You can get the same improvement with "About $5 of materials and an hour of time." [1]
That's by Dale Andreatta, a mechanical engineer that's been tinkering with improved stoves for decades. But he's not the only one, there are plenty of pot tweaks that achieve comparable or better the the improvements cites in the article.
Like many commenters below bring up, there are other design constraints to cooking technology than raw throughput -- performance at low temperature, manufacturing complexity, ease of cleaning, evenness of heating, performance under varying ambient conditions (humidity, wind, temp).
I encountered many such rocket scientists (literally) while designing improved stoves over the last few years. The engineering of stoves only superficially resembles the engineering of jet engines: the quantities are all different (low flow rate, low pressures, lower temperatures) and, as a result, the overall drivers of performance are very different (for example, stove to pot efficiency is largely governed by excess air control, NOT surface area)
A good example is that I got many recommendations to add "swirlers" [2] to stoves to improve mixing and reduce output CO. This works great in a jet, but it's useless in a stove: there's not enough pressure generated by natural draft to make the device effective.
Personally, I'd much rather buy his version than make my own. The newer design has the fins going all the way up the pot, which seems like it would make it more efficient at heating the sides, although it might be inconsequential (I'm not a rocket scientist). The newer design is also much much nicer looking that the cobbled together one, and the single piece body seems more durable. I don't think this is an example of NIH syndrome, I think this an example of a commercial implementation of a good hack.
Eta pots (and similar models from jetboild who popularized the concept) are awesome but they aren't meant to hold up to kitchen use as they are designed to be light weight for hikign and climbing.
That is a good point. Although it might be popularity that was holding it back, and this article seems to have helped with that. I wonder how far this thing will go.
According to the video in the product pages [1] the creator of this pan came up with the idea on a mountaineering trip because "it takes forever to boil water at high altitude".
What?! Isn't it the other way around? Lower atmospheric pressure means that water boils at significantly lower temperature [2].
The boiling point of water is lower but there are a few other things going on:
Most water is snow or ice so you need to raise it from that point not room temperature.
Snow also has lots of air in which means it and is a really good insulator and floats so to get a pot of boiling water you need to sit there making snow balls and dropping them and waiting for them to melt then bring that water up to temperature.
All of your water for drinking, cooking and cleaning comes from snow since there often isn't any liquid water. You don't need to boil all of it unless it might be contaminated (like at a crowded camp) but it takes a lot of time just to melt a water bottles worth of snow.
The ambient temperature may be lower and there will be wind. You will loose a lot of heat to convection (wind blocks or cooking in a tent help).
The air is thinner and lots of stoves don't get the fuel/oxygen mix they need.
The boiling point of isobutane is 10F so if you are using fuel canisters and it is cold you'll need to work to warm the fuel up as well or you'll get much less power then normal (use a propane blend, keep one fuel canister in your pocket to warm it up, put it in a warm water bath while cooking, use a stove that has a preheat loop to warm cold fuel and can be used with an inverted canister).
Then once you get your water up to boil it takes longer to cook things because of the lower boiling point.
They say mountaineering is for people with selective memories that prevent them from recalling suffering ;)
The problem is that it's cold up there, so the vapour pressure in a cartridge of liquified gas is much lower, and the flame in your stove is pretty marginal.
Hi carlob; my thoughts exactly! The boiling point is lower. It takes longer to boil foods because of the lower temperature, but that's a different problem from time-to-boil, which should be shorter, if anything.
It does take longer to cook food by boiling it, but having a more efficient pan won't help for that. As a matter of fact it becomes almost impossible to make risotto at altitudes over 3000 m.
I'm not sure this is what he meant, but I think he refers to the temperature of the water. If you lower the pressure, it takes a lesser temperature to get the water to start boiling.
So if you go on a mountain and put a pot with water over a fire, it will start evaporating rapidly(boiling) at a lesser temperature than 100 degrees Celsius, so he needs a more efficient way to transfer more heat into the water to get it to 100 degrees Celsius(normal boiling temperature).
Indeed, at t=98 it's really clear. I wonder if they tried the pan with no fins under the handle, or with a protrusion to prevent the rising gas heating the handle? Heating the handle to extremes, it seems as hot as the hottest parts, seems like a pretty serious deficiency for a design for domestic use.
I wonder what the beta testing (ie end-user testing) was like. These look like they'd burn your sauce?
