Boat heating wish list

[GILow]

Darn, I read up on the whole microplastics thing and yeah, polar fleece doesn’t come up well.

Back to sheep rustling for me.

[wingssail]

Originally Posted by GILow

Dockhead, you make a very good point...

It will be interesting to do the numbers. Here in Oz power has become VERY expensive indeed, and the markup charged by the marina varies.

Actually, you've made me realise I should do the numbers on this one...

Hang on... (grabs pen and envelope)....

OK, REALLY rough figures, Diesel has around 44MJ/kg, or about 36 MJ/litre, which in Australia currently costs about AU$1.50. So that's about 4.464 cents per MJ. No idea what the furnace efficiency is though. I am going to pull a WAG and say 50%, so call it 9 cents per MJ of usable heat.

Power in Australia varies, but 37 cents per kWh is about the current domestic rate where I live, and I have heard of 40 or even 50 cents on the meters at some marinas. Using a conservative 40 cents I get...

Electrical power, 1 MJ = 0.28 kWh = 0.28 x $0.40 = 11.2 cents per MJ (Assuming 100% efficiency, reasonable enough when it comes to electrical heating.)

So, even with the horrible efficiency assumption of the diesel, at least the running costs are comparable, with diesel slightly better than electricity, BEFORE factoring in maintenance. And that maintenance is a big question as you have correctly noted.

Once I am tied to a marina again for work I will do some careful experimentation to see just how the costs really stack up. I am lucky enough to have the kind of electronics skills and equipment to make some very accurate measurements.

But that's SUPPOSED to be years away, and I plan to spend the next few years a very, very long way from mains power. So short of a really long extension lead, diesel is going to be the way to go.

One big advantage to the diesel heater is that it exhausts the products of combustion out a stack, which hugely reduces the moisture inside the cabin. The electric just heats it up and makes the condensation worse.

Finally, you have to figure out how much heat you need. In the USA a 1500 watt heater is about all you can find and shore power systems are usually 30 amp, which is 3,300 watts. My boat, for example, requires 11,000BTU which is the max I can get out of a 30amp connection, using 2.5 heaters.

[dannc]

Back to insulation.

Dashew used an EPDM insulation,https://setsail.com/fpb-78-1-the-ins...ry/#more-32942. A guy who built his own steel boat used a similar product to prevent warm, moist air getting to the steel hull and then used batt insulation.

Kasten talks a bit about insulation, Metal Boats For Blue Water - Kasten Marine Design

Insulation

Many schemes are used to insulate metal boats. Insulation is mentioned here in the context of corrosion prevention mainly to point out that regardless of the type used, insulation is NOT to be considered an effective protection against corrosion. As with anywhere else on a metal boat, epoxy paint is the best barrier against corrosion.
Sprayed-on foam is not to be recommended. While popular, sprayed-on foam has many drawbacks that are often overlooked:

• Urethane foam is not a completely closed cell type of foam. With time, urethane foam will absorb odors which become difficult or impossible to get rid of. This is especially a problem when there are smokers aboard.
• Nearly all urethane foam will burn fiercely, and the fumes are extremely toxic. Blown in foam should therefore be of a fire retarding formulation, and should additionally be coated with a flame retarding intumescent paint.
• Sprayed-on foam makes a total mess, requiring extensive clean-up. The clean-up process actually further compromises the foam due to breaking the foam's surface skin.
• Sprayed-on foam requires that an intumescent paint be applied, both for the sake of fire suppression, and in order to re-introduce the seal broken by the clean-up of the spray job.

A much better insulation system is to use a Mastic type of condensation / vapor barrier such as MASCOAT, which adheres well to painted steel surfaces, as well as unpainted aluminum surfaces. It creates a barrier to water penetration, and an effective condensation prevention system. Applied to recommended thicknesses of around 60 mils, it is effective as insulation. Further, it is quite good at sound deadening, is fire proof, and will not absorb odors. Mascoat DTM is used for insulation, and Mascoat MSC for sound attenuation, very effective on engine room surfaces and above the propeller. Both are effective whether on a steel or an aluminum boat.

These mastic coatings can be painted if desired. In more severe climates the mastic coatings can be augmented by using a good quality flexible closed cell cut-sheet foam to fit between the framing. The best choices among these flexible cut-sheet foams are Ensolite and Neoprene. There are several different varieties of each. The choice of insulation foam should be made on the basis of it being fireproof, mildew proof, easily glued, easy to work with, resilient, and if exposed, friendly to look at. Ensolite satisfies all these criteria. Ensolite is better than Neoprene in most respects, but is slightly more expensive. One brand offering good quality flexible foam solutions for boats is ARMAFLEX.

