In a lot of South American countries, instead of having central hot water, they have electric heaters on showerheads. Every once in a while, there's an accident and someone is electrocuted in their shower.

What I propose is a microwave that goes over the heater pipe in the wall. It heats the water in the pipe, so there's no risk of the wires touching the water.
-- lawpoop, Jun 26 2010

They can't be metal pipes, or they would reflect the microwaves. There's still a risk of wires touching the water, as there's always the chance of leaks in the system. As far as heating to a large-ish temperature goes, you would be better off (and cheaper in electricity) pumping the water down 90 feet or so into a heat exchanger. It will come up at 80 degrees or so.
-- Cedar Park, Jun 30 2010


The one good thing about an electric immersion water heater is it's 100% effeciency (in turning electrical energy into heated water).

A 3kW microwave transmitter is bulky, heavy and has some ineffeciencies (heat loss to atmosphere, RF leaks etc.)

The risk of electrocution comes from faulty heaters. A microwave transmitter is more complex, therefore more prone to faults. (-)
-- Twizz, Jun 30 2010


Not real certain if the physics would work out this way, but water can act as a waveguide for microwaves. Which could produce interesting and not necesarily safe results from this as well.

Have to agree with the above, though. A properly sealed heater and a GFI connection (Ground Fault Interrupt, pretty sure it's US for what bigsleep said) should minimze risk of immersion heaters.
-- MechE, Jun 30 2010


Among the many issues with this idea (some noted above), you have to remember that microwave ovens use standing waves. This means that the tap would be limited to specific sizes to avoid destructive interference. It might also mean that you'd need a closed volume (rather than open tap).
-- Jinbish, Jun 30 2010



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