Off the Grid
Net Zero
The colder your climate, the more likely you are to burn wood for heat. So let’s dig in for a bit. It’s good for the soul. It also helps inform our decisions about what is important in our lives.
Wood provides great heat for a home with the right wood burning equipment. Wood is comprised of organic compounds, mostly cellulose (like sugar) and lignin (like glue). [Visualize a thick maple syrup dripping from a tree. What a wonderful thing from nature that is. My favorite is on the darker side.] Simple combustion of methane is a good place to start. CH4+ O2 à CO2 + H2O Or in English, methane and oxygen (air) combine to produce heat, carbon dioxide, and water. Of course in the very beginning the water is mostly steam and then vapor.
[Global Warming?]
Wood molecules are much more complicated but the process is very similar. One of the first things to raise an environmentalist’s attention is Carbon Dioxide emission. Yes, Greenhouse Gas – GHG. The second, and not so obvious, is that it takes air, to be more accurate, oxygen, to burn wood. And, it’s a lot of air. We’ll dig in on this along with the impact on your comfort and pocket book some lines down, but first, let’s address the environmental issue, Green House Gas Emissions.
Although wood combustion contributes to atmospheric CO2 levels (GHG), it’s highly preferable to burning fossil fuels. Both, though, are stored solar energy captured in the photosynthesis process as the sun’s energy is converted into the biomass of the plant. Or in English, sunlight makes plants. Wood is very recently stored solar energy and is what I call quickly renewable. The name Fossil Fuel tells the other story. [natural gas, oil, coal, tar sand oil, fracked gas, shale oil, peat,, Powder River Basin Wyoming coal, and the beat goes on.] Old carbon, I mean very old carbon, that’s been trapped for millions of years is now combining with fresh air (oxygen) making new amounts of CO2 beyond what typically cycles in the planets current biosphere. This creates in imbalance for both carbon and oxygen.
[Thank you Neil deGrasse Tyson for the EDUCATION]
Earth’s entire supply of fossil fuels is as much as 2 billion years old. The planet is a little over 4 billion. Our total planet fossil fuel reserves are the result of 2 billion years of storage of solar energy. Experts as well as producers agree we’ve used about half of it in the last 150 years. [Dwell on this a moment] That is about 2 billion years worth of stored solar energy being released in only 150 years. How can we not be heating the planet a bit? What if the conditions needed to form deep reserves of fossil fuels don’t exist now and won’t reoccur in, say, the next 500 or even 1 million years, or never? What if we learn better uses for it than burning it up?
Using trees as heating fuel comes with the need for balance and responsibility. Quickly renewable materials are sustainable when the extraction rate does not exceed the production rate for an extended period. New growth, through photosynthesis, incorporates the carbon dioxide released from combustion into new trees. It’s a cycle, like everything, but on a short time frame when compared to the geologic timescale of fossil fuel generation in the earth. Sustainable production management and a growing list of alternative biofuels is an issue… yet another blog?
[We could be Hozed! (a.k.a. SKROD)]
I’ll tickle the conversation by saying when photosynthesis occurs, plants breath in carbon dioxide. The carbon part is incorporated into complex cellulose and lignin molecules (makes wood) along with some of the oxygen but much of the oxygen left from splitting carbon dioxide into carbon and oxygen contributes to breathable air. It’s an amazing loop that’s highly beneficial to those of us that breathe oxygen. Bottom line here… we’re hosed without plants and the volume and growth rate are VERY important.
[What a bunch of HOT AIR]
So, back to the air needed to keep your fire burning. Burning wood produces hydrogen as well as other gasses. Oxygen in the air supports the burn and combines with the hydrogen to make water as steam and vapor. Note that chimney smoke is mostly steam and particulates. Remember the EPA certified stove and burn it according to directions.
This background might not have been necessary to understand that you need an outside air feed for your wood burning equipment. An open fireplace or burn box needs lots of air. With no outside feed, it must come from your home. In a conventional home it comes through the cracks and there are plenty. A 20 pound load of wood will need over 200 pounds of air. I could drag us through PV=nRT but, that’s about 2,600 cubic feet (a living room full) of warm air at sea level. All that must come rushing through the cracks and across your home to the fireplace.
Start with a good wood burning stove or zero clearance unit with an outside air feed option, or, if you have a fireplace consider an insert with an outside air feed option. A 4” or 6” pipe will do the trick and the best systems have a port on the side, bottom, or back where the air pipe attaches.
[What About Fireplace Inserts?]
Our first opportunity to break the rule comes with inserts. Some use a second layer outside the actual flu pipe that draws incoming combustion air. If you don’t have that on your stove, it’s OK. Using an insert with closing doors stops the loss of huge amounts of dilution air going up the chimney. Close those doors and enjoy the warmth.
[What about Zero Clearance stoves compared to Free Standing Wood Stoves?]
another blog I suppose.
[Those Species are just Feces]
Hickory, Oak, What wood to use? That’s another story fraught with broad opinion and complications like regional supply. The heat content of almost all wood though is in a narrow range of BTUs/pound. A stove load of heavier wood provides more heat than a stove load of light wood.
[om]
Finally, I started with a soulful intent so I must recognize the power of fire. Although capable of huge devastation it provides connection to our environment, and our resources. The process engages our lives in our condition. We become more intentional in all things as we insert ourselves into our natural cycles. This also helps keep us in tune. Namaste.
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