Eric Johnson (00:00)
If some of it's good, more is better, right? That's what you would think when you are replacing a boiler. If some efficiency is good, more efficiency is better. The manufacturer's efficiency is higher than the boiler we have. So we should replace it with a more efficient boiler and therefore the more efficient boiler save us money. Well, not always. Welcome back to Boiler Wild. My name is Eric Johnson.
Eric Johnson (00:24)
On this podcast, I talk about boiler industry topics as well as personal development. I will be talking about boiler stuff today. I know boiler stuff. And actually we're taking it over to hydronics. I've been on a steam kick and been talking about steam. And most of the time when I think about a boiler, I think about a steam boiler. But hydronic boilers are also part of the boiler world and
Eric Johnson (00:47)
I do love a good hydronic system, especially one that is appropriately sized or in our and has appropriate flows. If you've ever been on a startup for a hydronic system that does not have the appropriate flow, you will know what I'm talking about. Especially when you have a very, very expensive and
Eric Johnson (01:07)
Fragile, dare I say, high efficiency boiler. And no manufacturer would say that their high efficiency boiler is fragile, but they really are kind of fragile in terms of boilers when compared to everything else. But that's kind of just how it is. When you increase the efficiency, when you add more sensors, when you use high
Eric Johnson (01:37)
More expensive metals such as stainless steel, and not all stainless steel is built the same. There's tons of different grades of stainless steel. You got duplex stainless steel, all that stuff that will lead to issues versus just a normal carbon steel Scotch Marine hot water boiler or a copper fin boiler that is very simple and easy to work on. And why am I talking about this? Well
Eric Johnson (02:06)
If you have been around at least a little bit in the boiler industry, you may have heard ASHRAE ASHRAE is a global organization that is basically for engineers. I don't want to say engineers because there's more than engineers a part of it, but it they essentially help to push education and standards for HVAC.
Eric Johnson (02:35)
in the global space. I think that's a good representation of it. They're a huge global player. You may, if you want to be involved, you can go to your local chapter, ASHRAE, if you are in the United States. I don't know about anywhere else. I'm sure there's other local chapters. If you are in the United States, you can go to your local chapter. You gotta be a member. I'm sure you could go once if you want to check it out before becoming a member, but you should be an ASHRAE member.
Eric Johnson (03:04)
And then pay your local chapter dues.
Eric Johnson (03:07)
Shout out to the West Coast Florida ASHRAE chapter that I'm part of. Typically the ASHRAE meetings will be a dinner meeting. Sometimes they can be a lunch meeting, but they'll do events and you can meet other people in the HVAC industry around you. And you'll be saying, Well, I'm part I'm part of the boiler industry. I don't have time for that. Schmoozin'. And I would say
Eric Johnson (03:28)
Yes, but at the same time it is good to get out and be aware of other
Eric Johnson (03:33)
Problems and people around you that are working through things. So you may see tests and balance agencies, you'll have engineers that are actual like design engineers and you'll have a just a whole mix of people that come to these dinners and it even though you may not be doing business with them and you may not have any kind of overlap, you do have the overlap in that you are part of
Eric Johnson (04:00)
the larger HVAC industry and you will be typically trying to solve a problem about keeping people comfortable on the inside of a building. so I that's my plug for ashtray dinners. Some some chapters are better than others, but for the most part I have been very pleased with the
Eric Johnson (04:23)
ASHRAE chapter that I've been a part of and that I regularly go to, the meetings and the events. Just a great way to meet people, especially if you're an engineer. Great way to meet people. Get out, get involved, be a part of something, take on some responsibility.
Eric Johnson (04:38)
It's hard to do, but at the same time, it's the most rewarding thing because we should all be a part of a community. Just going to our job, coming home and not contributing to the community, not getting to know people and not expanding our horizons is a poor way of
Eric Johnson (04:57)
Growing our career, growing our self development, and you will probably end up becoming pretty lonely and think you're on an island where if I go talk to somebody that is very smart and interesting and maybe they don't know anything about boilers, but they can teach me about their subject and it's in the HVAC industry. I'm all for it. I wanna hear it and it gives me more perspective on what other people are doing. So anyways, there's this
Eric Johnson (05:26)
journal that ASHRAE publishes. It's a monthly journal that it goes out to the members. It's a magazine. And there is a guest column in there. I am sure this guy will never hear this. And no, th this is no shade to or disrespect to the writer. You know, putting yourself out there is always a hard thing.
