Hi everybody,
I´ve already filled out the template, but I´ve a doubt. In the design building we have installed faucet with a min pressure of 7.25 psi, max pressure of 21.76 psi and 1.59 gpm.
The Baseline building has 2.2 gpm and 60 psi.
Should I consider also in the Design building a pressure of 60 psi? Or the pressures can be different?
Thank you in advanced.
Pietro.
Bill Swanson
Sr. Electrical EngineerIntegrated Design Solutions
LEEDuser Expert
734 thumbs up
February 26, 2010 - 2:57 pm
Yes, at 60 psi. I remember reading a CIR asking about gpm at different psi for some multistory dorm building. The response was that you had to use the gpm value at a standard psi for all fixtures which I think was 60 psi.
Bill Swanson
Sr. Electrical EngineerIntegrated Design Solutions
LEEDuser Expert
734 thumbs up
February 26, 2010 - 3:37 pm
here's the wording of the actual CIR ruling.
8/27/2004 - Ruling
[Note: this ruling was revised on 9/1/04.]
The underlying assumptions used for calculating projected water use savings should remain consistent between the baseline and design case. Supply water pressure varies across the United States and within individual buildings (as you note in your inquiry). Flow rates at 80 psi are used for the calculations in this credit for consistency and to reward use of efficient fixtures. It is recommended that all projects use the flow rates reported by the manufacturer at 80 psi for comparison with the Energy Policy Act of 1992 flow rates. If you wish to use on-site tests to report the most accurate volume of water use, you must be consistent throughout all fixtures and test both baseline and design fixtures. It is not acceptable to use flow rates at 80 psi for some fixtures and actual flow rates for other fixtures. Measurement can also be used to account for the benefits of whole-building strategies, e.g., flow restrictors at the water service entrance.