Selfsufficientish.com

Hi All

A quick question for all you Scientists or Mathematicians out there.

When we boil a kettle for coffee or washing up (we don't have any other method of heating water) we always fill up a flask with any surplus so if we want a coffee later on we don't have to boil the kettle again.

Now, is it better to boil more water than you need and put it in the flask or is it better to boil a kettle with just the right amount of water everytime we want a cuppa

mamos

Don't you find that you alway boil a little too much anyway?

I also store hot water in a flask, though mostly for using for cleaning (we don't have hot running water either) I occasionally use it for hot drinks.

I had always thought it was better to boil twice the amount, that boil the kettle twice - though I base this presumption on nothing in particular.

I'm not a scientist.. but I think - it must take so much energy to warm up the body of the kettle, and so happens whether you boil 1 pint or 2. so in theory, it should take less than twice the energy to boil twice the volume. but.. you have to balance this against how fast the water cools in the flask, whether you actually need water at boiling point for washing etc.

but why not try just measuring the units used both ways? I would.. but we use a kettle on the rayburn...

I will try it out and let you know

mamos

red wrote:I'm not a scientist.. but I think - it must take so much energy to warm up the body of the kettle, and so happens whether you boil 1 pint or 2. so in theory, it should take less than twice the energy to boil twice the volume. but.. you have to balance this against how fast the water cools in the flask, whether you actually need water at boiling point for washing etc.

but why not try just measuring the units used both ways? I would.. but we use a kettle on the rayburn...

Yes, I think you are right Red.
If I remember rightly a BTU (British Thermal Unit) is the amount of energy needed to raise 1 pound of water through 1 degree Fahrenheit
Also I seem to remember a Calorie is energy needed to raise 1 gram of water through 1 degree Centigrade.
I also think both units are pretty well obsolete now ... but then so am I