General advice for cabin heat in northern lattitudes

[Dockhead]

Originally Posted by conachair

. ..

From memory the procedures would have worked had they been adhered to.

The problem was a non gas tight gas locker. I think they followed their procedures very well, even pumping out the bilges every day with a manual pump. Whoever was maintaining the boat -- very very well maintained by the Royal Navy, no less -- simply missed a defect in the gas sealing of the locker. If it could happen to the Royal Navy, it could certainly happen to any of us.

The Lord Trenchard is a great lesson on the inherent risks of LPG on board. Many of us like to think that "it can't happen to me, because I'm careful." Certainly, being careful helps a lot to reduce the risks, but the risks are still quite large.

People have different attitudes about it, but I just don't like it, personally, and I am looking forward to having a gas-free boat as soon as possible.

I'm actually largely gas-free now. As long as I don't have a lot of people on board cooking big meals, I just leave the gas shut off at the bottle, and cook on an induction hot plate which I find to be absolutely adequate for one person (occasionally two). Supplying the necessary electrical power is absolutely no problem, even at anchor. I haven't had the gas on since September.

And in my opinion that's the only condition in which an LPG system is really, really safe -- gas shut off at the bottle and left like that.

[sailor1924]

Originally Posted by warrior 90

A coil taking heat from the drip pot stove and running hydronic radiators !
That is an interesting concept to me)) Mmm Yes and heat under the cabin sole. That is the best. That is the concept of the radiant floor. If I remember right from the early days it only takes about 2-3ºC temperature differential at the human height of the eyes to feel comfortable. This to say.... the floor has to be only 2-3ºC warmer then at let´s say 180 cm height of the eyes. Now the big advantage of a radiant floor is the low temperatures it requieres. Of course lower temperatures also requiere a lot less fuel. Let´s say an ambient temperature of 25ºC is comfortable. Then the floor needs to be 27-28ºC. However, if the temperature at height of the eyes is 30ºC and Your feet are cold then You are still not comfortable.

In my old boat when I first installed the hydronic loop the air temp at head height was about 16C cold but tolerable since my feet stayed warm. I had installed the diesel heater in a ventilated locker remote from the main living area. I eventually added an enclosure (12" diameter) around the the exhaust flue made from a high temperature fiberglass pipe insulation. I made two 4" diameter ducts into the vertical enclosure at bottom and top of the exhaust stack. I installed a muffin fan on the outlet, which was ducted into the main salon. This brought the headheight temp to 20C a very comfortable living space. My big mistake was installing the muffin at the outlet, it melted.

You mentioned......
with wide distribution and even heat under the sole, so no cold feet. It was also pretty frugal electrically using a single small circulating pump that could be shut down after establishing a convective flow.

I believe You experienced the concept of a radiant floor/cabin sole. Well that takes us to the next thought. What max temperature do we need for such a concept. Speculating I would say a max of 35ºC with a decent flow rate of the water or whatever medium is used for heat transfer, should do the trick. I think at least it is a lot lower then any other heater required.

My intention was to create a quasi radiant floor, so I ran the hose without insulation under the sole and used fin tube radiators under the sole in the remote areas where I wanted to deliver more heat. The first problem I faced when setting up this "hybrid" drip pot/hydronic system was boiling the coolant and preventing steam blow outs. Once I was able to add air bleeds to completely evacuate air from the system, add an expansion/header tank, and, the circulating pump, the system the convective flow was more like 90C at the outlet and 75C at the return. I had made a 1/2" 9 turn copper coil in the combustion coil and in retrospect I'm pretty sure it was a bit of overkill, i.e. it could have had fewer turns. Also I never had the system really efficiently balanced for the most effective heat transfer. It certainly could have delivered more heat from the coolant loop, but I had a tankless water heater (calorifier) and didn't have enough incentive to tweak it further.

Of course the next problem is incorporating the heat under or in the cabin sole which might not be convenient in some locations. How ever, distributing the heat eaven under the cabin sole and directing it to certain areas might not be such a challenge. That would also mean.... the lower the heat source is in the boat the more efficient it will be to distribute.

