Finding EcoFriendly Windows for "green" building

\Doug is building a sustainable home at Hickory Nut Forest Eco-community.  As he builds, he is sharing his experience so others can learn from his research.  Below is his investigation into "green" windows....

It’s time to place the orders for the windows. We just need to decide size, shape colour and finish  then find the best deal right….. no actually it’s a lot more involved than that. Here are some of the other considerations

1. Construction – air leakage
2. Ability to capture heat from the sun – solar heat gain coefficient (SHGC)
3. The rate at which a window conducts non-solar heat flow – U factor
4. Type of opening –  with a passive solar house, it’s critical to move the heat from the heated zones out into the rest of the building. These vital cross ventilation needs and opportunities dictate selection of casement vs double hung vs awning style openings

All of the above need to be considered and treated differently for each individual face of the house. To the south the priority is to soak up the sun so lots of glass. To the north, where there is minimal sun, we need to focus on minimizing heat losses and for east and west, somewhere between the two.

We chose Herd H3 frames with Cardinal glass (SHGC 0.7, U 0.3). The devil’s in the detail, look at the difference in construction quality

The Hurd product has a great seal and fully contacts the seal, reducing your energy costs and increasing your return on investment.

This product is supposed to be “the best” but look at this poor seal! Not to mention it has half of the wood structure as the Hurd product.

To complete the job, after careful installation and tight  sealing and insulation we will need to carefully select window shades and add window quilts for our biggest windows otherwise, when night falls, we’ll lose all our heat gains back through the windows…….!