Beneteau supplies a blower with their diesels, which runs whenever the engine runs. I think it's a great idea, and plan to add one to our boat for the reasons listed above. If you can arrange for the blower to run say, 5 minutes after shutdown I expect the residual heat from the engine could be reduced.. a nice idea in summer.
1984 Fast/Nicholson 345 "FastForward"
".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)