THERMAL MEASUREMENTS

There has been extensive test method development to quantify the overall heat transfer coefficients or U-factors of fenestration systems (windows and doors). Over the past decades, many ASHRAE publications document experimental results obtained through laboratory and field hot box test measurements (Rennekamp 1979, Lowinski 1979, Klems and Selkowits 1981, Ducas et al 1986, Elmahdy and Bowen 1988, Klems 1989). In North America, American Society for Testing and Materials (ASTM) has designated the hot box test method, ASTM C1199 (ASTM C1199 - 97 1997) as the standard test method for measuring the steady state U-factors of fenestration systems by using a calibrated hot box test method. In Europe, ISO/DIS 12567 (ISO/DIS 12567 1997) has been widely adopted.

Hotbox Facility

Using University of Massachusetts Research Calibrated Hot Box, many different types of fenestration product have been measured during last decade.

Casement Window Marvin’s Windows ISO PVC-U Window French Patio Door IEA Glazing Unit Insulating Glazing Units

University of Massachusetts Research Hot Box has been designed and constructed in accordance with ASTM C 976 – 90 (ASTM C 976 – 90 1990). It is used as an experimental facility to investigate extensive thermal performance of building assemblies (windows, doors, walls, ceilings, roofs, and floors) and their components using both ASTM and ISO/DIS standards. Under controlled air temperature, air velocity, and radiation conditions established in a metering chamber on one side and in a climatic chamber on the other of the hot box, measurements of heat transfer through a specimen can be made. These measurements include standard thermal transmittance or U-factor, detailed air velocity profile and temperature distributions on the surface of the specimen (Gatland II 1997).

Example Test Specimen -ISO window