Eric Johnson (05:51)
And there's a lot of nuance in writing a column. You're limited in the amount of space. But his column is titled The Business Case for Paying the Premium for Above Code High Efficiency Equipment. And it goes through some different pros of why you would buy high efficiency equipment, which are all valid and everything. But
Eric Johnson (06:14)
When it comes to the example, it actually was a boiler example. So ASHRAE once again covers all of HVAC. So seeing boiler stuff in the ASHRAE journal isn't always super common, but it is a good read once again to expand your horizons and also to see new and exciting products from the HVAC industry.
Eric Johnson (06:37)
In any news. But going back to the example, there was an example, and he just used an office building in Detroit replacing a 1.2 million BTU gas fired hot water heating system boiler. The boiler's been installed since 1999, so since it's 2026. So you know the boiler's been installed 26 years. That is pretty average.
Eric Johnson (07:04)
For a hot water boiler installation, it is longer than the what people are typically getting today. If you get 26 years out of a boiler that you're installing today, that's a high efficiency boiler, you are doing pretty good. And I'll talk about that. But it goes through why the math of why this building order would replace this boiler. And the two examples he used was a 82% efficient boiler.
Eric Johnson (07:32)
versus a 95% efficient boiler. And the math worked out and the building owner would save money potentially on that math problem. But what I want to talk about is there is math that is missing from this example. And he uses a 95% efficient boiler. And this is probably the most common misconception when you are talking to people who are not in the boiler industry. I guess they could be in the boiler industry, but if you are talking to a general
Eric Johnson (08:02)
contractor to a general owner and even engineer, they may not realize that a ninety-five percent efficient boiler that is just a best case scenario and that is not always the boiler running at ninety-five percent efficient. So a ninety-five percent efficient boiler that all depends on the return water temperature.
Eric Johnson (08:24)
And there's other math that needs to go into the full life cycle cost of the boiler. And I will get into that. But first I want to talk about boiler efficiency. So hot water boiler efficiency, typically a boiler will be 82 to 85% efficient, and that is a typical normal hot water boiler running at 180 degrees of
Eric Johnson (08:44)
Temperature and that is going to be outlet temperature. And then you typically have a 20-degree delta. So you'll have 160 degree water coming back. That is common HVAC engineering design up until the 90s, 2000s, and when high efficiency boilers started coming out. And we went through a pretty rough period. And that was before I was professionally working, but we went through a pretty rough period of high efficiency boilers and designs.
Eric Johnson (09:12)
But we are getting better, I believe. I believe it seems like with the controls. The controls are getting better. We've we went through a weird phase with the mid 2000s of we can use touch screens, but they're very clunky. Now the touch screens seem to be pretty good. Manufacturers are getting a handle on the controls of a boiler
Eric Johnson (09:38)
That are their own versus just using off the shelf controls. But going back to boiler efficiency, a hot water boiler is only efficient as the return water temperature allows. And what do I mean by that? Physics is physics. unless I am unaware and uninformed, no boiler manufacturer has found out a way to defy physics. And if they have, let me know.
Eric Johnson (10:04)
Drop me an email or DM me on LinkedIn. I want to know about it. But as far as I know, every boiler manufacturer across the world, we are all playing on the same level as far as physics and return water temperature is what determines the thermal efficiency of the boiler. Now, when the boiler says in this example it is 95% efficient, that means that the manufacturer has done testing and they have designed the boiler to
Eric Johnson (10:31)
up to ninety-five percent efficiency and what does that mean? So in the best case scenario, the boiler could run at ninety-five percent efficiency. And once again I I will highlight and underline best case scenario. And what do I mean by that? The return water temperature, every manufacturer will have a graph of a thermal efficiency curve. I pulled two of them up. One I have from Fulton, another one I have from RBI, but the graphs are typically the same. They'll vary slightly
Eric Johnson (11:01)
But once again the graphs will reflect physics, but it is independent testing that is around the AHRI certified performance of a boiler product. So looking at this Fulton one, the efficiency of a boiler first will vary with the input.
