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This page updated:
August 2006

I asked "Do you need a heater on the boat if you are living on it in Florida and the Caribbean ?" and got this response from John Dunsmoor:
We saw one person who had no oven and had three clay flower pots that nested together forming a thermal mass. This they sat on a stove burner and it made a very effective heater. That along with a small 12 volt fan does a fine job. We tried the same with a single pot and it did well also.

If the vessel has an oven, it can be a good heat source. Of course since you are burning oxygen you have to be careful. We never used the stove as heat except when we were awake. Good wool blankets or a sleeping bag are fine for temperatures below freezing. Actually a small boat will maintain a fairly even temperature with two bodies and sitting in water that is not frozen.

If you were planning to winter over in some non-tropical destination, such as some of our cruising friends did in Boston, then I would suggest some robust heater. Most of the time when the weather was cold, we were at a dock and these small 1500 watt electric heaters do a fine job and also dry the vessel out. Another thing a couple of bodies do is liberate a lot of moisture into the vessel.

Even propane has a tendency to be a bit wet.

So why are we in such a position? Cruisers that have no ties should be someplace warm for the winter. You will not need a heater in the Caribbean, you might in the Bahamas, but I would not think that the temperature would ever get cold enough, long enough to worry about a dedicated heater once you are south of 22 degrees.
Got this response from Gary Elder:
Tampa can experience a few overnight 'hard freezes', but usually has comfortably cool winter days. [At end of November,] Marco Island has been having lows in the mid 50's and highs in the high 70's. Yesterday was 79-80. I like a heater for the late evening and early morning only, but don't have one on the boat. If I were going to sit in the cabin at midnight, reading a book, I would want a heater.

Again from John Dunsmoor (much later):
> How did you guys cope with cold and wet nights and days on the boat ?
> I worry about that, even on a bigger boat than you had.
> Maybe we'll have a primitive heater. Did you just snuggle up under blankets or something ?
> Was there ever a time where you just said "Can't take this any more!" and
> headed for a motel for a couple of days ?

We used the stove at times. A couple of clay flower pots nested upside down over a burner with the stove set to low and the hatch cracked open. This was rare though. Mostly we were at a dock and used a small electric heater which works quite well. Electric heat also dries the boat out quite a bit.

For the most part we never stayed on the boat in really cold weather. Even at its worst we would just pile on an extra blanket. We did have ice on the deck for a few days in North Florida once. But the space is small and well-insulated and just with body heat the inside of the boat stayed above fifty with outside down to ten degrees. A pot of tea and the inside was nice and toasty.

On our current boat we have an oven, and during the winter months I take along buttermilk biscuits. Nothing like starting the morning to some quick bread or biscuits, tea or coffee and the interior comes up to temperature quickly.

We have never wintered in such a place like Boston or such and if you did this I would suggest a proper diesel heater or something. It is different if you are in a position where without heat for 12 hours you could die. Venting, BTU's become factors. We knew a couple who winter over in Boston. They had the boat shrink wrapped. They set up a frame and then covered the boat with plastic and then heat gunned it so that the entire boat was covered in this white shrink wrapping material. This kept the snow and ice off the deck. Added another dead air space of insulation above the deck. They said the space between the deck and covering material was fifteen degrees warmer than the outside. Once the sun came out strong this went to thirty degrees and got so warm at times that they were able to open the hatches and vent the boat out a bit.

Now the point is, you are a sailor and the best method of dealing with cold, inclement conditions is a change in Latitude. Sail south. You are pretty much out of the cold fronts by the time you get to the Exumas or further south. This is but a half of a degree change in L' attitude.

Types of heater:

Survey article by Michel Savage in 10/2001 issue of Cruising World magazine
Sailnet - Mark Matthews' "Wintering Aboard"

From Bob Goth on The Live-Aboard List:
In the world of heaters there are three types of heat. Those that add moisture, those that don't, and those that remove moisture. Combustion heaters such as free-standing kerosene heaters and non-vented propane add moisture as a by-product of combustion. Electric heaters do not add or remove moisture. Any heater with a chimney removes moisture and falls into the dry heat category. Living in a bottle, oops sorry "vessel", ventilation is king. Without air flow the only way to rid the air of water is to saturate everything on board. When we moved aboard Windquest another puzzle was the pile of parts that ultimately assembled into a Dickinson Newport diesel heater. As our first winter came on, the moisture was unbearable. When I finally lit the diesel stove we watched the fog leave the window from the top down. It was the single device on board that made it possible to winter on board.

