There have been a number of fine ideas on this site about how to keep the bath water hot without using it all up continually adding more from the water heater, but they all involve some degree of foresight and/or plumbing skill. Not so this simple add-on device.

You need a ceramic tub for this to work. (That, or an urge to live dangerously.) The device consists of a series of standard magentrons - the same kind you get in a microwave oven. They are arranged in a housing with suction cups, which is attatched to the outside of the bath and plugged in. Suitable care is taken, of course, to ensure the waterproofness of the device.

Microwave ovens are great at getting water very hot. Dielectric heating works best with water, and less well on solids. So, the net effect will be to turn the side of your bathtub into a heater, as the microwaves will only penetrate a short distance in. However, manually agitating the bath water should keep the entire bath comfortable, and amuse your rubber ducky.
-- gisho, Jan 02 2011

if it can heat the water then it can heat my insides. (-)
-- WcW, Jan 02 2011


Well, yes, but don't you want to be warm?
-- gisho, Jan 02 2011


A cusory examination of the math indicates that this idea is not entirely unfeasable, merely extremely dangerous and inadvisable, so we award a bun.

The trick is to make sure that the mangetrons are not in direct proximity to the bather. Correctly placed, the energy will, as [gisho] asserts, merely heat the bath water, and due to the high absorbtion the risk of tissue damage is probably acceptable.
-- 8th of 7, Jan 02 2011



random, halfbakery