There's no such thing as a 100% efficient "engine". But in this case, since the waste heat is put to use (heating the house), OP thinks there's a loophole.
But, house would also need to be soundproof. Any noise leaking to the outside is lost energy.
Ah, but that’s by design: it also acts as a soothing white noise machine.
Then you might point out the exhaust and all it’s associated wastes, but that’s by design: it produces a heady and aromatic product for recreational huffing.
Then you might point out the vibrations, but that’s by design: the engine also provides invigorating massages to relax taut muscles.
Most engines are less than 30% efficient at producing movement. The majority of the energy is lost as heat.
Thermodynamics tells us that pretty much all energy ends up as heat. In a closed system, any device that uses energy is 100% efficient at making heat. A 1000W computer will make exactly as much heat as a 1000W heater.
A 100% efficient engine can only exist if the desired output is heat, thus making it a pretty useless engine. Also, in a closed system, the exhaust cannot leave.
But even a furnace/fireplace is subject to incomplete combustion, where some portion of the wood is transformed into byproducts that rob some of the energy of the fire. There's actually a big difference in the amount of energy you can get out of a fire, depending on the type of stove that's used.
That's some of what NGOs have tried to do for developing countries - find cheap and easily produceabke stove designs that can reduce the amount of wood needed and improve air quality in the home.
27 Comments
mvirts@lemmy.world · 22 pts · 2y
Ive been testing combustion engines made of wood but keep getting more energy out than I put in...
troyunrau@lemmy.ca · 12 pts · 2y
Lisa, in this meme we obey the laws of thermodynamics!
buycurious@lemmy.world · 10 pts · 2y
Sorry, I’m a bit dumb for this one.
Could someone please explain?
DemBoSain@midwest.social · 49 pts · 2y
There's no such thing as a 100% efficient "engine". But in this case, since the waste heat is put to use (heating the house), OP thinks there's a loophole.
But, house would also need to be soundproof. Any noise leaking to the outside is lost energy.
Ellie_The_Nurse@lemmy.world · 24 pts · 2y
Ah, but that’s by design: it also acts as a soothing white noise machine.
Then you might point out the exhaust and all it’s associated wastes, but that’s by design: it produces a heady and aromatic product for recreational huffing.
Then you might point out the vibrations, but that’s by design: the engine also provides invigorating massages to relax taut muscles.
Dieinahole@kbin.social · 14 pts · 2y
You. Come sell my book
Valmond@lemmy.mindoki.com · 5 pts · 2y
Let's allow a rounding error for 99.51% shall we?
18107@aussie.zone · 9 pts · 2y
Don't tell anyone, but I actually only used 1 significant figure, so anything above 50% will do.
I'm also using the version of significant figures where I work backwards from the answer, otherwise I'd need 95% or higher and that's too difficult.
18107@aussie.zone · 30 pts · 2y
Most engines are less than 30% efficient at producing movement. The majority of the energy is lost as heat.
Thermodynamics tells us that pretty much all energy ends up as heat. In a closed system, any device that uses energy is 100% efficient at making heat. A 1000W computer will make exactly as much heat as a 1000W heater.
A 100% efficient engine can only exist if the desired output is heat, thus making it a pretty useless engine. Also, in a closed system, the exhaust cannot leave.
RvTV95XBeo@sh.itjust.works · 10 pts · 2y
All space heaters should be coin miners (or some other borderline useless energy wasting tech, like AI training). Change my mind.
wahming@monyet.cc · 6 pts · 2y
We have enough of a chip shortage, tyvm
owenfromcanada@lemmy.world · 3 pts · 2y
If you want to be philanthropic, there are programs you can run that use your computer's idle time to process data for cancer research and such.
someguy3@lemmy.world · 2 pts · 2y
You can sign up for research crunching.
someguy3@lemmy.world · 9 pts · 2y
Furnace.
Hello_there@kbin.social · 3 pts · 2y
But even a furnace/fireplace is subject to incomplete combustion, where some portion of the wood is transformed into byproducts that rob some of the energy of the fire. There's actually a big difference in the amount of energy you can get out of a fire, depending on the type of stove that's used.
That's some of what NGOs have tried to do for developing countries - find cheap and easily produceabke stove designs that can reduce the amount of wood needed and improve air quality in the home.
someguy3@lemmy.world · 2 pts · 2y
Yes he is incorrect. NG furnace is 95% efficient iirc.
EmoDuck@sh.itjust.works · 8 pts · 2y
I'm more impressed by that fact that if either runs perfectly silent or that your house has perfect sound insulation
18107@aussie.zone · 28 pts · 2y
I have a spherical frictionless house in a vacuum.
EmoDuck@sh.itjust.works · 23 pts · 2y
In this economy?
Crackhappy@lemmy.world · 2 pts · 2y
At these prices?
muntedcrocodile@lemmy.world · 8 pts · 2y
Wait till you hear about reverse cyxling air conditioning it exceeds 100% efficiency.
general_kitten@sopuli.xyz · 6 pts · 2y
this is true only if you dont vent the exhaust outside making the air inside quite fun to breathe
Wilzax@lemmy.world · 1 pts · 2y
He burns h2
18107@aussie.zone · 1 pts · 2y
He doesn't burn very well.
general_kitten@sopuli.xyz · 1 pts · 2y
so a heater and a humidifier all in one, now just have to make sure that it doesnt eat all the oxygen or make it rain inside
TheOneCurly@lemmy.theonecurly.page · 2 pts · 2y
It's only 100% efficient if you're also letting all the exhaust into the house too...
someguy3@lemmy.world · 2 pts · 2y
Fyi I think they're around 95%.