extra heat needed

[Wxx3]

Hi all,

I thought i would run this by you before i spent any more time thinking about it.

The only heat my boat has now is an electric element in one of the ac systems. Great if plugged in, but I am trying to make the boat as free from shore power and gen power as I can.

I need more heat as I will be on the boat for much fot the winter.

So i am thinking the my long term solution is probalby the Wallas diesel fed, hot air system. I can use the existing AC ducts.

But in the short term, the other day, it was quite chilly and I was thinking of getting one of those little hot water heaters with small fan that I think trucks use sometimes. But my real idea was to plumb it into the hot water line that's right under the pilot house for the head. then I would only have to make a return line and i would just put a "T" into the intake to return hot/warm water.
On this little heater, I would have a valve to turn it on or off. When on, it would mean my water pump would be sending water thru.
I'd only use it to take the chill off the pilot house on chilly mornings and yes, only when engine is running (if not running, I won't be in pilot house)

What am i missing?? seems too easy??

Richard

 

[boatpoker]

You are not missing anything, I did it 20 years ago and it works great. You can buy a used truck heat exchanger and make up your own box or there is a company that makes them in 2, 3 or four outlet boxes for boats but I cannot remember their name.

 

[Sailor of Fortune]

Red Dot Heaters

 

[Northern Spy]

Might want to consider a larger expansion tank. Keep in mind high point venting as well.

 

[twistedtree]

This is commonly done, but the hot water loop that is tapped is usually the one between the engine and HW tank, not the domestic hot water itself. That way there is no need to run your domestic water pump to circulate hot water, and you don't kill the water pressure for domestic water (both hot and cold pressure will be impacted).

The down side of course is a little more plumbing, and I believe the whole loop needs to stay below the reservoir tank on the engine.

 

[FF]

How you get the right number of BTU into the boat does matter , a BTU is a BTU so if 10,000 or 25,000 are required the source of production does not matter.

What does matter is the cost and reliability .

Any system that requires 120V dock power is suspect if you will depart for days.

The Dickinson oil range , or furnace , with gravity feed is a great choice if you will be gone very often.

At 1-4 GPD a 40 gallon tank should give a couple of weeks of away time.

I lived aboard for over 20 years and you need to plan for the worst case , no 120V and outside below 0F.

I have seen -17F for a few days and it was brutal.

In really cold weather , the hull will be locked in a foot of ice and unprotected lines will freeze , unless there is plenty of heat .
The engine and noisemaker and every other item that cam be winterized MUST be in case you loose heat.

Sure 20F most nights and 35F days are "normal" , but stuff happens, and after a winter storm a marina is not high on the restore power list.

At 25c a KW or more electric costs may be brutal .Most marinas will not treat you to $400 a month worth of electric .And few boats or docks are wired with enough power for resistance electric heat.

Depending on the equipment chosen and who installs it , your first winter will cost $3,000 to $5,000+ to survive comfortably.

 

[Tingum]

One thing to consider is that without running the engine you will have no heat! If you are like me and like to hang out in quiet anchorages for long periods of time a diesel heater is the most practical, least expensive, and easiest to install.

 

[LaBomba]

Here is one link but they also sell them for school buses and as we all know if it says marine the price is higher.

Heater 28 000 Btu 12V Basic Kit with 2 Outlets

 

[DavidM]

For heat in the pilot house while underway the "red dot" heater is a good solution. But I would plumb it to the engine coolant system as other posters have said. And also if you plumb it to the hot water potable side, you won't get much heat for the first hour until the hot water heats up.

For long term usage at anchor or at the dock, there are a number of choices. For moderate climates a Dickenson or similar bulkhead heater will do pretty well. For zero degree nights you need a hydronic diesel heating system just like in a house.

David

 

[Wxx3]

Might want to consider a larger expansion tank. Keep in mind high point venting as well.

Holy Moly, High point venting! It's amazing what i don't know.
I think I will probalby stick with plan A as I will need heat during the winter on those days i don't run the engine.

Thanks for helping me think thru the process.

now, let me go see why the boat is swinging now
R