Dee Davis (00:00)
Good morning and welcome to the management under construction podcast. I'm your host, Dee Davis, and I have so much exciting news for you today. I am getting ready to go on a European vacation. Vacation is something I don't do very often. I don't do it enough. I'm trying to take your lead and take a little bit of time for myself. But in the meantime, we want to make sure that we keep bringing you great content. So what I've done for you today,
is we are going to re-listen to our most popular episode on Legionella. it started out as a blog. I took a class from the American Society of Plumbing Engineers years and years ago on Legionella. And it stuck with me. as something that we never talk about. We don't really pay enough attention to. And
these Legionella outbreaks happen from time to time. They happen more often than we really talk about. Once in a while, it'll be a big outbreak and it hits the news. That led me to writing a blog a couple of years ago about Legionella, which is some facts and figures. And here's the temperature range that Legionella likes to live in. Here's the environments it's in. Here's some of the risks to us in construction. And I kind of left it. Not a lot happened with it. It didn't strike.
a lot of chords at that very moment. Fast forward a couple more years and I decided to write a podcast episode about Legionella. That thing has gone off the charts. If you haven't listened to this episode yet, now is the time. As I'm on vacation and taking a slight little break from the podcast, you're going to get a chance to listen to our most popular episode by a long shot.
Not only has this episode been popular, I have been contacted repeatedly about doing classes on Legionella. This is something that we need to pay attention to in our designs, in the construction, in the operations and maintenance of the buildings that we live and work in. So I've put together a Legionella course that I've submitted to AIA for certification for ongoing education credits. So stay tuned for that.
So you get some updates on some information on the Legionella course that you'll be able to take on demand on my website. Then I've also developed an in-person Legionella training course for designers. we'll be giving that in-person or on demand for ongoing AIA credits as well. I'm super excited about this. this has inspired me.
to submit this class for additional construction education certification through ACCE. So ACCE, if you're not familiar, is the American Council for Construction Education. It is the number one accrediting body for construction education in the industry. I've been an ACCE member for a few years. I got my TLP certification through them. And I'm going to go ahead and submit this one and probably a few other of my
ongoing courses for certification. So stay tuned for some of that update as well.
Dee Davis (03:04)
And the last tie-in that we're going to have for you with Legionella is we are going to have in a future episode, Tom Hobbs. He is a local water wizard. also happens to be my brother. So I might be a little bit prejudiced, but he is a industrial water treatment expert. Tom, make sure that all our boilers or chillers are
cooling towers, all that stuff stays nice and healthy in these buildings. I'm going to have him on as a guest very soon. We're going to talk about why water treatment is so important for preventing the spread and growth of Legionella, as well as all kinds of other nasties that can happen in our building systems. So stay tuned and listen to our Legionella episode. Thanks and have a great week.
Brad Wyant (04:00)
Good morning and welcome to management under construction. I'm Brad Wyant.
Dee Davis (04:04)
And I'm Dee Davis. And today we are going to talk about managing the risk of Legionella or Legionnaires disease through design, construction, operation, and maintenance. Brad, what have you heard about Legionella? â
Brad Wyant (04:17)
Not a whole lot.
I only heard about it a little bit when I was working on a bigger project where we had cooling towers. If you don't do that right, it could kill people. was like, what? They said, it probably will be fine. And then I was like, okay. And moved on with the rest of my day. I didn't really register it as a risk and wasn't directly involved in implementing those cooling towers. So I didn't get a whole lot into it, but I'm excited to learn about it today.
Dee Davis (04:41)
thing that isn't talked about very much in the industry, and it really should be talked about more because it's really a pretty interesting situation that we have in the industry. There's a lot of opportunities to get it wrong. We can manage it through how we design it, how we build it, how we operate it, and how we maintain these various systems. So, you know us, we're going to do a quick little history lesson before we dive into the topic.