I found that as designed above; once there was a flow, though it would be useful, and ease some installation problems, there could be ups and downs in the system, without an absolute need to have the heater located at the lowest point.

Another thought that comes to my mind is... the engine with it´s coolant system is the biggest storage of thermal mass on board and many times in a convenient location for such thoughts. What if we keep the engine... let´s say at 30-35ºC and use this water for under the cabin sole heating. Using this thermal mass would be a very stable system and maybe we get away with some 10-15 minutes of heating the water every hour. Now the heat source for the engine could be anywhere on the boat close to the coolant hose. The only energy required would be a small pump that compensates for temperature fluctuations of the engine block.


I believe in a catamaran with the engines under the bed that could open up new dimensions. The saloon where the highest temperature is required would be the most benefited area.
Hahaha yeah, that is a lot of speculation. I admit it.
But on the other side... today the concept of a radiant floor is the most efficient way of heating a space. I see all the other forms of heating a boat and there are lot´s of trade offs. Maybe this is easier then it looks at the first sight. What about sandwiching the radiant tubing in the cabin sole ? I think in small and close loop systems with anti freeze coolant they use tubes of inside Dia 1/4". The rest is a question of sufficient surface area in the different locations of the boat.

Well sorry, don´t wanna Hijack the thread

I can see a couple of issues in using the engine as a thermal mass, perhaps not insurmountable but needing some attention: the fresh air for engine combustion may need to be direct rather then simply an air supply from the outside to the engine compartment, alternatively the engine compartment may need to have a damper system installed to stop outside air entry.
Also the insulation that is pretty much universally installed around the enge would interfere with using the engine as a direct passive thermal mass so unless you install air ducts from the engine compartment into the living area you don't get benefit from the thermal mass except through the hydronic coolant system which seems like transfering energy to a remote spot and then trying to harvest it. It only works if there's another energy source added into the equation like using electricity to pump water to a higher elevation so that you can generate electricity.
Additionally, I think, you are thinking of the way the Espar/Webastco/Planar hydronic furnaces work, a drip pot does not cycle and there won't be a benefit from or economy from it cycling, that said, you might be able to run a lower fuel flow, but BTUs are BTUs and when it's cold insulation and air leaks are really what cost you.

I currently have an engine coolant loop that runs hot coolant through the water heater (calorifier) and separately through a bus heater, the bus heater is a fancoil that functions like a radiator in an auto engine and scavenges engine heat. It will provide plenty of heat when the engine is running under load. The water heater is installed with a small circulating pump on a bypass from the water jacket that responds to the engine temperature and runs coolant through the water heater when the engine is hot enough. I'm not sure what would be needed to add a separate hydronic loop into that system. I'm sure it can be done as hydronic heaters are often used to to preheat engines in severe climates. I think that the thermal mass would probably only be useful if hydronic loop flow was started after the engine was at operating temperature. In my mind thermal mass is only useful if I've got excess energy available: the Sun, a running engine that needs cooling, wind, temperature differential between air and water, gravity so I'm unclear what would be accomplished by heating the engine with a hydronic system unless you're in the arctic.
The idea of a radiant floor for a catamaran seem a natural as a shallow structure like the main salon deck could lend itself to its installation.

[conachair]

Originally Posted by Dockhead

The problem was a non gas tight gas locker.

Bit more than that it seems -

Anyway, it's an old forum favourite for discussion , apologies for feeding the flames of thread drift. Filling the outboard with petrol looks like it can be just as dangerous to put it some perspective.