The article doesn't mention how the saucepan performs at low heat, which is a pretty important part of cooking. Especially if you don't have a great stove, the low end of the heat range will often be too hot, and so you rely on having a good, heavy, low conductivity pan that will keep its contents from getting too hot.
Boiling water quickly is nice, but ruining your custard because it boils is very not nice.
I'm pretty happy with the steady low heat I can get with a good conventional pan. But claims that this is the pan of the future will only hold up if it not only heats up very efficiently at high temperatures, but also doesn't heat up too efficiently at low temperatures.
Looking at this immediately made me think of my induction hob back home in London. I think they're popular in Asia, but not at all in UK.
I think in the UK people get them mixed up with other forms of electric hobs. I take great delight in placing a piece of paper on one of the rings, placing a pan of water on top, and turning it on full blast. Visitors are amazed when the water boils extremely quickly, and the paper is just slightly warmed.
So IMO induction is far more controllable, efficient, and faster than gas, not to mention so much easier to clean, and even a better pan for gas isn't going to change that.
I don't understand what high and low efficiency means in this context and how it applies to the environment. All electric stoves convert electricity to heat; do you mean to say that natural gas is the better environmental choice? Please correct me if I'm misunderstanding you.
It is hard to use clear terminology without getting very technical. The basic idea is that a gas power station has a limited efficiency, I think about 55% of the chemical energy in the gas becomes electrical energy. This is due to a mixture of engineering limitations and fundamental thermodynamic limits of a heat engine (http://en.wikipedia.org/wiki/Heat_engine#Efficiency).
So for gas hobs to beat induction hobs, if we assume 100% efficiency for an induction hob (electrical energy to heat energy in the food), the pan needs to get >55% of the chemical energy from the gas into the food.
I don't have any figures but it isn't infeasible that a gas hob could be more efficient.
Gas is certainly more efficient. And every time local fire departments get called out for CO alarms or gas smells, I'm reminded why I had the gas line on the house I bought disconnected anyway.
Electricity is usually generated by turning heat into motion, which is then turned into electricity. You lose energy at each stage, but the heat to motion stage is limited by Carnot's Theorem, which puts an upper bound on the efficiency of heat engines. Efficiency varies based on implementation, but it almost never rises above 50%.
If you need heat, it's much more fuel efficient to just burn fuel and not bother turning it into electricity in an intermediate step.
"If you need heat, it's much more fuel efficient to just burn fuel and not bother turning it into electricity in an intermediate step."
This isn't always true. Carnot's Theorem works in reverse as well, so you can use a heat pump (like an air con unit) so get more heat out of your electricity than just dumping it into a coil. This is actually practical and is being done today for heating houses, you can easily beat the other inefficiencies because the temperature difference that you are trying to create for your house is much smaller than the one between the gas furnace and the ambient temperature around the power station.
For heating a pan though I think this is unlikely to be practical any time soon.
However, it's extremely inefficient to move that heat from a burner to a pot by just sticking the pot above the burner. It's much more efficient to, say, heat your house by burning stuff locally than it is to use electricity, but the heat transfer losses are huge for flames and cookware, so induction wins out.
Efficiency varies based on implementation, but it almost never rises above 50%.
"According to the U.S. Department of Energy, the efficiency of energy transfer for an induction cooker is 84%, versus 74% for a smooth-top non-induction electrical unit, for an approximate 10% saving in energy for the same amount of heat transfer.[20]" -- http://en.wikipedia.org/wiki/Induction_cooking#Efficiency_an...
I advise caution about various percents being thrown around without enough context. I understood the 50% figure above as describing the conversion of heat energy into motion, e.g. inside of a natural gas power plant. The figures you quote are defined as being on the customer side of the energy meter.
Further below that calculation is updated to try and reflect the source fuels using some US EPA numbers: "The (US averaged) inefficiencies recalculated relative to source fuels energies are hence 25% for induction cooking surfaces using grid electricity, 84% for induction cooking surfaces using on-Site Solar, and 38% for gas burners.
The original point (that burning fuel to heat things to spin things to make electricity which is moved to your home to heat a pan is less efficient than moving the fuel to your home and burning it there to heat a pan) is maybe better illustrated by the EPA source-site ratios given to make that adjustment: "3.34 for electricity purchased from the grid, 1.0 for on-site solar, and 1.047 for natural gas. The natural gas figure is slightly greater than 1 and mainly accounts for distribution losses". So if the "electricity purchased from the grid" was generated with natural gas in the first place, you can and see the difference there.
