How should demand be estimated for a system with both continuous and intermittent fixtures?

Estimating the demand for a plumbing system that incorporates both continuous and intermittent fixtures requires careful consideration of how each type of fixture operates. Continuous fixtures, such as faucets or toilets, contribute a steady flow of water over time, while intermittent fixtures, like showers and washing machines, are used in bursts or for shorter durations.

To achieve an accurate demand estimation, it is critical to evaluate the demands of these fixtures separately. Continuous demand is typically calculated on a per-hour basis, representing the ongoing usage of water. In contrast, intermittent demand involves assessing peak usage periods and the flow rates during those times.

By estimating continuous and intermittent demands independently, the designer can account for variations in usage patterns and operational characteristics of each type of fixture. This method ensures that the system is adequately sized to handle both the base load from continuous fixtures and peak demands from intermittent fixtures without causing issues such as low pressure or inadequate supply during high demand times. Once the separate demands are calculated, they can then be combined for a comprehensive estimation of the system's total water demand. This approach provides a more accurate and reliable calculation, leading to optimal plumbing system performance.