Heating System for My Multihull

[giamba]

I'm living and cruising around the world on my Outremer 55 std since 8 months. Since than I've been cruising in the Med and I'm planning one more summer here and than to move to the Antilles. This winter was colder than expected and a heating system would have been greatly appreciated. In my plan there is also the wish to visit Patagonia before moving towards the Pacific. I suspect that I will definitively need a serious heating device over there. My boat has 4 cabins/4 head layout. I ear many comments on the efficiency and effectiveness of diesel stoves (ie Dickinson or Refleks) but also the complication in tuning properly these devices. Similarly over my future cruises I will be sailing in very worm and mild climate with the exception of Patagonia, so I do not want to install a very complicated system which I will rarely use.
I would appreciate all possible suggestion, from those among you have approached this dilemma.

[Oliver L.]

Giamba,

I am just in the process of installing a heating and cooling system on my boat. 5 fan coils, a diesel fired heater and a chiller. PM me if you're interested in details...

Oliver

[rivonia]

Originally Posted by giamba

I'm living and cruising around the world on my Outremer 55 std since 8 months. Since than I've been cruising in the Med and I'm planning one more summer here and than to move to the Antilles. This winter was colder than expected and a heating system would have been greatly appreciated. In my plan there is also the wish to visit Patagonia before moving towards the Pacific. I suspect that I will definitively need a serious heating device over there. My boat has 4 cabins/4 head layout. I ear many comments on the efficiency and effectiveness of diesel stoves (ie Dickinson or Refleks) but also the complication in tuning properly these devices. Similarly over my future cruises I will be sailing in very worm and mild climate with the exception of Patagonia, so I do not want to install a very complicated system which I will rarely use.
I would appreciate all possible suggestion, from those among you have approached this dilemma.

We use WEBASTO heating on our Cat.

Peter

[Sand crab]

Why not install reverse cycle A/C units. The best of both worlds. You will need a genny.

[ScuzzMonkey]

I dunno much about cats or the particular challenges of heating them, but it strikes me that the major factor complicating the diesel stove approach would be the twin hulls... radiant heat from a single stove in a monohull works pretty well, even better with a few fans. I would imagine with a cat you'd end up either installing two stoves (with all the attendant installation and operating difficulties thus doubled) or heating only one ama effectively.

I would think that would leave you with hydronic or forced air as your primary options, and having looked pretty carefully at a lot of forced air systems recently, I'll say this: alone of the major forced air manufacturers, Wallas makes units that have two heat outlets built-in directly to the furnace unit. Two outlets / two hulls! Sounds perfect.

You can Y off any of the other systems, of course, but the friction will reduce the efficiency.

Anyway, maybe there are better off-the-shelf systems for cats, I dunno, just thought I would throw that out there.

[Palarran]

Originally Posted by Sand crab

Why not install reverse cycle A/C units. The best of both worlds. You will need a genny.

The seawater is too cold in Patagonia for a heat pump

[geoleo]

Ask Paul,owner of web forum www.multihulls4us how his Webasto diesel heater worked on his recent very cold trip down USA Atlantic coast. He has a 50ft Cat

[Palarran]

Originally Posted by georgetheleo

Ask Paul,owner of web forum www.multihulls4us how his Webasto diesel heater worked on his recent very cold trip down USA Atlantic coast. He has a 50ft Cat

It probably didn't work because it was installed wrong, just like everything on his brand new boat. It really would be better to ask Oliver or Rivonia who are active on this forum.

[geoleo]

Why not ask them both? Paul has painstakingly corrected most everything on his ST Francis 50. I saw it yesterday in Ft Lauderdale and it looked great.

[geoleo]

Better yet, contact Kent at Just Catamarans www.justcatamarans.com he worked on Pauls boat last spring to get the Webasto heater installed correctly. Plus he is the USA rep for Outremer Catamarans!

[mark_morwood]

Our cat came with an espar diesel forced air heater, with vents to the cabins in each of the hulls. I'm very happy with the unit itself, but a single unit in a cat has challenges with the plumbing. In our case, you just don't get enough hot air down in the hulls to really warm the boat if it is really cold.

If I were to start from scratch with the goal of heating our cat, I would follow the advice I read somewhere else, which was to install a diesel forced air heater unit in each engine room with a simple single vent blowing air in to the aft end of each hull. Obviously this only heats the aft cabins if you leave the doors closed, but if you open all the doors, you'll get both hulls heated and the main cabin heated with the air rising up into the cabin. Seemed like a simple and practical approach that avoided the very real plumbing challenges (either air or hot water) for other types of installs.

Mark.

[Serrano]

I installed a Webasto diesel system in my 48ft Chris White Atlantic catamaran last year. I put a separate unit in each engine room then ducted the air through each hull, basically a straight run with 3 outlets (2 closeable) in the port hull and 4 outlets (3 closeable) in the stb hull. Did the install myself -all aspects were straightforward, including the ducting. In each hull I have an outlet below the steps up into the main cabin - as hot air rises, there is plenty of heat there.

All works like a charm. Things to note: I'm sailing in not very cold areas (eg southern Tasmania), so I installed their smallest unit, as my advice was it is better to run a small unit hard than to let a big unit idle along at low settings. Where you are going, you would need one of the bigger units. Also, there are strict limits on how much ducting, how convoluted the duct route can be and how many outlets (min and max) each size of unit can cope with. You will need to find the Webasto ready reckoner to calculate this

[GordMay]

Greetings and welcome aboard the CF, giamba.

[St. Elsewhere]

I have used Webasto hydronic systems over the past 24 years. The advantage over forced air is that it enables moving the heat over distances more effectively. One system could do both hulls. Proper installation is key to success.

This is the installation manual: http://www.techwebasto.com/heater_main/907506.pdf
And the Service manual: http://www.techwebasto.com/heater_main/LIT699745A.pdf

[Sand crab]

Originally Posted by Palarran

The seawater is too cold in Patagonia for a heat pump

So when you really need heat they won't work because it's too cold outside.
Crazy. Are they only good for those chilly days in Miami? I looked at the specs on different units but couldn't find any low seawater temp threshold. Anybody got data?