The exchanger you mention is the engine exhaust exchanger or engine cooling
system exchanger? Do you maybe have any links to practical solutions?

I have found 24V water heater heating elements which could be used as auxiliary.

Regards M



I came accross this Webasto heater:

http://www.navstore.com/pdf/webasto/Webasto%20TSL17.pdf

What do you think?

I did not check your link, but what you might want to ask your engineer for
would be a design for a water-to-water (Glycol based)heat exchanger to keep
your shower water HOT. This could be done with off-the-shelf electric
components if you have the space, and need only be configured to your space
by your architect and engineer. The electric would be your seldom-used
backup, and you could have your choice of 120, 240, or custom voltage
standard mount heating elements (check off-the-grid, solar, and wind power
resources for these items).

Rob
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