Wednesday, September 14, 2011

Heating our home with wood, Part 2

We are moving into fall here in Maine. A few of the maples have begun to change color, the nights are cooler and the days relatively insect-free. So, we are approaching the home heating season with curiosity. How much will our investment in wood heat pay off? I'll post an update in May when all is said and done. I'll summarize where we are and the associated costs.

As stated in the last post, we purchased a Vermont Castings Defiant (model 1975) with a catalytic converter. There is quite a bit of negative press about catalytic converters but it's important to note that there are many stoves with these out there with happy users. This particular stove can be operated with a damper open, bypassing the converter, or closed, utilizing the converter. The stove came with two EPA energy efficiency tags for each of the above. The tag for the open damper gives an approximate efficiency of 77%; the tag for the converter gives an efficiency of 84% (a 7% increase). This may not seem like much but consider that this is 7% less wood needed to heat. As I get older, I'm sure I'll appreciate that 7% less cutting and splitting!

I investigated all sorts of chimney options. Stainless steel or a regular masonry flue; inside the house or outside the house. All the advice I received regarding location told me to put the flue inside the house for two reasons. One, the chimney stays warmer and this is better for draft. Two, the chimney itself heats up and that heat contributes to keeping your home warmer. The stainless chimney was going to cost upwards of $2500. and the masonry chimney we installed cost about the same when all was said and done.

I chose masonry because I felt more comfortable putting something made of concrete inside my home. I also liked the idea of having the thermal mass of a concrete block chimney to absorb and radiate heat energy. I feel metal will eventually corrode (though this may take years) and because the flue has to be enclosed inside sheetrock, I felt there was no way to monitor this. Metal would have been quicker but helping to build the masonry chimney was much more enjoyable for me personally. Plus, I like learning how to build things, I got to know one of my neighbors much better over the course of the few weeks it took to construct the chimney and it looks better on the house.

The cost of the chimney was approximately $1000. in materials for three floors; from the basement to the new brickwork around the whole chimney above the roofline. Labor was also $1000. This probably cost less than usual as I used the masons discount and went to the masonry supplier myself to purchase supplies (they delivered). And, one of my neighbors who is a mason by trade, built our chimney over a few weekends as I played laborer and did all the grunt work. I also removed and replaced the walls inside our house and did all the associated structural work to create a chase next to the existing chimney. Then, there was the plumbing and wiring that needed to be relocated....yeah.

An expense I didn't account for was the cost of connecting the stove to the chimney. The heavy gauge, single wall stove pipe and insulated double-wall stove pipe (by code for thru the wall into the chimney) cost close to $800.

I decided to build a brick heat-stop behind our new wood stove. The mason had a large pile of used brick he said I could scrounge for free. With a bit more sweat-equity and a rudimentary knowledge of masonry, I built a pretty decent looking brick wall.

To date, we have only test fired the stove a few times as suggested to season the stove and burn off the organic components of the stove pipe paint. This involves starting a fire, regulating the temperature to let the stove get no hotter than 500 degrees and then letting the fire go out. Based on the instruction manual, this is a low temp fire. I can't wait to crank this baby to see what it will do!



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