I replaced my old Russo hand fed with an Alaska 140 auger in Feb 2011. I had been burning wood in the Russo in the fall and in the spring as needed and then also used about 3 ton of nut. The coal bin in my basement will hold 3 ton, so I ordered 3 ton of rice and didn't worry about running out since I'm only using it to heat my 1500 sqft house and a portion of my unfinished basement. I think I finished the 2010-2011 heating season with about 1.5 ton left in the basement.
Fast forward to the fall of 2011 and with a full heating season before me I started to get pretty nervous about how much fuel I was going to use. I was also dying of curiosity to know how the Alaska 140 did with wood pellets. I had used coal in it but not wood yet. My local TSC (or mecca as I affectionately refer to it!
) had a good price at the time on a ton of pellets for $197 so I picked up a ton.
I decided to keep track of my usage and correlate the pounds of fuel consumed to the outdoor temperature. As with the Russo, I burned the wood in the fall and spring and the coal in the colder weather. My plan was simple. I put a bathroom scale next to the hopper and weighed the coal scuttle I use every time I dumped it in. I recorded the date and time, and pounds of coal every time I filled the hopper. I've also got a thermometer which attaches to my computer so that I could automatically record the outdoor temperature.
Here's what I ended up with.
The wood data is a lot noisier than the coal data. I suspect the noise is from the sun. A sunny day or two in the spring or fall caused me to burn less fuel.
Thankfully last winter was relatively warm, so I made it through with the fuel I had on hand. The next thing I wanted to know was how much coal to order for the next heating season. With my fuel consumption data, that question was easy to answer. I fit a line to my data and then had a formula to use to calculate how much coal I'd use given an average daily temperature. After downloading the historic daily average temperatures since 1973 from some website (can't remember where that was any more) I could plug those numbers in to my formula and take a look at how much coal I would have used for all of those years. If I didn't use pellets, I'd need about 3.75 tons on average with a standard deviation of about 0.25 tons to heat for the entire season. Here's that data thrown into a histogram.
So, here I am at the start of a new heating season sitting on 4 ton of coal and looking forward to a warm house!