An arguement

[n00b 0f l337]

Point 1) Is it possible to have something at or greater than 100% efficeicny.

Example 1: Can a refrigeration unit move more energy than it consumes?

Example 2: Can a peltier move more heat than it consumes?

I dont think either of these are possible. Example 1 of course is subject to an abundant amount of energy to move in the first place of course.

[boshuter]

I'm agreeing with you on this one.... neither is possible ;)

[babalouj]

Efficiency can be over 100% but only because of tricks. One such trick is to define the system (in which the efficiency is being measured) in such a way that all energy put in is not accounted for. For example, lets be absurd and say that phase change is 99% efficient and the system is defined as the phase change unit and the heat source that it is connected to. Well you could make a chill box and stick the phase change and heatsource in the chill box. The chill box would remove more heat from the condensor and help the system achieve over 100% efficiency but this is only because you used more energy but defined the system as only the phase change and heat source. In my thermo class we discussed these tricks. In reality, nothing can be 100% efficient.

[n00b 0f l337]

Right.
You decide to move 4000 watts of energy. You spend 1000watts of energy moving it.
In the end you have 4000watts, but initial energy was 5000watts.
That is 80% efficiency.

[Xeon th MG Pony]

yup, nothing can exceed unity. All forces require an out side force to alter them to any one end, and to create thees forces energy must be consumed.

Think of energy like water, it all ways flowes from a high point to a lower point and never in revers, to make it move in revers we must add more energy then the downward force, & this is basicly what we are doing, forcing heat to flow up hill, and it will all ways require more energy for a given amount to force it to flow in revers.

[zabomb4163]

http://www.walmart.com/catalog/product.do?product_id=3387597
What i pointed out to him is that in the united states federal law requires air conditioners to have at least a 9 EER rating.

EER = BTU rating over wattage
http://home.howstuffworks.com/ac4.htm


refrigeration systems are heat pumps. i think the reason he has gotten confused is because he as gotten accustomed to computer cooling systems and thinks 200watt load = 3/4HP compressor. Talk to ANYONE in the hvac industy. 3/4HP is a rediculous amount of power for such a small load (at normal temperature differentials).


http://www4.shopping.com/xPF-Carrier_XQB153D
15,000 BTU system. so according to your theory it pulls 4400watts!!!!!!! and a 6hp compressor. jeez. that thing must be heavy huh.

(15,000BTU = 4400watts........ 745watts = 1HP)

[n00b 0f l337]

Not really what you were saying. You did say that its possible to be more than 100% efficienct. Its not possible, energy moved requires energy to be there at the beginning of an equation.

You can't cool something at absolute zero because there is no energy to move out.

[Weee]

Here's an interesting read.

http://www.newton.dep.anl.gov/askasci/eng99/eng99018.htm

[Xeon th MG Pony]

Again it is bassed on what they are comparring it too.

It will do X amount more work per energy unit then say a oil burner would, so we can say that it is 120% more efficiant then the oil burner IE it will move more heat into the environment then the oil burner can generate by consuming X amount of fuel!

I'm sory if I'm being confusing, text isn't my area of proffession lol. I build the things, not write the manule!

[wdrzal]

hmmm why can a a/c unit provide 12,000 btu of cooling and use a 1hp motor ???? 1 hp motor is 746 watts and since 1 watt = 3.412btu

That means I can provide 12,000 but of cooling using 2545 btu's?????

[n00b 0f l337]

The compressor takes 2545, and there is 12,000 in the air.
Your removing 12000 from one space and moving it to another.

[wdrzal]

read the
zeroth law of thermodynamics
first law of thermodynamics
second law of thermodynamics
third law of thermodynamics

[Xeon th MG Pony]

exactly so you're adding the additional heat to the condencer!

Heat of room > Heat of compression > Concer Heat > Air

Inside Ambiant Minuse 12K/BTU to Out side Ambiant +12K/BTU + X/BTU of compression.

[wdrzal]

The compressor takes 2545, and there is 12,000 in the air.
Your removing 12000 from one space and moving it to another.
right

effienicy is all relative as what your comparing, usually expressed in ratio's

[n00b 0f l337]

So that example..
Starting NRG(energy) is 14,545 BTU. End NRG is 12,000.
Efficiency is not 100%.

