However, there is such a thing as an even dirtier burning gas stove. For instance, put a natural gas regulator on a propane supplied burner, or vice versa.

Also, even a properly tuned range will emit all sorts of things that are much worse than methane.

Methane (at the volumes we're taking about) does not have significant health effects; the paper you link speaks mostly about its effect as a greenhouse gas.

And I'm measuring my NO2 and it's within safe levels. So should I believe you or my own lying eyes?

Granted, a lot of this may be due to other effects (e.g, ventilation) and I agree my next stovetop won't be gas.

But clearly some setups are less problematic than others and it's not the case that everyone is poisoning themselves unless they go buy an electric tomorrow.

> But clearly some setups are less problematic than others and it's not the case that everyone is poisoning themselves unless they go buy an electric tomorrow

I didn't say everyone should go electric tomorrow. But people are exposing themselves to (IMO high) indoor air pollution by using gas stoves without running an extractor fan and opening windows.

A lot of people (everyone I know at least) only run the extractor to get rid of food smells, not for natural gas combustion byproducts, which is a mistake.

though any gas other than air will kill you at a high enough dose, methane is pretty extremely safe; wikipedia claims the major risk if you avoid blowing yourself up is that it can displace air and thus oxygen

That article claims the stove is leaking ~1% of its burned fuel. Which seems really unlikely, and deeper in they seem to claim its largely from the ignition cycle. Which is still _really_ hard to believe even on my old stove which generally takes a few arc's before there is enough gas near the spark igniter to catch.

Even if you assume that 100% of the gas loss in the time between when I turn it on, and it goes whoosh and burns all that fuel is wasted (say up to a full second) I would then have to leave the stove on for less than 100 seconds at full blast or double that if I turn the flow down by 1/2 for that gas to equal 1% of the gas used during the cycle.

Anyway, compared with the volume of methane in human flatulence, I would be worried more about how good the bathroom ventilation is than how much of unburnt methane manages to avoid being burned and also sucked out the fume hood.

So, I too am skeptical about these home air sensors, I have one of the egg ones, that claims to measure PPM (CO2/etc). Yet it was spiking every morning, and at first I thought it was my wife putting on perfume, but it happens even when she isn't home in the morning... After watching it and what happens in my house, I suspect its largely measuring the humidity in the air from the shower.

Doing nothing but turning the shower on causes it to spike a few mins later and then gradually go down for the rest of the day. I guess I didn't think that the majority of the PPM "pollution" in my house is actually just water droplets. Thats a lot different than all the fly-ash or whatever they want you to think is the problem. (edit: just to be clear, I'm not denying indoor pollution, only that the sensor I have, while marketed as such, isn't actually measuring pollution if most of what its measuring is mist from the showerhead).

>deeper in they seem to claim its largely from the ignition cycle

Not so. In the abstract, they say that over three-quarters of their 1% estimate was when the appliance is not in use ("steady-state-off"). See Figure 5.

>the sensor... isn't actually measuring pollution if most of what its measuring is mist from the showerhead

It's possible that your sensor is actually measuring particulate aerosols created when the small water droplets evaporate, leaving behind tiny particles due to dissolved solids. The effect is similar to the "salt spray" aerosols formed by ocean wave action.

The long reported residence time ("gradually go down for the rest of the day") makes this more likely IMO, since water droplets evaporate relatively quickly at typical indoor humidity levels.

https://pubmed.ncbi.nlm.nih.gov/17195485/

It's interesting to find out what the sensor may be actually measuring, and that it might actually be something, but I'm still left with the questions:

Is that stuff actually harmful?

If so, what could you even do about shower mist (at scale, as a reasonable thing to make a policy applying to all 7bn of us)?

And doesn't it still sound like the gas stove does not stand out as some special problem?

Or at least that, no article based on this source of data can be said to justify that conclusion.

Maybe the stove is doing something so much worse than farts and showers that it's worth giving up the utility and efficiency*, but this source of data does not show it.

* Efficiency including other gas appliances, ie, a gas clothes dryer is more efficient and interestingly, less fire risk than electric, but mostly the utility. Nothing else comes close to cooking with gas, it is simply by far the best tool for the job, and that is not an insignificant dismissable item.

> gas clothes dryer is more efficient and interestingly, less fire risk than electric

A regular electric dryer is 100% energy efficient, just like an electric resistance space heater. A heat-pump electric dryer can be 2-300% "efficient" (really COP) because it uses a heat pump.

A gas dryer is strictly less than 100% efficient - because like with any combustion device, some portion of the fuel is unburned and is sent out the exhaust/flue. Even the most expensive gas condensing modulating furnaces are only in the 90-97% combustion efficiency range.

