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Window/Wall Rainscreen Interface Research project gets renewed

October 5, 2022  By Jon Eakes

In 2012 I was part of the CSA FIT committee looking at window installation practices.  I was very interested by the five year NRC IRC research project on moisture penetration of window installations and brought the first couple of freshly published reports to the committee; particularly the one that stated that you should not even attempt to try to stop the water and the wind at the same plane, it was doomed to fail often.  Only one other member of the committee was even interested.In 2018 a series of circumstances led me to beginning speaking at window conferences, starting with FenCon 18 in Winnipeg, challenging the industry to look at the potential for applying rain screen and pressure equalization principles to the window/wall interface of residential windows – completing the NRC work that was canceled after two of five planned technical reports were publish.  Most of the residential window industry was concentrating on perfecting the face sealing of the outer wall – not daring to think there might be a better way.  The essence of my presentation at these window conferences is on my website, together with a video showing dynamically what it is all about: click here.In 2020 after five window conferences, two colleges which have climate simulation chamber research facilities, stepped up to the plate to try to complete this research.  We started the planning and financing for two research projects on using rainscreen type pressure equalization in the narrow space of the window/wall interface with the object of determining if advanced control of moisture might not simplify residential window installations while giving them a greater resistance to water penetration making installations more durable and less expensive.   That got started in both labs, but then covid shut them down.In September 2022 with the colleges opening back up – the project is coming back to life.  Colleges can function with video conferencing, but not physical lab experimentation.  With the students back in the schools, the labs are reopening.George Brown College in Toronto, having some expertise on pressure equalization in the presence of Professor Chris Timusk, agreed to focus on the details of functional pressure equalization.  With recent financial support from Fenestration Canada and SAWDAC, we are starting that project back up now in September of 2022.  The windows, previously supplied by Jeld-Wen, are finally getting installed and testing will get underway this Fall.The BETAC department of Red River College in Winnipeg managed to keep portions of their project working, in slow motion, during the pandemic.  They have completed thermal testing designed to determine just how much space within the window/wall interface could be used for a drainage plane in a cold climate without a thermal compromise.  The data was collected but the staff to analyze that data are only becoming available now.  They are also completing the testing of various configurations for moisture penetration.  Reports from both those activities should be available this Fall.I will be giving a presentation at the WinDoor conference in Montreal in November to see what is coming to light and where that will be directing the rest of the research.  I will be sending a copy of that report out to all of you who have signed up for this newsletter as well.

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