Really small heater for 18ft boat

Was working on the Centaur, upgrading my security system with a special offer remote control motion sensor from B&Q, was ice,y outside and I needed some immediate heat.
I lit the grill and placed a couple of foil grill sheet across the cooker top opening were I often place the kettle to heat up while I,m cooking rashers etc.
10 minutes to go from frosty to pleasant. Had the first washboard in and hatch closed. Cabin top condensation dried right up and the CO alarm stayed silent.
My normal sleepover routine is to have something hot before turning in so the cabin gets a heat boost before the tea lights take over. On cold nights I put the last washboard in just before lights out.
 
chrisbitz said:
When I'm sleeping in my Micro Challenger, it can get a bit chilly overnight...

Something like an eberspacher or a charcoal burner with a chimney are a bit overkill. Is there anything more practical that might help?

I've looked at a 300w 12v heater, but that works out at about 25A, so would flatten my battery in 4 hours!

any other ideas?

thanks!
Click to expand...

I've read all seven pages of responses, and they're all wrong..... if it's getting too chilly, just stop sleeping on the boat - problem solved...... :D
 
Fantasie 19 said:
....if it's getting too chilly, just stop sleeping on the boat....
Click to expand...

I can assure you that, if it gets too chilly, all sleep on the boat just stops....

....and I shiver, wide-awake, until well after dawn. :eek:


Does anyone remember that instruction on the treatment of hypothermia, from the days before PC?....... "Put into a sleeping bag with a fit young companion"

I seem to remember I had no problems with hypothermia when I was still able to wriggle into a sleeping bag with a 'fit young companion'. ;)
 
Night time isn't a problem if you are wrapped up in a good sleeping bag. It's in the evening and morning you need something to take the edge off but a bit of dinner and breakfast sorts that out along with something producing 2KW (block of any compartments you don't need heating if you have a big boat!). Hopefully during the day you will be largely active so no need to keep heating the cabin.

It's the same philosophy as caravanning or even tenting through the winter. Biggest problem is thawing out any ice or drying condensation from your bedding as I found out last weekend. Luckily it was a sunny day but I take my hat off to people that stay on board in the cold for any length of time with proper heating :eek:
 
Fantasie 19 said:
I've read all seven pages of responses, and they're all wrong..... if it's getting too chilly, just stop sleeping on the boat - problem solved...... :D
Click to expand...

Problem solved?

Isn't that "problem circumnavigated"? Might as well advise selling the boat and buying an armchair, blanket & bar-heater.

Even in what used to be known as 'summer' in England, there are so many spirit-sapping days and nights when the drying effect of a decent heater (and the freedom it grants, not to wear four layers) is enormously welcome. Why would you say just don't stay aboard?

Sounds like a flippant SWMBO-solution.
 
dancrane said:
Even in what used to be known as 'summer' in England, there are so many spirit-sapping days and nights when the drying effect of a decent heater (and the freedom it grants, not to wear four layers) is enormously welcome.
Click to expand...

And not only England. In Greece in April we ran the Eberspacher for several evenings, first time it has been turned on for five years at least.
 
Been following this thread with interest.

I have my Ebay finger poised above the 'Buy it now' button on an Origo Heat Pal.:eek:

I understand the debate about condensation and the bit about being able to put out an alcohol fire with water.

But I have a nagging doubt about safety (not when filling , I would do this outside) if the heater is knocked over etc.
My boat is small and the floor area also correspondingly small and it's going to happen one day.

Do any forumites have any experience of their practical safety ?
 
I worry about the ad nauseum bit, but here's my theoretical idea...

Can you build a storage heater of some sort? So you put a heat brick or something on your cooker, heat it up to 10,000 degrees or something, with tons of ventilation, and then turn off the cooker, stop all ventilation (draughts) and allow the heat brick to give out all its heat over a period of time, without dying of CO poisoning?

Does anyone know of a heat brick or something like this?

