[Stoves] Water heating fuel efficiency formula

[ajheggie at gmail.com]

[Default] On Sat, 5 Oct 2013 09:28:51 -0400,"Lanny Henson"
<lannych at bellsouth.net> wrote:

>AJH,
>Are we mixing calories per gram and kJ per kilogram

I hope not; I was trying to stick with Joules, kilo Joules and Mega
Joules. Joule was the chap that established the relationship between
shaft power and rate of heat production, so he measured what motion
energy he had to put into boring a cannon and how much that raised the
temperature of the cannon. A he established the relationship the SI
unit of work/energy was named after him. A Joule is the work necessary
to move a force of 1 Newton through 1 metre. Do that work in 1 second
and your power is one Watt.

Your calorie is the amount of heat necessary to raise 1g of water
through 1 degree centigrade. You need to deliver ~4.2 Joules to do the
same so to raise 1kg of water through 1 degree centigrade requires 4.2
times 1000 Joules.

AJH