I'm going a bit off the reservation to try something experimental when I attempt my own HVAC installation and I'm having some trouble determining a few things. I want to transfer heat from water flowing in a 3/4" copper tube that is submersed in a larger body of water.(adsbygoogle = window.adsbygoogle || []).push({});

The copper pipe has a wall thickness of .035" so that makes an inside diameter of .68". I'd like to determine how much heat I can transfer in a 100' length of pipe for every gallon per minute flow. Being that I know just enough to be dangerous, I'm not comfortable with many of the various units, so don't laugh at my selection of units. :) My calculations show 1.887 gallons of water are in that pipe at any one time.

So to make things conceptually simple (I think it does?) lets assume the water is moving at 1.887 gallons per minute. I would think from there you could just calculate it as if the pipe was a long cylinder with no flow rate Ignoring friction heat, etc. although I would assume as the heat transfers you would start to get turbulence inside the pipe and in the tank as convection begins moving the water around. In the tank, if the pipe was suspended in the middle (not laying on the floor of the tank), the cooler water would sink being replaced with the more plentiful warmer water. In the pipe the top would be warmer than the bottom, but with flowing water I would suspect more turbulence and a better temperature distribution within the pipe? I would like to calculate the total temperature change in the pipe over 1 minute.

Water in pipe = 40 degrees F

Water in larger tank = 50 degrees F

Water in pipe after one minute = ? degrees F(and I would actually like to know how to do it myself. :) Like they always told me in school... show your work. lol I want to come away from this a little smarter than going in.

Any suggestion, corrections, etc. are very welcome. College physics was 20 years ago and to my detriment I had very little interest in any class let alone physics. :(

Thanks in advance for any input...

-Steve

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Thermodynamics for a geothermal heat pump

**Physics Forums | Science Articles, Homework Help, Discussion**