My dream house has no carbon footprint. Unfortunately the schoolhouse is not it.
At first, since it was on a south facing slope I thought photovoltaics might be possible for electricity generation. But the dormers (which make the second floor habitable) make it impossible for solar panels to work on the roof. Then I looked into the possibility of solar panels at the back of the lot. Unfortunately the lot is long and narrow, and the trees on either side cast too much shadow for panels to work on the ground there. So I’ll be buying my electricity from Western Mass Electric for now. The LED lighting should help with conserving electricity, and my refrigerators won’t have icemakers, which are real power drains. I don’t have a television, which is another power hog, but I realize I’ll have to have one in the rental unit or I’m not likely to get any customers.
As for heat, I considered geothermal but came to the conclusion that the initial installation costs were prohibitive. Then I looked at wood pellet boilers and was quite intrigued by them. But the nearest distributor of bulk pellets is pretty far away, meaning lots of fossil fuels would be burned in the delivery and I was a little nervous about the reliability of the supply.
Dave the builder recommended a hydronic forced air system fueled by propane. I’ve had experience with hydronic systems where hot water circulates through baseboard radiators, and I’ve had experience with forced hot air systems, where air is heated by a flame and circulates through ducts, but this is kind of a hybrid, and is new to me. There is one boiler (actually a tankless hot water heater) which heats the water for three uses: the radiant tubes in the basement floor, domestic hot water, and hot water that flows through tubes that heat the air that flows through ducts. There will be a small storage tank for domestic hot water but the hot water supply will be “limitless”. It is supposed to be very fuel efficient, and the heat is supposed to be more even and the air less dry than in regular forced air systems.
Heating system going in
By the way, the propane tanks were installed, buried and filled in mid-December before the ground froze.
The one thing that will make the most difference in fuel efficiency is the amount of insulation that is going in the walls. Once all the rough plumbing and wiring were done, it was time to start that process.
The target R factors are 40 in the exterior walls and 60 in the roof, which qualifies as “super insulated.” Most of the insulation is “bio-based” in particular the soy-based foam that was sprayed 12 inches thick in most of the exterior walls. But some of the exterior walls were not that thick, so a petroleum based spray foam with a higher R factor per inch had to be used in those. Zero carbon dreams dashed again. Cotton batting is going in the interior walls. And of course the windows, which were there when I bought the place, are new energy efficient ones (double pane, though, not triple). I don’t know what the U factor is on my windows, because the labels are gone, but Pella says their windows exceed the EnergyStar requirements in all 50 states. So for Massachusetts, that means it should be under .35.
Dining room, east
North bedroom, east side