What should be considered when determining available domestic water pressure for a building?

When determining the available domestic water pressure for a building, it is important to consider the conditions under which the water supply system operates most effectively. Using calculated pressure from summer months is beneficial because it accounts for peak demands that occur during this time. Summer months typically experience higher water usage patterns due to factors such as increased outdoor activities, irrigation systems, and higher consumption by households, which can reveal fluctuations in pressure more accurately.

Additionally, in many regions, summer demands can stress the water supply system more than winter months. This leads to a better understanding of the actual available pressure when the system is under typical usage conditions. Hence, calculating and assessing pressure based on summer usage patterns gives plumbing designers a realistic expectation of the system's performance during peak demand, enabling the design to accommodate potentially reduced pressure conditions.

In contrast, relying solely on past data from five years may not accurately reflect current conditions, while assuming design pressure equal to the stated available pressure can neglect real-world pressures experienced at peak usage times. Also, winter months may not represent typical water demands and may give an overly optimistic view of available pressure due to decreased outdoor water usage. Therefore, calculating pressure during summer months aligns most closely with the needs of the plumbing system in a real-world scenario.