Temperature Systems Inc.

Compressor Failures

Part 2
By Glenn Minch

If a refrigeration or air conditioning system fails or is not performing according to design the focus is almost always directed to the compressor.  After all,  the compressor makes the most noise so our attention naturally goes to the component of the system doing the work.  In all reality the “boss” of the whole system is the evaporator.  The “work” we need to do is remove heat from a refrigerated space.  The evaporator needs to perform at its design capacity to achieve our goal.  A poor performing evaporator not only affects the room or product temperature but also has an effect on the life of the compressor.  That being said, we must make sure that the evaporator is set up to optimize efficiency and performance.  Listed below are a few evaporator issues that have an effect on compressor life.

• Coil cleanliness……..May cause liquid flooding back to a “vapor” compressor.
• Improper air flow…..Same result as above.
• Too much evaporator superheat……….High return gas temperature causing overheating on a suction cooled compressor.
• Not enough superheat……….Liquid flood back to  a “vapor” compressor.

  

There are times when an evaporator may experience changing performance due to increased or reduced loads.  At that point we need to look at system protection components like suction accumulators, etc.