Which factor is least relevant when sizing a cold water storage tank?

• A. Building height
• B. Color of external cladding
• C. Water demand
• D. Venting/overflow requirements

Answer: (B)

When sizing a cold water storage tank, the key factors are how much water is needed (water demand) and the pressure head available to deliver that water (which depends on the building height and the venting/overflow design). Water demand determines the required storage volume to cover daily and peak usage and to provide a cushion during fill cycles or outages. Building height influences the static head—the vertical distance from the tank to the fixtures—which affects the pressure at outlets and, in turn, the need for pumps or adequate gravity feed. Venting and overflow requirements are essential for safe operation, ensuring air can escape during filling and that the tank has a safe discharge path if it fills beyond capacity.

The color of the external cladding does not impact any of these hydraulic or safety considerations. It might affect heat absorption to a degree if the tank is exposed to sunlight, but that does not change the sizing calculations for capacity or pressure.