Eric Johnson (11:20)
If you don't already know, the most efficient way to run a condensing hot water boiler plant is all the boilers that you have. You want as many boilers to run at the lowest firing rate as possible. So the lower the firing rate, the more efficient the boiler. So and that is called parallel modulation. And each boiler will talk to the other boilers.
Eric Johnson (11:45)
They'll all modulate together. So if you have four boilers, you'll have four boilers running at 20% versus two boilers running at 80% or whatever that maths out to. If you have sequential modulation, you'll have a boiler that ramps up to maybe 80% firing rate, and then it'll kick on the next boiler. So if we the same example, if we were to have four boilers, the first boiler would run at 80% modulation, the second boiler would run at 60% modulation.
Eric Johnson (12:15)
The third boiler may run at fifty percent modulation. And if we need the fourth boiler, they'll run at twenty percent modulation. And that all depends on the settings. And when you're commissioning or setting up a boiler plant, you can change those settings. Each manufacturer will have off the shelf settings that a lot of people just leave as they are, but you can change them. I change them sometimes, but
Eric Johnson (12:38)
Every manufacturer will tell you the most efficient way to run a condensing hot water boiler plant is to have as many boilers on as possible and to run them at the lowest firing rate as possible. And that is what these thermal efficiency curve data sheets reflect. So looking at this Fulton data sheet, you have multiple efficiencies. You have 8%, 20%, 40%, 60%, 80%, and 100% input.
Eric Johnson (13:05)
And there are lines on a graph. And on this chart, the x-axis is the return water temperature, and then the y-axis is the thermal efficiency percentage. And it goes between 86% to 100% thermal efficiency. And the return water temperature goes between 80 degrees and 180 degrees. And that's return water temperature. So going back to a ninety-five percent efficient boiler, looking at this chart.
Eric Johnson (13:34)
We have ninety-five percent efficiency and if we go over, we match it at if at a hundred percent input, the return water temperature has to be one hundred degrees. And then if we go at the lowest input,
Eric Johnson (13:48)
The return water temperature can be 112 degrees. So if your return water temperature is 112 degrees, you will be running a set point with a 20-degree delta of around 132 degrees, which is pretty low but not uncommon. But going back to this example, they had a 82% efficient boiler, and that is a non-condensing boiler.
Eric Johnson (14:13)
And if you don't already know, a non condensing boiler is a boiler that does not recover the latent heat that goes up the stack. So there is heat, there's two kinds of heat. There's latent heat and sensible heat. Latent heat is the heat that is used in the change of a phase of water. So when the water goes from a gas to a liquid
Eric Johnson (14:42)
We are absorbing that heat and typically it is a gas and it is f pushed out with
Eric Johnson (14:50)
The rest of the flue gas and part of the products of combustion is water vapor. We if we recover that water vapor and and we condense it into a liquid, now we are recovering that latent heat. And that is why condensing hot water boilers have condensate drains and condensate neutralizers. Condensate will be acidic and we have to neutralize it before we send it down the drain.
Eric Johnson (15:15)
Non-condensing boilers, they don't recover that water vapor, they don't recover that latent heat, and they just send it out the stack. So we are pushing excess heat out of the stack. Why is that important? So if we are just replacing the boiler in this example, the 82% efficient boiler probably if it's been installed since 1999, and maybe the building is from 99.
Eric Johnson (15:40)
Or maybe the building's older, but it's if it's been installed since 1999, the building is probably running anywhere from a hot water set point from 160 to 180 degrees. And this example was Detroit. So Detroit gets cold, Detroit snows, and in the winter it's probably gonna be 180 degree set point with a 20 degree delta. You'll have a return water temperature of 160 degrees. In this case, if we were to install this high efficiency boiler from
Eric Johnson (16:10)
this Fulton example at a hundred and sixty degree return water temperature, no matter the input, the boiler maximum thermal efficiency will be eighty-eight percent.
Eric Johnson (16:23)
If we go down to 140, the it starts to vary, but the average efficiency will be 89 and a half to 90% of thermal efficiency. So why is this important? If you are just replacing the boiler and you push in front of the building owner a better and best kind of options, and you say, Hey, you need to replace the boiler, you know, and you push out
Eric Johnson (16:51)
Different options, you know, good, better, best, however, you want to do that. But all I have for the example is better and best. And you say, Hey, this is a like for like, this is only 82% efficient, or maybe you can put an 85% efficient boiler in there and it's still non-condensing. And you just say, like, hey, this is what it is, or we can go to this 95% efficient boiler, and that's gonna save you some money.