Legionella or Legionnaires disease was discovered in 1976 after an outbreak in Philadelphia, Pennsylvania at an American Legion convention. So of course it existed before 1976, but we didn't really know what it was before then. This bacteria, which is what it is, it was present in the hotel's air conditioning system. The Legionella has
pneumonia-like symptoms causing a bacterial infection of the lungs. Symptoms are typical flu pneumonia type symptoms, off muscle aches, fever, headache, all those kinds of symptoms. It's treatable, but here's the thing, it's fatal about 10 % of the time. So that's kind of a big deal. In the 1976 outbreak, 25 people died. And like most diseases, the people that are most vulnerable
have compromised immune systems of some kind, respiratory systems or other kinds of comorbidities. There's about 8,000 cases per year, which is not a lot. But when you consider that 10 % of those people are going to die, that's kind of a lot of people. I'm a member of the American Legion. I can tell you that most of the members are older. And that's probably why so many passed. A lot of them probably had other health issues that aggravated it.
Outbreaks of Legionella are commonly in drinking water, fountains, hot tubs, evaporative condensers, and cooling tower systems. Legionella is naturally occurring bacteria that thrives in manmade water conditions that are not properly maintained. It's transmitted by airborne water droplets. So when water is aerated in any way, like when it's brought through a cooling tower, when it's brought through an aerated faucet,
And in a drinking water situation, fountains, hot tubs, things like that, it's more easily transmitted to humans through the aerated droplets that we then inhale. And that's how we end up getting Legionella. And by the way, drinking water chlorination does not kill it. So that's not an odd answer. Okay. Yeah. So we have to prevent it from growing in these manmade systems that we design and install.
We have to prevent it from growing through design, construction, operations, and maintenance so that we don't have these kinds of problems in buildings. We had an outbreak recently. In July, 2025, there was an outbreak in Harlem, New York. 90 people were diagnosed. Three people died or three people have died so far. This is August that we're recording this episode. So it's possible that.
more people could die from that outbreak. Interestingly, New York passed a law about 10 years ago requiring registration, inspection, cleaning and disinfection and testing of systems that can grow Legionella. And the outbreaks have only risen in New York. They're actually leading the nation right now in Legionella outbreaks.
Wow. Studies show that there is a clear link between heavy rainfall and an increase in outbreaks. And before we started recording, Brad and I were talking about this episode and you said it seems like there's more outbreaks back East than there are in the West. This could potentially be one of the reasons is that it's linked to heavy rainfall. And this latest Harlem outbreak occurred about 10 days after a heavy rainstorm.
which is the incubation time for Legionella, not surprisingly.
Brad Wyant (08:43)
So how did the rainfall connect to the infection? Is the rain impacting people when it falls on the street and it's just misty out? Or is there something going on between the building system and the rain?
Dee Davis (08:57)
There's certain types of fixtures where it might be more predominant. So like if you have a cooling tower, that water is recirculating back. It's an open system. And so it's open to the atmosphere. You get rainfall in and you're constantly introducing new things into the system. If you're getting rainfall in and you're recirculating that back into your building system, the same thing can happen with an evaporative condenser. And it can happen with
open fixtures like fountains that are recirculating water in. You're getting the rainfall in there. It's naturally occurring bacteria, I don't forget. So you're getting all these environmental things that could also have to do with temperatures during rainfall events. There's certain temperatures that Legionella really likes and rainfall events kind of fall into that category. We'll talk more specifically about the temperatures that Legionella likes to grow.
Brad Wyant (09:53)
So Legionella is a bacteria that causes Legionnaires disease. It's related to respiratory issues and the bacteria grows under certain conditions that we can prevent or cause with good or bad design in our buildings. Is that about sum it up? Yes. All right. So let's talk about design. What can we do to prevent this bacteria from growing in our building systems?
Dee Davis (10:16)
Well, we need to avoid dead legs. So a dead leg in a piping system is a leg or a section of pipe that has water in it. It's wetted, but doesn't get circulated. So that's what we call a dead leg in design. So if it's not circulating or seeing regular flow of water, it's considered a dead leg. We need to avoid those because all kinds of little buggy bugs can grow in dead legs of pipe. And it doesn't matter what kind of system it is. It's a bad thing.
to have a run of pipe that doesn't see circulation. We want to avoid designing systems that run in the Legionella hot zone, which is 77 to 113 degrees. Or for those of you who operate in Celsius, that's 25 to 45 C. One thing that I've noticed in building designs recently is the introduction of tepid water systems. This is a really interesting.
challenge that we have presented ourselves here. We're trying to solve one problem and we're sort of creating another one in design. I've had three or four different design reviews that I've done in the last couple of years where tepid water systems have come up. The reason we're starting to see these is there was a code change a number of years ago that says we're required to provide tepid water and the ANSI definition of tepid is 600... I'm sorry.
the ANSI definition of to 60 degrees to 100 degrees Fahrenheit for eye washes and safety showers instead of just whatever comes out of the cold water line. These are emergency devices that are found in laboratories and anywhere where there's chemicals in buildings. Imagine you're working in a lab or you're working somewhere there's chemicals, you get splashed with chemicals, you need to rinse those off of you. We go to an eye wash or a safety shower for that. We'll imagine you go over there
and it's ice cold water, that's not fun, especially in the winter time. Splashing all over you, you're probably not going to adequately rinse that off. What we've done traditionally in these eye wash and safety showers, we've provided warm water at the point of use by running hot water line and a cold water line and using a mixing valve right at the eye wash or the safety shower. And we mix it right there so that it comes out warmish, tepid, right?
that's a little bit more comfortable for the person that is having to do that. Have you ever had to use an eye washer or safety shower?
Brad Wyant (12:38)
No, thankfully I have seen them. I've put them in and I have always thought, boy, that would stink to be in a situation where you have to use that. There's a lot of dangerous chemicals in the plants that I've built and you just don't want to ever be in an instance where you're risking your eye safety. Wear your safety glasses everybody. Wear your goggles or whatever PPE you have to wear because having to use an eye wash station is a bad day.
Dee Davis (13:02)
It's a very bad day. I've had to have my eye flushed before it wasn't a chemical I got something in my eye and the safety person had to come and like Forcibly flush my eye that was not pleasant I can tell you and it was not tepid water It was room temperature water, which is a little bit colder than you really want it to be for that But you got to flush for a long time to get something out of your eye
It's not fun. So you don't want to be slamming people with cold water or hot water when they have to use these. So in an effort to minimize cost, which is something that we're always trying to minimize cost in construction, somebody said, Hey, why don't we put a tepid water loop instead? And we'll just have it feed the eye washes and the safety showers. And then that way we don't have to run separate services to all these.
and by mixing valves that then need to be maintained and replaced. Sounded like a great idea. And so the tepid water loop is born. Here's the problem. Tepid water runs between 75 and 90 degrees, which is the sweet spot for Legionella.
We want it to be comfortably warm without it being scalding. Lots of bacteria besides legionella grows in that temperature range. And these fixtures, again, are not used except in the event of an emergency. They are the absolute definition of a dead light.
Brad Wyant (14:28)
And as far as building maintenance goes, there are probably a million things further up on somebody's priority list. If they're running a plant that has a safety shower and an eye wash station to try to keep people safe, to try to make the building profitable above this kind of thing. One of those things that gathers dust in everybody's building, or at least they hope it does, that it only is needed if you really, really need it, which is very infrequently.
But when you need it, you really do need it. So expecting somebody to do something like flush that dead leg once a week would probably be a pretty egregious requirement. It would be an undue, odorous burden for somebody to take on.
Dee Davis (15:10)
When I started seeing these tepid water loops come into designs a couple of years ago, I already know what building maintenance does on a regular basis. When you're working with labs, hospitals, places like that, they do flush certain fixtures on a regular basis. It's not weekly though. It's monthly. It's typically, and when you've got just hot and cold water in a mixing valve, monthly is all that's required because your dead leg isn't
sitting at that, the temperature that grows this kind of stuff. So your dead leg is sitting at room temperature.
Brad Wyant (15:46)
Like you said, the incubation is 10 days. So 10 days you're flushing maybe once a week. And that's a lot of, that's a lot of flushing.
Dee Davis (15:53)
Exactly. So that was the first question that I had when I saw this start popping up in designs. said, Whoa, whoa, whoa. Have you talked to facilities maintenance about this? And they're like, what do you mean at this temperature that you're circulating? You would have to flush these fixtures weekly. And they said, well, don't they already do that? And I said, no, I'm going to guess that they flush monthly, but ask them. And they went and asked and facilities maintenance said, we're not doing that weekly. There's no way we can. Are you kidding? It would be a full-time job. Somebody.
And this is a larger facility that had a lot of eye washes and safety showers. And they said, we'd have to hire somebody to just go around and flush fixtures all day, every day in order to do it weekly. Flushing isn't just turning it on for a second. In facilities where you have all these chemicals and solvents and stuff, you're not allowed to put floor drains underneath these showers and these eye washes. So you have to run a 55 gallon trash can on wheels.
underneath the safety shower and you have to let it run for several minutes to really flush the water out. So it's a very manual process.
Brad Wyant (16:59)
Okay, let's divert for a moment because I'm interested in what you just said. You can't have a floor drain under an emergency shower.
Dee Davis (17:06)
In a lot of facilities you can't because of the chemicals because if you think about it, if you put the floor drain there, the floor drain then has to tie in where's it going to go. You've got chemicals that you're washing off. Now it's a chemical drain. You don't know which chemicals are going to be there. You don't know the volume of chemicals that are going to be there. It can't go into the sewer.
Brad Wyant (17:29)
you'd have to plummet to some waste line that may not even exist in the building systems.
Dee Davis (17:34)
hard to say. So in most jurisdictions, you are not allowed to put a drain under a safety shower. It depends on what they're doing in that space. I've seen it in some spaces, but in most spaces, we get told no.
Brad Wyant (17:47)
solution because it's like, okay, well, you can't drain it to the sewer, but you can splash it all over the floor of your controlled facility where everyone else is going to try to be working where it might be so acidic that it chews through people's shoes. That's a great idea. Yeah, totally.
Dee Davis (18:04)
Well, that's what PPE is for and, and training and there's proper cleanup procedures in a facility like that.
Brad Wyant (18:11)
It goes to some waste stream eventually. It's just interesting. I'll give my final thoughts at the end. don't want to spoil it, but there's certainly a lot of best intentions gone awry is a theme I'm seeing in these regulations and these ideas here.
Dee Davis (18:24)
Well, a conventional sewage system is not equipped to deal with acid waste and base waste and things like that. The piping that is on a typical drain is not intended to deal with that. The system that it goes through is not intended to deal with that or reduce that. Usually in these kinds of facilities, any cleanup that you would have to do from a spill like that gets put in a very specific container and is hauled away by a trained
third party company that then properly disposes of it. Now, what is that proper disposal? That's beyond my area of expertise. I know who to call and these companies are on contract with these facilities and come and remove liquids from the lab all the time that are, you know, wasted liquids that they've used in tests or whatever, liquids and solids, and they take them and properly dispose with them. And I don't know exactly what that means. I don't know where they.
Brad Wyant (19:22)
But we have a guy
Dee Davis (19:23)
There's a guy, call the guy. Yeah, absolutely.
Brad Wyant (19:26)
All right, so we've kind of covered design. We don't want to have dead legs. And if we do, we need to design into the system and let buildings operations know that they're going to have to flush this thing. But the risk of Legionnaires in these 75 to 90 degree zones is much higher and having dead legs, which is what these showers and eye washes end up being is a very dangerous thing, even though it's per quote unquote code.
Dee Davis (19:51)
Correct. That particular code is dealing with one thing and that one thing is, the water going to be too hot or too cold for the person flushing? That's the only thing it's addressing. It's not addressing Legionella or any other thing. It's not addressing building maintenance. It has one thing in mind. Sometimes when we're trying to solve one problem, we create a different problem and we have to pay attention. And I would caution any designer who's considering a tepid water loop, not to just
willy-nilly make that decision without talking to facilities maintenance because we as designers do not get to dictate to facilities maintenance, hey, we're going to design a system that's going to cause you to have to do way more maintenance on a way more frequent schedule. We don't get to make that decision. That's an owner decision. We need to advise and say, look, hey, if we do this, these are the consequences. The owner gets to decide we're going to either going to do that or we're not going to do that.
Right, so far, all the owners that this has come up with have declined the tepid water loop except for one. I had one owner that accepted it and we added a UV system to it. you know, I can only hope that that's going to be enough. We recirculated the water and UV.
Brad Wyant (21:09)
So at least it's not still and you're adding something that bombards the water with ultraviolet rays in the attempts to kill any bacteria.
Dee Davis (21:17)
Yeah, but you still have dead legs. I'm not confident that in the long run, this is going to be the right answer because you're still going to have dead legs that yes, they've been UV treated. But then once the water gets into the dead leg and it sits, then what? wasn't thrilled about the outcome. I would have preferred to get rid of the tepid water loop, but this owner did not choose that route. So there we go. We'll find out.
Brad Wyant (21:40)
So
tell us about operations and talk about design. This UV system seems like a very interesting and challenging thing to implement, kind of fun. What can the operations people do to prevent Legionnaires within their buildings?
Dee Davis (21:53)
There's a number of things. The CDC recommends that building water systems run at temperatures higher than 124F and lower than 68F to avoid waterborne diseases. So when I think about that, I can think of a whole lot of buildings that I have been a part of that run their domestic hot water at 120 or 118 because they're so terrified of scalding somebody.
which in reality, I don't know, I've always thought that 120 is a bit on the low side. Well, according to the CDC, it needs to be at least 124. So that's something to consider. When we run piping systems in the temperature range for the purpose of human contact, as in the case of sinks, eye washes, and safety showers, it's considered the same category as drinking water and must be treated as such. It's considered domestic water.
And I guess that's again, where my concern comes in when we're running something that's considered hot water, but we're running it at a temperature below 124, we could still be growing something. With any fixture, you're going to have some kind of dead leg. So be aware of that as a facilities maintenance person. When you're looking at the operations of your facility, think about the sinks and faucets and fixtures in your facility that maybe don't get used very much. If it's not used, it's a different kind of dead leg.
It's a dead leg by default. If you have a remote sink or shower in a room that doesn't get used very often, that's a dead leg. I've been in facilities where in the changing rooms, their showers, well, do those things really get used? In some facilities they do, and in some facilities they don't ever get used. Well, that's a dead leg. Now, when somebody does go to use it, guess what's coming out?
Brad Wyant (23:43)
gonna
want to have to shower off themselves.
Dee Davis (23:45)
Yeah, it could be a drinking fountain, a shower, a faucet, anything like that. It is a default dead leg if it's not used. So in operations, you have to really think about that kind of stuff. In addition to your eye washes and your safety showers, what else in the facility doesn't get used a couple times a week at least. And even in a couple times a week, if it's got a metered faucet on it, it gets used once a week.
and it's a boop boop, they just turn on and off by sensor faucet. There's not enough flow there to flush anything out. They're automatically turning on and off very quickly. Those need to run for several minutes in order to flush out what's in that dead leg.
Brad Wyant (24:27)
Well, engineer in me wants to solve this problem by designing a better solution, by designing showers that automatically turn themselves on at 1 a.m. once a week for four minutes and with faucets that run themselves every so often. But that's sort of a fantasy. We don't have that kind of technology yet. We don't have that. And it would be so costly if we did choose to go that route that it would beg your belief. We'd be selling platinum.
building systems to people that can't afford them. And we'd be raising the costs of construction artificially. But this, is a very scary thing. The idea that the systems we build could be hurting people if they don't give them any correctly, if they don't get flushed often enough, there's a lot of risks here. So do you think that there's enough awareness around this risk? Or do you think that this is the kind of thing that gets reported on and then we forget about it and go on with our daily lives? I mean, I know the way I feel about the water. I don't think about the water coming out of my tap until
I moved to a new building and then test with my little zero water filter and see how bad it is. And then I usually use my water filter, even though it's not too bad. It's one of those things that we isn't always at the front of our minds because it's so accepted as part of our lives.
Dee Davis (25:39)
Yeah, I think it is not in the forefront of our mind enough as building professionals, which is why wanted to bring it up in the podcast. It's something that, especially in healthcare facilities is mostly where people are finding Legionella. Yeah. Well, you got to think about it. And I don't know if you've ever built a hospital before. The last hospital that I built was about a half a million square feet.
Brad Wyant (25:57)
Wow, really?
Dee Davis (26:07)
10 stories plus a couple of basement level service areas, thousands and thousands of plumbing fixtures, faucets, eye washes, safety showers, showers. Every single patient room is private and there's hundreds and hundreds and hundreds of patient rooms. And every patient room has two sinks and a shower. They have one for the staff. When you first come in to the room, you have one in the bathroom and you have a shower in the bathroom.
So you have three fixtures in every single patient room, almost without fail, individual patient rooms. There's certain kinds of patient rooms where you maybe wouldn't have a shower or you wouldn't have a restroom. But then you have the nurse's stations and then you have the break areas. There are countless fixtures. So to think about how the different spaces are used, I've been back into that hospital recently in the last year.
And some of the spaces that were designed as family waiting areas are no longer being used as family waiting areas. There's sinks in those rooms for people to wash their hands and now they are not being used. They're vacant 99 % of the time. Are those faucets being flushed on a regular basis? I don't know.
Brad Wyant (27:25)
And I'll bet a part of that too is that the people who end up in hospitals, like the people at the American Legion are usually a little bit older, a little bit more susceptible to disease. The hospital bug that people talk about when you go to the hospital, there's just so much in the air, no matter how good the ventilation circulation is. It's just more sick people around each other are going to get each other sick. And I can just imagine healthcare workers being told, yeah, you got to do this other thing where you just go around and flush sinks and nurses just being like,
No, I have no time for that. It's such a high demand environment that expecting additional burdens to be accepted to the community of people that work on those buildings, it's probably a thing that falls to the bottom of priority list like in other buildings.
Dee Davis (28:09)
Well, in that particular facility, I know the facility manager and he's very diligent and very good about most things. But when you have a case like that particular room that I'm talking about, it was designed and built for one use and it's being used in a completely different way now. And that's probably happening on multiple floors and multiple areas. mean, that's just the nature of what happens when we build buildings.
build them in these spaces with a certain thing in mind, but that's not always how it's utilized. So is anybody thinking about that room with that sink and that fixture? And is it on the list of being flushed on a regular basis? I don't know. I hope so. But things like that, that don't seem like a big deal or easy to fall off the list.
can create these kinds of problems for us. So in the case of eye washes and safety showers, since they are only used once in a while, those we have a tendency to keep more in the forefront of our mind because we know that they are very rarely, hopefully never used. Here's the good news. I found this out in one of the buildings that the Teppid Water Loop was proposed in was a building out in California.
And so I looked into the regulations for what is considered tepid water, according to code. What is that temperature and what is the building inlet water temperature? Do I even need a tepid water loop in a mild environment like Southern California? According to AC standard, Z358.1, if your incoming water temperature to your building is in the range of 60 to 100 degrees F, you're good.
