When it gets really, really cold, like -10°F and below, we get beautiful ice patterns on our door and windows. Even with the modern double thermal pane glass with argon and such between the panes the cold comes in. I was a bit disappointed that the expensive Marvin windows we had bought for the bedroom and bathroom don’t perform better in our extreme climate.
The photo above is the kitchen window in the early morning light. It faces west and the mountain snow is on the other side making for a good background when shooting frost feathers. This and most of our windows are pairs of single pane glass we recovered from an office building. We framed them in back to back creating double pane windows. These do as well as the expensive commercial double pane windows. The big recycled windows were essentially free.
When I have time I will reseal the big windows – the putty needs replacing. We did one set last year and they came out great. We’ll also add a set of thin Tedlar membranes between the glass panes to divide up the air space. I made two of these “Super Windows” about twenty years ago down in the old farm house. They perform wonderfully. At -45°F we see a little frost on the bottom of those. This is far better than the commercial thermal pane door and Marvin windows they’re testing against in the cottage.
Other things I’m planning to eventually do is inner thermal curtains and outer shutters to conserve heat during the coldest nights of winter. The tricky thing with those is that one must be very careful when opening them so as not to thermally shock the glass and crack it. They are a refinement, an incremental improvement.
We will also be making the walls thicker at some point, doing real rock work rather than the artificial rocks we drew with our fingers in the outer stucco parge that protects the insulation from sun and chickens. This real rock work, about a foot thick, will create more depth at the windows moving the wind further away from the glass. With proper angling of the walls around the windows we will lose little in the way of light but gain more outer thermal mass for stability. An additional layer of insulation will be incorporated that that time in the walls. The final roof is waiting on this detail. Everything in its time. Then we’ll bury the house setting it fully into the cozy nook of the mountains arms.
During the winter we only burn about 3/4 cord of wood a year despite these having such a large window surface area leaking heat and the roof insulation not being completed yet. This is most likely due to two factors, those big windows gain a lot of passive solar energy during the winter and that energy gets stored in the 100,000 lbs of thermal mass of the cottage masonry. This keeps the cottage from overheating – by design. Conventional stick construction with this much window area would overheat from the sun unless special provisions were made to store all that energy somewhere. With our cottage the building’s mass is the storage. In the summer the sun slips up to the front window ledge but by winter solstice it is back kissing the rear wall of the cottage.
As we tweak the windows and roof this will improve although it is hard to imagine heating with less wood. It’s nice to have a fire. As it is now we often go for days or even a week without a fire during the winter months. Ironically, the coldest days also are the sunniest days so during the bitter weather we burn the least wood.
Outdoors: 38°F/23°F Sunny
Tiny Cottage: 67°F/61°F
Daily Spark: A government should serve the people, not make serfs of them.