The effectiveness of an evergreen windbreak for reducing residential energy consumption.

Describes experiment to determine the effect of an evergreen windbreak on residential heat losses attributable to air infiltration. Eight-meter tall pines were arranged as an experimental windbreak to shelter a townhouse for nine weeks Air infiltration was measured continuously using SF6 as a tracer gas to compare air change rates before and after the windbreak. A dimensionless parameter was derived to distinguish between wind-and temperature-produced air infiltration and to determine the effects of wind direction. Concludes that for wind speeds of 5.6 m/s with the wind perpendicular to the row of trees and house air infiltration was reduced by 42%. Found that the shelterbelt had no effect on windfrom other directions than across the break. states that results of experiment followed the predictions from wind tunnel simulations.