boat/diesel motor/hot water shower

[beav350]

Oddball, but I have a Volvo 2 cylinder diesel inboard motor in my houseboat, and I'd like to rig up a hot water shower. So far the plan is to use a electric pump to suck up lake water, pass it through a heat exchanger on the manifold, and onward to the fixture. Questions: Brass or copper heat exchanger? I think copper has a better heat conductivity rating, & I want it as hot as possible. Second, what is the average temp. I should see at the manifold? More than a gas motor? Will it be too hot? What would the ideal exchanger/pipe length be? 2,3,4 or more inches? Lastly, if anyone has seen the MD-11 Volvo exh. manifold, what would be the best way to attach the exchanger? It is a strange shape, and would hose clamps melt? Thanks guys, Europe's biggest lake awaits, and the water is cold!!

 

[The Hard Struggler]

First question, what is the displacement of your Volvo diesel? Is it raw water cooled? If I read your post right your thinking of adding an exchanger after the exhaust manifold to include raw cooling water? Be SURE to not slow the flow of raw water through the exhaust manifold! Without seeing your cooling plumbing layout its difficult to give advice. The normal house hot water from a motor comes from an additional outlet on the heat exchanger ahead of the manifold, with the additional flow coming from your faucet activated pump.

The reason I ask the displacement is if the motor is very small, especially a diesel, you may not get enough hot water to take a shower without a holding tank.

As far as materials for boat plumbing goes, I use only Marelon or stainless. I may cut corners on my XJ but on my boat NO WAY! Be very sure you know what you're doing, there can be deadly consequences for hack jobs onboard. If your at sea or a lake bigger than you and your passengers can swim accross there is no "pull over and call for help". :repair: Sorry i'm not more help...... join a boating forum, do some research, be safe & have fun!

 

[beav350]

It is a 1.0L motor, and my plan was to simply straddle a heat-conductive pipe of a certain length along the side of the exh. manifold, with heat resistant tubing coming up from the water, attaching to the pipe, and out to the faucet. Like what some guys do for a "trail shower" on their Jeeps. Would that setup provide enough heat? I was curious to see if the exhaust manifold is hotter on a diesel than a gasoline motor, and if so possibly have a higher temp. water supply for the shower. Brass or copper does have a higher heat conductivity than steel, copper more so I think, but I can't say for sure. Holding tank? I hope that wouldn't be a nessecity.