This study was undertaken to alleviate the void of an established standard for testing window treatments and movable insulations. The development of such a standard must be based on systems that can furnish accurate and reproducible data. A major objective of our concerted efforts was to assess the precision of two thermal transmission systems, the Window Transmission Instrument and the Heat Transfer System, and correlation of results. Testing was done at three selected temperature differences: T 30, T 40, and T 50 F.

A comparative analysis of the two systems, using pairwise t-tests, indicated that different levels of variation were present between the two systems. There was less variation in the data obtained from the Window Transmission Instrument.

Units: I-P