Thermal expansion values/comparison/chart/refrigerants

[pippo]

People,

 

Wondering if the term thermal expansion coificcient is correct for evaluating the effectiveness/efficiency of different chemical compounds that are used in ac applications. Is this term correct? For example, such a table would make clear that R12s more effieient (colder) that R134a, ceritus paribus..

 

I am searching for a table that compared different - mostly organic compounds (yes, including R12, R134a. propane, butane, etc ) For that matter, even inorganics like ammonia, CO2, etc etc etc.

 

Thanks!

[pippo]

so far, I found that desirable properties of a good refrigerant are low bp, high critical temp, high heat of vaporization, and others. Thing is, If one had to choose the single biggest factor among the 2 or 3 properties above, would you choose low bp over high critical point? Opinions appreciated.

[fshegg3]

get yourself a copy of "modern refrigeration and air conditioning" and study the "enthalpy" charts.

 

the advantage of R-134a over R-12 is the lack of the chlorine atom which is part of the R-12 molecule.

 

the chlorine atom in the R-12 molecule is easily separated and being lighter than our atmospheric mix of

 

nitrogen and oxygen migrates to the upper atmosphere where it attacks O3 (ozone). this "attack" strips

 

an electron from the O3 and makes it an O2 (plain oxygen). what makes this chemical reaction insideous

 

is once the chlorine atom strips one ozone atom of an electron, it moves on to the next O3 and repeats the

 

process over and over. hence the term "ozone depleting". fortunatly, O3's are constantly being created by

 

nature. enjoy the charts.