I am totally remiss. Today was the last heating day of the winter.
Actually today was the day I turned off the active Solar... the 8'x12' section of hot air panels facing south (right into our now giant cottonwood) which pump heat into a rock-bed under the floor of our house. I don't have a precise number on how much heat they provide to the house but I'd roughly guess half of our BTUs come in that way. It tends to run for a few hours in the morning and a few in the afternoon when the big tree is not shading it completely.
It still dips below freezing most every night and may for another month or more, but the days, when sunny are in the 60's and the solar gain is high.
I did some significant pruning on the tree's lower branches which might allow good sun in during the coldest months, when the sun is very low... Fall and Spring are not as important in any case. The new Sunroom will definitely pick up the added exposure right away. The sunroom was dried in, 90% sealed and 50% insulated for the cold months. It was dropping below freeze inside during the colder nights, sometimes even if I ran the woodstove. Of course half the windows didn't have their double panes (snap-in-storms that were broken, now repaired), and half the ceiling insulation was not in, many of the cracks not sealed well, and the floor is dirt, not the heat-absorbing, higher specific-heat brick floor and bancos planned. For the moment it was merely a big insulator for the south side... in place of the R20 wall is probably the equivalent of an R100 buffer. The heat-flywheel effect will be fairly important, especially if we have the courage to let it get hot in there in the Autumn, rather than follow our summer instincts to keep it as cool as possible!
We haven't burned wood for maybe a month, or maybe only once or twice. I fire up the cookstove with a few days worth of trash (mostly junk-mail) on a cold morning and the warmth from that is often welcome in at least two ways! We burned maybe 1.5 cords of wood this winter, compared to 2-2.5 normally. Part is a mild winter, but some is the sunroom I'm sure. And extra, large, convenient, airtight stove in the sunroom will make it easier to pump heat into the house "on-demand" and when the sun is not out, but also an opportunity to burn more wood. The branches I pruned might yield as much as 1/4 cord... again, a double bargain from the sun. At $150/cord purchased, I don't mind a $300-$500 winter heating bill. I plan to build some flues through the bancos/floor/etc. to capture/re-radiate some of that heat, to add to the flywheel effect. I might even couple in the solar heat system somehow... to pump that heat into the floor rock-bed. It is, like life, all a big experiment.
