Research Engineer, Swedish National Testing Institute, Borås,
Pages: 16 Published: Jan 1990
At the Swedish National Testing Institute (SP) window thermal transmittance (U-value) measurements are carried out in a Guarded Hot Box (GHB). It is shown that the GHB meets the requirements of the relevant Swedish Standard (SS 024212,13) and International Standard Draft Proposal (ISO/DP 8990). The SS 024213 measurement routines are discussed.
A survey of measurement results acquired during the last ten years shows the continuous improvement of the U-value of windows produced in Sweden as well as the increasing importance of additional panes and improved sealed glazing units.
By way of comparative Guarded Hot Plate (GHP) and GHB measurements on sealed glazing units it is shown that the GHP method should be examined thoroughly and its results handled with care in order to prevent misinterpretation by, for instance, the client. It is further noted that the GHB technique, although commonly used, is not completely investigated and that on the level of standardization much work is yet unfinished.
gasfilling, Guarded Hot Box, Guarded Hot Plate, low emissivity film, measurement, round robin, sealed glazing unit, standard, surface resistance, testing institute, thermal conductivity, thermal resistance, window
Paper ID: STP23321S