Friday, October 28, 2022

stoves and furnaces

It feels like someone's doing battle-space prep when I read about how natural gas carries pollutants: "even low-level gas leaks from kitchen stoves when they are off can generate benzene concentrations in homes up to seven times California’s recommended exposure limit."
Last month, California air regulators approved a first-in-the nation commitment to phase out the sale of gas furnaces and water heaters by 2030—a move that will transition millions of homes to electric alternatives, such as heat pumps.

Never mind that gas is more efficient than electricity, and cooks better too.

The study itself cites others which found (in California) that only 30% of the methane leaks were from the pilot lights--which surprises me. CA's benzene limit is 0.5ppb in air (reduced in 2007 from 2.5ppb in 1990--a factor of 5. The old limit is about the same magnitude as the highest enhancement cited above. I don't know about your home, but in ours the furnace and water heater exhaust outside, and we generally run the overhead exhaust fan when we cook. This doesn't sound excessively risky. But I have friends who will take the report as proof that de-carbonizing is super-urgent.

3 comments:

Assistant Village Idiot said...

We need to find an energy source that never has anything go wrong.

Korora said...

In this broken world? The probability of that is an oval.

Douglas2 said...

I also several weeks ago concluded that there's a concerted effort underway to demonize home use of natural gas as a health hazard, based upon the 'news' articles and ads that I've been seeing on the subject.

Why I know that these articles and ads are making mountains from molehills:
When I was a regular participant on an internet home improvement forum several years ago, I noticed that it was an every-winter thing that people in new-to-them unheated homes or with newly-broken obsolete furnaces would ask about the group's wisdom on the subject of unvented "ventfree"/"flueless" gas and propane heaters as a stopgap, supplement, or replacement for a traditional central heating system.
When responses were virulently against their air-quality hazards but only on the basis of anecdote, that was like a red-rag to a bull to me, and I had to look into it.
My conclusion was that the unvented type of heater really is something that I wouldn't use in my own home --- but 85% because of humidity issues rather than other emissions. That 15% is still real however. The amount of gas used for space heating is (usually) considerably larger than that used by cooking and baking in a home, but the NFPA 54, IFGC, and other common building regulations on installation of gas cooking appliances require intentional adequate venting for kitchens with gas appliances so that they will be safe even in extensive use situations.

There's long history and really good science behind the safety factors used in the fuel gas codes, and they really did consider long-term exposure as well as short, and consider benzene, leaks, and everything that we're suddenly being warned about.

I hate eco-"solutions" that are counter-productive.


Douglas2, who just completed installation of a hyper-efficient works-at-extremely-low-outdoor-temperature heat-pump system in his home.