From Pierre Mitham on IRBS live-aboard mailing list:
We've had a Newport diesel heater on board for 2 winters now and love it (34' sailboat). It generally takes 20 minutes to get the boat really warm from first light. The trick is to put a small fan on near the flue to blow air across it. That really improves its effectiveness. ...

From George Geist on the IRBS live-aboard mailing list:
I find ceramic heaters not to my liking. I use oil-filled electric heaters from DeLonghi, have so for five years and none wore out yet. They make absolutely no, zero noise, give off nice comfortable radiant and convection heat, their surface never gets too hot to touch (guaranteed to only 25 above ambient temperature), in case of temporary power failure, they provide about a 15 minute ride-through and you can hang your towel, socks, underwear etc over them on a cold winter morning and then slip into warm things - aaah! Oil-filled electric heaters (sold also under other brand names but all made by DeLonghi) are a tad more expensive than ceramics, but they have lasted for me five years, compared to [ceramics] two years. They have more than made up. Oh, and since there is NO fan, no moving part, no mechanics - all electricity gets 100% converted to heat. Can't get more efficient than that!

About Force 10 kerosene heater,
from Jack Ganssle on the SailNet liveaboard-list:
I never had it go out on me and leak kero as I've heard expressed on this thread. Even in heavy seas (and I'm talking midatlantic at 50 north!) it ran fine.

Problems I had were:

- the burners are a high maintenance item if you use the thing a lot. They clog up. Some folks I know used premium kero at $10/gal; I always used K2 from the gas station as you go through quite a bit of fuel living aboard.

- You can't imagine how hot the heater gets. I wound up putting a chicken wire cage around it at sea.

- It can develop a "rain of carbon" - sort of like a kero lamp turned up too high - that covers the boat with soot. I had one really bad experience with this and afterwards kept a more careful eye on it.

It does make a roaring sound that's quite pleasant, especially when it's nice and toasty below but nasty outside. A fan is critical to distribute the heat - I had best luck aiming it at the heater itself.

The pumping of the tank with the bike pump is a little bit of a hassle, but good exercise! My wife (ex now) wasn't strong enough to properly pressurize the tank.

Heating tips summarized from "Living Aboard" by Janet Groene and Gordon Groene (on Amazon):

From Tim Lochner on The Live-Aboard List:
For diesel heating I think you have three choices:

1) a stove-type drip furnace (i.e. Dickenson Arctic, Faball, etc) which are floor or bulkhead mounted, and can be part of an oven/cook-stove, or not.

2) Forced Air furnace (ESPAR, Webasto), with a remotely mounted unit which circulates heated air via ducting thoughout your boat,

3) Water circulating systems (ESPAR, Webasto, Hurricane) with a remotely mounted unit which circulates hot water thoughout the boat, with individual blowers doing the heat transfer from water to air.

From your question, it seems that you want a system that will run without you needing to be on board to start the system. Although I had a Dickenson drip furnace which ran 24/7 for the entire winter last year, and a Faball on my previous boat which also ran 24/7 (i.e. even when no-one was on board), my assumption is that you would like a thermostatically controlled unit. This then limits you to either hot air or hot water.

I personally have no experience with ESPAR. Anecdotally however, I have a number of friends and neighbours who either have ESPAR systems and hate them, or have replaced their ESPAR systems with hot water systems (either due to a new boat, or an ESPAR breakdown). The only thing I have first hand information on is that they are very noisy, even with a muffler.

I personally spent the summer installing a Hurricane hot water system. Before choosing the Hurricane I was seriously considering a Webasto system. Living in Vancouver BC, however, Hurricane (made by ITR) is manufactured here and I have an installer as a neighbour (so my reasoning is somewhat biased, based on price and on convenience). I have been running the system now [1/2001] since October 2000 and it has been working flawlessly.

