Hi all,
I have a question in regard to the flowrate of faucet, whether it should be based on the 60psi specified by LEED or local water supply pressure. There have been a few discussions on this subject previously in this forum. However, could someone please help me to rationalize it again accounting my following comments.
1. Understood that the baseline is using 60psi and therefore if the design case is referencing to actual supply pressure, it seems unfair. From my literature research, 60psi is the maximum supply pressure outlined in the design code of USA while the actual supply pressure may vary. Therefore, the base annual water usage calculation per LEED instructure would be the maximum allowable water usage. To compare to that, it makes perfect sense that design fixture flowrate should be input under the same condition. However, for international projects, the water supply pressure by code is actually quite different. In China, the maximum water supply pressure is 30psi. By theory, the water flowrate would drop by roughly 1.4 times. the reduced flowrate may not be very functionable and pleasant to use at the actual flowrate when further reduced to gain points under LEED. Essentially, we are trying to save amount of water consumed rather than sacrifice on the functionality.
2. Then this comes to the point that if we are comparing flowrate at the maximum allowable supply water pressure, would this be considered a task of comparing apple to apple even though we are not referencing to the same code? Should we then use local water saving code to determine the water usage reduction? What is then considered as elegible local equivelent by LEED?
Your inputs will be highly appreciated as this is bugging me for a while.
Thank you very much.