Tym-space-heater-design,

Is it a good idea to burn fuel in a confined space?

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JHG

The exhaust gases are co2 and h2o so as long as I open the door for a little bit or have an exhaust pipe it should be fine. I have a true ion generator, no ozone generated so I should be fine.

I've actually designed an ethanol vortex flame I will probably use instead. It's simpler and even more efficient.

if you're trying to heat a space it's because it's cold outside. Then you open the door to vent the gases ... yeah, not very practical.

This sounds a lot like previous scams "heat your house for pennies ...".

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

You're right about opening the door but since there's heat storage, it will heat the room for 6h after the heater is off or the two other options which is my ion generator (doesn't produce ozone) or an exhaust pipe insulated to go out my window. I respect your input but a bit more optimism would be greatly appreciated. :)

what is the chemical energy you're burning to heat this room ?

what is the thermal energy you're using ? how cold is the outside ? how big the room ??

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

I'm using ethanol, with the vortex it should be 200% more efficient. The outside of this mineral foam insulated building should be between 17 to -2c. The building is 25msq and the height of the room is 2.6m tall.

Thank you

Unless most of the fuel is becoming soot it is already near 100% efficient. Efficiency is lost in heat escaping the room while exchanging combustion air, but I see no heat exchanger. The vortex appears to add nothing but make it visually interesting.

so you're not looking for much heating ... the building is insulated but no central heating ??

I'm not sure by what you mean by "200% more efficient", but it clearly means a lot to you. I'd've thought (in my ignorance) that when you burn fuel, you release the chemical energy, mostly as heat, some as light and noise (which are waste). But this chemical energy is the upper limit of what heating you can achieve.

It seems that you're trying to heat the sand and use this to heat over time (6 hours after burning fuel, sure, maybe, we'll see). It is actually an interesting heat transfer exercise ... near the flame gets hot, heats the sand, heats to room, convection currents, and opening the window too ...

Optimism ? nah, here we rain of parades ...

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

The vortex mixes oxygen into the flame maximizing the flame burn increasing the height to 2x the height (burns hotter and cleaner).
Thank you for your input :)

At this price, efficiency is important.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

gallon ... US or Imperial ? (I always hear myself "African or European ?") ... ad looks to be US = 3.8lt

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

Thanks but can't I use regular ethanol? It's very cheap 5l is about 10 dollars here :)

Double the flame height doesn't equal double the efficiency. As others have mentioned, as long as there is near complete combustion, which is not difficult to achieve, nearly all the stored energy in the fuel is converted to heat and light, so the only true losses are the heat and light that escape the room. A 200% gain in efficiency over other ethanol heaters is not possible.

I think what he's saying is he has a 200% "useful" heat exchange region (the height of the flame). Like you I don't think this means a 200% heat transfer ... but possibly if you had a crappy 40% you may be getting 80% but I don't know anything about this (so I'm not saying it'd happen, just I think that's what he's thinking). Like you once you get to 100% combustion, it's "very hard" (= impossible) to get more. Oh, and I forgot much of the chemical energy is lost in forming the products of combustion, CO2 and H2O.

But go ahead and build this. Show us that you can heat your room to a comfortable level for pennies. And have a very interesting sculpture too.

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

I mean thhat, the air mixing causes more oxygen to produce a cleaner, and yes larger flame. :)

As long as all of the fuel combusts, there is no efficiency to be gained.
As I mentioned, many ethanol heaters are selected for visual effects.
Less efficient mixing of fuel and air may result in a more colourful flame.
The different colours in the flame are the result of different combustion temperatures.
Don't confuse temperature with BTU output.
If you want heat, I suggest that you research the comparative cost per BTU of various fuels.
Ethanol may not be the most economical fuel.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

Thanks, I'll look into it :)

Quote (Tym-space-heater-design)

I mean thhat, the air mixing causes more oxygen to produce a cleaner, and yes larger flame. :)

This isn't like an engine where excess fuel us pumped out the exhaust, in this case the fuel sits there until there is enough O2 for it to burn, which it then does with near 100% efficiency. Putting a turbo on your car an giving it more air doesn't automatically give you more power, you have to add more fuel too. Your vortex may well give you a larger flame, at the cost of a higher fuel consumption rate.

You came here for advice and continue to ignore people telling you that your math is wrong....why ask for help in the first place?

to be fair, he's not concerned about "increased consumption", in fact that'd help with heating ... more flame = more heat ? yes, but (there's always a but) the same amount of fuel will get consumed quicker ... so no net gain (in fact I suspect some small net loss, because of the immutable Laws of Thermodynamics).

Still it'd make for an interesting sculpture ...

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

Quote (rb1957)

to be fair, he's not concerned about "increased consumption", in fact that'd help with heating ... more flame = more heat ? yes, but (there's always a but) the same amount of fuel will get consumed quicker ... so no net gain (in fact I suspect some small net loss, because of the immutable Laws of Thermodynamics).

Exactly, I agree and that increased output is likely a good thing, I'm just saying you can't just increase you gross output then claim improved efficiency.

Okay, guess I'm fine with that :)