Building energy-efficient homes, or making green renovations, is only half the battle in regions with cold winters. Another challenge is finding the right heating system.
Financial cost often drives the decision. But increasingly, builders and homeowners are asking: “What is the environmental cost?”
It’s easy to generalize. Wood is good. Oil and gas? Maybe I’ll pass.
But the real answer is much more complicated.
Wood-burning, in general, has a lighter carbon footprint. Trees grow back, and because the carbon dioxide emitted in the atmosphere is on par with the CO2 released when wood rots in the forest, burning contributes little to global climate change. That’s good for the planet.
Burn the wood in a fireplace, however, or in an old-style stove or outdoor boiler, and it releases tiny particles that can be a major source of local air pollution. That’s bad for your neighborhood. Modern, EPA-certified wood and pellet stoves are better at controlling this particulate matter, but not as clean as burning natural gas.
Boilers and direct-vent heaters fired by natural gas are the clean air champs, with very low levels of particle emissions. Modern oil heating systems aren’t far behind, when they’re fueled with ultra low-sulfur oil.
Climate change is a different story, though. Burning oil releases carbon dioxide that was sequestered in the earth; natural gas gives off methane. These two gases trap heat and warm the planet.
And here’s another layer of complexity: These considerations don’t include the environmental impact of producing and transporting the heat source. Problems with forcing natural gas out of shale deposits, or drilling for oil deep under the ocean, are being closely scrutinized and widely debated.
What about electric heat, which produces no local pollution? It’s the heat of choice in 3 out of 10 American homes today. Using electricity to power a heat pump, for instance, can be very energy efficient. But when electricity is produced by burning coal, as is common in much of the country, CO2 emissions can be off the charts.
Perhaps there’s no environmentally perfect heating system. Even passive solar homes typically need some backup heat in cold climates. So it makes sense to weigh the pros and cons of the most popular alternatives in your region.
Here’s a primer to help.
The Facts about Gas
Half of all American homes heat with natural gas, according to census figures.
Gas is abundant in North America, and the current supply glut and price advantage over oil are increasing its popularity.
Gas is composed primarily of methane. The main products of combustion are carbon dioxide and water vapor, making it the cleanest-burning fossil fuel.
Gas Boiler
Natural gas produces the least amount of particle emissions, especially when it’s burned in the latest condensing boilers, which boast average efficiencies above 90%. On the downside, gas drilling and exploration can be tough on the environment. Brand shown: Viessman
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