How long would it stay hot for?

Is this genius :-) idea fatally flawed in some way?
 
heat an achor

chrisbitz said:
I worry about the ad nauseum bit, but here's my theoretical idea...

Can you build a storage heater of some sort? So you put a heat brick or something on your cooker, heat it up to 10,000 degrees or something, with tons of ventilation, and then turn off the cooker, stop all ventilation (draughts) and allow the heat brick to give out all its heat over a period of time, without dying of CO poisoning?

Does anyone know of a heat brick or something like this?

How long would it stay hot for?

Is this genius :-) idea fatally flawed in some way?
Click to expand...

I think heating an anchor on the gas ring would work

D
 
At a restaurant in Shanklin where we ate one night this August, steaks were served raw, but on a slab of volcanic rock, heated to some hellish temperature, so that as I sat there slicing off mouthfuls, I was able to cook each morsel, medium rare, par excellence...

...but 30 minutes after I finished all sixteen ounces, the chunk of rock was still alarmingly hot...a splash of wine spilt on it made a sound like a steam engine opening its valves.

Not that I'd want one sizzling its way through the floor of any boat I was sleeping aboard. A colourful idea, Chrisbitz, but all it aims to do is transfer residual heat caused by vented combustion, inside a sealed zone.

Surely that's better done by heating air or water outside, and ducting it indoors? I haven't done it myself yet, but I cannot believe it's too complicated for the practical contributors to this thread. Must find a free afternoon, to revolutionise winter boating...:rolleyes:
 
CAPTAIN FANTASTIC said:
Catalytic, which means no production of CO2, this is why is suitable for indoors; this is in theory, however, I would never have an open flame heater in a small area like a yacht cabin; it is always advisable to have a small air opening. People here talk about condensation, yes, in theory, however, in practice i have not noticed any; breathing causes condensation anyway. This is our only form of heating in the yacht and we love it, the cabin warms up within 2 minutes even with the hatch opened a couple of inches. This particular heater has an oxygen depletion valve and anti tilt valve. The only other viable alternative is to step up to a heating system with chimney.
Click to expand...

Ive discussed this with Captain F elsewhere as we both have the same sort of portable gas type heater and I too have to say that I am a real fan. Mine gives off approx 1.5 KW and and it heats the cabin in minutes. I understand the chemistry but must report that I too have never had any problem with excess condensation - if any at alll. I always keep the cabin hatch open about an inch, and have UFO type vents on the cabin ceiling which I ensure are open. Mine has an oxygen depletion sensor and flame out sensor which cuts the gas in the unlikely event the flame fails. I also have a carbon monoxide alarm (two in fact because Im paranoid!) but have to report it has never alarmed.

The whole condensation thing really intrigues me. In theory I understand that whatever fuel you use be it paraffin, methanol or gas, the amount of H2O produced in condensation should roughly equate to the amount of fuel consumed. IE a 0.250kg butane cartridge should produce approx 0.250 kg of H@O in the form of condensation. this however is not my experience, in fact I notice far less condensation inside my heated cabin than on a cold night produced by breath alone.

To test this thoroughly however I last night decided to run an experiment. and placed my little heater inside a sealed internal bathroom in the house with tiled walls. There are no external windows and the internal volume is probably about the same as the cabin on my boat. There is only one small ventilator, which probably produces about the same amount of ventilation as the slightly open hatch and vents I employ onboard. I ran the test for two hours (and no I didnt stay in the bathroom during the process, as both my CO alarms were still onboard..) End result? shock horror! I was expecting to enter and find he room dripping wet with condensation, and having read some of the comments on this thread and elsewhere I wouldn't have been surprised at all to find it literally pouring off the walls? But no - the bathroom was warm and dry, the walls warm and dry and my little heater happily chugging away, without even a single drip of condensation anywhere found! Could the chemists/physicists among us please explain?
 
