What is referred to as the vertical tube that carries refrigerant from a lower to a higher level?

The riser is the term used to describe the vertical tube that is designed to transport refrigerant from a lower elevation to a higher elevation in a refrigeration or air conditioning system. This component is crucial in systems where refrigerant needs to be moved vertically, such as in multi-story buildings or among different levels of equipment.

The riser allows gravity to assist in the movement of the refrigerant, facilitating efficient circulation through the system. It helps maintain proper flow rates and ensures that the refrigerant reaches the necessary components at the higher level where it can undergo expansion or condensation, depending on the cycle phase.

Understanding the role of a riser is essential for proper installation, maintenance, and troubleshooting of HVAC systems, as any obstruction or malfunction in this vertical transport tube can lead to decreased system efficiency or operational failures.