What two components are considered as critical as the four major components of a refrigeration system?

The two components identified as critical alongside the four major components of a refrigeration system are piping and refrigerant.

Piping is essential because it facilitates the movement of refrigerant throughout the system, connecting all components and allowing for the efficient flow of heat exchange. Proper design and maintenance of piping help maintain the system's pressure and ensure that the refrigerant circulates smoothly, which is crucial for the overall efficiency of the refrigeration cycle.

Refrigerant, on the other hand, is the working fluid that absorbs and releases heat as it circulates through the system. Its properties directly impact the system's efficiency, temperature control, and ability to perform its intended function. The choice of refrigerant, its charge level, and how it interacts with the system components is vital for effective operation.

While other options such as intercoolers, receivers, floats, and level controllers are important to specific applications or within particular conditions of a refrigeration system, they do not hold the same fundamental importance as piping and refrigerant which are integral to any refrigeration system's structure and function.