To account for a refrigerant circuit that could become restricted, a commercial refrigeration system's liquid receiver should be sized by how much larger than the total liquid volume in the system?

In commercial refrigeration systems, it's crucial to have an adequately sized liquid receiver to ensure the efficient operation of the system. Sizing the liquid receiver 15% larger than the total liquid volume in the system accounts for potential restrictions in the refrigerant circuit.

A larger receiver provides a buffer that can accommodate fluctuations in refrigerant volume and helps maintain system pressure and efficiency under varying operating conditions. This additional capacity is essential because if the system experiences a restriction due to factors like debris buildup or freezing, having extra storage space for the liquid refrigerant can prevent potential issues like liquid carryover to the compressor, which could lead to compressor damage and system inefficiency.

Specifying a 15% increase strikes a balance by providing enough capacity to handle typical variations while minimizing excessive sizing, which could lead to unnecessary costs or operational inefficiencies. This practice aligns with industry standards that prioritize system reliability and performance by allowing for uncertainties in refrigerant flow.