Causal factors
The immediate causes of the accident were:
the failure to properly tighten the connection on the aft gas bottle in the ready-use
locker when the bottles were changed between 14 and 20 June 1999;
the non gas-tightness of the ready-use locker allowing LPG to migrate into the hull
of the vessel;
24
the failure of the gas alarm system to identify the presence of gas in the hold space.
The root cause of this accident is considered to have been the divided responsibility for
the management of the vessel between JSASTC and other parts of the MoD.
Underlying causes were:
The procedures in place for testing the gas alarm system did not ensure that the
sensors were tested:
The vessel management system did not identify that the vessel’s stability data had
not been submitted to MSA for approval;
The lack of stability approval by MSA resulted in the vessel not commencing the
annual inspection programme required by the Code;
The vessel management system did not identify that the documented inspection and
testing of the gas installation during a refit in 1996 did not demonstrate compliance
with the Code, British Standard or refit specification;
The vessel management system did not identify a lack of progress on stability
submission or non-compliance with refit specification;
The lack of consistency in labelling gas sensors and the spaces they served
generated doubt in the minds of skippers and crews;
The bilge ventilation procedures, using bilge pumps, were not suitable for
removing large volumes of gas.

[Dockhead]

Originally Posted by conachair

Bit more than that it seems -

Anyway, it's an old forum favourite for discussion , apologies for feeding the flames of thread drift. Filling the outboard with petrol looks like it can be just as dangerous to put it some perspective.

Fine, but that just confirms that the main cause was lack of gas-tightness of the gas locker, sine qua non . . .

And yes, no argument about petrol. The other really very dangerous fuel.

I have a good place to store petrol on my boat -- behind the transom platform, well separated from the main hull volume. The next boat will have a good dedicated locker for petrol cans.

[Mike OReilly]

Originally Posted by Dockhead

This statement may be true on land, but it is definitely not true with regard to boats. Propane/butane explosions are one of the leading causes of death of sailors in the UK, and I suppose the same must be true everywhere. Someone is killed here every year, sometimes several people. Number of people killed from fires started with diesel fuel systems? Or explosions of diesel fuel? Never heard of such a case.

DH, this may be the case in the UK. I don’t have easy access to the stats. But we can all look at the USCG stats on this question.

Over the 12 years of American national data they show a total of 55,100 “accidents” including 8,115 deaths. Of these there were 621 accidents resulting in 10 deaths caused by "Ignition of Spilled Fuel or Vapor.”

Looking at the Accident Type category, the dataset ranks "Fire/explosion (non-fuel)” as the 14th most common cause of accidents — 14 out of 29.

I’m not trying to diminish the danger of propane on a boat, but it is no where near the leading cause of death — at least not in the USA (nor in Canada).

[Pizzazz]

I have been happy using my Original alcohol stove as a vented heater. Following the advice of someone on the forum, I put a glass cylinder on top of the stove, then a stainless steel funnel and then a 1" flue pipe. It is not sealed bit it vents quite well. I believe this setup has many advantages (does not take space, totally silent, safe, easy to light, adjust and extinguish, has a nice ambiance). The only down side is cost. It is about 10x more expensive to heat with alcohol vs. diesel.

[Juho]

Originally Posted by Mike OReilly

DH, this may be the case in the UK. I don’t have easy access to the stats. But we can all look at the USCG stats on this question.

Over the 12 years of American national data they show a total of 55,100 “accidents” including 8,115 deaths. Of these there were 621 accidents resulting in 10 deaths caused by "Ignition of Spilled Fuel or Vapor.”

Looking at the Accident Type category, the dataset ranks "Fire/explosion (non-fuel)” as the 14th most common cause of accidents — 14 out of 29.

I’m not trying to diminish the danger of propane on a boat, but it is no where near the leading cause of death — at least not in the USA (nor in Canada).

In Finland sailing clubs typically require boats to be inspected every year. Propane systems are included in the requirements, but I'm not sure how strict each sailing club is with the yearly pressure tests. But in any case, this approach probably reduces the number of accidents.