You don't need to do anything else. We were actually able to delete a tepid water loop in this design and do nothing and just run cold water to those emergency fixtures without doing anything. No hot water, no tepid water, no nothing, because we meet the standard.
Brad Wyant (30:09)
So that ocean use and the best Mexican food in America is what you pay those higher California state income taxes for,
Dee Davis (30:15)
No mixing at all. That's good for people who are environments that can take advantage of that standard. Cooling towers is the other major offender for anybody listening who doesn't really know what a cooling tower is. Sometimes when you're driving along, you see behind a building and there's this big vapor cloud that's coming up, especially in the morning when you have a temperature differential, that's more than likely a cooling tower.
And what a cooling tower is, is the open side of a cooling system. So you have a chiller on one side and you have the condenser water on the other side. The condenser water goes outside, drops through the top of the cooling tower and comes down, gets mixed with some more water. have tons of evaporation, which is why you see those billowing clouds coming out of those things on a regular basis. What they're doing is they're ejecting heat in that process.
heat is leaving. Also, it's kind of misty around there. You're getting a lot of water droplets, which is where Legionella loves to be transmitted. So we have to pay very close attention in cooling tower loops to make sure that we are putting proper treatment in that water. We can't just run raw water without it being treated. There's inhibitors that are designed to keep that water.
from scaling those cooling towers and building up all kinds of lime scale. And it also keeps bacteria in check. I have seen cooling towers, my goodness, growing moss on the side. That is an indication really bad scaling, moss growing, practically looking like barnacles on the side of a ship. That is a bad system that is not being maintained.
And that can create illness. It's a very good idea to have a third party water treatment company be responsible for proper maintenance of your cooling towers. do routine chemical treatment. have chemical feed systems that are constantly feeding so that you don't have to manually do it. And then they come out once a month at least and check levels and tweak things if they need to and make sure everything keeps in check. The flip side of that is you have to keep
your chemical treatment people in check. There should be somebody on your staff that knows something about chemical treatment and is checking on those guys pretty frequently. I have had great experiences with chemical treatment people. I've also had the fly-by chemical treatment people that come by your facility, they're there for five minutes and they're gone. Well, guess what? They're not actually doing anything.
Brad Wyant (32:50)
In this particular circumstance, not doing much or anything is really unacceptable. Doesn't sound good.
Dee Davis (32:56)
And your systems will reflect it. Proper maintenance of your cooling towers and your condenser water system will prolong the life of your equipment. Cooling towers are not cheap. It is not something you want to be replacing every five to 10 years. You should be getting 20 years out of those things. And I have had phone calls from clients that say, hey, I replaced these cooling towers five years ago, seven years ago, and I'm having problems with them. 99.9 % of the time, it's in...
proper chemical treatment.
Brad Wyant (33:27)
I can't imagine that that would be such a bummer to spend that much money knowing that you were very penny wise and pound foolish effectively there. If you're not paying the right chemical treatment company, if they're shoring you on their service and that's causing you to have to buy a whole new cooling system every five to seven years, the math on that gets aggressive, aggressively bad.
Dee Davis (33:50)
And you'll
see it in your cooling towers first, but you can also foul your chillers this way too. mean, cooling tower replacement could cost you hundreds of thousands of dollars, depending on how many cooling towers you have and how big they are. Your chillers are going to be even more expensive. You have to properly maintain those. If you're having to perform maintenance on your chillers more often than you should, then that's telling you a story too, because the scaling will happen inside the chiller as well. And
Your water treatment is incredibly important in an open system like that. It's even more important, I would say, than in a closed system, a closed cooling or closed heating system, although those are also very important. You can be eating pipe and boilers and things like that too.
