Which of the following elements is key for the successful operation of a chilled-water system?

Chilled-water flow is a critical element for the successful operation of a chilled-water system because it directly impacts the efficiency and effectiveness of cooling provided to the spaces being served. This flow ensures that the chilled water circulates properly throughout the system, absorbing heat from the interior spaces and transferring it to the cooling equipment, typically the chiller.

Maintaining the correct flow rate is essential, as it affects both the temperature of the water entering and leaving the cooling coils and the overall energy efficiency of the system. If the flow is inadequate, it can lead to insufficient cooling, poor comfort levels, or even system strain, which may result in equipment failure or increased operational costs.

In contrast, while refrigerant type, cooling tower design, and thermostat accuracy play important roles in the broader context of heating, cooling, and temperature control within a building, they do not specifically address the immediate requirement of maintaining an optimal chilled-water flow, which is fundamental for the primary function of the chilled-water system.