[fourlyons]

We used to heat with a Dickinson diesel drip pot heater. It worked quite well, but my wife hates the smell of diesel, so I built a small wood stove for heat. We love it. We don't get soot or ash on the deck, probably because the stove is super efficient. I studied what design elements went into clean burning and efficient wood stoves and tried to replicate them in a stove sized for our boat. We have an insulated fire box, adjustable primary air, adjustable secondary air, an exhaust baffle and a relatively long stack. This was 10 years ago, when a small stove like this was not available. The Cubic Mini Stove from Canada incorporates all these now, there may be others. The Dickinson solid fuel stove is ok, but has none of these, it's barely better than a fireplace.
We don't find it difficult to carry the wood aboard for long trips.We have gone for two months in Nova Scotia in the fall and early winter when heating in the evenings only, after a day of sailing. The fuel fit in about 4 cubic feet. We mostly burn Biobricks, basically compressed saw dust bricks so they are compact to store, and have a stable burn rate. One an hour usually. We cannot bank a fire for the night however (the firebox is too small), which works for us as we like a cold room for sleep. We can sail with the fire going if we are not beating, too big a chance of back drafting then. For living aboard over the winter full time, at anchor, I would prefer the diesel drip pot heater. For wintering over at the slip, I would be looking at a heat pump.
We just watched the fireworks anchored out in Baltimore Harbor, it was 12 degrees Fahrenheit out, but we were quite comfortable below.
However, I think the first objective should be a draft free boat and especially a well insulated boat, especially the deck. It keeps the boat warmer in the winter of course, but also much cooler in the summer. We have 1 1/2" of closed cell foam in our deck, 1/2" in the topsides.

Mike

[Jammer]

Originally Posted by conachair

apologies for feeding the flames of thread drift.

No prob, thread seems to have run its course for the most part.

Filling the outboard with petrol looks like it can be just as dangerous to put it some perspective.

Or the inboard.

One of the local marinas on the Mississippi had a refuelling fire a few years ago that resulted when someone was loading gasoline into the tanks in their boat from a 15 gallon gasoline caddy on the dock. I'm not sure exactly what went wrong. The 15 gallon wheeled caddies are commonly used by motorboaters here to purchase gasoline from automotive gas stations and avoid the high prices of fuel at the marina. They are the largest size portable container permitted under state laws.

Anyway, several boats were destroyed, more were damaged, and it took a year to get the marina put back to rights.

Originally Posted by Dockhead

And yes, no argument about petrol. The other really very dangerous fuel.

I have a good place to store petrol on my boat -- behind the transom platform, well separated from the main hull volume. The next boat will have a good dedicated locker for petrol cans.

It's pouring it from one container to another that will get you.

Originally Posted by Dockhead

Fine, but that just confirms that the main cause was lack of gas-tightness of the gas locker, sine qua non . . .

Originally Posted by Mike OReilly

DH, this may be the case in the UK. I don’t have easy access to the stats.

The U.S. laws and regulations on propane are more strict. The valves now in use here, while compatible with the British POL fittings, are fail safe and will not allow gas to flow unless they are tightened enough that they won't leak. We now also have float valves (OPDs) on every portable propane container, unlike Britain where they are only used on cylinders filled by untrained operators. ABYC rules (USA) don't allow fittings on propane lines inside the cabin, while BSS rules do. USA regulator-to-valve fittings are now typically equipped with an excess flow check valve (that closes in the event of a substantial leak) and a thermal cutoff (that closes in the event of fire).

I don't think propane is practical for a heat source, in most cases, because of the difficulty sourcing it and storing it onboard. I believe it can be used safely. Diesel systems pose their own fire hazards because of higher stack temperatures and the cumulative effect that small leaks can have when wood and textile components of the boat become saturated with fuel over time.

[Mike OReilly]

Originally Posted by fourlyons

We used to heat with a Dickinson diesel drip pot heater. It worked quite well, but my wife hates the smell of diesel, so I built a small wood stove for heat. We love it. We don't get soot or ash on the deck, probably because the stove is super efficient. I studied what design elements went into clean burning and efficient wood stoves and tried to replicate them in a stove sized for our boat. We have an insulated fire box, adjustable primary air, adjustable secondary air, an exhaust baffle and a relatively long stack. This was 10 years ago, when a small stove like this was not available. The Cubic Mini Stove from Canada incorporates all these now, there may be others. The Dickinson solid fuel stove is ok, but has none of these, it's barely better than a fireplace.

