Using Genny (NL 6kw) Coolant Loop to Heat Water?

[jreiter190]

Forget the science and just do it.Sometimes ignorance is a blissful shower and clean dishes.

[leftbrainstuff]

Originally Posted by jreiter190

Forget the science and just do it.Sometimes ignorance is a blissful shower and clean dishes.

+1 for just doing it

I would recommend logging temps. I use an infra red temp gun. They're cheap, reliable and non contact.

You'll find that having to high or too low flow through your hot water heat exchanger will impact your heat times.

We currently take an hour and 20 minutes to heat our 6 gallon tank. My calcs suggest 50 minutes to be the practical min. Our flow is a little high. I havent had the time to optimise our heating circuit restrictor.

You also need to ensure that the original closed loop generator circuit is not affected. Your temp gauge reading may not reflect actual cooling effectiveness.

Measure generator head and oil temp before and after. Again using the IR gun at 5 minute intervals. You'll quickly identify any issues and be able to root cause the offending circuit.

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[jreiter190]

If your left brain works this well, I'd like to see thoughts from the other half. Got one of those guns, use to use it to measure my wood stove in the belly of the fire, the stack half way up, and at the ceiling where it went through the roof on my ranch. Now, I use like you do on the boat; rum bottle, cat and, of course, my engine. .

[wrwakefield]

Originally Posted by mainesail

Wow, that's alot of running-your neighbors will love you-NOT.

I suggest you read the Dashews works. Not sure if they are still sailing, but they are extremely experienced sailors and cruisers and meticulously refine their systems and procedures for efficiency and reliability. They developed their systems to maximum efficiency, high efficiency alternator, using cooling water for heat, highly insulated icebox to really holds the cold, big battery bank capacity etc.-all to minimize the time needed to take care of system demands, while living in comfort anywhere in the world.
I must also mention the damage that many folks do to their engines while running them at low loads for long hours.
Not sure why you feel the need for a genset, but if you do the above, maybe you can toss it, but PLEASE PLEASE do not think it is a good idea to run any engine at anchorage for hours.

Mainsail,

I agree. We don't want to have to listen to engines drone on for hours when we are in a peaceful location- especially during generally accepted 'quiet hours...'

However, at least in the case of generators, they don't have to be noisy. My boat came with a 10KW Panda installed [boat is from the tropics and has 3 air conditioners...] with a water separating exhaust set-up. You cannot tell it is running if you are on deck unless you lean over the side and cock your head where the exhaust is expelled underwater- and listen for the bubbles. I kid you not.

When we approach the boat by kayak, we cannot hear the bubble blower until we are within a few feet of the exhaust location. We have had more than one visiting dinghy or kayak come alongside right at the exhaust port when the generator is running, and then realize they should move if they don't want to smell the diesel exhaust...

Prior to this boat I have never personally experienced such a quiet, neighborhood friendly generator. [Or perhaps I have but didn't know it since it was so quiet...?]

Anyway, I just wanted to let everyone know that these beasts can be silenced...

Now if I could further squelch the slight hum below decks...

FWIW

Cheers!

-Bill

[LakeSuperior]

Originally Posted by leftbrainstuff

+1 for just doing it

You'll find that having to high or too low flow through your hot water heat exchanger will impact your heat times.

Not sure how there could be a too high of a high flow rate. Higher is better for total amount of heat transferred. Consequently, your water will heat faster with higher flow.

Fundamentally, total amount of heat transferred is a function of the temperature difference. So the higher the mass flow rate the more heat exchanged.

A couple scenarios come into play depending on the amount of waste heat generated by the engine source but if we take minimum desired operating temperature of the generator out of equation then the above relationship stands.