Why do induction steam boilers not exist?

Waher

With induction cooktops becoming more common, I wonder why the same technology hasn't matriculated into boilers and water heaters compared to heat pumps.

Jamie Hall

Against heat pumps -- no contest. A heat pump does a rather neat conjuring trick involving differential pressures to transfer heat at one low temperature to a sink at a somewhat hgiher temperature. Most heat pumps, operating within their design temperature range, will transfer two and a half to as much as five or six times as much heat as the power it takes to create the pressure difference (that's what the COP is all about).

Induction heating, on the other hand, does not do that. While it does save some power by heating only the steel or iron of the pan or pot in question, it still takes the same power, or very nearly so, as would a contact heater, never mind an immersion heater as would be found in, for instance, an electric water heater or boiler. There is no power reduction. Thus in terms of power consumption, an induction boiler or water heater would take very nearly exactly the same power as a direct contact immersion heater would take, but would be a considerably more complex --and expensive to build and maintain -- piece of equipment.

This is not to say that there aren't applications where induction heating at high powers isn't used -- the most outstanding example is in some types of heat treatment for steel alloys in oxygen free environments. But that's a very different application where the motivation is in providing large amounts of heat without chemical contamination.

espire

Induction is uniquely beneficial to stovetop cooking, where with traditional gas/electric burners, a majority of the heat would flow around the sides of the pot and be wasted. So while electricity is generally more expensive than gas per BTU, with induction burners you are getting much more of the energ into your food.

On the other hand, boilers and water heaters are fairly efficient in terms of getting most of the energy into the water. Comparing the design of a pot to the design of a boiler, you will see many more opportunities for the heat to contact water in the latter, instead of just flowing around the edge. As a result of this, the increased cost of electricity per BTU at 100% efficiency will be higher than gas at, say, 80% efficiency.

EdTheHeaterMan

IN-DUCT-SHOWN
I just broke down the word phonetically and I still cant see how the heat IN a DUCT has SHOWN any benefits over heat in a PIPE. Maybe I am looking at it the wrong way. but I like Steam and Water heat, and even radiant floor heat better that heat from a heat pump coming out my DUCTwork.

But that's just me!

SlamDunk

https://www.inductionmachinery.com/induction-water-boiler-for-warming/

Maybe in the future, it will be available

Jamie Hall

SlamDunk said:

https://www.inductionmachinery.com/induction-water-boiler-for-warming/

Maybe in the future, it will be available

Probably. But why? Ah yes. Looks good. You can't beat the conversion efficiency of an immersion direct resistance water heater.

SlamDunk

Why? I dont know. Speed?

ratio

I've seen a place with induction heaters. They fuse quartz into blanks for manufacturing. They're on metered primaries.

Jamie Hall

There are some things for which induction heaters are preferred. There are some things for which they are the only realistic heat source. There are some things, however, for which they are overkill -- and heating water in a tank or boiler is one of those (this is NOT the same as boiling a pot on the stove. There they are more efficient). So... for your very hot water or low pressure steam -- go immersion resistance heaters. For lower temperature hot water air to water heat pumps, or ground source, are much more efficient. For high pressure steam, so far at least you are better off with combustion or nuclear sources.