Monday, October 6, 2008
Today I want to talk to you a little about how Stu and I heat our home in the cold New Jersey Winter months. We moved into the house two years ago, only to find a very nice pellet stove in the basement, stratigically placed in a location that would allow hot air to blast up the stairs of our small, bi level home. Faced with the daunting tasks that came with a pellet stove - buying pellets, lugging them to the garage, and the worst - keeping the stove clean, we weren't even sure at first if we were going to use it. Then we learned of the savings - both to our wallets and the environment. Pellet stoves are a great way to heat your home. They look cool, they are odorless, and our pellet stove saves us a ton of money. I'll explain.
An average 20 to 30 year old home of 1500 to 1800 square feet like ours, will consume approximately one 40 lb bag of pellets within a 24-hour period of time with a 40,000 BTU stove. We have baseboard heaters and they do not even turn on most of the winter months, and it gets down below 15 degrees for many days in the winter.
Pellet fuel is made from the sawdust left over from lumber manufacturing. It is dried, ground up to the consistency of course flour and fed through a mill that compresses it into small cylinders 6 mm in diameter and up to 25 mm in length. The mill puts such pressure on the wood flour that the natural lignin that gave strength to the original tree is reformed to produce a shiny glazing on the surface of each pellet. In fact, pellets are much denser than natural wood. You can test this by dropping a pellet in a glass of water: it sinks!
You can't burn pellets in a regular wood stove; they would just lie there in a smoldering pile. But a pellet stove is smart. A turning auger slowly feeds pellets from a storage hopper to a small pot in the firebox that holds just a handful of fuel. A fan pulls air through the pot to produce a bright and hot, yet clean and controlled fire. The exhaust is then passed through a heat exchanger that transfers the heat into the room. A solid state circuit board controls everything: the auger speed, combustion air fan and heat circulation fan, turning them all on and off at the right times. Once properly set up, a pellet stove is a clean-burning and reliable heater. There is no visible smoke in pellet stove exhaust.
The burning of pellet fuel is such a controlled process that a regular wood stove chimney is unnecessary. Instead, a simple double-wall pellet vent is used to route the exhaust to outside. Under ideal conditions a stove can be vented horizontally through the wall like a clothes dryer, but a rise of at least five feet is usually recommended, so you need to get advice from your dealer.
The environment gains in a couple of ways when wood pellets are used for heating. First, pellets are made from sawdust that would otherwise end up as waste in a landfill where it would decompose and emit carbon dioxide and methane, the two most important greenhouse gases. Rising amounts of the greenhouse gases create the problem of global warming and may also be responsible for the climate changes that have produced extreme weather events in recent years. Although carbon dioxide is also a byproduct of pellet burning, at least homes are heated in the process instead of just letting the sawdust rot in a landfill.
The second environmental benefit is that home heating with pellets almost always displaces the use of fossil fuels like oil and gas. Burning fossil fuels increases greenhouse gases because the million-year-old carbon they are made of is converted to carbon dioxide and sent on a one-way trip into the atmosphere. In contrast, the carbon dioxide from wood pellet combustion is re-absorbed by young trees as they grow, so it is a renewable cycle.
Why is pellet heating such an appealing option? For one thing the 20 kilogram bags of pellets are convenient to use and compact to store. Also, a pellet appliance can run unattended for up to 24 hours on a hopper load of fuel, which is a big advantage for working families. Perhaps a less obvious reward is the knowledge that you are using a renewable fuel that will not contribute to the global warming problem, one that is also a recycled waste product from lumber operations that might otherwise end up in a land fill site.
When you heat your house with a pellet stove, you can feel good about it in more ways than one. Check back with us in a couple years when we hit phase 2 of our "Go Green" house plan...installing soloar panels and buying a hybrid minivan!