from current methods of estimation were lower than those actually experienced.

Outlines ventilation measurements being made on two storey semi-detached houses using helium as a tracer gas. Describes measurement of decay rates in single rooms, the recirculation between two rooms and by summation the ventilation rate of thewhole house. Describes installation used to measure ventilation rates when homes are occupied without interfering with the normallife of tenants.

Gives measurements of air infiltration made in ten houses in Indiana using helium as a tracer gas. Assumes linear dependence of infiltration rate on temperature difference and wind velocity and calculates infiltration rate per unit crack length. Change rates ranged from about 0.6 to 1.5 changes per hour.

Reports measurements of infiltration rates in two research houses in Minnesota under different wind, temperature and inside operating conditions using helium as a tracer gas. Suggests linear dependence of infiltration rate on temperature difference and wind velocity. Found infiltration rates varied from 0.1 to 0. 4 changes per hour

Developes mathematical model of air infiltration based on crack flow equations. Describes measurements made on test house. Shows that actual pressure distributions in walls deviate considerably from values in guidebooks. Finds background leakage area of house by pressurizing house with electric fan and measuring pressures. Suggests two distributions for leakage areas. Measures infiltration rate using helium tracer gas, recording temperature and pressure differences. Concludes that comparison between prediction and experimental results is encouraging.

Describes how in 1960-62 National Research Council of Canada conducted air infiltration measurements on 2 single-storey houses using helium as a tracer gas, followed in 1967-68 by measurement of air leakage characteristics using house pressurisation technique. Describes procedure developed from these tests for calculating infiltration rates. Gives equations for calculating infiltration due to stack effect and that due to wind action. Gives equation for combined effect.