Eric Johnson (17:20)
And you do some math and you say this will save you this much. And so here's the payback. So from a building owner's perspective that knows nothing about boilers, they see the efficiency rating and they just think off the top of their head, Well, a eighty-five percent efficient boiler, or if we did like for like an eighty two percent efficient boiler versus a ninety-five percent efficient boiler, well that makes sense.
Eric Johnson (17:44)
There's a 13% efficiency difference between those boilers. So the added cost of the 95% efficient boiler will easily pay for itself. I'm going to buy the 95% efficient boiler. The contractor installs the 95% efficient boiler. They have to add a couple other things, which makes the install cost a little bit higher. And now the building owner goes, Great, I'm going to save all of this money. And
Eric Johnson (18:10)
They change nothing on the water temperature. They have changed no convectors or radiation or nothing about the pumping or any of that. Everything is the same in the building. And in the winter, they are running a hundred and eighty degrees. And the building owner thinks in their head, I am running at 95% efficiency. And actually, you're running if the if it was going to be this Fulton boiler, you're running at 88% thermal efficiency. Well
Eric Johnson (18:38)
Who lied? It's nobody really lied, but the contractor has the duty to inform the owner that a 95% efficient boiler isn't always running at 95% efficiency. And in this case, you can typically get away with an outdoor reset. And in the shoulder months, so the shoulder months are gonna be the fall and the spring. In the shoulder months, you are going to
Eric Johnson (19:07)
Turn down the water temperature, and that is where you can get some efficiency and payback and actually start condensing. But in the dead of winter, if it's 10 degrees outside, the all the coils, all the radiation, and everything is probably sized for 180 degree water temperature. So the boiler is going to have to run at 180 degrees. And you will at this, if we were to install this Fulton boiler, it is going to be the maximum 88% efficiency. If you turn it down.
Eric Johnson (19:36)
All the way to a hundred degrees to get that ninety five percent thermal efficiency. The building won't heat itself.
Eric Johnson (19:45)
In this case, if we're having a 20-degree temperature differential, so we would have a 120-degree set point. So we're going to be keeping our header. The outlet of the boiler is going to be 120 degrees. The return water will be 100 degrees. Since this building will probably be primary secondary, but we will have a 20-degree differential, and at the 100-degree return water temperature, best case scenario, we are getting 95% efficient.
Eric Johnson (20:14)
And that would would be the boiler running at 100% input. And then we could bump it up to 110 degrees. So we could run 130 degree water temp. So if the contractor doesn't change the set points of the building, if they don't put an outdoor reset on, the owner is saving no money. The owner just bought a more expensive boiler and is not getting the efficiency out of it. Yet the owner will probably never check. They just move on with their life.
Eric Johnson (20:45)
And they just have trusted the contractor and the contractor just keeps repeating that. And you know, a retrofit can be a mess messy situation. Sometimes contractors are just trying to get the sale and maybe they only have the option of installing a high efficiency boiler. but throwing a high efficiency boiler in a retrofit into a building that is not designed for a high efficiency application.
Eric Johnson (21:10)
where you can actually condense and run condensing water temperatures, you are wasting money buying a boiler. It's like buying a sports car and putting a governor on it for at fifty miles an hour. You just bought a sports car that has the capability of going 160 miles an hour around a track and you're like, no, I'm good. We're just gonna put a governor on it. Well, there's no reason that you can't just go out and buy a normal sedan that will easily go 50 miles an hour. You don't need a sports car that could go
Eric Johnson (21:38)
160 miles an hour round track safely, you you're fine with the sedan. Yet contractors are selling repeatedly selling high efficiency boilers and installing them when it is not needed. So now a year or two goes by and the contractor's knocking on the door of the owner and they're like, Hey, we need to do that annual service.
