The power is proportional to the cube of the pump speed.

You will need to create the pump curves for your pump, or the vendor may have one you can use, or adapt to your fluid with a density coefficient.

http://www.engineersedge.com/fluid_flow/

It’s a Marthon 27′ cabin cruiser with a Chevy/OMC 350 stern drive. I would like to convert it and was wondering what the cheapest and best way to do this is. I want to take it in salt water for extended periods and I don’t want to ruin the motor. I’ve been researching heat exchangers but it’s kind of confusing. Any advise appreciated, thanks.

in Heat exchanger what cause the flu gases to separte from the regular combustion air that goes out to the rooms for circulation?

This link provides info on the geothermal heat exhchanger system. http://en.wikipedia.org/wiki/Geothermal_…
Its very much the basic exchanger system.
Can anyone explain to me how heat is extraced from the house during the cooling process??