Wouldn't it be more energy efficient and or safe to use microwaves to heat our home's water boiler instead of using dangerous gas or hot electric coils that could catch other things on fire? I'm kinda asking two questions at once, safety and efficiency.
It seems to me that a microwave heats water very quickly and would be a lot safer than using gas or electrical coils because they have to heat a container that then heats the water in a two step process, whereas, microwaves could directly heat water itself. During a usual two step process, you risk the chance of heating unwanted things around it and it'd be easier to confine microwaves, (A simple mesh screen on a microwave oven) than to confine heat. Can anyone shed any information on this?
Best Answer
A microwave oven is only about 65% efficient i.e. 65% of the electricity consumed is converted to microwaves and the rest is dissipated as heat. I suppose you could use the 35% dissipated as heat to heat the water as well, but then why not just use a heating element that dissipates 100% of the electricity as heat?
As for speed, this is normally limited by how much current you can draw from the mains. In this respect there wouldn't be any difference between microwaves and elements, except that unless you can use the waste heat from the microwave magnetron it will take 50% longer than a heating element.
It's not obvious to me that a microwave magnetron is inherently safer than a heating element. If there's a risk from water heating (is there?) it seems to me a better strategy would be to improve the design of heating elements.