How does the end-to-end efficiency of an electrical generating plant connected to an induction cooker compare to the combustion efficiency of a small, cheap gas burner and the thermal transfer efficiency of sticking a pot above the flame?
Some random googling shows total efficiency for gas is around 25-30%. Induction outperforms it by a comfortable margin, in that case, even ignoring the possibility that some of your electricity comes from renewables.
And by "preferred" you presumably mean "most used". I live in a town that, inexplicably, does not have access to natural gas lines. A lot of people here would "prefer" gas stoves but we're stuck with electric. :(
But yes, I'd love to see a map like that. Before I moved here I assumed that pretty much everywhere in the developed world had natural gas piping, but evidently not.
When I lived in a suburb in Texas, there was no natural gas available in the neighborhood.
Now I live in a Northern city, and could probably generalize to a reasonable extent: Cities are plumbed for gas, and newer houses will have gas appliances. Many older houses -- even in neighborhoods with gas service -- were heated with oil, and most but not all have been upgraded. Quite a lot of people I know buy a house and discover that there's a gas furnace but everything else is electric.
For instance while living in one house, I extended the plumbing so I could install a gas clothes dryer. Folks tend to prefer gas stove. In my house, running gas to the kitchen would require quite a lot of drywall trauma, and I learned to cook on a gas stove, so it's not a big deal for me.
In rural areas, it's mostly propane.
The house I lived in during grad school had a coal chute.
Is channelling the hot combustion gases up the side more efficient than having a recessed or concave bottom (e.g. a flange that fits down around the circumference with insets to fit the grid on which the pan rests)?
The links between aluminium cookware and Alzheimer's are inconclusive. From your article:
It can migrate to food from cookware and packaging materials such as foil and cartons. One study found that around 20 per cent of aluminium in the diet came from the use of aluminium cookware and foil, according to the Food Standards Agency. Tomatoes, rhubarb, cabbage and many soft fruits should not be cooked in aluminium pans, it says.
Older studies into the relation between aluminium and Alzheimer's have shown that aluminium has neurotoxic effects. A direct link between aluminium exposure and contracting Alzheimer's was only found recently:
Overall, these results suggest very strongly that occupational exposure to aluminium contributed significantly to the untimely death of this individual with Alzheimer's disease.
Now inhaling aluminium dust through a dust mask is a lot different from cooking in aluminium pans, but I won't say the link is weak at best.
This remains very difficult to study, due to the long-term effects, and unfortunately also due to little funding and pushbacks from the aluminium industry itself.
For pretty much any pan that's not a saute, nearly every meal in every restaurant (at least all the ones I've worked in or been in the kitchen of) is cooked in aluminium. Go to your nearest restaurant supply store -- almost all of the saucepans and larger pots are spun Al.
I'd like to see the benefit of each pan type analysed. If the fins are on the sides of the pan, then I can see there being little benefit on a frying pan.
I'm sort of disappointed this is patented and only available on a saucepan costing £60+. It's the type of invention that would specifically benefit poorer house holds.
As an 'evolution' of this, what would the impact of a cpu heat sink 'vortex' base have on the efficiency of a pan. Go crazy and have a double skinned pan (attached by many internal fins), then vent the hot air up through the gap between the pans via the 'vortex'.
Now I know cleaning this could be an issue...but I'm assuming you would capture quite a high amount of the heat from the burning gas.
This kind of pot should cool down its contents significantly faster than a normal pot too. Whether that's an advantage or disadvantage probably depends on the application though.
I'm not convinced that even heat up the sides is actually what cooks want from a pot, certainly not always. I can't say I've ever thought, as I was cooking, what this pot needs is heat distributed up the sides. It also presimably makes the pots heavier, harder to clean, and hotter to handle.
I doubt there are fins inside. It would be almost useless for any application if there were. Surely not? Can't find any reviews online - just repeats of the announcements. Surely someone's bought one?
Much greater surface area, so that part makes sense at least for flame-based cooking. I doubt it offers any benefit for non-flame-based cooking (elements, ceramic, etc. It might actually be a detriment because it would dissipate more energy. It goes both ways).
It looks like the inside of the pan has the same fins, which makes sense otherwise they'd have uneven thicknesses. That would be a serious cleaning issue.
> "It looks like the inside of the pan has the same fins, which makes sense otherwise they'd have uneven thicknesses. That would be a serious cleaning issue."
