Field measurements of attic ventilation rates made in a house with and without a turbine ventilator indicated that the enhancement provided by the ventilator was a function of wind direction, with greatest benefit in the direction with the most upwind shelter. Operation of an attic turbine ventilator was found to reduce attic air temperatures in the test house by less than 1 deg.F which has no effect on occupant comfort.

KEYWORDS: ventilation, attics, temperature, ventilators, measuring, winds.