5 ms·

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 cyc

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).

schiffern 4y ago
>they seem to claim its largely from the ignition cycle Not so. In the abstract, they say that over three-fourths of their 1% estimate was from 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 your sensor is actually measuring particulate aerosols created when the water droplets evaporate, leaving behind tiny particles due to dissolved solids.[1] The effect is similar to the "salt spray" aerosols formed by ocean wave action. The long residence time you report ("gradually go down for the rest of the day") makes this almost guaranteed, since tiny airborne water droplets will evaporate in under one minute at a typical indoor humidity of 50%.[2] Hope this helps! [1] https://pubmed.ncbi.nlm.nih.gov/17195485/ https://pubmed.ncbi.nlm.nih.gov/17195485/ [2] (see Table 2) https://link.springer.com/article/10.1007/s10867-020-09562-5#Tab2 https://link.springer.com/article/10.1007/s10867-020-09562-5...
- StillBored 4y ago
  "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/IRwin-brochure-9.25.19.pdf 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?
- Brian_K_White 4y ago
  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.

schiffern 4y ago

>they seem to claim its largely from the ignition cycle Not so. In the abstract, they say that over three-fourths of their 1% estimate was from 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 your sensor is actually measuring particulate aerosols created when the water droplets evaporate, leaving behind tiny particles due to dissolved solids.[1] The effect is similar to the "salt spray" aerosols formed by ocean wave action. The long residence time you report ("gradually go down for the rest of the day") makes this almost guaranteed, since tiny airborne water droplets will evaporate in under one minute at a typical indoor humidity of 50%.[2] Hope this helps! [1] https://pubmed.ncbi.nlm.nih.gov/17195485/ https://pubmed.ncbi.nlm.nih.gov/17195485/ [2] (see Table 2) https://link.springer.com/article/10.1007/s10867-020-09562-5#Tab2 https://link.springer.com/article/10.1007/s10867-020-09562-5...

StillBored 4y ago
"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/IRwin-brochure-9.25.19.pdf 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?
Brian_K_White 4y ago
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.