Styrofoam or any other styrene type of foam should be strictly avoided. Go get a piece at your local lumber yard and throw it onto a camp fire.... You will be immediately convinced. The same applies to any of the typical rigid or sprayed-on urethane foams. They are an extreme fire hazard and cannot be recommended.

Later,
Dan

[Dockhead]

Originally Posted by GILow

Dockhead, you make a very good point...

It will be interesting to do the numbers. Here in Oz power has become VERY expensive indeed, and the markup charged by the marina varies.

Actually, you've made me realise I should do the numbers on this one...

Hang on... (grabs pen and envelope)....

OK, REALLY rough figures, Diesel has around 44MJ/kg, or about 36 MJ/litre, which in Australia currently costs about AU$1.50. So that's about 4.464 cents per MJ. No idea what the furnace efficiency is though. I am going to pull a WAG and say 50%, so call it 9 cents per MJ of usable heat.

Power in Australia varies, but 37 cents per kWh is about the current domestic rate where I live, and I have heard of 40 or even 50 cents on the meters at some marinas. Using a conservative 40 cents I get...

Electrical power, 1 MJ = 0.28 kWh = 0.28 x $0.40 = 11.2 cents per MJ (Assuming 100% efficiency, reasonable enough when it comes to electrical heating.)

So, even with the horrible efficiency assumption of the diesel, at least the running costs are comparable, with diesel slightly better than electricity, BEFORE factoring in maintenance. And that maintenance is a big question as you have correctly noted.

Once I am tied to a marina again for work I will do some careful experimentation to see just how the costs really stack up. I am lucky enough to have the kind of electronics skills and equipment to make some very accurate measurements.

But that's SUPPOSED to be years away, and I plan to spend the next few years a very, very long way from mains power. So short of a really long extension lead, diesel is going to be the way to go.

I think you'll find that the maintenance really adds up.


I was spending £500 to £1000 every other year on my Hydronic 10, and that's using it somewhat sparingly. I don't know whether the new M12 will be as maintenance intensive or not.


You can get this cost down by learning how to decarbonize yourself and do things like glow plugs etc. The new ones may be easier to deal with because they have on-board diagnostics.



By the way, you can reduce maintenance a lot if you set up an alternative fuel tank, keep kerosene/paraffin in it, and run on that for a couple of hours, every 50 hours or so. This keeps the carbon down.


But I would still gladly spend money on electrical power, just to entirely avoid the issue as much as possible. YMMV!


BTW, $0.37 per kW/h is INSANE!! Off the chart! We pay about £0.17 in the UK and about €0.13 in Finland. So to run a 2kW of heat for 12 hours a day costs about £4, which would be £120/mo if you did it for a whole month at a time. But the power is not metered at my berth in Cowes -- included in the berthing fees.

[Dockhead]

Originally Posted by wingssail

One big advantage to the diesel heater is that it exhausts the products of combustion out a stack, which hugely reduces the moisture inside the cabin. The electric just heats it up and makes the condensation worse.. .

Well, no. Electric heat does not make condensation worse. The only advantage of a diesel heater in dealing with moisture is that it forces a certain amount of air circulation -- sucks in make-up air. Otherwise the effect is exactly the same, and this will be an imperceptible difference in a reasonably ventilated boat. Neither type adds moisture to the air like unvented propane heaters.


Because the same quantity of water vapor in a given volume of air is less humidity in warmer air (humidity is measured as a % of saturation, and warm air holds more), the air feels dry in a warm boat in cold weather unless you've got some serious ventilation problem causing water vapor from people's breath to accumulate, or from propane cooking.

[cj88]

Originally Posted by dannc

Back to insulation.

Dashew used an EPDM insulation,https://setsail.com/fpb-78-1-the-ins...ry/#more-32942. A guy who built his own steel boat used a similar product to prevent warm, moist air getting to the steel hull and then used batt insulation.

Kasten talks a bit about insulation, Metal Boats For Blue Water - Kasten Marine Design

Later,
Dan

The Mascoat is really acting as a thermal break rather than providing effective insulation. Another product that can also do this is sprayed cork. The downside to these products is that they should realy be applied during construction for ease of access to provide effective coverage. I suggested he look at Armacell which makes Armaflex but it seems he has a problem with not enough space for installing insulation.

[GILow]

Originally Posted by Dockhead

I think you'll find that the maintenance really adds up.


I was spending £500 to £1000 every other year on my Hydronic 10, and that's using it somewhat sparingly. I don't know whether the new M12 will be as maintenance intensive or not.


You can get this cost down by learning how to decarbonize yourself and do things like glow plugs etc. The new ones may be easier to deal with because they have on-board diagnostics.



By the way, you can reduce maintenance a lot if you set up an alternative fuel tank, keep kerosene/paraffin in it, and run on that for a couple of hours, every 50 hours or so. This keeps the carbon down.