It would also make it nearly impossible to cook anything that needed to be stirred to prevent burning. Stirring a regular pot with a rubber spatula is pretty easy, but getting into all of those nooks? That looks like a royal pain.
It's probably alright for things that won't burn though, like soups.
So, methods that don't rely on the convection of air to the pan. I would guess an induction cook top would be a better example than a ceramic element.
At a quick glance, if these efficiency percentages being thrown around are actually comparable(maybe not), than induction still beats fancy convection pots even with heatsink bottoms like these:
http://www.appliancemagazine.com/editorial.php?article=2257&...
> It looks like the inside of the pan has the same fins
I couldn't find out if it does. I found others, like the pots in the link above that have a flat inside.
My guess is that using a pressure cooker with an induction cooktop fed by on-site solar would be the most efficiency possible, but I have not done the math and would love to be corrected.
>It looks like the inside of the pan has the same fins, which makes sense otherwise they'd have uneven thicknesses. That would be a serious cleaning issue.
Doesn't look like that at all to me; in fact I think if the inside was finned it would be an immediate no-go for most, for the very reason you've stated.
Given that the company goes to enormous lengths to never show or talk about the inside of the pan, I have to assume this is the Achilles heal. If the fins aren't replicated on the inside, then some areas will be mm from the flame, other areas cms (which, as an aside, means an enormous amount of material per pan) -- aluminum is a decent heat conductor, but that would still be a very bad recipe for cookware.
In addition they would be ridiculously expensive to manufacture if the fins were only on the outside. Normally cookware is made on a lathe (http://youtu.be/8uuFWzkRcAg?t=1m12s) or a press from sheet metal. So, if you have areas that are thicker than others you'd need to use an entirely different method of manufacturing them... like casting or welding on the "fins" after the rest of the pot/pan was shaped.
That reminds me of the guy who tried to protect his fingers from the pedestal grinder by using the sleeve of his hoodie instead of walking 20 feet to the tool room to get some gloves. His sleeve got caught at torn completely off. Fortunately he wasn't hurt and banned from the metal shop.
Might be wrong, but I suspect they don't show the inside because it looks like a normal saucepan and it's the futuristic exterior that likely gets them sales. Just can't see how a saucepan with those fins inside would be at all useful, whether they're far more efficient or not. Couldn't stir a sauce or easily cook pasta, etc?
It does mean they're covering maybe 60-70% of the UK's market (where this pan is sold) - gas use is very prevalent in the UK due to historically having being cheaper than electricity.
I don't see where it looks like there are fins on the inside, and I disagree with your insistence below that it must for heat-transfer reasons - the fins are (relatively) thin, so I'd estimate no point on the inside of the circumference would be several centimetres from the [hot air]. Besides, part of the point of the fins is that they capture heat from the air. Without any math required, if the fin is a reasonable conductor, this means the air is hotter than the fin, which is hotter than the inside of the pan. Where fins join the pan there's a large surface area capturing heat from the air going to a smaller area of pan, compared to gaps between fins where the area in contact with the air is approximately equal to the area of inside pan.
edit:
[Disclosure] Dr Povey was one of my tutors, and the bearded fellow with glasses in the video was a peer at college (six engineers in my year).
You can get the same improvement with "About $5 of materials and an hour of time." [1]
That's by Dale Andreatta, a mechanical engineer that's been tinkering with improved stoves for decades. But he's not the only one, there are plenty of pot tweaks that achieve comparable or better the the improvements cites in the article.
Like many commenters below bring up, there are other design constraints to cooking technology than raw throughput -- performance at low temperature, manufacturing complexity, ease of cleaning, evenness of heating, performance under varying ambient conditions (humidity, wind, temp).
I encountered many such rocket scientists (literally) while designing improved stoves over the last few years. The engineering of stoves only superficially resembles the engineering of jet engines: the quantities are all different (low flow rate, low pressures, lower temperatures) and, as a result, the overall drivers of performance are very different (for example, stove to pot efficiency is largely governed by excess air control, NOT surface area)
A good example is that I got many recommendations to add "swirlers" [2] to stoves to improve mixing and reduce output CO. This works great in a jet, but it's useless in a stove: there's not enough pressure generated by natural draft to make the device effective.
[1] pg. 14 http://www.vrac.iastate.edu/ethos/files/ethos2008/Sat%20AM%2...
[2] https://www.google.com/search?q=swirlers+jet+engine&espv=2&t...