Eric Johnson (22:06)
And they go, Hey, well well, we didn't really do annual service with our other boiler. Why what are we doing? What is the annual service? well, that boiler, in order for the warranty to stay good, like the pressure vessel warranty, we need to be doing the annual service, which includes changing the igniter, cleaning the burner. Most high efficiency boilers have mesh burners and a mesh burner. It looks like
Eric Johnson (22:35)
can almost like a five gallon bucket. A lot of them are smaller than five gallon buckets, a lot more narrow, but think of it as like a five gallon bucket and it's a tightly woven mesh and the air and gas premix before it goes into the burner. So you have a pre-mixed air and gas and then when you ignite it, the premix flows through that mesh and it will burn the air and fuel mixture right off the
Eric Johnson (23:03)
surface of the mesh and that is how you get low nox but most condensing water boilers will have a mesh burner and they require cleaning they have air air filters and the heat exchangers will require inspection so you have to pull the heat exchanger apart which requires gaskets they also have usually custom
Eric Johnson (23:26)
controls to the manufacturer. So most manufacturers, I believe, today in twenty twenty six have their own control system. Fulton has their own control system. Lochinvar has their own control system. RBI has their own control system. Cleaver has their own control system. So each of those control systems is unique to the manufacturer. They're not using off the shelf parts that are just general industry parts like a boiler from nineteen ninety nine would typically use. And
Eric Johnson (23:56)
If any of those parts go bad, the cost to replace them is going to be typically much higher than the parts on a 82% efficient boiler from 1999 or even a 82% efficient boiler from 2026 because the extra parts and everything to make that efficiency, to make the boiler more efficient, all the sensors and maybe you have O2 trim.
Eric Johnson (24:23)
All that costs money. And then when it starts alarming and you start having issues, you have to replace it. And then you find out that a board for these high efficiency boilers are fifteen hundred dollars. Or if a screen goes out, that's another thousand dollars. And all of sudden, maybe you didn't keep up on your air filter changes and cleaning, and now you've ripped the mesh can and you blew the sides off your boiler and your technician comes in.
Eric Johnson (24:50)
And they Hey, your burner ripped. The burner will be $3,200. And now, as an owner, you're looking at it and you're going, Well, we bought this high-efficiency boiler. It's supposed to be saving us money, but now our maintenance costs seem to be way more than what we did the past 26 years. I've been here since whatever, and we can look at our maintenance costs. And we had somebody show up once a year because we were super good on maintenance, and that's typical.
Eric Johnson (25:19)
not typical on most buildings, but we had somebody show up once a year. They were here for three hours. They checked combustion. They cleaned the flame rod and they said everything was good to go. And we replaced a couple parts here and there, but there was nothing that was that crazy. And we can adjust for inflation over those 26 years, but the amount of money I'm spending on this boiler is two to three years old is way more than I've ever spent on the boiler that adjusted for inflation.
Eric Johnson (25:47)
The previous 26 years. So why am I buying this high efficiency boiler? So now I'm looking at my gas bills and my utility bills, and you're going, Well, they they seem to be the same. Everything the everything seems to be the same. I thought we were supposed to have 13% more efficiency. Well, the contractor didn't do an outdoor reset, contractor didn't change any of the radiators. You're still running the same water temperature that you did, which is non-condensing water temperatures.
Eric Johnson (26:16)
And going back to the thermal efficiency charts, a ninety-five percent efficient boiler that is under the perfect conditions with a lower return water temperature. But if you are still running non-condensing water temperatures, you're going to be getting non condensing thermal efficiency. And the building owner doesn't understand that. So now they are still spending the same amount on their gas. And they're looking at the math and they're saying after three years, you're like, We've actually spent more money now.
Eric Johnson (26:44)
And we don't seem to be saving any money. What is the change here? And then hopefully not, but maybe five years down the line, contractor comes in and they're like, you have a crack in your stainless high efficiency boiler, they can't be repaired. Now you need a new boiler after five years. And the the building owner goes, Wait, what? I thought I just bought this. Cause in their mind, when somebody buys a boiler who isn't a boiler person,
Eric Johnson (27:09)
A five-year-old boiler is a brand new boiler in their mind. Whoa, we just put that in. Why would we have that? Because they have their experience in their mind. And a lot of people, their biggest mechanical purchase is a car in their mind. And a five year old car is not that old. And typically the manufacturer's warranty on a car will span a couple years. So they take that same thinking, whether it's correct or not.
