Source
r/AskPhysics•
Ten7ei

Copper wire for heat transport

I want to transport heat away from my woodstove to heat other places. My idea was to contact a copper wire on the top or wall of the stove then put the wire through the wall into the room beside. In the room I dip the wire inside of a bucket of water to heat it.

I would be happy if you can provide helpful formulas or maybe solve an example like this: At the touchingpoint in the oven the copperwire (diameter 1cm) has 300°C then it goes in the air (20°C) without isolation 3m then it enters 20cm in a waterbucket (20°C) with 10l water inside.

How hot is the wire after 3m? How much heat will enter in the other room trough the cable (watts per hour)?

Posted May 1, 2023, 4:36 PM UTC

18
John_HaslerEngineering•

How hot is the wire after 3m?

Barely warmer than the air.

How much heat will enter in the other room trough the cable

Perhaps a few watts. Not enough to perceptibly heat the water.

(watts per hour)?

Watts.

To effectively heat the other room you need to circulate air or water.

2
parrotlunaire•

The heat conduction will be nowhere close to enough.

Consider having water flow slowly through a copper pipe in contact with the hot stove. Then the hot water it could go into the neighboring room to fill a reservoir.

1
Ten7eiOP•

Thank you. I thought the relatively complicated assembly of central water heating which also needs pumps and a body for expansion is too much effort. Maintance and needs electricity. maybe copper wire with 10cm diameter works better, or a very good isolation...

any formula to calculate the Temp. at a certain distance?

1
agate_Geophysics•

copper wire with 10cm diameter

Take a look at the price of copper before you go any further. A copper rod that size will run you about USD $1000 a meter.

1
Ten7eiOP•

thanks for the hint, maybe 10cm Aluminum will be affordable and still do somethinhg. Anyway ill look more into convection

1
ChemomechanicsMaterials science•

Heat transfer along a fin—which is what this is—is analyzed here and in most introductory heat transfer texts such as Incropera & DeWitt.

The heat transfer rates are given in the Wikipedia article. The temperature for the values you give is predicted to drop down to room temperature within a meter (calculated characteristic length 1/m = 0.3 m), which doesn't really accomplish anything.

Diffusion is generally a poor heat-transfer method for macroscale distances, with convection holding the upper hand, as others have noted.

1
Ten7eiOP•

thanks a lot! Thats more what i was looking for.

1
jpipersson•

In the olden days they just put a register, basically a hole, in the wall or floor to allow heat to move through convection. If you want something more active, you can put in fans.

1