Running engine at anchor for hot water - load

[s/v Jedi]

Originally Posted by donradcliffe

Wrong again. Engines use thermostats to quickly bring them up to operating temperature in about 5 minutes.

You sound convincing but for what I know about it you are very wrong.

On my Yanmar the connections for a water heater are straight onto the coolant channels at both sides of the belt driven coolant pump, while the thermostat regulates flow through the raw water heat exchanger.

This means these hookups are actually damaging the engine or wearing it out more.

But what do I know, I’m an EE, far from ICE engineering.

[donradcliffe]

Originally Posted by s/v Jedi

You sound convincing but for what I know about it you are very wrong.

On my Yanmar the connections for a water heater are straight onto the coolant channels at both sides of the belt driven coolant pump, while the thermostat regulates flow through the raw water heat exchanger.

This means these hookups are actually damaging the engine or wearing it out more.

But what do I know, I’m an EE, far from ICE engineering.

You could fix your system if you could T into the hose from the engine to the heat exchanger,if there is one.

[Adelie]

Originally Posted by FlyingScot

I had done a quick observational estimate about 100 Ah to heat 6 gallons of water from our battery bank from out old solar/battery setup. That was from ambient to around 120F. ….

Define ambient. There’s a big difference between ambients in Florida, Maine, Newfoundland, the Great Lakes, the North Sea, the Med and Guam.

[donradcliffe]

The 100ahr is in the ballpark.

5 gallons is 48 lbs.

Heating it 50 degrees F requires 2400 btu

Dividing by 3412 btu per kwhr gives 0.7 kwhr.

Assuming a 12v battery gives 58 ahr. The rest is inefficiencies.

I could run my whole boat for a day on 100 ahr.

[Letterkenny]

Last time I used about 600wh. Not sure the temp differential but I’m assuming 60s to low 70s ambient to the scalding temp that my 4.8g (or so) tank gets to.