Alternative way to replace CFC?

[scilover89]

Since CFC is hazardous to our atmosphere, are there any better substitute to replaced CFC in fridge, air conditioner etc.?

 

[SwAnK]

I always though you could use water because of its high heat capacity. Nuclear power plants do this, except in this case, for a fridge, an antifreeze would prbably half to be added. And some way of cycling the water, through something that could cool it off quickly, so it could gather more heat again.
Thats my though anyways.

 

[brewnog]

The Montreal Protocol is already in place, the purpose of which is to phase out CFC uses, particularly in refrigerators. It may be interesting to note that the insulating foam used in the construction of a fridge can contain as much as four times as many CFCs as are used for the refrigerant itself.

Other substances are already being used, since the use of CFCs in fridges is now outlawed in many countries. Various hydrocarbons can be used as refrigerants along with ammonia. R134a is an example of a HFC which is now widely used for refrigeration, R717 is ammonia. R12 is now widely disused for fridge manufacture.


Any more information, google up the Montreal Protocol.

 

[Astronuc]

I always though you could use water because of its high heat capacity. Nuclear power plants do this, except in this case, for a fridge, an antifreeze would prbably half to be added. And some way of cycling the water, through something that could cool it off quickly, so it could gather more heat again.

Two things to consider - heat transfer - which is a function of $\Delta T$, and the absolute temperature - T_cold.

Using water (without antifreeze) would require a T_cold greater than 0°C (32°F).

Instead of CFC, ammonia can be (and is) used in industrial refrigeration systems. There are however inherent safety issues - e.g. leaking of ammonia (forms ammonium hydroxide, is flammable, harmful if inhaled) - for application in households.

An alternative to the conventional refrigeration cycle is "Ultrasonic Refrigeration" based on "Thermoacoustics" - http://www.lanl.gov/projects/thermoacoustics/

It is recommened to search Google using "Thermoacoustics".

 

[Clausius2]

Using water (without antifreeze) would require a T_cold greater than 0°C (32°F).

Would it not be possible (practical) to design a pressurized water circuit to avoid its freezing?. I mean, if you work with a pressure little above of the atmospheric one, the evaporator could reach less temperature than 0ºC.

 

[Astronuc]

Would it not be possible (practical) to design a pressurized water circuit to avoid its freezing?. I mean, if you work with a pressure little above of the atmospheric one, the evaporator could reach less temperature than 0ºC.

Offhand, I don't believe that it would be practical (but I could be wrong). What pressure level would one consider?