What Is the Maximum Ambient Temperature for Effective Refrigeration with R-134a?

[noo1]

Homework Statement

A refrigerator uses R-134a as the working fluid and operates on an ideal vapor compression refrigeration cycle between 0.15 MPa and 1 MPa. Mass flow rate is 0.05 kg/s. If a minimum of 5 deg-C difference is used in the condenser design for effective heat transfer, what is the maximum value of the atmospheric temperature under this operating condition?

Homework Equations

The Attempt at a Solution

No idea. Wouldn't it not matter since its atmospheric temperature? Or would it be the lowest temperature in the cycle?

 

[BvU]

The working fluid has to evaporate at the lower pressure and to condense at the higher pressure. The saturation temperature at the higher pressure has to higher (by five degrees as specified) than the ambient temperature. That sets an upper limit to the ambient temperature !