Hi Mike, I’d love to install a wood stove, and the Cubic Cub looks great to me. I understand double-combustion wood stoves well, having heated with one on land for 10 years while living in a shack on Lake Superior.

However, I just don’t feel comfortable about with the volume of wood/bricks required to make it functional. You mention using 4 cubic feet of Biobricks for a whole season in Nova Scotia? That sounds incredible. I want to believe it is so…

Here’s a clip from a Youtuber review. His burn rate seems far greater than yours. Can you offer any thoughts?

https://youtu.be/pK7wWt7Fa_I?t=2m47s

P.S. I’ll be cruising Newfoundland the next few years, so heating is an issue.

[fourlyons]

Originally Posted by Mike OReilly

Hi Mike, I’d love to install a wood stove, and the Cubic Cub looks great to me. I understand double-combustion wood stoves well, having heated with one on land for 10 years while living in a shack on Lake Superior.

However, I just don’t feel comfortable about with the volume of wood/bricks required to make it functional. You mention using 4 cubic feet of Biobricks for a whole season in Nova Scotia? That sounds incredible. I want to believe it is so…

Here’s a clip from a Youtuber review. His burn rate seems far greater than yours. Can you offer any thoughts?

https://youtu.be/pK7wWt7Fa_I?t=2m47s

P.S. I’ll be cruising Newfoundland the next few years, so heating is an issue.

Hi Mike,
Your question sent me back to the log. You are quite right, I understated the amount of wood we used over 60 days. We could store 120 biobricks in 4 cubic feet. We used 3 or 4 in an evening and collected or bought kindling to start the fire, so of course that must be included. We also cut up one small hardwood pallet on that trip. That produced about 1 1/2 cubic feet of fuel. In a way the storage issue wasn't really a problem because it was easy to find or buy fuel everywhere we went, people do of course heat with wood in many places where you might want heat. Not to mention, people were always trying to take us shopping in their car, when they didn't just insist we take their car and drive ourselves.

You also should note that we did not have a fire every evening on that 60 day trip, some nights we baked, which warmed the boat nicely. Remember also, we have 1 1/2" of closed cell foam for insulation, that makes a huge difference. By the end of the trip we were being snowed on but still quite comfortable. However, as I said in the post, wood heat would not be my first choice as a continuous, all day heat source through a real winter.

As a side note, this last weekend I helped my daughter install the smaller Cubic Mini stove, the Cub, on her Freedom 40. It is very nicely made, but especially so at it's price. And it's Canadian made . We wavn't yet fired it up though.

I was not able to view the video link so I can't speak to that.

Enjoy your trip, I love the Canadian Maritimes, have been back a few times and will return soon,
Take care,

[Typhoon]

This is another thread on this subject.

http://www.cruisersforum.com/forums/...er-149641.html

Now in the fourth winter with our boat in the water . Just finished replacing the complete exhaust system. I used corrugated stainless 1.5 in pipping designed for this application. Then wrapped with a heat wrapping . I knew this was not the best solution , but I needed to get it in quickly as the cold was on the way .

I installed an all copper exhaust , this should last a very long time.

Be very careful of installing any exhaust from any furnace , they get very hot and will burn your boat down . 700F will ignite wood .

Regards John

[dannc]

I happened to see this yesterday on Panbo, https://www.panbo.com/archives/2018/...e_service.html, and I thought it was quite interesting.

Later,
Dan

[rbk]

Just a note for solid fuel burning; While out cruising and planning on gathering most if not all your solid fuel it would be good to remember that in cooler temps in the PNW for example tends to accumulate large quantities of rain and can last for months; Sourcing solid fuel that does not require a week long drying period before burning can become quite difficult if not impossible.

[bbalan]

Hi All,
I may be repeating what has already been said, but after sailing from Japan through the Aleutians and down to CA this year, I would never sail high-lats again without a drip diesel heater. We have a Webasto 2010 and it is far too power hungry to use at sea and on the hook in those temps. Every boat we met that seriously sail high-lats all the time have drip diesel.

Their boats did smell like diesel though...
Cheers,
Bruce
s/v Migration
migrations.brucebalan.com