Most effective, cost efficient, and reliable way to heat trawler cabin

[kazenza]

I have a 42' Nova Sundeck with a large salon and forward and aft cabins and I'm trying to get advice on the best way to heat it in the wintertime that don't involve plugging in various space heaters while we're at dock which obviously doesn't help us at all on the water.

I'd be interested in hearing people's experiences with this issue especially how efficient hydronic forced air systems are compared to diesel fueled or propane fueled heater systems. With hydronic forced air heaters, how effective is it to circulate water from the hot water heater rather than the engines and what kind/size hot water heater would I need for that. Our former trawler (CT 40) had a much smaller interior and we are likely to move full time onto the NOVA in a couple years so would like a solid solution.

Randy

 

[Portage_Bay]

By hot water heater if you mean domestic hot water it likely won't do the job. It's probably 1500 WATTS, same as a single space heater. You're going to need a lot more heat. 30,000 to 50,000 BTU. 8.79 to 14.65 KW.

 

[Mac2]

Diesel hydronic heat. Not really any other practical solution. Propane puts moisture in the air. Electric works, but always maxes out the electric system and limits the use of appliances without continually tripping breakers. A diesel stove is great, but it only heats one area of the boat. The hydronic heater I installed on my previous 36 foot boat used about 120 feet of hose. This hose is hot and runs all through the bilges and cabinets heating these remote areas with the radiant heat. I have a residential HVAC on my current boat and it fails when I need it the most (below freezing temps). I can always count on my hydronic heater at the dock and at anchor.

 

[Portage_Bay]

By hot water heater if you mean domestic hot water it likely won't do the job. It's probably 1500 WATTS, same as a single space heater. You're going to need a lot more heat. 30,000 to 50,000 BTU. 8.79 to 14.56 KW

 

[Comodave]

The first thing to do is insulation. Without insulation you will either still be cold or will be using a lot of whatever fuel you choose to heat with. If you plan to liveaboard then the extra effort in doing it correctly will be worth it an pay off with warmer cabins and less fuel consumed. I would plan on dropping the headliner to install insulation. Also make some removable panels to stick into the windows. Maybe find some flexible foam insulation sheets. Cut to size for the windows. Then use something like Sunbrella or Stamoid and cover them in something like a pillow case. You could then use snaps to secure the panel to the windows.

 

[SteveK]

Diesel hydronic heat. Not really any other practical solution. Propane puts moisture in the air. Electric works, but always maxes out the electric system and limits the use of appliances without continually tripping breakers. A diesel stove is great, but it only heats one area of the boat. The hydronic heater I installed on my previous 36 foot boat used about 120 feet of hose. This hose is hot and runs all through the bilges and cabinets heating these remote areas with the radiant heat. I have a residential HVAC on my current boat and it fails when I need it the most (below freezing temps). I can always count on my hydronic heater at the dock and at anchor.

120 of hose, like 5/8 engine heater hose? sounds interesting to run off engine coolant loop.

 

[mvweebles]

Not exactly cost effective, but our solution was to move to Florida.

Peter

 

[Mac2]

120 of hose, like 5/8 engine heater hose? sounds interesting to run off engine coolant loop.

It was 5/8 heater hose run off the hydronic heater. I ran a red dot off the engine-about 5 feet of the same hose.

 

[Lepke]

I have an 83' boat with hydronic heating. I have large Wabasto and a rarely used older boiler. It's a shipyard job to get the boiler removed. The system can be heated with coolant from either main engine. In cold weather, the system can be used to warm the engines before starting. Heating for cabins is with a marine heater, similar to a car heater, embedded into cabinets. When I bought the boat it had baseboard radiators. To heat a cold boat from about freezing weather took 4+ hours with radiators and 30 minutes after changing to marine heaters, but does use more fuel until warm. The heaters I use can have 2-4 ducts or blow directly. Mostly I use the ducts so there are no cold spots in the cabins. The heaters have 3 speed blowers.The hydronic system has 5 zones and solenoid valves so the whole piping system isn't heated when one cabin calls for heat. Also there are valves to separate the engines from the system. It all uses the same coolant. It is important to insulate the piping/hoses in both directions if you are concerned about how much diesel you burn. Otherwise you are heating bilges or spaces behind cabinets that don't add much to overall room comfort. Also insulating the boat and thermal pane windows or window covers saves s a lot of diesel.
I have a diesel stove with a coil that heats the 50 gallon water heater tank. I use induction plates for cooking in hotter weather. I also have a wood stove and a pellet stove. Each with a coil. I rarely heat with wood, it's not practical on a boat, but if I do it heats the hydronics. I use it mainly for disposing of all the paper that comes with groceries. In the winter I usually heat with the pellet stove. It also heats the hydroinc system and is by far the cheapest way to heat. I live on board but mainly use it when at my private dock.
If the price of diesel goes back to pre-Biden, I'll probably heat with it again because the fuel is already on board. I also have a couple Chinese heaters that are used in mild weather when I don't need the heat of something bigger. They heat opposite ends of the main cabin and have remote controls and have built in thermostats. Not a bad solution if you don't need a lot of heat.
When was young, I grew up in a hot place before AC was common. Later spent some time in the mid-west with its' heat and humidity. And several years in an even worse place. So in old age I prefer cool or cold places and the boat is setup for that.

