HVAC Metering Devices Practice Test

The pressure drop in a capillary tube is influenced by several factors, which include the length of the tube, the inside diameter, and the number of turns or bends the tube makes.

The length of the capillary tube plays a significant role because a longer tube introduces more friction against the refrigerant flow, resulting in a greater pressure drop over the distance. The inside diameter also matters; a smaller diameter increases resistance to flow, leading to a higher pressure drop. Likewise, the configuration of the tube, including the number of turns, can create additional friction and turbulence in the refrigerant flow, further contributing to the pressure drop.

When taking all these factors into account, it becomes clear that they collectively determine the overall pressure drop from the condenser to the evaporator in a vapor-compression refrigeration cycle. Therefore, acknowledging that all these characteristics influence the performance of the capillary tube justifies selecting the answer that encompasses all of them.