But I would still gladly spend money on electrical power, just to entirely avoid the issue as much as possible. YMMV!


BTW, $0.37 per kW/h is INSANE!! Off the chart! We pay about £0.17 in the UK and about €0.13 in Finland. So to run a 2kW of heat for 12 hours a day costs about £4, which would be £120/mo if you did it for a whole month at a time. But the power is not metered at my berth in Cowes -- included in the berthing fees.

Maintenance is going to be interesting. ColdEh has had a good run with the Webasto using the approach of long run times to avoid coking. Hopefully I will get the same outcome.

And yes, power here is expensive, however when you factor in exchange rates the difference is not as great as it first appears to your costs. Of course one of Australia’s major cost factors is transmission distance and our low population density which makes things like power and internet very costly.

[Dockhead]

Originally Posted by GILow

Maintenance is going to be interesting. ColdEh has had a good run with the Webasto using the approach of long run times to avoid coking. Hopefully I will get the same outcome.
. . .

Good luck, and let us know how you get on.


If heat is mission critical, then carrying a complete spare heater is probably prudent. Then you can swap it out and get the heat right back on, then fiddle with the bum one on your bench at your leisure.


One good thing about hydronic heaters is that if you manage to find an accessible place to mount them, they are very straightforward to pull out or reinstall. I guess it takes me less than half an hour to pull mine off, or reinstall it. All the electrics in a single plug, one small fuel line with one clamp, two water lines (install valves so you don't have a flood every time you disconnect these), and one exhaust pipe with one clamp, four bolts. Et voila.

[GILow]

Originally Posted by Dockhead

Good luck, and let us know how you get on.


If heat is mission critical, then carrying a complete spare heater is probably prudent. Then you can swap it out and get the heat right back on, then fiddle with the bum one on your bench at your leisure.


One good thing about hydronic heaters is that if you manage to find an accessible place to mount them, they are very straightforward to pull out or reinstall. I guess it takes me less than half an hour to pull mine off, or reinstall it. All the electrics in a single plug, one small fuel line with one clamp, two water lines (install valves so you don't have a flood every time you disconnect these), and one exhaust pipe with one clamp, four bolts. Et voila.

Once I move to Tasmania I suspect it will be mission critical, at least in winter, but if I am at the marina then I guess I’ll just use the mains power and ignore the cost if the furnace goes phht.

My planned cruising grounds are somewhat warmer than your usual haunts. 🤣

But I will heed your cautions and ensure the furnace is readily accessible.

[bcboomer]

I installed 3/4" pex and found it relatively easy to bend if it was warm.
The Sea Tech quick connect fittings are really easy to use.
Be sure to use the pex designed for hydronic heating since it has an oxygen barrier.
I did mine in "ladder" form but, if I did it again I'd do series.

[GILow]

Originally Posted by bcboomer

I installed 3/4" pex and found it relatively easy to bend if it was warm.

The Sea Tech quick connect fittings are really easy to use.

Be sure to use the pex designed for hydronic heating since it has an oxygen barrier.

I did mine in "ladder" form but, if I did it again I'd do series.

Interesting, what was it about parallel (or ladder as you so nicely put it) that makes you think you’d go series next time?

[bcboomer]

Initially I had trouble getting all branches to flow.
Plus there was more tubing and more fittings, probably an unnecessary extra expense and a heck of a lot of extra work.
Our boat has an internal grid that doesn't make it particularly easy to run the tubing.
The result is really nice heat and no mold in the lockers.
Our system heats the hot water tank, Radex heater in the salon, in-floor heat under the table, and a towel bar in the head. The main supply line runs through the storage lockers on the port side and the return lines go across to the starboard side and return through the lockers on that side. One loop goes around the perimeter of the v-berth. The v-berth is storage, we sleep in the aft cabin. All the lines are insulated except where we want heat. There is an intercooler so we can use engine heat.
Regarding heater hose instead of pex, I think SailorChic posted the details of why it is a bad idea.

[Pete7]

Originally Posted by GILow

I DARE you to wear one.

From that link:

"Russian males are in the forefront when it comes to knowing how to extend their life expectancy."

Who writes this bollicks

[Uncle Bob]

Originally Posted by Pete7

From that link:

"Russian males are in the forefront when it comes to knowing how to extend their life expectancy."

Who writes this bollicks

Russian males of course!!

[alaskanviking]

I always had a suspicion that you could tuck a solar waterheater of some type on top of a bimini or davits. ColdEh's design would be good to store that energy. not sure that idea is worth the squeze, but it tickles my mind and i may play around one day.

has anyone seen the hurricane heaters? they are hydronic systems that combine the furnace and tank. canadian adesign and looks like it ould work well. they have one that is a combo water heater and hydronic heater. was thinking of getting one but theyre expensive and i cant find anyone with experience with one.