Saturday, November 5, 2016

Cookware thermal isolation [closed]

We like to waste a lot, particularly, in the kitchen we like to wash the hot water down the tubes, literally, right into the sink. We even heat up much more water than we need: 2 leters of water to make a cup of tea or boil half of pan with just two eggs in it. We like to flush the boiling-hot water into the sink. Probably, that is the answer to my question, but I would like to ask it anyway: why do you like the cookware not to be thermally isolated from the environment?
I know some physics and chemistry to understand that, in order to cook something boiling, you need no more than to heat up the water to 100°C and leave the pan at that temperature. You should not waste more energy to maintain the temperature. It is the principle of Galileo, who taught us that you spend energy to speed up your car (raise water temperature), but, as soon as you reached your target speed (water is 100 degrees hot), you stop the acceleration. The cooking can proceed to completion, despite of zero energy inflow, because cooking is a flesh denaturation, which is driven by temperature rather than energy wasted. The only reason that you need to add some energy is the thermal leakage or friction. But, theoretically, if you reduce the thermal leakage to almost zero (nobody says that you cannot), you can cook anything for free as long as you like. Theoretically, you can even use heat pump to transfer the heat from ready cooked pan to a fresh one, exchange their temperatures and cook as many dishes as you wish with zero energy (waste).
This makes me to ask, why don't you like it? Many of you, if not most, prefer to cook without the lid (!) and nobody cares about thermal conductivity of the lid and walls, where you have the leakage even when pan is covered with lid.
I read in WP that thermal conductivity has a significant effect on the cookware items. What does that ever mean? I see that any pan is a 3D object, which means that it has 6 surfaces: top, bottom and 4 walls. Only one of 6 surfaces needs the thermal conductivity. Why don't you see that and make your cookware of homogeneous material? The energy that you supply from the bottom leaks from all other surfaces! The more conductive material you make, the higher is leakage. I would make the bottom highly thermal conductive whereas insulate the walls and the lid.
Currently, I have to drop a towel on top of the pan, but that is risky. I therefore would prefer to see the thermally-isolated cookware in the store. But you do not like it. Why? Why don't you want to travel the infinite distances at a finite drop of the energy?
It may be fine to leak the heat at winter but you do that all the year along, even during the hottest summer days. You use your cookware to heat up the rooms. I can guess that the answer is "it is irrelevant since losses are negligible contrasted with the bath/shower, for instance". But, please, confirm anyway.

closed as primarily opinion-based by MóżFredTHelper May 14 at 14:41

Many good questions generate some degree of opinion based on expert experience, but answers to this question will tend to be almost entirely based on opinions, rather than facts, references, or specific expertise.If this question can be reworded to fit the rules in the help center, please edit your question.
I do not get it. Why would you heat more water than needed in the first place? E.g. making tea, why not just heat the amount of water required? – Ghanima May 1 at 20:29
Welcome to the site! You raise some interesting points, but you seem to assume that I, as a reader, don't agree with you in the first place, which is largely incorrect. There are also far too many questions raised here to fit well with the clear Q&A format for this site. I suggest you separate this into independently answerable questions so that answers can be written more clearly and be more useful to everybody. I'm voting to close this in the meantime. – Highly Irregular May 2 at 0:30
@HighlyIrregular I have only one question. Which questions have you counhted? I assume that you do not like it because nobody does. As summarized in Wikipedia, people do not differentiate between walls/lid conductivity and bottom conductivity. I am asking like an alien from another planet, who cannot understand what is happening.– Little Alien May 2 at 6:35    
@LittleAlien "why do you like the cookware not to be thermally isolated from the environment?" being your one and only question? In that case,please delete some of the extraneous text as your long explanation is at best misworded (by assuming I disagree with you), rather than encouraging me to post the solutions I use to the problem you have identified. I have several, but since you have clearly identified me as not wanting or having those solutions in your question, why would waste time answering? – Ⴖuі May 2 at 7:58 
@LittleAlien I count 6 question marks, though some of them may have been rhetorical? – Highly Irregular May 2 at 9:05
Voting to close as 'opinion based'. This is a debate, not a question looking for a solution. – Jan Doggen May 2 at 14:21
Two minutes in a search engine found this interesting article on the topic which doesn't even mention the new thing I use - an induction cooker, which means it's quite safe to wrap the pot in towels or anything which saves significant energy even over just using the induction cooker. And of course the rice cookers and slow cookers that fill whole isles in shops that sell kitchen appliances. The latter makes your "no-one other than LittleAlien likes them" claim seem weak. – Móż May 4 at 4:10 
I think there's an objectively answerable question here, but I think it's more engineering than sustainability. And that's: "why are most pans made with sides and lid that are just as thermally conductive as the base? Wouldn't it be more efficient to have thermally insulating sides and lid?" - is that a fair summary? – EnergyNumbersMay 4 at 7:57
@EnergyNumbers That is a perfect summary but, as you see, we are looking at a wrong planet. In the planet that I posted the question on, the assumption, that most of the people are unaware/don't care about the heat leakage at the kitchen, was clearly dispelled by the Mσᶎ. As experienced citizen, he must be right and majority of voters join his position, as we see in the voting. So, I am sorry for researching your planet so inaccurately. – Little AlienMay 4 at 12:04   

No comments: