Christoph Lohr:
Welcome to The Authority Podcast: Plumbing & Mechanical. When talking about the built environment, we would do well to remember: We shape our buildings, and afterwards, our buildings shape us. Therefore, on each episode, we'll discuss the latest trends from my IAPMO in plumbing and mechanical safety, sustainability and resiliency. Join me, your host, Christoph Lohr, and together we’ll explore the ways we can make our buildings shape us for the better.
Christoph Lohr:
And welcome back to The Authority Podcast: Plumbing & Mechanical. On this episode, we’re going to be talking about structural and behavioral water waste. And I’m very excited to have Mr. Jim Lutz, professional engineer and retired researcher, joining me on this episode. Jim, thank you so much for being part of this.
Jim Lutz:
Oh, it’s a pleasure joining you. Pleasure to talk about stuff I know.
Christoph Lohr:
I was going to say, it’s a pleasure to learn from you. I’m really excited to have you on here because frankly, for me, this is a little bit of being in session with Mr. Jim Lutz and learning from you. And so I’m super excited to do this and then to share your knowledge with our listeners as well. Before we dive into kind of talking about specifically the study on behaviorand and structural water waste, do you want to tell our listeners a little bit about yourself?
Jim Lutz:
Yeah, I was a researcher at Lawrence Berkeley National Lab for a couple dozen years and retired about 10 years ago. Started out there doing the cost-benefit analysis for water heater standards for the Department of Energy, and that got me into hot water. And I’ve been in hot water ever since. It’s a bad pun, but from there it’s not just the water heater efficiency — and they were worried about energy efficiency — it’s also what the water heater’s connected to, the plumbing, how the hot water is distributed, how it’s used, and when you start talking water heaters you tie into water so you get water efficiency and it’s, the whole system got a lot more complicated once I dug into it and I was able to get a bunch of other projects, one of which we’re talking about here. And also through that work I got active in ASHRAE and I’ve been on the ASHRAE service water heating technical committee and was the chair of the water heater efficiency test methods standard that ASHRAE wrote, which is pretty much what’s adopted by the Department of Energy for the Uniform Energy Factor now.
Christoph Lohr:
Excellent. And then, Jim, for our listeners, can you tell them a little bit about what Ernest Orlando Lawrence Berkeley National Laboratory is; some of them might not be familiar with the national laboratory system in the U.S.?
Jim Lutz:
Yeah, it started back actually before World War II. Lawrence was a physics researcher at UC Berkeley, so the lab’s right up the hill from UC. They did a lot of research on radiation. I think that’s where plutonium was first made. They’ve gotten into all sorts of things beyond physics. They still have accelerators up there; they’re doing that. They do astrophysics, they do a lot of fancy materials, they do supercomputers and an energy-efficiency section and on buildings, and that’s where I got in.
Christoph Lohr:
So definitely an official laboratory that has a long history of impacting, you know, the U.S. That’s really amazing. And your role there, you were in the energy analysis department?
Jim Lutz:
Yeah. There were people in that department working on the electric grid and analyzing that, trying to figure out what to do with it. There’s people in there doing building modeling, simulation, indoor air quality, testing lab simulation, windows, researchers there; I was with the appliance efficiency standards part originally and we were doing basically the cost benefit for the energy efficiency standards the U.S. Department of Energy puts on appliances. And I got on there and stepped into water heaters; that’s how I got into it.
Christoph Lohr:
That’s awesome. Now, from water heaters you ended up looking at the plumbing system — specifically the hot water system — and there were two studies that, well, I guess a study that was done and I’m going to share screen here, so let me see if I can get this up and running. So there’s two of them. For our listeners,
Christoph Lohr:
We’ll put this links to each of these studies in the podcast description. But for our audio-video participants, you’re going to be able to see these. So this is the one that I first found, which was released in September 2011, which is of water and energy wasted during residential shower events, finding from a pilot field study of hot water distribution systems, and there was a subsequent one; you sent me this one.
This, I guess, was the follow-up from in June of 2014. That was reducing waste in residential hot water distribution systems.
Jim Lutz:
Yeah.
Christoph Lohr:
And it's kind of the same topic, just slightly different studies.
Jim Lutz:
Well, it’s actually the same study, just an earlier version and a final version. I got an opportunity to take early retirement before we’d done all the analysis on the data, so these are, unfortunately, early results and not as thorough and in depth as I would have liked, but they are what they are, and they do reveal good stuff.
Christoph Lohr:
Yeah, and I was going to say what it reveals is some scientific evidence for structural and behavioral water waste. And I know that's the title of the session.
One of the questions I have for you, Jim, is what kind of discussions or when you were presenting this research, obviously you’re talking a lot about energy and there’s this whole water-energy nexus.
But in terms of water conservation, do you think this is a growing hot-button item in the scientific community of right-sizing water systems to help address water conservation? Again, it’s not the only thing — I’m not saying it’s a silver bullet — but a contributing factor.
Jim Lutz:
It is a contributing factor. And the other thing is because of the structural waste in the showers that I was pointing out, it turns out that low-flow shower heads probably haven’t been doing as much water conservation as you would expect, because if you have a low-flow showerhead, you’ve still got to get rid of all that water in the pipe.
A low-flow showerhead doesn’t save you anything on all that structural waste. It only gives you water conservation during the actual shower itself. So on the water utilities, they’ve pretty much given up on low-flow showerheads as water saving, as water conserving. But I think it’s actually hidden because of the structural waste, sort of hides how much savings a showerhead has.
I mean during the shower they’re definitely using less hot water, less total water. So there are savings there. But the structural waste built into it means just swapping out a showerhead isn’t going to give you the water conservation you would like.
So this has been, well, many of your listeners will know Gary Klein.
Christoph Lohr:
Mm hmm.
Jim Lutz:
This has definitely enforced and informed a lot of his thinking on this, and put some numbers on what he had already been talking about. So when you talk about the efficiency of a hot water system, you don’t want to talk about just the efficiency of the water heater; you’ve got to talk about the plumbing system and all that. It’s also, I think, supported the pipe-sizing work that Dan Cole and those folks have done that’s now in Appendix M if I’m correct.
Christoph Lohr:
Yep, of the UPC; that’s very true, Jim. I think you’re totally right that between Gary and Dan, and Toju Omaghomi and Steve Buchberger from the University of Cincinnati, and I think Tim Wolf and the rest of the team there, the water conservation and energy conservation was a large part of that effort and WE•Stand and researching this.
Jim Lutz:
But that is based on existing systems. So those pipe sizings have this structural and waste and behavioral waste built into them. So if you did your plumbing system, if you put where you’re going to use the hot water really close to the water heater, you wouldn’t need as long a pipe so you could make them skinnier.
Christoph Lohr:
Depending on pressure drop and everything else, yeah. Usually it’s with the calculations we’re using, for like longest length, I think typically for a home, the PSI per feet is going to make too much of a difference from one size to the other on that alone, but there’s a simultaneous usage as well, and that’s ultimately the data that was analyzed for the Water Demand Calculator, was based on how often the fixtures turned on and how frequently those ones were on simultaneously. And so that’s where you get that closer to alignment. You have like a factor of 2X for safety factor with the Water Demand Calculator as what Gary Klein found out when Water Demand Calculator, he presented his work to the state of California to get the Water Demand Calculator adopted there. When you look at the Hunter’s Curve, it’s like 20X depending on your building time. We knew it was grossly oversized because it’s congested use. The Water Demand Calculator was done with no computers in 1940, assuming every building kind of worked like a sports stadium at halftime, which was better than assuming 100% flow.
Christoph Lohr:
I mean, everything on at the same time, which was what it was kind of before. But yeah, I think structural water savings, it’s interesting. I think some people have seen it, others haven’t. I think there was an IGC, trying to remember what it was, but there was an IGC created for a product that tries to control for behavioral water waste and showers.
And you kind of pull the lever. And so that’s where I first became aware of it and started doing digging several years ago. I think for you must be really interesting to see this work that you’ve done now coming back to sort of fruition in an industry.
Jim Lutz:
It takes awhile.
Christoph Lohr:
But it must give you a good feeling. What else was done with the research once you were done? Was there like a peer review process, was it presented at ASHRAE conferences, was it put in academic journals?
Jim Lutz:
I presented it at ASHRAE a couple times. It led to more research at the Energy Commission, work that Gary and Yonda? and I did on trying to characterize this. I think it definitely led to better understanding of the importance of making your hot water system as compact as possible, which is something that plumbing and plumbers don’t really have control over, but you’ve got to talk to the architects and say, No, don’t put the water heater in the garage over here and the kitchen over here; what are you doing that for? All you’re going to do is have unhappy consumers. Put them closer together.
Christoph Lohr:
And then there’s energy and water savings involved. Let me ask this let me ask you this, Jim. When it came to the work, so a national laboratory, when I saw the original report, the one from 2011, it said that the work was sponsored by the Department of Water Resources, and that it was supported by the U.S. Department of Energy.
These are these are government studies, in essence.
Jim Lutz:
Yeah, and funded by the California Energy Commission as well.
Christoph Lohr:
And last word. What would you say to those that think that structural water waste or eliminating structural water waste through right-sizing of piping systems isn’t a viable means of trying to reduce water?
What advice would you give those that are skeptical of structural water waste? What would you say to them?
Jim Lutz:
I would say, Do you remember that time you got into a shower and had to wait two minutes for hot water to get there?
Christoph Lohr:
Yeah.
Jim Lutz:
Everybody’s experienced it. Hopefully not in your own home, but everybody’s seen it. Everybody’s felt it. I don’t see how anybody can argue with it.
Christoph Lohr:
Gotcha. And you think there’s a reason to go toward reducing structural water waste and behavioral water waste in the U.S. to try to help promote conservation?
Jim Lutz:
Of not only energy, but also water. Yes. And unfortunately, the structural waste is literally built into the building. When the building is first built and plumbed, that’s when the decisions are made on how long those pipes have to be and what size they are. And it’s going to be in your house, in the building, for 50, 100 years. Unfortunately, it’s the sort of thing that’s really hard to fix after the fact and really easy to fix before.
Christoph Lohr:
Yeah.
Jim Lutz:
So think about it when you’re designing a house and Christoph, I don’t know how much influence you have or connection you have to architects and designers, but when you’re designing a building, cluster your hot water uses close to your water heater. Then you can use the short pipes and then you can make them skinny.
Christoph Lohr:
Excellent.
Jim Lutz:
That’s where I’d leave it.
Christoph Lohr:
I love it, Jim. Well, on behalf of The Authority Podcast: Plumbing and Mechanical and IAPMO, want to say thank you for joining me on this episode. And I hope at some point maybe we'll have you on again to kind of continue the conversation.
Jim Lutz:
Well, if anybody is going to do this sort of research, I’d be quite willing to help them.
Christoph Lohr:
Excellent.
Jim Lutz:
Point out things not to do.
Christoph Lohr:
I love it, Jim. Thank you so much. Appreciate it.
Jim Lutz:
Sure thing. Good talking to you.
Christoph Lohr:
Thanks for joining us on this week’s episode of The Authority Podcast: Plumbing & Mechanical. Love this episode of the podcast? Head over to iTunes to subscribe, rate and leave a review. Please follow us on Twitter @AuthorityPM; on Instagram @theauthoritypodcast; or email us at iapmo@iapmo.org. Join us next time for another episode of The Authority Podcast: Plumbing & Mechanical.
In the meantime, let’s work together to make our buildings more resilient and shape us for the better.
