I have received my second metered lav faucet submittal with less than 12 sec from factory duration. This American Standard faucet is a 0.35 gpm faucet that is factory set for 7.5 seconds for a 0.044 gpc. I am aware that LEED does not permit a duration less than 12 secs in the metered faucet calcs because they don't believe that hands can be washed effectively in less than 12 seconds.
Obviously I can do the calc with 12 secs despite the duration noted, but my concern is that the faucet itself may be rejected for the shorter preset duration. Am I supposed to reject this faucet or have it manually reset to a longer duration because it's too much water reduction?
Charles Nepps
NH Green Consulting97 thumbs up
March 4, 2015 - 5:56 pm
That's an interesting question. Yes, LEED requires you do the calcs and determine the gpc based on 12 seconds, but obviously with a factory pre-set of 7.5, if it's activated twice, for a thorough hand washing, that would be 15 seconds. The reality is that it will average out over time: some 7.5 sec, some 15 sec, some 0 seconds. Just enter the value based on a 12 second cycle and you'll be fine.
Michelle Rosenberger
PartnerArchEcology
519 thumbs up
March 4, 2015 - 6:36 pm
Hi Charles,
I agree that is probably what the answer will be, but I find the issue interesting because it is a conflict of imperatives - water reduction vs. "effective handwashing duration". When this duration cap was originally set, it appeared to be within a context of people trying to game the calcs for points. And that made sense, despite the somewhat arbitrary seeming number 12.
But now the industry has responded with even lower fixture durations and this approach disincentivizes water reduction below a certain level. While I don't disagree with your comment about activating it twice and averaging, that could also be said of all the low flush fixtures, particularly dual flush, and we are not obliged to overstate their use.
Charles Nepps
NH Green Consulting97 thumbs up
March 5, 2015 - 3:05 am
Michelle, I agree; whether or not LEED guidelines accurately predict individual behavior is difficult to say. I would assume as more actual water usage data is collected from certified projects and compared to the predicted performance, the guidelines will be refined. My gut feeling is the current limits probably overstate water usage in most public/office restrooms.
Jean Marais
b.i.g. Bechtold DesignBuilder Expert832 thumbs up
March 5, 2015 - 5:01 am
The installation time limit doesn't matter for LEED. In LEED theory, if the setting is 5 seconds, the user will switch the faucet on enough times to reach the 12 second limit.
Michelle Rosenberger
PartnerArchEcology
519 thumbs up
March 9, 2015 - 11:53 am
FYI, answer as expected is "Projects should use a 12 second design case duration for LEED calc purposes, which allows projects to earn some savings for autocontrol faucets, but not for the durations where users are likely to reactivate in order to fully wash their hands. As such projects may select faucets with cycles of any duration, and may set those faucets as they see fit".
Charles Nepps
NH Green Consulting97 thumbs up
March 9, 2015 - 12:41 pm
Interesting. Does the faucet have a proximity sensor, or is it simply on for 7.5 seconds, then off`? I have had success with faucets pre-set to turn off after 6 seconds, once hands are removed from the "active range".
Ashley Hu
Jr. Sustainable Building AdvisorPerkins+Will
8 thumbs up
January 18, 2018 - 8:30 pm
Hello everyone,
can someone please point me to the section where the Canadian reference guide prohibits the use of less than 12 seconds for the duration of a lavatory faucet? Please note that I am using the LEED Canada Reference Guide for Green Building Design and Construction 2009. I see that on page 172 of the reference guide that 12 seconds is defaulted, but it does not appear to prohibit the use of a shorter duration.
Thanks in advance!
Carlie Bullock-Jones
PrincipalEcoworks Studio
LEEDuser Expert
220 thumbs up
January 18, 2018 - 9:22 pm
Hi Ashley,
You're not prohibited from using/installing an auto lav with a shorter duration; but durations less than the 12 second default are not permitted for LEED calculations since shorter intervals are considered insufficient for typical hand washing.
Navisa Jain
APMSBS, EllisDon
3 thumbs up
June 21, 2018 - 11:17 am
Hello everyone,
I am using the LEED Canada Reference Guide for Green Building Design and Construction 2009. which states default 12 seconds for the duration of a lavatory faucet (page 172). Assuming that the duration of use, number of users, and uses per person per day must be the same in both the baseline and the design cases, if factory setting for metered faucet is at 45 seconds, can Baseline duration also be changed from default 12 secs to 45 seconds?
Thanks in advance