Poll: Heating Concepts

[EFLImpudence]

Well, at least we have discovered the reason for your inability to understand the Willis and other hot water systems.

... it sounds as if you are perhaps one of those people who takes the ('colloquial') phrase "hot air/water rises" far to literally. As I have repeatedly pointed out, that 'rising' does not usually result in any 'net physical movement' of air or water.

Ah! Those people.

Have you never lit an open fire or seen a hot-air balloon?

 

[Harry Bloomfield]

Consider a vertical glass tube with a closed bottom (e.g. a long test tube) filled with cold water. Heat a little of the water at the very bottom. The region where water is 'hotter' will rapidly 'rise' to the top of the tube, but there will be virtually no change in level of water at the top (only a tiny amount due to expansion) (i.e. no water will 'rise up') and there certainly will not (could not possibly be) any cold water 'drawn in at the bottom.

No one, has ever suggested that the quantity of water will change, only that the heated water will quickly make it's way to the top - the water will move, due to convection currents. If you doubt the movement, then try the food dye test.

Rather than denying it can works, and defies your idea of physics - try what seems to everyone else, to be simple physics in action. If it didn't work, then the water in a kettle would remain hot at the base, where the element was located, and you would never be able to boil your tatties.

Why might you suppose a candle flame, or in fact any flame, burns vertically?

 

[JohnW2]

Well, at least we have discovered the reason for your inability to understand the Willis and other hot water systems.

I wish that were true because, if it were, you might be able to help me understand the aspects I'm struggling with

Ah! Those people. View attachment 409497

Yes, "those people" - i.e. those who take the colloquial 'heat rises' a little too literally.

Have you never lit an open fire or seen a hot-air balloon?

Of course I have, but I don't see its relevance to the issues being discussed. No-one, and certainly not me, has ever suggested that hotter air/water will not rise to the top of a body of cooler air/water which it is within.

 

[JohnW2]

No one, has ever suggested that the quantity of water will change, only that the heated water will quickly make it's way to the top - the water will move, due to convection currents.

... and, as I've just written, no-one has denied that. The hotter water will rise through the cooler water, displacing that cooler water which therefore ends up below the hotter water.

If you doubt the movement, then try the food dye test.

I'd love to - but before I try, and the be clear/sure, could I ask you to 'spoon feed' me with an explanation of exactly what you're suggesting - maybe with a rough hand-scribbled sketch?

Rather than denying it can works, and defies your idea of physics - try what seems to everyone else, to be simple physics in action. If it didn't work, then the water in a kettle would remain hot at the base, where the element was located, and you would never be able to boil your tatties. ... Why might you suppose a candle flame, or in fact any flame, burns vertically?

As above, I'm obviously not denying any of that, since it's really the most basic of physics, as well as being what we all observe, all the time.

 

[ebee]

I once had a trip in a hot air balloon over the valleys of Kings, queens and nobles, it was very interesting, no Willis heater in sight

 

[Harry Bloomfield]

Of course I have, but I don't see its relevance to the issues being discussed. No-one, and certainly not me, has ever suggested that hotter air/water will not rise to the top of a body of cooler air/water which it is within.

Then what are you actually disputing John? You agree the heat rises, so it follows on that the Willis system simply must work, and that while ever that heat source is applied, the rise must continue, simply because the localised temperature around the element, is higher than anywhere else.

 

[JohnW2]

I once had a trip in a hot air balloon over the valleys of Kings, queens and nobles, it was very interesting, no Willis heater in sight

We see a lot around here. A few years ago, one landed in our garden

 

[EFLImpudence]

As I have repeatedly pointed out, that 'rising' does not usually result in any 'net physical movement' of air or water.

No-one, and certainly not me, has ever suggested that hotter air/water will not rise to the top of a body of cooler air/water which it is within.

 

[Harry Bloomfield]

We see a lt around here. A few years ago, one landed in our garden

Did scare the balloonist who landed, with your theory that hot air cannot rise?

 

[JohnW2]

Then what are you actually disputing John?

I'm not "disputing" anything. In what I would have thought was an intellectually-responsible fashion, I have been indicating what aspects I don't yet understand and seeking help in gaining an understanding

You agree the heat rises, so it follows on that the Willis system simply must work ....

I have agreed with that, in relation to water above the level of the Willis heater ... and I've also suggested that it will probably only offer a pretty small benefit over 'doing the same' with an internal horizonal immersion at the same height as the Willis heater.

... and that while ever that heat source is applied, the rise must continue, simply because the localised temperature around the element, is higher than anywhere else.

I suppose that essentially the only thing I don't yet understand is (IF it happens) how either an external Willis or internal immersion can result in significant heating of water below the level of the heating element (other than slightly/slowly by conduction from the water and cylinder wall above).
I'm a bit uncertain about your position because, although you continue to refuse to vote in this Poll, in posts you appear to have indicated (per my current belief) that you are not suggesting that heating below the heater does happen significantly.

 

[JohnW2]

Did scare the balloonist who landed, with your theory that hot air cannot rise?

I assume that he had deliberately let out some of the hot air and/or after having thrown out some of his ballast

I forget the explanation as to why he effected this unintended 'emergency landing' but I can but assume that he was having some difficulty in maintaining altitude as he was approaching higher ground.

 

[Harry Bloomfield]

I'm a bit uncertain about your position because, although you continue to refuse to vote in this Poll, in posts you appear to have indicated (per my current belief) that you are not suggesting that heating below the heater does happen significantly.

With a Willis system, it can heat water effectively, below the element, in a none-Willis system it cannot. The reason being, the Willis acts in some respects, as a 'pump', to enable the circulation.

 

[Harry Bloomfield]

I assume that he had deliberately let out some of the hot air and/or thrown out some of his ballast

Dumping ballast, would allow the balloon to rise

 

[JohnW2]

As I have repeatedly pointed out, that 'rising' does not usually result in any 'net physical movement' of air or water.

I think you have probably misunderstood/misinterpreted my words. When I spoke of "net physical movement" I was talking about a situation in which the upper surface of the body of air/water 'rose', in such a manner as to result in 'pumping'

 

[JohnW2]

Dumping ballast, would allow the balloon to rise

Good grief - my typing fingers made a right mess of that

What my brain had wanted them to type was " deliberately let out some of the hot air and/or after having thrown out some of his ballast. Now corrected. Thanks for noticing!