Tuesday, July 27, 2010

Windows and really good Windows!

Conversation with Stephen at Thermotech was very enlightening.  Here is some info about their windows and windows in general.

Only 3 NA companies make the high-performance windows needed for Passive House.
  1. Serious Windows
  2. Thermotech
  3. Fibertec
The 2nd and 3rd are Canadian Companies.  you can also buy Optiwin, and Gaulhofer in North America.  Prices need to be determined.  This is a Blog http://blog.loadingdock5.com/?p=192 where they found windows from France for about $30,000 as opposed to the NA ones for about $10k.  That seems crazy, so I phoned up Thermotech to see if I can use theirs.  They apparently have performance data good enough to use in the PHPP software, so I'll be able to see if our house design can use their windows effectively.  Their frames are smaller and lower profile than the Optiwin and other Euro ones, so this makes some difference when choosing, as smaller windows may benefit substantially from the increased glass areas that low profile frames can provide, compared to the larger framed euro windows.  Thermotech windows use both Truth (operator) hardware and Roto (euro multipoint locking) hardware.  The Roto hardware operates multiple locks with a single lever.  The pultruded fibreglass frames are filled with insulation and joined using an injection-moulded grn corner piece, to which the frame stanchions are screwed (4 screws per corner).  The joints are then sealed with a marine-grade sealant (not silicone).  Thermotech windows all open outward.  There is no tilt and turn feature like the Optiwin and other euro styles. 
Here are some numbers on sizing:
  1. Tilt and turn windows work best at about 3 to 4ft wide.
  2. Triple pane casements should not be wider than 34" or the hinge hardware becomes inadequate
  3. Casement dimensions are max about 34"x72".
  4. Awning windows are good up to 4'x4' sizes.
  5. Pricing is by perimeter, except the customer base prefers 'united length'.  At a certain size, windows jump in price due to the need to thicken the glass, which is determined by wind pressures and CSA codes.  This size is 95 united inches (outside dim of windows, length plus width).  Above 95 Ui, glass must be 4mm thick, rather the 3.
  6. Thermotech recently began offering a triple pane glass with low -e, argon, and now low-iron glass called their 322 Gain Plus.  The low iron improves SHGC, though drops R value slightly.  Krypton fill adds about $20 to $30 per SF to window costs (!).
  7. Nice window hardware is by Roto, Segania, G. U. 
  8. Energy Rating (ER) rating is a Canadian rating system for windows that takes solar heat gains into account as well as R-value.  Thermotech windows perform very well in this rating system, in which solar gains over 200 days in the year are averaged.
  9. Here is a window discussion in GreenBuildingAdvisory.com:  http://www.greenbuildingadvisor.com/community/forum/energy-efficiency-and-durability/14850/serious-windows-vs-thermotech-fibertec-inline


  1. Sorry, the information that you have posted is incorrect. The only Passive House in Canada which also attained LEED Platinum certification used windows from Inline Fiberglass Ltd.

    Furthermore, according to Energy Star Canada, Inline has the highest ER rated fiberglass window in the country along with the top 6 of the top 10. Two of the companies mentioned(Serious and Thermotech) are not even listed with Energy Star Canada.

  2. Passive House Institute Certified First Passive House Window in US


  3. Its been some time since this post, but these two comments were great, and much has happenned in the window industry also. There are so many manufacturers which I did not mention in my first post, offering Passive House windows in North America now. And there are numerous others with very good performance that were there from before that I did not mention. Serious, Inline Fibreglass, Duxton, Accurate Dorwin, Tiltco, and a number of European brands including Rehau, Internorm, Reider, Zola, and others.