I`m thinking about replacing my old electric water heater with one of the combination electric/ heat exchanger units. The questions I have is, Do I need to buy something extra for on my 15hp yanmar diesel engine for the exchanger to work ? Or where does the water lines get hooked to on the engine ? And how hot will the water actuslly get ? Its an open system, not closed. Thanks,CHET
Hot water heater engine exchanger ?
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2QM15 Hot Water?
Hopefully a 2QM owner with hot water will see your query Chet. I sold my 2QM20 with hot water connections but have no pictures or good memory of the connecting points. The outlet I do remember. It went into a 1/2" pipe on top of the exhaust elbow. But the hot water from engine to tank connection I do not recall exactly. However my 2QM was not raw water cooled. It was a closed system with a heat exchanger. After a half hour of motoring the water in the tank(6 gal.) was hot. I have read here on HOW that it is difficult to heat with a raw water cooled engine. So for connection I guess I would do two things: 1) find someone on the dock with the 2QM or 3QM engine that has the connections, and/or 2) maybe you have a friendly local Yanmar rep. I had a 2QM/3QM manual and I do not think those connections were even displayed in there.
Hopefully a 2QM owner with hot water will see your query Chet. I sold my 2QM20 with hot water connections but have no pictures or good memory of the connecting points. The outlet I do remember. It went into a 1/2" pipe on top of the exhaust elbow. But the hot water from engine to tank connection I do not recall exactly. However my 2QM was not raw water cooled. It was a closed system with a heat exchanger. After a half hour of motoring the water in the tank(6 gal.) was hot. I have read here on HOW that it is difficult to heat with a raw water cooled engine. So for connection I guess I would do two things: 1) find someone on the dock with the 2QM or 3QM engine that has the connections, and/or 2) maybe you have a friendly local Yanmar rep. I had a 2QM/3QM manual and I do not think those connections were even displayed in there.
If raw water cooled .....
break into the cooling line between the exhaust manifold and the injection nozzle. Raw water will cause more rapid corrosion to the coil inside the hot water heater and may require you to 'pickel' the hot water heater more often to remove the constant buildup of fouling scale. Use an inhibited commercial boiler descaler when 'pickeling'. from where you break in --> hot water heater ----> back to the other end of where you 'broke into' the line ---> injection nozzle. If fresh (w/ heat exchanger) water cooled... break into the fresh water side between the engine outlet and heat exchanger'. Both locations will give you the hottest possible water hence heat transfer from the engine cooling loop into the hot water heater. For both installations provide a means to allow for 'bleeding' air from the cooling loop if the hot water heater is physically mounted 'above' the engine - to prevent trapping air and forming an 'air block' to the cooling water flow. Use as large as possible hose, etc. in making the 'run' to and back from the heater so you dont inadvertantly limit the amount of cooling water through the engine. When done check to see if the output of the 2QM or 3QM has a water flow at about 3 gallons per minute at 2000 rpm out the exhaust outlet .... use a bucket and a stopwatch.
break into the cooling line between the exhaust manifold and the injection nozzle. Raw water will cause more rapid corrosion to the coil inside the hot water heater and may require you to 'pickel' the hot water heater more often to remove the constant buildup of fouling scale. Use an inhibited commercial boiler descaler when 'pickeling'. from where you break in --> hot water heater ----> back to the other end of where you 'broke into' the line ---> injection nozzle. If fresh (w/ heat exchanger) water cooled... break into the fresh water side between the engine outlet and heat exchanger'. Both locations will give you the hottest possible water hence heat transfer from the engine cooling loop into the hot water heater. For both installations provide a means to allow for 'bleeding' air from the cooling loop if the hot water heater is physically mounted 'above' the engine - to prevent trapping air and forming an 'air block' to the cooling water flow. Use as large as possible hose, etc. in making the 'run' to and back from the heater so you dont inadvertantly limit the amount of cooling water through the engine. When done check to see if the output of the 2QM or 3QM has a water flow at about 3 gallons per minute at 2000 rpm out the exhaust outlet .... use a bucket and a stopwatch.
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