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NC-2009 WEp1:Water Use Reduction—20% Reduction

Pre-rinse valve

The project has a pre-rinse valve with a flow rate of 1.27gallons per minute. How do I estimate daily uses and duration? Thanks!

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Thu, 03/21/2013 - 13:28

Note that if your project is registered after 11/01/11 then the pre-rinse spray valve flow rate must be 1.6 gpm or less in order to comply with the prerequisite, and no savings can be claimed for this fixture (as outlined in the Addenda found here https://www.usgbc.org/ShowFile.aspx?DocumentID=10509 ). If your project was registered before 11/01/11 the pre-rinse spray valve may be included you should provide a narrative and calculations to support a reasonable estimate for the performance values and usage assumptions (duration and uses per day).

Thu, 03/21/2013 - 13:41

Carlie, The project was registered after and the flow rate is less than 1.6gpm. However, when inputting this on the online form, no total daily uses or duration appear as they do with other fixtures. I was wondering if there is a way to estimate these figures? Thanks

Thu, 03/21/2013 - 13:45

Correct, there is no default daily usage for the pre-rinse spray valves. You will need provide a narrative and calculations to support a reasonable estimate for the performance values and usage assumptions (duration and uses per day) and enter this data in the form calculations. Hope helpful!

Thu, 03/21/2013 - 13:59

MD - Since you say that your project registered after the November 1, 2011 Addenda, you can't include the pre-rinse spray valve fixture in the Flow Fixture Table anyways ("no savings can be claimed for this fixture"). Instead, you must only demonstrate that the flow rate is less than the 1.6gpm maximum limit. You are not allowed to estimate the usage rates in as you registered after that particular Addenda was posted. To demonstrate compliance, there are two ways to handle this: 1) If you have form version v4.0 or later for WEp1, you should be putting the flow rate for the pre-rinse spray valve in the separate pre-rinse spray valve section which follows after the Flow Fixture Table. That section has the question asking whether the project includes pre-rinse spray valves or not. When you select yes, a new field appears asking you to input the highest flow rate for the valves in the project. 2) If you have form version 3.0 or earlier for WEp1, you should not include the pre-rinse spray valve in the Flow Fixture Table. Again, as your project registered after that particular Addenda, you're not allowed to claim any water savings for the pre-rinse fixture. Instead, I would recommend writing up a supplemental narrative and uploading it under the special circumstances section which includes information regarding the manufacturer, model number, and flow rate for that pre-rinse spray valves to clearly highlight that it is below the 1.6gpm maximum. That would allow you to demonstrate compliance without having to go through the forms upgrade process.Requesting an upgrade to the most recent form is always an option if you don't want to do the supplemental narrative route. Hope that clarifies how you would need to include your pre-rinse spray valve for this project as it was registered after the November 1, 2011 Addenda. It can be a little confusing if you are looking at an older version of the form.

Thu, 03/21/2013 - 14:22

Carlie, Kristina, thanks! On another note, if we are including toilets for disabled occupants that have different flush rates but we cannot obviously know how many occupants will be there to use them, is there a way of estimating this number or should I just put the number of occupants the same as the number of toilets we will be installing (38 disabled toilets)?

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