if i mix 40 gallons of 50 degree water and 40 gallons of 80 deg. water, does that make it 65 degrees?

Question

i’m just wondering how fluid & heat transfer works, if you mix water that is 20 or 30 degrees apart in temperature does the hot or cold have an advantage or does it meet in the middle and equalize?

In: 6

Answer 1

Yup, they meet in the middle.

Funny enough, I studied almost this exact scenario in college, with respect to industrial processes. The scenario was, you want to fill a tank with water at a certain temperature, and you have a hot water line at one temperature and a cold water line at another temperature. You can precisely determine or control the temperature of the water in the tank by changing the ratio of hot water to cold water you’re pouring in.