Monday, January 28, 2008
I installed a Quadra Fire wood pellet stove to heat the barn for the winter and to provide supplemental heat once the in-floor system is completed. Having no experience with wood pellet heating, I was skeptically hopeful about how this would work. Conceptually, it seems ideal- sawdust (in this case, a waste product from the wood products manufacturing industry) is formed into pellets by a relatively simple extrusion and drying process, then sold as fuel. It's natural, renewable, locally-produced, and inexpensive- Sustainable, Carbon Neutral heating at its finest! The whole idea still seems too good to be true.... So, after looking at several different pellet burners, we settled on the Quadra-Fire model for a variety of reasons- it had the lowest emmissions, highest efficiency, is American-made, and it has the rustic, aesthetic appeal we wanted in the barn. I set it in place, wired in a programmable thermostat, and installed the exhaust venting and air-intake systems through the wall (not too excited about ventpipes poking out the side of the barn, but this was about as low-profile as I could hope for). The little stove is loaded with pellets, then self-regulates the heat output by controlling the feed rate into the burner. Having insulated the roofs with spray foam, I was excited with the thought of finally working inside a warm, dry environment for the rest of the winter. So far, I love the stove- it burns and burns, requiring very little maintenance or attention. On the downside, the flame is not as "real" as a traditional wood-burning stove. But then, I won't have to spend a couple weeks of my year cutting, splitting, and hauling firewood. Unfortately, after running the little pellet burner all day with no appreciable temperature increase, I realized the laws of thermodynamics are working hard against me. The outside temp has been well below freezing for weeks (many days are below 0F lately), so the barn and its concrete slab floor are likely hanging at around 15 degrees inside. A quick calculation showed that it would take well over 750,000 BTUs of heat to raise the building temp up to 70 degrees, not including the heat loss through the walls (probably another 15,000BTUs/hour right now). The pellet stove kicks out a max of 30,000 BTUs/hour. Do the math- it isn't pretty. Once the building is insulated and heated up to room temp, the stove will be more than adequate to keep it toasty warm on a -40F morning, but right now it is like trying to melt a skating rink with a butane lighter while the A/C in running on high! Not. Gonna. Happen. Guess I'll be working in the cold for another few weeks :(
Thursday, January 10, 2008
While the foundation and framing have already received a skin of XPS, i've spent dozens and dozens of hours debating how to insulate the barn's interior framing. Early on, I had leaned towards blown-in cellulose for its high recycled content, thermal performance and reasonable cost. However, I was concerned with it settling over time, unless I hired a contractor who could dense-pack it. But dense-packed cellulose in the deep roof trusses required a huge amount of material, which would be very heavy and very expensive. So I got more excited with the idea of spray-foam insulation, and eventually decided to go with Icynene for a variety of reasons- namely, its contribution toward energy-efficient sustainable design. Plus, I found a very sharp and eco-conscious local contractor who made me feel confident about hiring out the work. Never mind the high price tag- it is money well invested when it provides a healthy, energy-efficient home for the rest of our lives. So before the hired help arrived, I had to frame in a roof in the upper level of the silo. I made a 2X6 roof, covered it above with OSB and strapped it below with perpendicular 2X4 framing. This would allow for 9" of insulation with minimal thermal bridging. Plus, the access door and decking above would give me future access to the domed silo roof from the inside. The foam guys came the next day and sprayed the milkhouse roof, barn roof and silo roof (they'll have to come back to spray the walls once i've done all the electrical wiring). It was nice to see them so concerned with doing the job well, no matter how long it takes (and it took about 10 hours just to do the roofs!). Fiberglass should be outlawed...
Tuesday, January 08, 2008
While I waited for the metal roofing to arrive for the milkhouse, winter snuck in. Having spent most of December finding other work to do and generally procrastinating, I finely decided to go for it. Compared to the technical difficulties of the barn & silo roofs, this job was cake- I spent almost as much time clearing away the snow and setting up scaffolding as I did to actually put on the roof. But it was cold, and the masochist in me chose a day with a high temp of 2 degrees F (but I'm sure the wind kept it below zero all afternoon). I put on every piece of fleece athleticwear I had, then finished up with a topcoat of construction-grade, redneck-approved demin and double ski masks. It almost felt warm. Almost.