Pros and cons. The biggest impact in going away from the Dickenson to the Hurricane have been:

1) Cost. The Hurricane (and probably the ESPAR, etc) cost significantly more than the Dickenson/Faballs. ($5000-$10000 Canadian vs $800-1500)

2) Condensation. This is probably the biggest difference I have noticed. The old Dickenson furnace sucked in the cold moist air from the floor/bilge of my boat and radiated hot, dry air. In fact, I used to have to put a tin can of water on the furnace to add some humidity. Now, the boat is a virtual rain-forest.

3) Speed. Within 10 minutes of turning up the thermostat, the Hurricane (and I assume the ESPAR) starts spitting out nice hot air and the boat is soon toasty warm everywhere. The one thing about the ESPAR that I've heard, is that in the beginning it blows cold air, until the unit heats up. Each seperate fan in the Hurricane is equipped with an aqua-stat so it only blows when the circulating water is warm enough.

4) Convenience. I can use the Hurricane in the windiest of conditions and while sailing, something I couldn't or wouldn't do with the Dickenson nor the Faball (even with the "Balanced Draft").

5) Cleanliness. I no longer have to scrub my decks to remove the black fall-out from the soot shower that results from startup and shutdown of the Dickenson and the Faball.

6) Noise. I really miss the peace and quiet of my Dickenson. The cycling of the heat exchangers drives me a bit batty.

7) Temperature Stability. I could achieve great temperature stability with my Dickenson by simply keeping a window or hatch slightly open. With the thermostatically controlled units it often gets too hot, then 15 minutes later it is too cold, then too hot.

8) Efficiency. I have probably cut my fuel consumption in half moving from the Dickenson to the Hurricane - especially nice when diesel is $.70 per litre. I now use about .75 gallons per day (or less - depending on the outside temperature).

So, in summary, there are certainly no ideal solutions. If you are considering spending $4k-8k US on an ESPAR, I'd seriously consider all of the heating options in that price range (including the Hurricane). 1 1/2" heater hose is sigificantly easier to run than 3" or 4" air ducting.

From Rufus Laggren on The Live-Aboard List:
Ventilation remains very important. Whatever boat-cover system you set up, be sure you can still ventilate somewhat in every living space onboard. I have never had mildew problems, and that may be because I have lots of air flow. Also, unless you like to enjoy the smell of cooking 24 hours a day, you need to ventilate the galley.

I don't use anything under the bedding, and rarely "flip" the cushions or do anything special with them. No problems at all in 5 years, but I believe that may be because I use a cheap yellow foam mattress cover about 1" thick on top of the cushions (under the bedding). This keeps moisture from getting down into and under the cushions. You can put a cotton pad over it if you don't like the feel of the rubber under the sheet. Available at Target and other maxi-cheap places. I also pull the bedding back and do not "make" it during the day so it gets as much air as possible.

You will want at least two ways to maintain some heat in the boat, so if the main heat goes kaput you can carry on without a major crisis. Since you have an Espar, you're all set (after careful servicing) for your main heat. However, you need some backup, either electrical, coleman "tent" heaters, large kero lamps, something. This is another reason to be able to maintain good ventilation, so you can use these heat sources safely if you need to. You may want to use some small fans to circulate the hot air a little - or not.

Others have far more good experience covering and insulating their boats, but one final thought: Don't try to heat areas that don't need it. If you're floating, your bilge must be above freezing and it can pretty well take care of itself. Put some nice thick rugs down and enjoy luxurious foot-feeling. For the most part, your lockers (and their contents) don't care if it's 72F or 36F. They provide an excellent layer of insulation around your living space. The upper cabin sides and top will be the coldest (unless you have a keel-stepped metal mast ...), but leave some opening ports accessible and don't seal or cover the forward hatch in such a way that you can't get out in an emergency. It might be a good idea to keep a sharp knife by the forward hatch if you tightly cover the foredeck with plastic or canvas.

The main hassle may be getting water to the boat. A heavy duty (read "carries 100 pounds and only requires ONE trip when it's 20F") dock cart might be very important. Also, big wheels (bicycle size) go over big bumps and don't get stuck between the dock and your car. Note, plastic gets brittle and breaks when it gets real cold.

Propane gets lazy at low temps. I've had no trouble at all down to about 35F, but can't speak for lower. That might be a spot for extra insulation and a big light bulb.

