Heating frozen water pipes by induction?

[sgphysics]

I have a mountain cabin where 2 water pipes, hot an cold, goes between the bathroom and kitchen. However, they tend to freeze in the winter. The obvious solution is to put a heating wire along the pipes, but access is cumbersome. So I have thought about following solution: I ensure electrical contact between the pipes at each end, and the pipes will now form a closed loop. In the bathroom, the pipes go parallell with 50mm distance over a length of 1m along the wall. For the rest of the distance, the pipes are closer. So I make a coil with many turns, square shaped, 50mmx1m, and put the coil over the parallel pipes. Plug the coil in the socket (220V 50Hz) Now the flux created by the coil hopefully induce a large current in the loop formed by the pipes, and whoops... the ice slowly melts away because of the resistive heating: Will this work? If so, how many turns do I need? I believe a total power of 200W would be sufficient, as the pipes are isolated and not much heat will escape to the surroundings. Would an iron core be of any help?

 

[jim hardy]

i would think you'd want an iron core encircling one pipe so that you've built a transformer where the pipe loop makes a one turn secondary.

here's a product that uses the principle..
http://www.timken.com/en-us/product...tools/installation/Pages/InductionHeater.aspx

 

[sgphysics]

i would think you'd want an iron core encircling one pipe so that you've built a transformer where the pipe loop makes a one turn secondary.

here's a product that uses the principle..
http://www.timken.com/en-us/product...tools/installation/Pages/InductionHeater.aspx

After a piece of basic math, I also came to that conclusion. The core increase the flux by several magnitudes. I need to make a low price (=home made) device. I'll check if my car battery charger have a useful core.

 

[patlar]

Why not just use an electrical pipe thawing device?

http://www.pipethaw.com/index.html

Hook it up to a thermostat and it will come on when the temp gets low enough to cause freezing, and turn off when it gets warmer.

 

[Burnerjack]

Are these pipes located in the living space? Where I live, you cannot by law run plumbing along an external wall for this very reason. Thawing is addressing the symptom. I suggest addressing the problem. If the issue is prolonged periods of vacancy, maybe repiping with purge valves would work better. Empty pipes don't freeze.