Testing Water Penetration Resistance of Window Systems Exposed to “Realistic” Dynamic Air Pressures R. A. Van Straaten 1 , G. A. Kopp 2 , J. F. Straube 3 1 Research Lab for Better Homes, University of Western Ontario, London, Canada. rvanstra@uwo.ca 2 Boundary Layer Wind Tunnel Lab, University of Western Ontario, London, Canada. gak@blwtl.ca 3 Building Engineering Group, University of Waterloo, Waterloo, Canada jfstraube@uwaterloo.ca ABSTRACT A method for testing a series of windows exposed to simulated real dynamic wind loads is proposed. Three vinyl framed residential windows installed in a full scale wood framed house were tested with the method. The windows were exposed to realistic fluctuating wind pressures on the surface of a building, obtained from wind tunnel experiments, and were replicated in full-scale using novel “pressure loading actuators”. In the series of tests reported herein, the incidence of water penetration was compared between static and dynamic pressure tests. It was found that the peak pressures at which the window’s gasket systems could tolerate water exposure were much higher for realistic wind pressures than for those in the static pressure tests. The test methodology has the potential of providing greater insights of the performance of such systems exposed to actual severe wind storm conditions. 1. INTRODUCTION Water leakage, and particularly water leakage associated with window systems, has been identified as a significant contributor to moisture problems in buildings [1]. The recent North American Fenestration Standard/Specification for Windows, Doors, and skylights AAMA / WDMA / CSA 101 / I.S.2 / A440-08 [2] includes testing requirement for a window product’s water infiltration performance under constant (i.e., static) pressure be reported as per test methodology ASTM E331-00 [3]. A methodology for water penetration testing under cyclical applications of air pressures is provided in ASTM E547-00 [4]. These cyclic pressures include application of a constant pressure for 5 minutes, reduced to no pressure for 1 minute, and repeated for at least 15 minutes. ASTM E2269-04 [5] includes water penetration testing with “rapid pulsed air pressure differences”. These tests involve cycling pressure between 50% and 150% of a median air pressure. The frequency of the cycles is 0.5 Hz. The standard includes the detail “The median test pressure used in this test method is defined as the specified test pressure supplied by the user and related to the maximum positive building design pressure.” This detail will be discussed later in this paper. The standard also includes the commentary “The pulsed pressure of this test method may act to pump water past dry seals and breather systems of units incorporating these features, thereby making the test method more severe than a static pressure