DescentBB

To day was humid as hell, in Austin and I wondered if the thick hot air contained energy.

I looked it up and apparently heat IS energy. That’s cool! Can you convert hot air into electricity?

No! We want to maintain our current supply of blondes!!

Google geothermal power. Question answered.

he said heat in air, MD.

heat, from any source, can only be used to generate power when you have a temperature differential. So yes, hot air could be used to generate electricity, but only if you had someplace much colder nearby.

Which means, NO, atmospheric heat is not very practical for generating electricity because it takes more energy to create a temperature differential than you get back out of it.

The reason geothermal DOES work is that the surface of the earth is much COOLER than the hot pockets deep underneath.

Kilarin said it. You need a temperature differential in order to be able to harness the energy in heat.

Heat exchangers work by using the hot stale air from your house to pre heat the cold fresh incoming air. In Summer you can hook up a pump to your geothermal system, or air conditioning to cool the incoming air.

Another Heat exchanger system uses humidity and air movement to cool incoming Summer air, (Swamp Cooler effect to nTh degree)
http://www.advancedbuildings.org/main_t ... y_heat.htm

Ok I used to mess with rooftops for a living too.

Canuck is right, in that you can do a little bit with the temperature differences between inside and outside, but you can't get much out of it- hardly enough to generate a decent amount of electricity with. A lot of systems use pressure to produce power, and heat is used to produce the pressure differential. Think of heat as kind of the \"waste energy\" in the world. Any perfect system will produce absolutely no heat, and an inefficient will produce lots of heat. Once you dump heat into the air really can't get much of the energy back. (For example, a common car engine runs at under 70% efficiency- that means that almost 1/3 of the energy in the gasoline turns into heat and is just wasted.)

Maybe the hot air in this thread could power the dbb.

Palzon wrote:Maybe the hot air in this thread could power the dbb.

You haven't been paying attention. To harness the energy you would need to have a temperature differential, and that means you would have to find a dbb thread that WASN'T hot air.

I'm surprised no one has mentioned the laws of thermodynamics

http://en.wikipedia.org/wiki/Thermodynamics

-ccb056

^^^ I was going to mention that, but look at the person who started the thread. The gray mass above the shoulders is lacking.

Ferno wrote:he said heat in air, MD.

Thank you, Captain Obvious! I was referring to the PRINCIPLE involved. [foamy]Jackass![/foamy]

Top Wop wrote:^^^ I was going to mention that, but look at the person who started the thread. The gray mass above the shoulders is lacking.

x2

I draw naked people at school. Sometimes an apple... counting things sucks.

Temperature differential is a valid means of generating power. I know for a fact that a hospital of the shores of one of the great lakes uses such a system leveraging the extremely cold water deep in the lake.

In theory, you could build multi-Megawatt ocean-based facilities - but in practice, the hardware takes too much of a beating in the sea. Fiords or something might work better?

inversly, a good deal of energy is spent to remove that energy from warm, humid air in HVAC systems. Oddly, water is the most effcient means of doing this.

If you want energy, the two best methods are either nuclear or petroleum. Both very viable, safe, and abundant.

ever hear of 'stirling engines'? oh btw car engines rate about 24% but a stirling engine rates about 70%. but then how would i know? iv only built one is why & did a stack of research of em
cheers
rij

rijruna1 wrote:ever hear of 'stirling engines'?

Stirling engines are cool, but they also require a temperature differential.

TANSTAAFL

a good sterling engine will operate using either nuclear or petroleum power

so after reading this, it looks like i'll have to invent magic first

Isaac wrote:so after reading this, it looks like i'll have to invent magic first

Bah, I'm sure Merlin is hanging around here somewhere.