[WirelessGigabit]

Okay? What kind of range hoods were tested?

Let's sous-vide a steak for 2 hours, and then throw it in a hot pan with oil, without drying off the steak. You'll get a lot of smoke, which will probably set of any kind of ionizing smoke detector.

Whether you're cooking on gas or electric at that moment really doesn't matter.

What matters is that you have a _PROPER_ range hood. One that vents outside and one that isn't integrated into a microwave oven.

Previous comment about range hoods: https://news.ycombinator.com/item?id=40161811#40163023

[kergonath]

Why do you jump on a specific scenario and then assume it’s the norm? The vast majority of people with a gas range never did anything like that, if even they’ve heard “sous vide” before.

There is no way around the fact that a gas range combusts stuff and that combustion products are mostly toxic. Regardless of what you put in your pan.

[pandaman]

The post you are replying to is saying that heating organic matter produces more emissions than the flame used to heat.

[bifrost]

uh, yeah, they did.

Do you not cook or something?

[throw0101b]

> What matters is that you have a _PROPER_ range hood. One that vents outside and one that isn't integrated into a microwave oven.

Not wrong, but given how many people have an 'improper' range hood, or a proper one that is never used (often because it is "too loud), or no range hood whatsoever (a common situation in rentals), you're stuck with chemicals in your home.

> Whether you're cooking on gas or electric at that moment really doesn't matter.

Yes it does: all cooking will generate chemicals, but you're adding extra ones by using a combustible heat source.

[amluto]

Never mind that almost no residential structure has an actual proper range hood: a proper range hood has a matching makeup air system to avoid depressurization the room, which has its own problems.

(Modern codes mostly require some form of makeup air mechanism for a hood rated 400cfm or higher. I’ve never seen a residential kitchen with an actual working setup like this, although it’s common in a well designed commercial kitchen. What actually happens is that lower end / smaller residential kitchens often have combination microwave/hood units, and they work very poorly. Large / high end residential kitchens end up with standalone hoods with far too much flow, poorly sealed ducts, crappy loud blowers, and no makeup air. If you enter the parameters of a residential stove into a commercial kitchen ventilation calculator, you end up with a rather small flow rate, and the high end residential brands love to advertise much larger numbers.)

[peteradio]

> Yes it does: all cooking will generate chemicals, but you're adding extra ones by using a combustible heat source.

All that goes up the hood and outside. Criticize the hood not the range if its not functioning properly. Browning meat or frying anything in oil is not exotic and is not good for you to breathe regardless of range type.

[throw0101b]

> All that goes up the hood and outside.

In theory.

In theory, theory and practice are the same; in practice, theory and practice are (often) different.

LBNL found that range hoods sometimes captured only 55% of pollutants like NO2:

* https://pubmed.ncbi.nlm.nih.gov/22044446/

Another study found it 30%:

* https://pubs.acs.org/doi/10.1021/es3001079

Even with range hoods, results can vary even for the same range, see (e.g.):

> These studies found that for many range hoods, [capture efficiency] is much higher for the back than for the front cooktop burners.

* https://www.sciencedirect.com/science/article/abs/pii/S03601...

Design for the real world, not the spherical cow idealized one, for example when it comes to make-up air (so you're not depressurizing your home):

* https://www.youtube.com/watch?v=hwSWOAkbhjA

> Criticize the hood not the range if its not functioning properly. Browning meat or frying anything in oil is not exotic and is not good for you to breathe regardless of range type.

Of course blaming ventilation is a standard go-to response:

> “Ventilation is really where this discussion should be, rather than banning one particular type of technology,” said Jill Notini, a vice president with the Washington-based [Association of Home Appliance Manufacturers] trade group. “Banning one type of a cooking appliance is not going to address the concerns about overall indoor air quality. We may need some behavior change, we may need [people] to turn on their hoods when cooking.”

* https://www.bnnbloomberg.ca/us-safety-agency-to-consider-ban...

But that may not help: In 2014, a group of researchers in Baltimore ran a study with 78 homes with gas stoves to understand the most effective ways to reduce indoor air pollution. In one group of homes, they replaced gas stoves with electric stoves. In this group, NO2 pollution levels fell by 50%. (Kephart told me the remaining NO2 probably came from cars and other sources of pollution outside). In another group of homes, they gave homeowners an air purifier with a carbon filter and NO2 levels fell by 22%. In the last group, they installed range hoods. In this final group they found no significant difference in NO2 pollution.

* https://pubmed.ncbi.nlm.nih.gov/24329966/

Many gas stoves leak pollution even when they are turned off (are you planning to run a vent 24/7?):

* https://sustainability.stanford.edu/news/climate-and-health-...

It's probably a lot easier to prevent pollution in the first place as compared to dealing with it after the fact.

Yes: a good vent (that is actually used) is necessary. But the vent has to be so much better for combustible fuel than non-combustible, and so non-combustible allows for more tolerance of errors.

[peteradio]

Hate to say it, but I don't know how trust worthy those studies are especially the one claiming vent hoods have no impact! If I cook bacon on my stove without a venthood the entire main floor would reek and require opening windows and doors to air it out. With a vent hood there is literally no issue with smell. Are you telling me that the vent hood is somehow picks and chooses which pollutants to expel leaving behind NO2? What mechanism would there be to cause it to behave this way? I'll choose to believe my lying eyes.

[throw0101c]

> With a vent hood there is literally no issue with smell. Are you telling me that the vent hood is somehow picks and chooses which pollutants to expel leaving behind NO2?

Yes:

> […]The results show that UFP reduction varies with range hood flow rate, particle size, and burner position. Higher range hood flow rates generally increased UFP reduction within a house, though the effect of the hood flow rate varied with the particle size. At the same exhaust flow rate, lower particle reduction effectiveness was observed for smaller particles, likely due to molecular and turbulent diffusion. With regard to burner position, larger UFP removal was observed for the back burner than for the front burner. Regular and appropriate usage of a kitchen range hood during cooking activities can potentially reduce UFP concentrations; however, decisions about the design and use of kitchen exhaust hoods for controlling UFP and other combustion contaminants require consideration of both the indoor air quality improvements and energy costs. What mechanism would there be to cause it to behave this way? […]

* PDF: https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=91081...

* https://pubmed.ncbi.nlm.nih.gov/22750181/

> I'll choose to believe my lying eyes.

What you perceive as present, and what is actually present, can be different things. Do your eyes (or nose) detect NO2? CO2? CO1 (carbon monoxide)?

Buy an IAQ meter and measure for yourself if you want to be sure.

[peteradio]

In particular I'm refuting the study that purports to measure NO DIFFERENCE with or without a hood. I am saying that is so far outside the realm of the every man's experience with vent hoods that I think the study is busted in some way. UFP is coming from the food you cook, its irrelevant for gas vs electric right?