IMPROVEMENTS ON PASSYS TEST CELLS

PASSYS test cells are outdoor test facilities for the evaluation of th e thermophysical parameters of real scale samples of facades and build ing components. The most important application is the testing of passi ve solar facades. While we have the advantage of measurements under re al weather conditions (real solar radiation) there is the disadvantage of non steady state boundary conditions. Various strategies are prese nted to enhance measurement accuracy. A so-called pseudo adiabatic she ll(PAS) was introduced to reduce the heat losses through the test cell envelope and the time constant by using a controlled electric heating foil. A similar approach is described here using heat flux sensitive tiles (HFS). A special heat flux sensor was designed and tested at ITW to meet the requirements of an accurate measurement of the overall he at flux passing the test cell envelope. By the application of a movabl e cold box in front of the tested facade steady state outside conditio ns can be provided for the evaluation of the U-value according to the requirements proposed by CEN/TC 89/WG7. Copyright (C) 1996 Elsevier Sc ience Ltd.