Lavatory Baseline Flow GPC

As per the guidance in the Water Use Reduction Additional Guidance document dated December 1, 2009 and updated August 16, 2010, “When using a metering (or autocontrol) faucet, please select the Metering Lavatory fixture in the Fixture Type pull-down menu of the Flow Fixture Data table. The Baseline case flow rate for a metering faucet is .25 gallons per cycle (gpc). Since the flow rate is measured in gallons per cycle, the duration is not necessary. Therefore the Duration can be disregarded and should not be modified for the metering lavatory fixture type. The “Installed” flow rate must also be entered in gallons per cycle. If the flow rate in gallons per cycle is not known, the value must be determined through a separate conversion calculation and then entered into the table. The flow rate is determined using the flow rate in gallons per minute (gpm) and the duration setting (in seconds) for the metering faucet. The typical duration setting for the installed metering faucet is 12 seconds, however a different duration may be used if supported by manufacturer’s specifications.” To sum, the baseline case flow rate for a metering faucet is 0.25 gallons per cycle (gpc). The design case flow rate should also be entered into the LEED Credit Form in gpc. However, if gpc is unknown for the design case, the project team may calculate the gpc by multiplying the flow rate times the duration, and divide that number by 60 seconds.

Carl, did you ever receive any guidance on the assumption of using 12seconds as the average for the "on demand" lav's? Please advise

Carl and/or Lorey, I have the same question about the assumption of 12 seconds average for the "on demand" faucets. Please let me know if you've got any info. Thanks!

Does anyone have new information about this? We have recently been made aware that our auto-sensor faucets come from the factory with a 30 second preset. This means if you hold your hands under the faucet continually, the faucet will shut off after 30 seconds. If you remove your hands the faucet shuts off. We have interpreted this as a 30 second cycle. The faucets can be reset in the field to 13.75 seconds, which we are doing so we can use a 13.75 second cycle time. Are we interpretting this correctly?