 

[Mac2]

Lepke: great system. Love the redundancy. I wanted a pellet stove on my boat, but couldn’t find a place for it. Definitely the cheapest form of heat.

 

[GrandWood]

I’m on a Grand Banks 36, forward vberth and aft cabin, center saloon. Have webasto diesel forced air, keeps both berths at 68 at the mid point of manual controller, you can get digital controller. Saloon at 60f when cloudy out. Otherwise at 62F.

5 gallon day tank lasts 4 to 5 days with current temps in mid 40f, I crank up a bit in am to knock off chill in saloon, then back down. Gal a day not to bad. So 120 a month to heat, will go up Jan/feb for sure.

Vevor is having sales right now on there diesel heaters, crazy prices compared to webasto, and there the same units, all parts interchange and such. I have one I bought on Black Friday for 76.00 that I’m going to dedicate to the saloon.

Also they are very easy to install yourself

 

[Moonfish]

We are on our second Wallas forced air diesel heater, which is the Spartan model. Our first Wallas (40Dt) had more than 5,000 hours on it. As liveaboards in the PNW, we would typically turn the heater on in October/November and leave it on low 24/7 until April/May. We would very occasionally turn it up to "medium" if the temps dropped into the 20s, otherwise we kept it on the lowest setting. The Wallas also only heats the three cabins belowdecks (a propane fireplace in the main cabin heats the "upstairs").

As far as efficiency, when diesel was ONLY $3/gal the 40Dt was pretty good. We'd spend about $100-120/month in diesel. We haven't spend an entire winter aboard now for a few years, but when we lived aboard I estimated the new Spartan was burning a fraction under a gallon per 24 hour period.

We also insulated the hull everywhere (behind drawers, cabinets, etc.) my wife could affix that thin silver insulation sheeting, and we applied .5-inch foam insulation sheets between the overhead and subdeck in our daughters forward cabin, all of which helped a lot.

 

[DDW]

No hydronic system I know of would heat the boat in the winter from dock power. I think if at the dock all winter, electric heating is the best way to go. Simple, reliable, and cheap, can be installed in the kick space of a lot of cabinetry. But you may need a 50A service to make it practical. If that isn't possible, then you're burning diesel, one way or another.

 

[Mambo42]

I have both reverse airco and a kabola heater in my boat. The reverse airco is nice if it is not too cold, but I need to keep it running all the time to keep the boat warm, since it only warms up the air, not everything in the boat.
The Kabola heater is my favorite. I have radiators in all spaces in the boat (even in the engine room and lazarette). It is a closed system, so the water circulates through the radiators, back to the heater and then via a pump back to the radiators. Temperature of the water in the radiators is controlled via a thermostat on the kabola and the temperature in the boat is controlled via thermostats on each radiator.
If it is really cold I may use 2 to 3 ltrs of diesel per hour, but once the boat is at temperature the kabola is controlled via the computer thermostat. It is basically central heating like we have in Europe in homes, works perfect. And best of all, it does not use a lot of electricity, so also this system I can run off the batteries, no need for a generator.

 

[tiltrider1]

I Have a Hydronic diesel heat system, Heat pumps, resistance heaters and an electric hydronic heater.

The cheapest to operate by far are electrical heat pumps but, if your water source gets below 45 degrees the system will become inefficient and/or stop heating all together.

The cheapest to acquire and install are resistance heaters like a King Pic a Watt. My experience is they are cheaper to operate than diesel.

Diesel forced air or hydronic is by far the most convenient. While operating costs are not as efficient as heat pumps their versatility often over comes their higher operating costs.

Electric hydronic heat is expensive both to add and to operate.

 

[Mac2]

Maybe the better question is, “what type of heat can you use at anchor to heat the entire boat”. Once you figure that out, you can use other sources of heat for your situation, including no heat and throwing a jacket on. It’s all subjective depending on how much of the boat you need heated and what temp you need it at. How do you compare propane that puts out great heat, but dumps moisture into the boat? I don’t see anything better than diesel heat at anchor, especially when it comes to not worrying about a fuel supply on a diesel boat.

 

[ksanders]

I lived aboard in Seward Alaska for many years, and before that kept my boat heated in the winter for frequent visits.

I used Wallas forced air furnaces, three of them, and loved them. When I returned one heater for service they told me it had over 27,000 hours on it, a record.

Today in Victoria BC we have reverse cycle AC units. Not the best, but so far they work.

 

[fractalphreak]

We have a diesel Webasto forced air unit. We replumbed the air runs when we got the boat, and updated the vent locations a bit. It gives us good, dry reliable heat when we need to. With the replumbing and balancing of the vents, we have fairly equal heating through the boat.