Eric Johnson (27:33)
And apply it to boilers. Well, I just spent all this money on this boiler. The warranty should cover all this. It's only two years old. Well, you didn't do this, you didn't do this, you didn't do this. And there's all this stuff that's outlined in the manual that the the building owner never knows about until there's a big issue, and then they all these things pop up. Well, you didn't have water quality tests, you didn't have the the owner's rep come out and do the annual service, you didn't do this, and the startup wasn't properly documented, so the warranty is denied, and now you're looking at all this huge bill.
Eric Johnson (28:02)
And and the owner's looking at it and they're going, What is happening? Why is this like this? I thought I bought a high efficiency boiler, I should be saving money, not spending more money. And that is where you got to get into the total life cycle cost. A high efficiency boiler really only works on a brand new building that is actually designed properly for high-efficiency boilers and actually is running at the proper return water temperature.
Eric Johnson (28:30)
I have seen it and you have seen it that you have seen a high efficiency boiler installed and maybe the engineer's a little bit older or maybe they're not super up to date on high efficiency boilers and why they actually are high efficiency. And they're like, well, we don't want to get too crazy, so we'll just turn down the water temperature to a hundred and forty degree set point.
Eric Johnson (28:57)
In the shoulder months and then we'll have a hundred and eighty in the in the winter.
Eric Johnson (29:00)
That while you will save a little bit in the shoulder months, doing that outdoor reset, you're not saving any amount of money running a hundred and eighty degrees in the winter. And I've seen it multiple times where after commissioning, the building will be cold, there'll be some issue, and somebody goes in there and turns up the water temperature.
Eric Johnson (29:23)
And nobody checks or comes back to the building or graphs everything after a couple years and says, hey, are we still running at optimum boiler plant efficiency? And now one maintenance person just turning up the water temperature because they're used to older boilers and well we can't heat a building with 120 degree water. We need to turn this up. So then they turn up the water temperature and now you take all that efficiency and you throw it out the window and now your boiler
Eric Johnson (29:50)
Is just running like a non-condensing boiler, yet you are paying for a condensing boiler and you're not getting the fuel savings. A condensing boiler only maths out when you are getting the the savings, and the savings have to be pretty dramatic. If you're teetering on the line of we only run condensing water temperature just a little bit, the math will probably not math out if you do the entire life cycle due to the added maintenance cost of the boiler and the
Eric Johnson (30:19)
reduced lifespan of the boiler. And depending on what boiler you buy, and I don't want to say there's a bad boiler out there, but there are boilers that are more expensive than other boilers that are condensing boilers. And typically the more expensive ones have a better heat exchanger. And I'll say typically, and I'm not an expert on this. I don't know everybody's boiler inside and out. I don't know all the pricing, but no manufacturer goes out and says, hey, we're going to build a bad boiler. But sometimes they build
Eric Johnson (30:48)
Contractor grade boilers, which are hey, can we just get the boiler in the building and get through the first 10 years? That boiler will probably be fine. Is that boiler gonna last 40 years or 26 years like the old boiler? Maybe, maybe not. It all depends on flow, how much air is in the system, and water quality. And that has a lot to do outside of the manufacturer, and a lot of contractors can't control that if the building owner isn't making that a priority.
Eric Johnson (31:18)
But say you have a boiler and the heat exchanger starts leaking at the 10-year mark. Now the contractor goes, yeah, well, they just don't build them like they used to. Here's a quote for another one. And you start replacing boilers every 10 to 15 years. You start replacing control systems because now you have PLCs, you these programs and everything, and everything's customized and more complicated. And a 10-year-old control system on a boiler that is like that versus just you know some push buttons.
Eric Johnson (31:48)
It ages super quick and the manufacturer doesn't make that card anymore for that. You need a full retrofit on these controls in order for that to be applicable and in order for this to keep running and that's gonna be four thousand dollars just for the parts and then plus labor and it just gets very expensive. So when you are looking at the math of hey, can we put a high efficiency boiler in?
