Potential use of heat exchangers in non-exchanger 318

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Potential use of heat exchangers in non-exchanger 318

Postby bcassedy » Tue Apr 02, 2019 7:45 am


There are times when the Admiral and I will be on the boat during the early, or more frequently, the later part of the season when it's chilly outside while we're cruising the Ohio. Under such instances, running the genny to power the AC's heating system comes into play while underway.

I was looking on my local Craigslist and noticed a heat exchanger for sale ( https://cincinnati.craigslist.org/bpo/d ... 55934.html ). It occurred to me that it might be possible (with some work involved) to plumb this into one of my 2 engines as a means of capturing the engine's heat and setting up a 12v forced air fan / coil system to heat the cabin.

Has anyone attempted/completed such an endeavor? And if so, how did you do it (ie. where did you plump the intake/outflow of the heat exchanger?)

Bill & Sharon Cassedy
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'88 32' Sedan Bridge
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Re: Potential use of heat exchangers in non-exchanger 318

Postby ddependo » Tue Apr 02, 2019 8:18 am

Sounds like a good idea and a automotive aftermarket heater would work fine. It already has the fan and you just plum it into the water line coming off the intake manifold. You would want to put a cutoff valve on it for summer summing running. I've used these in street rod building.
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Re: Potential use of heat exchangers in non-exchanger 318

Postby EWRice » Tue Apr 02, 2019 11:55 am

School bus heaters for under the rear seat. Self contained, 12v, caged fan and pretty inexpensive. I think the last one I bought was under $100 on ebay. Works great.
You have to be carefull where you plumb it in. I would have to see exactly which cooling system you have to give any suggestions.
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Re: Potential use of heat exchangers in non-exchanger 318

Postby Busia » Tue Apr 02, 2019 1:25 pm

Yes, I put a "Cat" heater under the steps blowing into the cabin. (Cat heater is from a big yellow piece of Caterpillar equipment) If you can find one make sure it is 12 volt and not 24 VDC. Or as Eric has said, a school bus heater. Put a ball valve in line for summer.
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Re: Potential use of heat exchangers in non-exchanger 318

Postby Tuggle » Wed Apr 03, 2019 12:22 pm

Summit and Jegs both sell them, key in Jeep Heater.
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Re: Potential use of heat exchangers in non-exchanger 318

Postby CapnGary » Wed Apr 03, 2019 8:40 pm

You might consider adding an inverter instead, and then just plugging in a small fanned heater available for $20 at any local dollar general or Walmart. The engines running, power the inverter nicely to run the boat outlets. If you plan or running a 1500w heater, make sure the inverter is at least 1500w. My 1100w inverter will run 700w of heat, or the 700w microwave, etc.. I personally disconnected the Onan "Gen and wired the $89 inverter into the control which switches the power to the generator. Then all the outlets work. I use it for the dorm frig, tv, which are not 12v.
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Re: Potential use of heat exchangers in non-exchanger 318

Postby barkleydave » Fri Apr 05, 2019 11:41 am

I have ran a Xantrex 1800 watt inverter for years on my boat. I run 2 deep cycle 6 volt golf cart batteries in series. Inverter works fine for light loads.
Using heavy amp like microwave etc. and it will draw your house bank down in very short order. 1500 watts will draw 125 amps DC. So lets say you have 200 amp hr battery bank... that is less than 2 hrs. In reality it will drop the inverter off line sooner since DC voltage will drop below 11.7 volts.
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