Kerosene Inverter Heaters.

[AntarcticPilot]

Thats interesting then. So better to choose a quality little paraffin heater than an unflued propane heater which are widely sold these days. The camping stove gas bottle types. If that sort of heater is wanted for portability reasons or cost.

Do you know how much worse it is? Its the higher hydrogen content is it as mentioned earlier?

Methane (the lightest aliphatic hydrocarbon) would give 36 grams of water for every 16 grams of fuel. Ethane would give 54 grams of water for 36 grams of fuel, propane and so on.

Carbon atoms	Weight of fuel	Weight of Co2	Weight of water	Water resulting from burning one gram
1 (Methane)​	16​	44​	36​	2.25​
2 (Ethane)​	30​	88​	54​	1.8​
3 (Propane)​	44​	132​	72​	1.636363636​
4 (Butane)​	58​	176​	90​	1.551724138​
5 (Pentane)​	72​	220​	108​	1.5​
6 (Hexane)​	86​	264​	126​	1.465116279​
7 (Heptane)​	100​	308​	144​	1.44​
8 (Octane - nominal petrol)​	114​	352​	162​	1.421052632​
9 (Nonane)​	128​	396​	180​	1.40625​
10 (Decane - nominal Diesel)​	142​	440​	198​	1.394366197​

 

[Adios]

So getting on for 20% more water from burning propane than paraffin. Still way more than the ideal zero level of added water but then a heater sitting on the cabin sole not far from a companionway hatch opened sufficiently its really about which heater design is better at radiating heat while most of the hot water vapour goes out the hatch. Also which fuel is safer to store, cheaper and easier to buy.

For a portable non-ideal boat heating solution anyway

 

[VicS]

Interesting. So kero will produce less water that propane? Any idea how much less?

Question then, if kero is burned at a lower temperature can it give off more water? Any reason why old style heaters could produce more water than new style?

In which case kero burnt cleanly and very hot will be better as an unvented solution than less clean diesel and more wet propane.

If you take the approx chemical formula for kerosene as C₁₂H₂₆ and write the chemical equations for the combustion of kerosene and propane

2C₁₂H₂₆ + 37O₂ → 24CO₂ +26H₂O​

and

C₃H₈ + 5O₂ → 3CO₂ +4H₂O​

you can see that 2 mols (340g) of kerosene gives 26 mols ( 468g) water while 1 mol (44g) propane gives 4 mols (72g) water

or 1 kg of kerosene gives 1.37 kg water while 1 kg propane gives 1.63 kg water

On the face of it propane produces more water but you have to also consider the difference in calorific values
If you take the net calorific values ( which assume the heat content of the water vapour is not recovered) into account you will find that you will get 32g water vapour / MJ of heat produced from kerosene but only 25g of water vapour / MJ from propane

This means in practice propane is the drier fuel

 

[Bristolfashion]

If you take the approx chemical formula for kerosene as C₁₂H₂₆ and write the chemical equations for the combustion of kerosene and propane

2C₁₂H₂₆ + 37O₂ → 24CO₂ +26H₂O​

and

C₃H₈ + 5O₂ → 3CO₂ +4H₂O​

you can see that 2 mols (340g) of kerosene gives 26 mols ( 468g) water while 1 mol (44g) propane gives 4 mols (72g) water

or 1 kg of kerosene gives 1.37 kg water while 1 kg propane gives 1.63 kg water

On the face of it propane produces more water but you have to also consider the difference in calorific values
If you take the net calorific values ( which assume the heat content of the water vapour is not recovered) into account you will find that you will get 32g water vapour / MJ of heat produced from kerosene but only 25g of water vapour / MJ from propane

This means in practice propane is the drier fuel

Thank you for that - I was just starting to work through the numbers and you've saved me the bother. I had a suspicion that propane was drier in terms of water / joule.

It seems that, with any form of fuel heating, a vent to the outside is to be encouraged, both to avoid water vapour and the more dangerous Carbon monoxide.

 

[AntarcticPilot]

Thank you for that - I was just starting to work through the numbers and you've saved me the bother. I had a suspicion that propane was drier in terms of water / joule.

It seems that, with any form of fuel heating, a vent to the outside is to be encouraged, both to avoid water vapour and the more dangerous Carbon monoxide.

I, and many others, would say it is essential, not encouraged.

 

[Adios]

I, and many others, would say it is essential, not encouraged.

For an installed heater I doubt anyone would argue but I've had more boats without the luxury of an installed heater than with it. For those boats the question about portable heaters and which fuel is still relevant. Nothing wrong with bringing a portable heater on board to take the chill off if the weather warrants it but I would say a CO alarm is then an essential thing to have and I do follow that advice myself.

 

[AntarcticPilot]

For an installed heater I doubt anyone would argue but I've had more boats without the luxury of an installed heater than with it. For those boats the question about portable heaters and which fuel is still relevant. Nothing wrong with bringing a portable heater on board to take the chill off if the weather warrants it but I would say a CO alarm is then an essential thing to have and I do follow that advice myself.

At least one party in Antarctica died from CO poisoning when the vent of their tent was blocked by powder snow; their cooking stove killed them. Unfortunately in such climates there isn't an option about using stoves in enclosed spaces; it's that or die of hypothermia! That's why I know of research into the dangers of primus-type stoves (gas doesn't work at those temperatures; it remains liquid in the bottles). The guys I'm thinking of didn't realize that the ventilation chimney had got blocked. Unfortunately, one symptom of CO poisoning is reduced mental ability! Ventilation that allows heat to build up is probably also ventilation that could potentially be blocked.

And yes, when I were a lad, I survived all sorts of fuel-burning stoves in cabins, including pressure lamps, a pressure paraffin heater and catalytic heaters! Mains electricity on a boat was not even a twinkle in anyone's eye in those days.