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It seems like we are damned if we do, damned if we don’t. I was starting to feel smug for having a 2-year-old catalytic wood stove fired by locally grown hardwo
by avidphantasm 4y ago
It seems like we are damned if we do, damned if we don’t. I was starting to feel smug for having a 2-year-old catalytic wood stove fired by locally grown hardwoods (I am in NH). Then I found this article [1] about a Finnish study showing high dioxin and furan emissions due to the catalyst.
Luckily we just added hyper heat air source heat pumps to the rest of the house. We also have hydronic heat from an oil-fired boiler, which we are planning to only use when it’s too cold for the heat pumps (less than 25 degrees F).
The boiler also supplies hot water, so looking to replace that with a heat pump water heater to avoid burning oil in the summer. However, even with the efficiency of heat pumps, the electricity is mostly generated with gas, which is <40% efficient (factoring in transmission and distribution losses). Our boiler is 82% efficient, so from a carbon/GHG point of view, heat pump water heater may not be any better. Of course electricity is fungible, so more nuclear, solar, and wind would change the equation.
What I want to know is, where is the Department of Energy, etc. guidance on this. I have a fair amount of experience with energy policy and technology and the right path is far from clear to me.
[1] https://www.familiesforcleanair.org/catalytic-wood-stoves-shown-to-increase-dioxin-emissions/ https://www.familiesforcleanair.org/catalytic-wood-stoves-sh...
- _0w8t 4y agoEven heavy oil for boilers requires some energy to produce from raw oil. Plus there are transportation losses. They are less than transport losses for electricity but not much.
- nkurz 4y agoGreat post. We're in a parallel situation in Vermont: current EPA woodstove using locally harvested wood, fuel oil backup that we use only when we aren't home. We did install a heat pump hot water heater and have been happy with it, but it was replacing electric so a clearer win. I'm not sure what to make of the Finnish study. Full version is here: https://sci-hub.se/10.1016/j.chemosphere.2012.02.027 https://sci-hub.se/10.1016/j.chemosphere.2012.02.027. It's hard to know how the elevated levels compare to other sources, since 2x of almost zero might still be negligible. It does mention though that the "PCDD/F level exceeded the emission limit in Europe for MSW incinerators" so maybe it's real. One other factor that might help us remain "smug" about our modern wood stoves is that the Finnish study was done on sauna stoves without secondary combustion and with high flue gas temps. I suspect the results might be completely different for compliant woodstove with good secondary and much lower flue temps. Of course, different might end up worse.
- avidphantasm 4y agoThanks for posting the original article. One of these days I’ll look for citations that might elaborate this work.