Brad Wyant (34:34)
water systems do not sleep on the on the
Dee Davis (34:38)
No, they do not. You're constantly losing water. So you're constantly adding fresh water, which requires even more chemical treatment. So domestic water systems, those are the ones that probably scare me more than anything. Design now as many dead legs as possible. If you have a hot water storage tank in your facility, make sure you're storing your hot water at at least 140 degrees F. Distribution should be 124 or higher. I know there's...
Tons of facilities, maintenance people listening right now going, no way, I'm terrified of the liability of scalding somebody. But you also got to remember that you lose a lot of temperature in your distribution. Insulate all your hot water piping to maintain your temperatures. Cold water systems ideally run at 68F or less. Take precautions with faucets that are used infrequently or in combination with low flow.
or automatic faucets and in frequent use. Review facilities maintenance program closely, including the flushing of domestic water systems and infrequently used sinks, showers. Don't forget places like gyms, standalone showers or rarely occupied or used spaces. Design water storage tanks that have recirculating pumps. Still water is a bad thing. I think everybody in this industry knows that moving water is better. So make sure you've got recirculating temps. only
to help maintain temperature, but to keep that water moving. You can install sample ports for regular sampling and testing to make sure that you're not growing anything funky in there. And weekly flushing programs are recommended by the CDC. And again, I know most facilities only do monthly flushing programs, but weekly is recommended. You can use microbial filters of 0.2 microns or less. If you have a specific
fixtures or maybe a group of fixtures that you know is hardly ever going to be used. You can use a microbial filter at that location, a point of use filter. But again, somebody's going to have to go replace it periodically. And it only manages the point of use. It doesn't manage the loop. It just manages a specific fixture.
Brad Wyant (36:44)
Yeah, I mean, it's just whack-a-mole with problems like this, isn't it? And this is the way with all design, when you solve one problem, you cause another, and you have to counter for that, there's no such thing as a perfect system that absolutely, totally, perfectly mitigates all the risks. There will always be things that have to be done, effort that has to be put in to ensure that systems are operated and designed safely. And there's no one size fits all.
perfect target silver bullet solution, but you can certainly help yourself out by studying these kinds of topics, understanding the science behind the systems we install and advising your clients, whether they be the facilities operations people or the owners on what is the best solution for them in their particular circumstances.
Dee Davis (37:33)
Yeah, budget often plays a role in the design decisions that we make early on. And that's really how the tepid water loop came into existence as it was a budget cutting consideration instead of running hot water and cold water and having mixing valves. we'll just run a tepid water loop. It seems like a great solution on the surface. And from a design side, it's beautiful. From a maintenance side, not so much. And every designer that I've come back and talked
to when I see these on the design and I call up the designer and I say, hey, how did we get to this place? They've never even considered the maintenance ramifications for it. It's just not even something that crossed their mind.
Brad Wyant (38:16)
And because as we talked about before, they're thinking about their realm, they're looking at their software, they're understanding the building from their perspective. They're not being forced to consider the life cycle costs of the building because they don't have an adequate way of estimating the life cycle costs of the building from all stakeholders' point of view in their software.
Dee Davis (38:38)
It's the whole picture. And that's the challenge that we always have in the industry is taking into consideration the entire picture. And we often don't within one company or within one group, we don't always have the expertise. I'm going to guess that most designers have never been a building maintenance person and vice versa. Most building maintenance people have never been designers. So they don't understand enough about each other's worlds to
think about the ramifications and to be able to adequately do that. It's why it's even more important to bring facilities maintenance people into the design conversation as early as possible. We have to consider all the aspects of design decisions, including upfront, long-term costs, savings, and implications, and make sure we consider all the aspects when we're tempted to jump into a money-saving solution. I can recount many, many instances in my career where
somebody jumped on to what appeared to be a money saving solution early on in a project only to find that it actually cost them more money in the long run. Exactly. Thanks for joining us. We'll see you next time.
Brad Wyant (39:45)
You get what you pay for no matter what.
