Which of the following scenarios would result in increased operating temperature in an HVAC system?

Increased friction among components within an HVAC system directly leads to higher operating temperatures. When there is excessive friction, energy is lost in the form of heat due to the resistance encountered by moving parts. This not only raises the temperature of those components but can also affect the overall efficiency of the system, causing it to work harder to maintain the desired temperature in the space it is conditioning.

In a well-functioning system, components are designed to operate smoothly with minimal friction, which allows for efficient energy transfer and heat exchange. If friction is increased due to factors such as wear, inadequate lubrication, or misalignment, it results in elevated operational temperatures that can lead to overheating and potential damage to the system.

Other scenarios, such as having proper refrigerant levels, excessive lubricant flow, or optimal outdoor temperatures, do not contribute to an increase in operating temperature in the same manner. Proper refrigerant levels are necessary for efficient heat exchange, while excessive lubricant flow can actually help reduce friction, and optimal outdoor temperatures support efficient operation rather than hinder it.