At the dock the diesel heater is turned off, and we use one oil radiator and two small "dryers" that have a little bit of heat output to them in the fwd and aft heads. We keep the oil radiator set at its lowest setting just to ensure we maintain some dry heat inside the boat coupled with our dehumidifier. We obviously don't live aboard.

I want to switch to hydronic though, for the sole reason of heating domestic hot water away from the dock. Staying out 3 or 4 days in the cold means genny run time to heat water. I haven't looked at them much because there are other pressing needs for my limited $ right now. It would be cool to find a diesel and electric combo hydronic heater, that will fall back on electricity when it is available.

 

[Lepke]

In anticipation of removing the boiler, I added a 20 gallon fast recovery electric water heater. The boiler holds 10 gallons. The Webasto only has a small tank around the combustion chamber. The 20 gallon is for reserve for the Wabasto. That way the oil burner doesn't come on as often when there is a heat call. I can only run the 20 gallon as a heater for hydronics when a generator is running. And I only run a generator in summer, so it doesn't get used often. The Webasto pump or the boiler pump answer the heat call. If the coolant leaving the 20 gallon goes below 130°F then the Wabasto burner comes on. Same for the boiler if used. Either can run the whole system to about 25°F.
My system is wired a little different because it saved a lot of diesel when using the boiler and was carried over to the Wabasto. When there is a heat call the pump comes on not the burner. The burner only lights when the coolant is below 130°F.

 

[ranger58sb]

I have a 42' Nova Sundeck with a large salon and forward and aft cabins and I'm trying to get advice on the best way to heat it in the wintertime that don't involve plugging in various space heaters while we're at dock which obviously doesn't help us at all on the water.

Where are you boating, and what are typical lowest seawater temps there?

-Chris

 

[Taras]

Watched a video from Tangaroa yesterday where they gave an indepth review of their Dickinson Diesel Furnace. Bottom line, the heat for the salon was great but the diesel soot was horrible. Made a complete mess

 

[sjisailor]

There is the old saying good, fast, cheap: pick two.

We have diesel forced air and it is relatively cheap (install/maintenance wise) and fast to heat up. Not as good as hydronic in other ways, but very simple. When/if it breaks, it will be easy to access. That assumes central air ducts in place where you want them.

 

[sjisailor]

I'll add that the diesel forced air keeps us very toasty in the PNW year round. It will heat the cabin from 40 to 65 degrees in an hour or two, depending on wind etc.

To keep staterooms warm it helps to close their doors.

 

[Mac2]

Watched a video from Tangaroa yesterday where they gave an indepth review of their Dickinson Diesel Furnace. Bottom line, the heat for the salon was great but the diesel soot was horrible. Made a complete mess

I saw that episode as well. I had the same stove on my previous boat. Put out great heat and I loved the fireplace look of the flames. Something was wrong with that setup. I never had soot on the interior of the boat. My only complaint was the fresh diesel smell left on my clothing after I left the boat.

 

[sjisailor]

I saw that episode as well. I had the same stove on my previous boat. Put out great heat and I loved the fireplace look of the flames. Something was wrong with that setup. I never had soot on the interior of the boat. My only complaint was the fresh diesel smell left on my clothing after I left the boat.

Agreed, we have never have soot inside or out from Webasto diesel heaters on two different boats. (Nor diesel smell on clothes for that matter. Or maybe I'm just used to it!)

 

[Taras]

Yes, I have a Webesto Diesel furnace on my current vessel and it leaves no diesel soot as the exhaust goes out the side of the vessel. I am happy with that unit. The video (Tangaroa) I was referring to was using a Dickinson diesel stove where the exhaust chimmey went up and terminated on the top deck of the boat . Not sure why he has so much soot from that set up but he was very frustrated and tried a million things according to the manufacturer to remedy the situation with no good result.

 

[mvweebles]

I had a Dickinson style heater (was actually Sigmarine). I had problems with back-puffing if there was a breeze. Back puffing sounds benign but it's far from it. The chamber is super heated and fuel continues to be fed into it and vaporized due to the heat. Except it can't ignite because the flame was extinguished. Very volatile and dangerous, an absolute stinky mess is the best case scenario

Builder said I needed to install a second flue pipe from the bottom so there would be two holes on the deck with two Charlie Nobles to balance the back pressure.

I liked the heater but wasn't willing to put a second 4" hole in my deck. So I just lived with it .... Sorta. No way would I leave it unattended. Sleeping with it wasn't entirely comfortable either.

Bottom line is that for me, those types of heaters are cute but not a practical and reliable heat source. Fine for occasional use.

Peter

 

[SteveK]

The Dickenson works too well heating with low flow passive burn which soots.
The webasto and others use fan aided burn to more efficiently burn less instead of smolder sitting diesel. IMO

 

[t/t CVN69]

Not exactly cost effective, but our solution was to move to Florida.

Peter

Some of the coldest nights I've spent on board were in Florida! November 2023, Englewood (S of Sarasota), reverse cycle ac quit reversing, 45F overnight. I used every blanket on board!

 

[magna 6882]

I have 2 espar heaters and they are fast to heat and hold the boat temps fine.