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frank
17-07-2006, 08:51 PM
Anyone enjoying the current high temps give a thought to the basic energy equation? :)

Having a cool shower tonight after a gruelling day with my head stuck in a ceiling void at 37C it caused me to think how clever the equation was. Q = m c dt.
2 components of the equation are constants (Q + c) and 2 are variables (m + dt)

As the water temp entering the house increases the dt decreases which must be compensated by an increased m. So you turn the temp setting down (which increases water flow)

I know I'm sad but it's just something that most take for granted ;)

Anyone know who discovered/invented the formula?
Sir Josiah Sodd
17-07-2006, 09:12 PM
Anyone know who discovered/invented the formula?




.... I thought you just did;)
Brian_UK
17-07-2006, 10:46 PM
Ah! but does the flow increase or do you just use 'less hot' ?
jamcool
18-07-2006, 01:53 AM
What were u having a shower with?:) BEEER:cool:
The MG Pony
18-07-2006, 04:04 AM
well hotter the water the lower its density, meaning for a given volume you will need more flow to make up for the lesser density. the inverse for cold, colder the water higher its density thus you will need less flow to move a given weight as you would for hot water.
frank
18-07-2006, 07:04 PM
well hotter the water the lower its density, meaning for a given volume you will need more flow to make up for the lesser density. the inverse for cold, colder the water higher its density thus you will need less flow to move a given weight as you would for hot water.

Density doesn't come in to the equation :)

BEER does though. :D mmmmmmm

On my second right now - trying to replace all that sweat today :p
Peter_1
18-07-2006, 07:32 PM
density = mass/volume
frank
18-07-2006, 07:54 PM
density = mass/volume
Quite right Peter but how does this relate to mass flow?
US Iceman
18-07-2006, 08:24 PM
Water density doesn't change that much at normal temperatures. The changes in density result in very minor differences in flow rate required.

Perhaps you should try pouring propane over your head Frank. That seems to be the cure all for some members.:p
US Iceman
18-07-2006, 09:06 PM
Anyone know who discovered/invented the formula?


Sir Isaac Newton.

See below...

http://scienceworld.wolfram.com/physics/NewtonsLawofCooling.html

What's the prize Frank?;)
frank
18-07-2006, 09:18 PM
What's the prize Frank?;)

Obviously, :) it's got to be a UK pint of Real Hand Pulled Ale served at 6C with a magnificent head, clear body and wholesome aroma - your choice from http://www.camra.org.uk/

:p
Brian_UK
18-07-2006, 10:25 PM
Never mind the beer Frank (sorry, did I say that out loud?); I was showering earlier after fixing the boiler as it wasn't making hot water - doh!

Anyway, I digress, there I was cooling off and thinking about your question/problem Frank when it it came to me:)

Frank, you and I have got to get a life :D
US Iceman
18-07-2006, 11:29 PM
Brian & Frank,

These are the sort of things that will keep you up at night. It always fascinating to learn where the information comes from we use every day.

In some respects, refrigeration is like the English language.

A little of this, a little of that...

I looked at the website for the ale Frank, my that looks tasty.:D