Mechanical Engineering - Heat Transfer, Refrigeration and Air Conditioning - Discussion

The correct answer is: Ammonia.

Ammonia (R-717) has a freezing point of -77.7°C (-107.9°F), which is the lowest among the options.

Here are the freezing points of the other options:

- R-11 (Trichlorofluoromethane): -111°C (-168°F), but it's already phased out due to its high ozone depletion potential.
- R-12 (Dichlorodifluoromethane): -157.6°C (-251.7°F), but it's also phased out due to its high ozone depletion potential.
- R-22 (Chlorodifluoromethane): -160.5°C (-256.9°F).

Ammonia is widely used as a refrigerant in industrial applications due to its excellent thermodynamic properties, low cost, and low environmental impact. However, it's toxic and flammable, requiring special handling and safety precautions.

R22 which can change its medium at very rapid way. So which is used in as comfortable way?

R22 freezing point temperature is -160 Celsius, i.e. -256 F.

Freezing Points:

R11 - 168 F.
R12 - 252 F.
R22 - 256 F.

Correct. The R22's freezing point is -160C.

Correct. R22's freezing point is -160C.

Correct answer is ammonia.