From Paul Esterle on the SailNet liveaboard-list:
I had heard some horror stories about Espars being unreliable, etc. In tracking them down, found them to be undersized for the applications, running far oftener than recommended duty cycle. Moral: size them right and get them installed by a professional. No problems Mon!

From Capt Fred on the SailNet liveaboard-list:
Have used a "Glo-Warm" "Blue Flame" propane heater for 4 years now on my 38' center cockpit Irwin. Works great! About 200 bucks at Home Depot. Use about 30 pounds of propane in 6 days. Heater is thermostatically controlled, has an oxygen depletion sensor and a built in ignitor. Leave it on all day long and it keeps the boat at about 75F at a very low t-stat setting. Located in the Stony Point, New York area on the Hudson river. (Also do the shrink wrap thing.) Hint: have shrink installed as far down on the hull as possible without getting into the water. It will help to create an air layer between the hull and the wrap ... will cut down on the condensation problem.

From Gregg Arlotta on the SailNet liveaboard-list:
The subject of cabin heat is a complicated one and you need to understand the differences between the various options available.

Espar heating systems ARE NOT SUITABLE FOR SAILBOATS UNDER 50+ FT. WHY - They are essentially a forced hot air furnace, just like in a house, and function in the same manner. They require huge amounts of air and exceptional ventilation. Two things a smaller sailboat lack. Besides that, they should be installed away from flammable material because they DO get hot. Lastly, if used with marginal ventilation, they begin to experience carbon buildup on the "nozzle" in the burner chamber. This causes incomplete combustion which equals a "fuel oil" smell in the boat and soot topsides. Diesel soot WILL STAIN GELCOAT. If this isn't enough they require the "heated air" to be ducted, usually via 4" ducting through the boat. This tends to eliminate a lot of valuable storage space under bunks and in hanging lockers etc.

Recommended solution:

First decide on propane or diesel as your fuel source. Then look at whether you want to combine heating and galley stove functions. Or do you simply want a "wall heater". Next be aware that Sailnet's catalog/website only carries a few of the models offered by the two better manufacturers. Bottom line is either a Dickenson or Force 10 heater will do a great job and they both come in either propane or diesel. Plus you can install them for under $1000. 1/4 the cost of the Espar !

For "latent heat" while you're away from the boat, simply use electric wired into a low temp thermostat. Your local hardware store can order these gems which can be set for temps in the low 40's and will keep things cool but not frozen - LOL. This alternative can be done for under $100.

Next, don't forget your batteries, keep them at least "trickle charged" and maybe even figure out a way to get some cabin air into the engine room to cut down on condensation on your engine and associated parts.

From Hank Janssen on The Live-Aboard List:
I had an Espar forced air diesel on my previous C&C 37 sailboat.

When it worked, it worked okay, but it had to be rebuilt on average every 18 months. I had that done once at the cost of 640. And when I talked to the company who did it they said that they are known for sooting up.

Which made the thing way too expensive for me.

Maybe the newer ones are better.

From Larry Dill on The Live-Aboard List:
I had the Dickinson Newport diesel heater in my boat for two seasons and was not happy with it. It gave off a lot of soot on the cabin top. I then switched to the propane Newport model that Dickinson sells and have been very happy with it. You do have to have a propane and carbon monoxide detector, just for peace of mind that you will be able to wake up in the morning.

From Philip Rosch on The Live-Aboard List:
I had an ESPAR on my Morgan 51. It worked well when it worked, but was a constant maintenance chore. My last winter in New England on my trawler was 2000 and I bought a propane room heater for $100 at Home Depot because I only needed one winter's worth of heat. It kept me warm as toast all winter and I never turned it above "low".

There is some risk with propane, but I did the connections and I found it acceptable.

From Norm / Bandersnatch on The Live-Aboard List:
There was a thread about boat heaters some years ago and the general conclusion was that hydronics (circulating hot water) was the hardest to set up but the best in operation.
From Jaye Eldridge on The Live-Aboard List:
We have had a Webasto hydronic system for about a year and love, love, love it. We've had no problems with it, other than regular maintenance. It was difficult and expensive to install, but very much worth it.

Insulation article by Michael Savage in 1/2001 issue of Cruising World magazine

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