chrisd wrote: quote="Keith_w" quote="chrisd" quote="Joat42"
Found this post on a blog today, and it ties neatly into the discussion we have had here. It's written by a guy called Alessandro Rossini and IMO it's spot on.
It starts with a quote:
quote="Wild Thing by Josh Bazell"
In metric, one milliliter of water occupies one cubic centimeter, weighs one gram, and requires one calorie of energy to heat up by one degree centigrade — which is 1 percent of the difference between its freezing point and its boiling point. An amount of hydrogen weighing the same amount has exactly one mole of atoms in it. Whereas in the American system, the answer to 'How much energy does it take to boil a room-temperature gallon of water?' is 'Go f*ck yourself,' because you can't directly relate any of those quantities. /quote /quote
let's take an Imperial Gallon = 10 Lbs. of water
Room temperature, as specified minimum under the "Offices, Shops & Railway Premises Act" of 60ºF to be raised to 212ºF = 152ºF change
Total Energy required is 10 x 152 B.Th.U. = 1,520 BThU /quote
And how does that work for a US Gallon? and British Thermal Units? No thanks, let's have good old U.S.ofA Thermal units please! /quote
Not being American, but isn't your mnemonic "A Pint's a pound, the world around" which would make a US Gallon to be 8 lbs.?
(Whereas our mnemonic is "A Pint of water weight a Pound and a quarter")
Investigation suggests that the American Heat Unit you mention is the same as the BThU; to my knowledge Air conditioning units are expressed in BThU to this day in US and Asia.
I apologize for not indicating that there was, supposedly, humour involved in that post.
