Although primarily designed for studying the dynamic net energy flows through fenestration systems over the full diurnal cycle, the Mobile Window Thermal Test (MoWiTT) Facility is also frequently used to measure nighttime U-values. These measurements have the advantage of incorporating the exterior film coefficient resulting from the true ambient conditions at a particular time and location, rather than relying on a laboratory simulation of some assumed average or extreme condition. On the other hand, the MoWiTT is a much more complicated facility than a laboratory hot box, and the number of potential error sources is correspondingly larger. The method of deriving the nighttime U-value from directly measured data and the effect of random and systematic errors are discussed.
BT - ASHRAE Transactions C1 -Windows and Daylighting Group
C2 - LBL-30032 CN - LBL-30032 CY - Baltimore, MD DA - 06/1992 LA - eng N2 -Although primarily designed for studying the dynamic net energy flows through fenestration systems over the full diurnal cycle, the Mobile Window Thermal Test (MoWiTT) Facility is also frequently used to measure nighttime U-values. These measurements have the advantage of incorporating the exterior film coefficient resulting from the true ambient conditions at a particular time and location, rather than relying on a laboratory simulation of some assumed average or extreme condition. On the other hand, the MoWiTT is a much more complicated facility than a laboratory hot box, and the number of potential error sources is correspondingly larger. The method of deriving the nighttime U-value from directly measured data and the effect of random and systematic errors are discussed.
PP - Baltimore, MD PY - 1992 T2 - ASHRAE Transactions TI - Method of Measuring Nighttime U-Values Using the Mobile Window Thermal Test (MoWiTT) Facility VL - 98, Part 2 ER -