Windows: Passive House Glazings and Fenestrations
|Extremely Energy Efficient Pazen ENERsign Passive House Windows Thermal Performance|
There are a large number of window manufacturers around the world, most with names you may not have heard of before. In the U.S. market names such as Andersen, Jeld-Wen, Simonton, Pella, and Marvin, may come to mind. Less known is Serious Windows. Finding a U.S. manufacture that produces windows well suited for passive house construction is most challenging as most are two pane designs. I believe this circumstance is changing for the better. I hope energy efficient triple-pane passive house windows--with the proper performance characteristics will eventually become the norm domestically.
But currently, there are many other windows--passive house ready--that offer high(er) levels of performance (and construction quality). Germany is generally regarded as producing the finest and best windows for passive house in the world (for a price). Exceptional windows are also available from other European countries. Examples include Pazen Fenstertechnik, Schüco, Optiwin, Gradwohl Fenster und Haustüren, Bieber, and Intus. Some of these manufactures produce certified passive house windows.
Purchasing high-end extremely energy efficient windows from Europe for U.S. consumption has historically been difficult, lengthy, and expensive, however even since the time we began our construction (nearly two years ago), they have been easier to obtain through an increasing U.S. presence. As a consequence, we may have selected a different manufacturer--which produces windows specifically tailored to Passivhaus--if we were starting construction today.
Canada is a good source for high performance windows that possess similar characteristics to their European counterparts--often for less cost and manufacturing lead-time. Manufacturers include: Thermo-Tech, Fibertec, Inline, Accurate Dorwin, and Loewen.
When comparing energy efficient windows from different manufacturers (especially from abroad), be aware that how windows are rated vary, so directly comparing them may not be as apples-to-apples are one would anticipate.
Our particular window and door selection of Loewen was certainly one of the limiting components of our passive house, as their u-values and shgc values were well short of those of the highest performing certified passive house windows and doors. This specific area of "weakness," especially since we had so many windows--some quite large--had to made up for in other areas of our passive house construction, such as an extreme airtight building envelope.