I am posting this comment here in addition to the CI forum because there haven't been any responses to questions posed on that forum and I am hoping to get Dylan's take on the removal of the metered faucets in the design case.
Dylan, you said in a comment above in response to a PSI question that "LEED is about fixture efficiency selection rather than actual operating habits". That has been consistently the case before. For example, even though dual flush toilets are flushed by many users more than once, we have never had to deal with the behavior side of the potential savings provided by having one. So why the change here on metered faucets?
On commercial projects, this change is a brutal blow. There are very few places to get significant reductions against baseline flow rates. Urinals and lav faucets being primary among them. Adding more point thresholds opportunities feels like just adding insult to injury when there don't seem to be any realistic ways to get there with water fixtures alone.
It seems like there are times that LEED is all about reflecting the reality of usage and times when they subjectively decide the way things should be. I find this issue particularly interesting when you consider the 50/50 gender directive which is often not the reality of a specific project's actual usage but is always an assumption we are required to make. So much for consistency. What's your take on this issue?
PS. It's also very confusing to have a water reduction calculator that looks identical to v4 but is actually for v2009 and leaves the metered faucet calculation in there. A whole lot of room for error.
Dylan Connelly
Mechanical EngineerIntegral Group
LEEDuser Expert
472 thumbs up
August 11, 2016 - 12:24 pm
Michelle,
I don't have the exact history on the meter faucet item. But IMO metered faucets are a water waster so I'm glad they took it out. I'd sometime just wash my hands for 3-4 seconds and it would run until 6 seconds. Or I'd want to wash my hands for 8 seconds and I'd have to pull out then put my hands back in to get it to start again.
Just slap some low flow aerators on there and call it a day. The water consumption from lavs is extremely minimal anyway especially when they are low flow.
It was BS that the calc pretended that people wash there hands for 12 seconds. Maybe 5% people do that. This is on top of the fact that only 12% of our country's water consumption is even in buildings. Mostly agriculture. It would be better to put a sign up that says use as much water to wash your hands as you want but just don't eat red meat.
Takayuki Hirota
izumi CONSULTING, Inc.7 thumbs up
September 20, 2017 - 2:44 am
I am also confused to see LEEDuser’s viewpoint that express the metering faucet are no longer allowed.
In the reference guide, Step 3. Complete calculations, Compliance Path 2. Usage-Based Calculation, STEP-BY-STEP GUIDANCE, it says;
Metering faucets measured in gallons (liters) per cycle (gpc, lpc) and cycle duration in manufacturer’s documentation must be converted to a flow rate in gallons (liters) per minute (gpm, lpm). Use Equation 2 to perform the conversion.
It looks like we can still count the metering faucets for water reduction but metering fixture type is no longer listed in the calculator like we used in the v2009 online form so that we need to convert to flow per minute. Otherwise, is there any addenda, interpretation or a new guidance released?
Nathan Gauthier
Director of FM Integration and SustainabilityShawmut Design and Construction
22 thumbs up
September 20, 2017 - 7:41 am
My understanding is that the reduced duration component of a metering faucet no longer counts as water savings. It isn't that you're not allowed to use them, but you can only show savings if the GPM is reduced compared to baseline (0.5 GPM for public lavatory faucets). You can show a reduction in flow rate if they are low GPM, you cannot show a reduction in flow duration in seconds. Below the step-by-step guidance you reference where it tells you to convert to GPM, it says "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." Since the duration of use is the same in both (30 seconds for public lavatories), you no longer can claim a few seconds less duration compared to manual on/off. This is reiterated in the section "Default Durations and Uses" where it says duration of use must use the defaults from Tables 8 and 9.
Takayuki Hirota
izumi CONSULTING, Inc.7 thumbs up
September 21, 2017 - 12:18 am
Thank you, Nathan. Now I see that.