Eric Johnson (32:12)
You have to do the full life cycle costs. You have to look at the gasket kits and what are the annual kits costs? What is the annual kit? Is there a two or three year kit that costs more? Or is the the annual kit the only thing? Go get a quote on the annual kit. Go get a quote on how long the contractor will charge to put the annual kit in. Typically they'll charge a day, but it'll depend. Sometimes you can do a bo two boilers in a day, but it really depends on
Eric Johnson (32:41)
The setup of your boiler plant and how many boilers you have and how close you are to the contractor. But go get quotes on that and go look at what you're actually spending on your current boiler system and actual maintenance of it. Because if you have a typical eighty two percent efficient boiler, you are probably a lot of boilers, especially if it's a cast iron boiler, they're coming in and they're cleaning the flame rod, they're checking combustion and they're just going, yep, that
Eric Johnson (33:11)
It it's fine, it's running great. Maybe they check water quality, but a lot of buildings, if you can't see it, they don't notice it. And they can't see the water quality until there's a leak. And nobody checks it. Nobody tells the building owner that they need to check it. They don't maintain a parameter. It just is what it is. But then they install this high efficiency boiler, you connect it to an old system.
Eric Johnson (33:37)
And now there can be all these issues. You fill the old boiler with debris. every single manufacturer's manual has tons of lines in there that say, do not flush the system into the boiler, do not fill the boiler with debris. Water quality is super important. Warranty is void if you do this, this, this, this, this. But a lot of installations don't allow you to flush the entire system without flushing it into the boiler. And it makes everything more complicated. So if you are a contractor or if you're a building owner.
Eric Johnson (34:04)
We're an engineer, you need to look at the total lifecycle cost of hey, we're gonna be putting in a high efficiency boiler. Does that actually make sense? Or can we just get away from the optics of we're installed a high efficiency boiler? Yeah, it sounds good, but the actual math, the actual engineering of it is hey, this eighty five percent boiler will work for you. It is a lower cost, but the actual water temperature that we're gonna be running at.
Eric Johnson (34:33)
We are going to be running at the same thermal efficiency because we actually can't change the water temperature. We have a little bit of outdoor reset right now from 180 to 160, and that is how the building has to run because we're not changing the radiation in the building. So putting in a high efficiency boiler would do no help. And you would also increase the amount of maintenance and increase the amount of parts typically.
Eric Johnson (34:58)
On the high efficiency boiler, and also you typically will, depending on the manufacturer, reduce the lifespan of the boiler because now the high efficiency boiler is a stainless boiler that is a little bit more fragile. Stainless boilers love to crack and they are typically not repairable. So that's what I have today. Once again, no disrespect or shade to the person who wrote this guest column in the
Eric Johnson (35:27)
ASHRAE journal. I would love to get an article in the ASHRAE journal. I don't I wouldn't know what to talk about, but that is just something when you are looking at the payback and differences of a non condensing boiler versus a condensing boiler. Non condensing is going to be the 82%. The condensing is going to be the 95% efficient boiler. So in that example, it masks out that it's no brainer for the 95% efficient boiler. But
Eric Johnson (35:53)
The actual math of the whole situation is a little bit more complicated. There's a couple more variables as I outlined that you need to go over and think about when you are actually approaching that situation. And that's why you should always work with an engineer who is familiar with and has installed or has other co-workers that install condensing boiler plants that all the time, or a contractor who only works on boilers.
Eric Johnson (36:20)
Who is only doing condensing boilers or steam systems instead of a general HVAC company that is just looking at a brochure, just like the owner is, and saying, Yup, brochure says 95% efficient. And this is what you want because this actually has the most markup on it and will make the biggest sale. And now we gotta change this and this and this. And they just care about the price of getting the boiler in there, making the sale, and leaving. You want somebody who's gonna be your partner.
Eric Johnson (36:49)
actually tell you the true facts of what it actually costs to run a condensing boiler plant over a 10 year period versus a non-condensing boiler plant and is the math actually worth it of installing a high efficiency boiler in a retrofit situation when the system is typically not running at condensing water temperatures. So that's what I had today. If you have any opinions or having comments about what I said or anything to add
Eric Johnson (37:17)
Please email me eric.johnson at boilearn.com That's B-O-I-L-E-A-R-N dot com or DM me on LinkedIn. I would love to hear from you. I always want to talk to people and learn from other people. I am far from an expert, but there are a lot of experts out there who I love to hear, meet, and learn from. So I thank you for listening to BoilerWild.
Eric Johnson (37:40)
And as always, stay wild.
