What should the pan be larger than, according to code?

The correct choice indicates that the pan must be larger than the dimensions of the unit or coil. This requirement is significant for effective drainage and to ensure that any condensate that forms has adequate space to collect and flow away from the unit. A pan that is larger than the unit or coil helps prevent overflow and potential water damage, guaranteeing that the system operates efficiently and without interruption.

When a pan is appropriately sized, it can accommodate changes such as fluctuations in condensate production—especially in air conditioning systems—thereby minimizing the risk of leaks or spills. This is crucial for maintaining indoor air quality and protecting building infrastructure.

Other options, while they might pertain to different aspects of system design or operation, do not specifically address the direct need for condensate drainage and overflow prevention as tied to the size of the pan relative to the unit or coil dimensions.