How Do Folks Heat Their Multihulls

[capcook]

Other than taking them south for the winter... wondering what the practical options are for heating a 40-50' Multi... I have seen where some folks are putting wood burning stoves in but if you are sailing I bet that cord of wood stacked up on the saloon roof is a pain to keep dry... so what else is an option, an LPG forced air furnance? Is resistance heating elements an option or would you just have to run the Ginny all the time? Part of our plan is to spend a year or so around Japan and it can get chilly... not looking for Artic heat, but enough to take the chill out of a 30 degree F day...

Thanks for any thoughts on the topic...

Cheers

[rebel heart]

Maybe not 30 degrees, but on a 50 degree night, an oil lantern will take the chill off.

[sctpc]

The stove with a teracotta pot covering it is quite good as the pot radiates the heat,

[Woods Designs]

I used a solid fuel Dickinson stove on my Eclipse. It kept us warm even with icy decks one Christmas in the UK

However, although I mounted it as low as I could in a hull, because hot air rises it only heated the saloon. The hulls and bunks stayed cold

So the only sensible answer is to have forced air central heating system. Diesel or LPG with outlets to each hull and onto the bridgedeck.

It is well worth sealing off unused parts of the boat in winter. We also found a deck tent/awning made a big difference when there was snow on deck and we were living on board.

Hope this helps

Richard Woods of Woods Designs

www.sailingcatamarans.com

[mojo]

The best way to heat a multi is to keep it in the tropics

[Hyprdrv]

Kind of a side question here, are most A/C systems installed on Cats a heat pump? Just wondering if the H/P systems are available.

Thanks,
Steve

[imagine2frolic]

I use 2 ceramic heaters at night. One in the owner's head. It's heat rises to our berth. We close off the rest of the hull. The second heater is under the salon table. It keeps that area, and the nav station warm.

[Tropic Cat]

Some are using a wood stove in the least used hull. I know one fella who removed his Nav Station and used that space for the stove. It seems like most Cat owners use the Salon table for route planning as we have more room there.

[rebel heart]

Originally Posted by imagine2frolic

I use 2 ceramic heaters at night. One in the owner's head. It's heat rises to our berth. We close off the rest of the hull. The second heater is under the salon table. It keeps that area, and the nav station warm.

That's actually a good point. It's a lot easier to heat the small area that you're sleeping rather than the entire interior.

[Talbot]

I fitted a 4kw eberspacher in the U berth at the fwd point of my saloon in my catalac. This enabled me to have outlets in the two fwd cbins, the saloon, and the two hulls. Kept my boat toasty warm even in the coldest, and never had to use full power. I suspect a larger boat would need different system.

[kevinmac]

I use Webasto diesel furnace and hydronic heat in mine. I also have two stand alone electric heaters to use when in port with power.

Kevin

[schoonerdog]

I guess it depends on at dock or at anchor? Basically you have to worry about moisture build up in the boat, not necessary it being too cold. The best way is to keep one small port open in each hull and then the top hatch cracked in the saloon. That will provide enough ventilation that you won't be dripping in the morning. You'll want plenty of insulation underneath bridgedeck type births, the difference in temp between the air under the boat and the inside is extreme, so I'd recommend 4" of closed cell insulation, dry deck panels, and then your mattress. The reason for so much is your trying to stop temperature differential condensation, and it's most extreme under your bridgedeck mattresses. Trust me, the constant dripping and waking up with all of your clothes and bedding moldy after 1 day will kill your trip far faster than simply being cold.

Then you'll want a powerful source of heat in each hull, webasto furnaces are the best. Heat only travels up, so the settee area will benefit for the hull based heaters but having something like a propane furnace up in the settee area will do absolutely nothing for your living space down in the hulls, so plan your heat to be placed down below. Webasto furnaces are very small, put out nice dry heat and are extremely powerful. One place down in one end of each hull and blasting its heat forward will be enough to keep that hull and the settee area above nice an toasty. Surprisingly it doesn't really need to be put through ventilation ducts, just have the one vent from the webasto shoot from your fore or aft cabin straight down through the hull.

[capcook]

Thanks all... I guess you need to have one of those hatches cracked open if you use the Webasto furnaces so that you do eventually wake up and fall victim to Cabon Dioxide...

I appreciate the valuable input...

Cheers

[GordMay]

Originally Posted by schoonerdog

... Heat only travels up ...

Heat doesn’t only travel up; but hot air rises.
There are three ways that heat “travels”, including convection*, wherein warmer air rises (travels up) & cooler air sinks.

* And also conduction & radiation - both omnidirectional - transferring in all directions.

[ImaginaryNumber]

Although I don't know any details, I understand that one multi in northern Europe used a central heater with radiators in each hull. They didn't like forced-air. Too noisy. They also hung a sail or tarp in front of and behind the deck bridge, between the hulls, to reduce the cold air flow between the hulls and underneath the deck. Obviously, this would only work while at anchor.

John