SailNet Community banner

1 - 20 of 108 Posts

·
Registered
Joined
·
103 Posts
Discussion Starter #3
Ha! You're probably right, but it's got to be safer than a "burn-o-matic" pressurized alcohol stove! Once I almost turned me and the boat into a bbq - not cool.
 

·
islander bahama 24
Joined
·
1,842 Posts
It does work but I will still use my two bit a day propane force ten bulkhead heater
 

·
Barquito
Joined
·
3,570 Posts
I find that if I bring my 300 watt work light, and am pretty active trying to fix something in the cabin, that I stay warm-ish. Anyone have any idea what percent of the 300 watts ends up as light versus heat?
 

·
Registered
Joined
·
1,844 Posts
That's our old friend Dylan Winter of Keep Turning Left - a great series of on-line videos from around (literally) England. Check it out!

He used to post here quite frequently but I haven't seen him for a while.

Dylan did stir up a bit of debate over the idea of cooking canned goods in their cans. Somehow or other canned Haggis became the focus.

Here's a link to that funny thread.
 

·
Registered
Joined
·
1,844 Posts
Hey! That's our own Dylan Winter!

Brilliant solution Dylan! I've gotta try that one.

Beat me! That's what happens when you spend too much time re-reading classic threads!
 

·
Registered
Joined
·
2,953 Posts
I find that if I bring my 300 watt work light, and am pretty active trying to fix something in the cabin, that I stay warm-ish. Anyone have any idea what percent of the 300 watts ends up as light versus heat?
All of it.

Incandescent light bulbs are only about 10% efficient, the other 90% is released as heat. But the light they emit gets absorbed by whatever it hits and warms them, so a 300 watt bulb is effectively the same as a 300 watt space heater.
 

·
Registered
Joined
·
571 Posts
I find that if I bring my 300 watt work light, and am pretty active trying to fix something in the cabin, that I stay warm-ish. Anyone have any idea what percent of the 300 watts ends up as light versus heat?
How much light (lumen) a particular bulb (lamp) produces compared to how much power it requires (watts) is called "luminous efficacy." Web search the term for more details, but efficacy is different for each type of lamp.

100% of the electricity that goes into any lamp is eventually converted into heat, regardless of its efficacy. So, for heating a room, a 300-watt lamp is the same as a 300-watt space heater.

Also a bare candle puts out the same amount of heat as a candle surrounded by a clay pot. I'll take the light bulb.
 

·
Registered
Joined
·
602 Posts
Im calling bs on this one. A candle only puts out so much energy. You cannot simply increase this output by channelling it into a terra cotta pot. It would be the same heat energy if you had left the pots off.
 

·
Registered
Joined
·
2,705 Posts
I haven't tried it but I have been told that the same ceramic pot over a burner on the gas stove set to the lowest setting will actually get the pot to glow and the heat emitted is substantial.

Yes, I know the gas stove will suffocate everyone within a square mile and the glowing pot will burn the boat to the waterline but seemingly it has been done many times and quite successfully. You just don't want to be doing this in a heavy, lumpy sea - catching the pot as it falls off the stove could smart a little.

Also, the concept of "a candle only puts out so much heat" - well yes that is true but a candle freely burning dissipates the heat very quickly whereas captured under a ceramic pot gathers the heat and absorbs it into the pot. I'm not saying it works effectively because I haven't tried it but it isn't the same thing.

As a parallel concept, I'll bet that the flame in the Force Ten bulkhead heater if left to burn free outside of the heater would have little effect on the heat in the cabin. If it had the same effect away from the heater, why would anyone buy the heater?
 

·
One of None
Joined
·
8,045 Posts
a candle is about 3,600 btu an hour. Electric, convert watts x 3.415 = btuhs
 

·
Registered
Joined
·
3,845 Posts
Exactly, Jwing and Minnesail have it. I remember and engineer exam, way back when; the question included all of the physical properties of the refrigerant, compression ratios and on-and-on, as well as the amp draw of the motor. We were to calculate the warming of the room. Kids toiled away, when all they needed was the amp draw and a few unit conversion factors.

I've even tried the flower pot method on a kitchen stove, because I was bored. Perhaps it would do something worthwhile in terms of radiant heat; not much. It did increase CO emissions until the pot got up to temperature. Bad.

Until someone finds a clay pot that generates it's own heat this will be nothing more than a durable urban legend. A dangerous one.
 

·
islander bahama 24
Joined
·
1,842 Posts
I does work fine for what it is BTW I first saw the idea in mother earth news about 25 years ago listed as emergency heating for under 200 sq ft I rather think the people huddled round it gave off more heat in the original article.ss
 

·
Registered
Joined
·
602 Posts
Also, the concept of "a candle only puts out so much heat" - well yes that is true but a candle freely burning dissipates the heat very quickly whereas captured under a ceramic pot gathers the heat and absorbs it into the pot. I'm not saying it works effectively because I haven't tried it but it isn't the same thing.
Where does the candle dissipate the heat to? Could it be the room... the same place the pots do?;)
 

·
Registered
Joined
·
2,705 Posts
Where does the candle dissipate the heat to? Could it be the room... the same place the pots do?;)
OK so this gets interestinger and interestinger. :)

Going back to my earlier corollary, if the flame in the Force Ten burner was left to burn quietly in the corner, would it produce the same heat as the Force Ten heater? Maybe it does. I have no idea.

See, if I look at this thingy below (Oh, it's a Force 10 heater), it appears to have a burner under the bulk of the body. If heating up the bulk of the body is not what creates the heat in the cabin, then why would one want the bulk of the body in the boat taking up space? Why not have just the burner? One (or at least I) must make the assumption that the burner (or candle) heats the body (or clay pot) which heats the space around it.



I'm not saying that I have done this flower pot thing or that I believe it works. I live in a part of the world where heating boats is unnecessary. But my question above begs an answer - What is it about the body (clay pot) above the burner (candle) that turns an ordinary flame into a cabin heater? I don't know the answer - seemingly you do.
 
  • Like
Reactions: tdw

·
Super Fuzzy Moderator
Joined
·
17,137 Posts
You live in bloody New Zealand ffs .... what do you mean you don't need a heater ? :p Just another fair weather sailor. No wonder the Kiwis couldn't beat the Australian in the AC .... :eek:
 

·
One of None
Joined
·
8,045 Posts
The inner pot has "thermal mass" the outer pot would cause convection air currents around the inner. The candle flame would not get hot enough to begin catalytic action of the combustion gases.. leastwise I don't think so.
 
1 - 20 of 108 Posts
Top