How many BTU does the heating loop on an Perkins 4.326 put out?

[Snapdragon III]

I am about to embark on installing a hydronic heating system in my new boat. I am going to use a small Kabola boiler, and about 10 fan units, divided into 6 control zones, plus hot domestic water heating. It is going to be quite a project. My big question is do I really need to tap into the engine heating loop of both of my engines? or would just one of them be plenty of BTU's? I do not really care about prewarming the engines. The engines are currently each heating one of 2 10gal water tanks. The tanks seem to take quite awhile to heat up, but I think that is due to them having a tiny pipe loop inside of them, as the water returning to the engine feels piping hot at the fittings, even when the domestic water is still stone cold. I have not actually taken supply and return temperature readings on the existing system, but plan to this week. The boiler I am installing is 30K BTU's. If one engine is capable of putting out anything close to that I could save a lot of spaghetti bowl piping in the engine room by just having one engine heat exchanger rather than two. If there were a couple times a winter when it was too cold to heat the boat while running off one engine, I can always just run the boiler too. I am not using the boat professionally, and while we use the boat in the winter, it tends to be local trips where we motor a few hours out to the San Juan Islands, and anchor for the night. It is not like we are motoring around 12 hours a day all winter.

So my question is. Does anyone have any idea how many BTU's the heating taps on my 85hp Perkins are likely to put out? I can't find much on the internet.

 

[ksanders]

I am about to embark on installing a hydronic heating system in my new boat. I am going to use a small Kabola boiler, and about 10 fan units, divided into 6 control zones, plus hot domestic water heating. It is going to be quite a project. My big question is do I really need to tap into the engine heating loop of both of my engines? or would just one of them be plenty of BTU's? I do not really care about prewarming the engines. The engines are currently each heating one of 2 10gal water tanks. The tanks seem to take quite awhile to heat up, but I think that is due to them having a tiny pipe loop inside of them, as the water returning to the engine feels piping hot at the fittings, even when the domestic water is still stone cold. I have not actually taken supply and return temperature readings on the existing system, but plan to this week. The boiler I am installing is 30K BTU's. If one engine is capable of putting out anything close to that I could save a lot of spaghetti bowl piping in the engine room by just having one engine heat exchanger rather than two. If there were a couple times a winter when it was too cold to heat the boat while running off one engine, I can always just run the boiler too. I am not using the boat professionally, and while we use the boat in the winter, it tends to be local trips where we motor a few hours out to the San Juan Islands, and anchor for the night. It is not like we are motoring around 12 hours a day all winter.

So my question is. Does anyone have any idea how many BTU's the heating taps on my 85hp Perkins are likely to put out? I can't find much on the internet.

If it were my installation I would at the very most install one heat exchanger off of the same loop that currently feeds your domestic hot water heater.

You can go through a awful amount of work, and complication to save a very small amount of diesel fuel.

 

[Lepke]

I guess about 30,000 based what heaters in a similar car engine could supply.


I use engine water to heat my boiler, but don't use heat exchangers. Each time there's a transition you loose efficiency. Both use water and anti-freeze, I don't see the point, and my system has worked fine 10 years (and the engines for 74).

I can supply heat to about 200,000 btu worth of air heaters. They are in 5 zones and don't all come on at the same time. Both main engines are plumbed into the hydronic lines, but separated by valves. I only use both in really cold weather. I have 2-Detroit 671s. I have a 48hp 4108 Perkins on a generator that's also plumbed in. Alone, it will supply one 28,000 btu heater poorly.
All my supply and return lines are well insulated, it makes a big difference when running on diesel.