Lets make one thing clear. If you turn fuel in to heat, no matter how you do that, THERE WILL BE CO2 or (really dangerous) CO with maybe two exeptions.

You can burn wood without producing co or co2, that leaves pure carbon. google "rocket stove"
And if you burn hydrogen, then there will be only water (vapour) and heat as a result
 
pongoglo said:
Ive discussed this with Captain F elsewhere as we both have the same sort of portable gas type heater and I too have to say that I am a real fan. Mine gives off approx 1.5 KW and and it heats the cabin in minutes. I understand the chemistry but must report that I too have never had any problem with excess condensation - if any at alll. I always keep the cabin hatch open about an inch, and have UFO type vents on the cabin ceiling which I ensure are open. Mine has an oxygen depletion sensor and flame out sensor which cuts the gas in the unlikely event the flame fails. I also have a carbon monoxide alarm (two in fact because Im paranoid!) but have to report it has never alarmed.

The whole condensation thing really intrigues me. In theory I understand that whatever fuel you use be it paraffin, methanol or gas, the amount of H2O produced in condensation should roughly equate to the amount of fuel consumed. IE a 0.250kg butane cartridge should produce approx 0.250 kg of H@O in the form of condensation. this however is not my experience, in fact I notice far less condensation inside my heated cabin than on a cold night produced by breath alone.

To test this thoroughly however I last night decided to run an experiment. and placed my little heater inside a sealed internal bathroom in the house with tiled walls. There are no external windows and the internal volume is probably about the same as the cabin on my boat. There is only one small ventilator, which probably produces about the same amount of ventilation as the slightly open hatch and vents I employ onboard. I ran the test for two hours (and no I didnt stay in the bathroom during the process, as both my CO alarms were still onboard..) End result? shock horror! I was expecting to enter and find he room dripping wet with condensation, and having read some of the comments on this thread and elsewhere I wouldn't have been surprised at all to find it literally pouring off the walls? But no - the bathroom was warm and dry, the walls warm and dry and my little heater happily chugging away, without even a single drip of condensation anywhere found! Could the chemists/physicists among us please explain?
Click to expand...


I think it's because you are ventilated and there's air coming in, and going out.

Air comes in and is warmed - it can now carry more water than it already is, and so takes in more water - the heat of your heater moves that air up, and out of your ventilation hole. Effectively you have made a dehumidifier, despite the introduction of more moisture.

We always had best results by opening a vent only at each end of whatever space we are in at the time, with the heater (Vapalux M320 in our case) nearer one than the other.

Result = increasingly dry boat + combustion products vented also.
 
pongoglo said:
To test this thoroughly however I last night decided to run an experiment. and placed my little heater inside a sealed internal bathroom in the house with tiled walls. There are no external windows and the internal volume is probably about the same as the cabin on my boat. There is only one small ventilator, which probably produces about the same amount of ventilation as the slightly open hatch and vents I employ onboard. I ran the test for two hours (and no I didnt stay in the bathroom during the process, as both my CO alarms were still onboard..) End result? shock horror! I was expecting to enter and find he room dripping wet with condensation, and having read some of the comments on this thread and elsewhere I wouldn't have been surprised at all to find it literally pouring off the walls? But no - the bathroom was warm and dry, the walls warm and dry and my little heater happily chugging away, without even a single drip of condensation anywhere found! Could the chemists/physicists among us please explain?
Click to expand...

There's another very big difference from your boat to your bathroom - insulated surfaces. The walls on my boat are very cold, so as soon as warm air touches a cold surface, it condenses.

I presume your bathroom walls weren't thin and cold and exposed to outside air, so my guess is that's why your walls weren't wet.

I wouldn't mind betting that the humidity in your bathroom increased massively though?
 
You must log in or register to reply here.

Other threads that may be of interest

cyberkryten
We finally bought a boat - Merry Fisher 895s2
2
Replies
21
Views
514
Anibal
Anibal

Share this page

Top