Concerning air-conditioning system hot-water heating coils, what statement is true?

Correct Answer: Option C — Steam heating coils are usually the serpentine type and horizontally installed.

Hot-water heating coils utilize a serpentine design to maximize the heat transfer surface area and ensure uniform fluid flow through the tubes. Horizontal installation is standard to prevent air pockets from forming within the coil, which would otherwise cause localized overheating or flow restriction, ensuring consistent heating performance throughout the unit.