Gas dryers are usually more time efficient though. They achieve such high temperatures (thanks to combustion) that they dry clothes 50% faster. And because gas is cheaper than electricity, they are cheaper to operate. The operational energy cost advantage vanishes when compared to heat pump electric dryers, however.

Then compare the parts & materials list of a gas dryer and a heat pump dryer.

You keep moving goal posts, but ok.

Yes heat pumps are more complicated. Likewise LEDs are more complicated than incandescent bulbs. Condensing furnaces are more complex than gravity furnaces. And nothing is simpler than a clothesline.

Higher efficiency usually involves higher complexity (EVs being an exception, although batteries themselves are pretty complex at tiny scales).

What's also great about heat pump and other condensing type dryers is that they are ventless. With a regular vented dryer, each time you run it you exhaust several thousand cubic feet of indoor conditioned air, which gets replaced by outdoor unconditioned (hot, cold, or dirty) air due to the depressurization of your house.

One way or another, you pay for reconditioning that air.

Depending on how much you do laundry, your local climate, and the price of energy, a ventless dryer (which can only be electric, naturally) can save you a lot in energy costs.

Electric dryers aren't 100% efficient if the source is the usual gas/coal/nuke/etc steam plant because the plant itself is only ballpark 50% efficient at converting the heat->electricity, then you take a percent or ten in transmission losses/etc. So, if the choice is pump the gas to a combined cycle gas plant, burn it, transmit the electricity to a resistivity heating dryer vs pump the gas directly to the dryer and burn it, the gas dryer will generally win.

Using a heat pump returns much of what is lost, but on balance in most places its sorta a wash. To be specific you have to look at the whole picture including the energy source, which requires actually picking a location/city and a particular product. And even saying maybe 100% of your power comes from PV+Wind (yah righ, haha) if you really want to lower the footprint the best plan is just to hang your cloths outside.

"The data for steady-state-off measurements were long-tail skewed, with the top 5 stoves (9% of sampled units) emitting half (49%) of all steady-state-off emissions."

So, they have a couple leaky stoves in the equation and they extrapolate the data. But they never bother to determine what was leaking, which is actually a fairly simple thing to do since there are commercial leak detectors that are quite sensitive (https://www.southerncrossinc.com/wp-content/uploads/2019/10/...) to at home units that detect NG/propane/etc.

Plus there were quite a number of other WTF moments in the document that don't match with my understanding of current install practices around NG heaters/etc.

Not the least of which, is that if 1% of the usage (which is a lot!) is leaking that will easily show up on peoples meters and be something that can be smelled. Which granted most people don't run outside and check their meter in the morning after having turned off all their gas consumers but people do smell gas. I've known at least one person who ended up ripping up a bunch of the piping in their attic because it was leaking, but i'm guessing its more likely someone forgot about an old appliance with an actual pilot light or the data was categorized improperly.

Lets just say, that if you were honestly trying to run this study, don't you think you would want to go investigate some of the outliers to at least note that the top couple cases were broken valves, or rusted piping, or just debris in the gas line damaging/keeping the valve from closing (which is why modern gas codes require sediment traps) fully?

How does a study that isolates the air around the stove in order to measure the emissions translate into the levels of pollutants that end up in the average home with a stove?

I should definitely fix my vent hood though.

>There is no such thing as a clean burning gas stove. Even when not in use, they leak methane, and the majority of methane they leak is when they are not in use.

How exactly does a gas stove leak methane (or anything else) when it's turned off, so there's no gas flowing?

The valves that open when the stove is operating are not perfectly sealed (they can't be). They allow a bit of methane to leak constantly.

Is this something about American-style gas stoves, or all gas stoves? Why would it be impossible to have a valve with a perfect (or reasonably perfect, obviously nothing mechanical is absolutely perfect) seal? A normal ball valve in a gas line is perfectly sealed; why would the valve in a stove be any different?

What magic world do you think we live in? Everything leaks at all times.

And when discussing policy and things at scale, you factor in the total picture where 80% of the individual examples will be one or more of: damaged, installed wrong, 35 years old, used incorrectly, cheaply designed, cheaply made, etc etc, not the perfect ideal lab example.

To be clear, I am firmly in the 'keep gas stoves' camp because they simply work the best for that job, the alternatives are not actually alternatives, and I don't think any of these articles actually show that they are harmful, or at least stand out from any other source of of stuff in the air.

But of course they leak. That isn't even remotely a remarkable claim. 'off' in the real world only ever means 'mostly off'.