Winter Heating system.

[Ray.]

Hi all,

I am looking for some guidance/feedback from experience of what I plan to install as a winter (Med) heating system.
I think the majority my go for an electrical system of plug in radiators or fan heaters.
I plan to install a wet system, utilizing a webasto water heater, fan matrix cabin heaters (individually controlled in the 4 zones (1. Master cabin fwd, 2. Saloon, 3. 2 x aft double cabins).
I plan to also use a twin coil calorifier for water heating. I can use this all year, just to valve out the heating circuit during the summer months.
Does anyone have any experience with something similar? what btu fan heaters to use? what Kw rating for the main heater unit?
I prefer the wet system rather than just air so I can use it for water heating. During the winter months I may still do some cruising so I will now always be on a shore connection.

any thoughts, suggestions etc greatly received.

Ray.

[Dockhead]

Many, if not most of us in colder climates, have such a system on board. But we typically do not use it when shore power is available. The Webasto/Eberspacher type hydronic heaters require regular maintenance and decarbonizing, and part of the maintenance builds up by hour used. Plus the fuel cost is generally more expensive than electrical power for heating, especially if the electrical power is unmetered.


So we typically use fan heaters at the dock. Just be really careful to be sure your electrical system is in good condition -- this type of heater does cause a lot of boat fires.


You will want your Webasto for when you are anchored, however, where it is a Very Good Thing. How to size the system and the fan coils is an engineering question which has to be calculated for every individual boat. If you read the installation manuals you can figure out how to calculate these values, or better yet, hire a professional.

[Ray.]

Hi Dockhead,

thank for your reply and advice, I have done some calculating myself by calculating the BTU's for the internal space, but it seems on the high side to me. When converting the BTU's to Kw I am ending up with around 15Kw, which seems really high, when usually 2 or 3 fan heaters totalling about 5Kw will I think usually heat the internal space of a 50ft 3 cabin yacht to a good temperature when on the dock.
I don't want a wet heater that is too powerful as it will short cycle and this can increase maintenance issues, longer running will often be the preferred way to run a wet heater as it should run more clean.
I will continue to search and check what would be my optimal solution

Thanks

Ray.

[Ivanvet]

Hi Ray,

I have a hydronic system from Webasto on a bene 473. It worked great last winter (and so far this one) in Boston. The model is the DBW2010 with 45,000 BTUs.
Although I don't have the system running through the water heater (the water heater only has one coil, for the engine), I added a heat exchanger for the engine, so when we motor I can keep the whole boat dry and warm (this is the best).

I think 45,000 BTUs is a little bit too much for us most of the time, but as full time liveaboards, when we are -20C for a week, this system keeps us totally unaware of what's going on outside.

When we are at anchor, this system is really power hungry so if you are going to use it make sure you have enough power. I replaced the nozzle at the beginning of this season because it clogs up pretty easily, smoking like crazy and burning way too much diesel. This is easy to do and cheap (the nozzles on amazon are around 5euros.

If I weren't planning on staying where I am for years, where the marina freezes for about a week or two, I'm not sure I would install this system. It's expensive and it takes a fair amount of space and weight. I see on your profile that your location is Denia. I'm currently in Valencia (I'm from here), and I have trouble imagining needing this system with such a wonderful weather
We have used our reverse cycle to see when it stops performing well. As long as the sea water stays over 4C (~40F) the system keeps pumping out heat. This, an extra space heater, and the best invention ever, an electric mattress cover, would be plenty. Sure it would be expensive to run, but when I crunched numbers comparing heating Vs. diesel heater, it would take 4-5 years with the Webasto to break even.

Good luck and enjoy Denia!

Ivan