[Jort]

The compressor takes 2545, and there is 12,000 in the air.
Your removing 12000 from one space and moving it to another.

so you move more energy then you put into it.

that hard to understand:p:

and when i put less energy in something and i get more its 100%+ effi;)

if you have a resistor heatload you put 200W in and get 200W out. that 1:1:)

when i give you 1dollar and you give me 2 dollar's back, whats that? profit doens't it...

[n00b 0f l337]

Money is different. Its all relative to what I can convince you your dollar is worth. You also dont get 200W when you put 200W in, theres a bit lost in resistance.

And no, divide the outcome by the original.

12000/14545

[wdrzal]

Zeroth law: "You must play the game."
First law: "You can't win."
Second law: "You can't break even."
Third law : "You can't quit the game."

these statements mirror the laws of thermodynamics, forgot who said them. ahhh think I finnally got a sig I like

[n00b 0f l337]

Thanks wdrzal I was trying to find those.

[wdrzal]

first law of thermodynamics states that ENERGY can neither be created or destroyed.(conservation) so is energy 100% effeicent?

[n00b 0f l337]

You cannot always reclaim expended energy. Heat is hard to recover 100% as ambient is as variable as my sanity.

[wdrzal]

The compressor takes 2545, and there is 12,000 in the air.
Your removing 12000 from one space and moving it to another.


you only paid for the 2545 btu,

[n00b 0f l337]

So? Thats like saying, I dont pay my electric bill making the efficiency of my air conditioner underfined/infinite % efficient.

[wdrzal]

How does Pythagorus's sig go: something like the more you know about thermodynamics the more you know ,you don't know !!!!!!

[n00b 0f l337]

I was quoted for the following on EOCF.
"Thermodynamics is a pain in the ass, the first time you research it, you think you understand it. Later on you'll reread it and realize you have no :banana::banana::banana::banana:ing idea whats going on. On read number 3 you'll finnaly realize you will never understand it, but maybe one day you can get a small :banana::banana::banana::banana:ing idea wtf is going on"

[Carlz0r]

"Thermodynamics is an interesting subject. The first time you research it, you don't understand it. The second time you research it, you think you understand it. The third time you research it you know quite well you don't understand it but you're so comfortable with the subject it doesn't matter anyways."

[Xeon th MG Pony]

hehe thats the one I know, funny and so true.

[wdrzal]

"Thermodynamics is an interesting subject. The first time you research it, you don't understand it. The second time you research it, you think you understand it. The third time you research it you know quite well you don't understand it but you're so comfortable with the subject it doesn't matter anyways."

ay there's john's sig. did change a few words. John going to ban you for plagerizing:nono: :nono: :slapass:

[star882]

"Efficiency" is misleading for a heat pump. Technically, Carnot efficiency is the proper term for effficiency of the unit.
http://en.wikipedia.org/wiki/Heat_pump
When comparing the performance of heat pumps, it is best to avoid the word "efficiency", as it has many different meanings. The term coefficient of performance or COP is used to describe the ratio of heat output to electrical power consumption. A typical heat pump has a COP of about four, whereas a typical electric heater has a COP of one, indicating units of heat exchange performance per units of electrical power input (resistive electric heat being 100% efficient whereas heat pump heating offering up to 400% efficiency).


Can a refrigeration unit move more energy than it consumes?
Yes, but it's restricted by thermodynamic laws. Therefore, it's possible, but only under certain conditions.

[wdrzal]

Carnot efficiency is the maxium "theoretical efficiency" that can be optained, by calculations, but actual efficiencys are lower because many small variables like friction and loss cannot be accounted for in equations.

[n00b 0f l337]

-wdrzal my inbox was full, didnt get your message-

[wdrzal]

-wdrzal my inbox was full, didnt get your message-

your allowed 500 messages !!!!! :stick: I spent 15 min typing the explanation to your question, its not in my box andI'm not retyping it:slap: If you ask a question don't you think you should have room for the answer :rolleyes:

[n00b 0f l337]

Sorry mate I didnt know I was that close to 500. :( Was 500 in inbox I deleted all my savebox.
It didnt go to your sentbox though?

[Xeon th MG Pony]

That means you didn't get that PM from me either *Blink* how the hell you end up with even near five hundred?

[n00b 0f l337]

I got yours Xeon, you were #500.
I receive about 50 PM's a day here...

[Ssilencer]

5o pm a day here?
Wow, what are you doing ??

[n00b 0f l337]

On average yeah bout 50pm a day? What? I figure chilly1 gets 100 a day or something... People ask me questions and stuff. When I was banned i probably missed 500 PM's. :(