Hey thanks for watching this is another video that was filmed live at the HVAC, our training symposium in Clermont Florida. This is my friend, Jim Bergman, talking about combustion analysis, specifically using the blue flame combustion analyzer from a cue tools, which is a really great tool that connects with some excellent diagnostic software that Jim helped to develop so hope you enjoy this. The quality isn't perfect, but we tried to edit it as best we could. Jim was kind enough to share the slides, really great training.

If you want to find out more about the blue flame analyzer, you can go to the Accu tools website or you can also find out more about everything Jim's doing over at measure. Quick comm hope you enjoy the video you want to be outside right, calibrate your analyzer outdoors, make sure that you're getting fresh air and that analyzer and then walk to the home. With that analyzer about chest height Co does not stratify. It does not go up to the top or does not go down to the bottom.

It mixes very evenly with the with the air in a home so about chest level, walk through all the areas of the home, make sure that you don't have Co on there. On there, a couple of characteristics of carbon monoxide, odorless, colorless, tasteless mix as well right, it does follow the air in a structure. Okay now and it is, it is poisonous. A lot of people think you can put like a lot of these personal Co meters and things like right in the in a hot air stream of the furnace.

Many of them are not temperature compensated and they will show Co. That does not exist, especially on some of the old ones. Some of the newer stuffs a little bit better, but you got to make sure that you're using the right tool on that when you get Co symptoms - and this is what happened to lady that bill and I went out there - the lady started getting CO poisoning. She thought she had the flu.

She stayed home so she's in this home with high levels of CO. She's got headaches, she's got dizziness, nausea, she's got the flu symptoms, he's tired and here her home is killing her right, and I think Joe will tell you later on he's going to be doing a presentation on healthy homes on there that your home is something that We don't we don't think about all the time and you guys when you walk into areas. You know you kind of be aware of what you're, what you're walking into years ago, just uh. I remember when I was probably about nineteen years old.

I walked into a flower cooler and had a dirty dirty evaporator, so I go with my tank of co2. I'm gon na blow that out and walk into this little. You know maybe eight by eight by ten cooler and I start blowing it out with Co co2, and I and also now I'm starting to get really dizzy. I'm thinking what the heck's going on here not realize I'm displaced on all the oxygen in the room right.

Those are simple mistakes. It's the same thing here. You walk into a big boiler room and we've seen some pretty big stuff dumping Co in spaces. Where you know you come back after lunch, you think the Chinese got you and again you're, exposing yourself.

The co. There's some Co health effects. It's all on the book there but 9 to 13 parts per million is a typical eight-hour exposure limit. We want to see, but you can get an idea when these levels get higher, they can cause death in a matter of minutes.

Co displaces the the oxygen in your blood. Ok, your body can't tell whether you're getting carbon monoxide or you're getting oxygen. It just is just displaced it, so as you're breathing what's happening is you're breathing in the co. It's displacing the oxygen you're, getting no air to your lungs and your body.

You actually die from basically from lack of oxygen to your brain right. That's what that's! What causes death? Don't get fixated on the appliance make sure that when you're testing other guys, when you go out there and somebody has Co in their home again, they try and fix everything at the furnace. Look at the hot-water tank. Look at the stove look at the the oven or range look at Auto emissions is probably the biggest one that we see people backing their cars into the garage automatic car starts.

We had an incident in Ohio where somebody was killed. Their son bought them a automatic car starter for Christmas. They wired it up to the car. The guy sat down in his recliner they'd hit the button started, the car car was in the garage running and it killed the occupants of the home.

So these type of things do happen in their fuel burning space heaters, fuel, burning boilers. All these things can cause Co, draught and spinach esting. You want to make sure a lot of guys when they're doing their combustion testing will walk through all the process, but one of the things when you're making your your draft test in there. You need to be away from the draft diverter 12 to 14, 12.

12. To 18 inches above the stack here when you're doing draft testing a lot of guys want to do all their testing down here and I'll talk a little bit about the drafter burger later here. But we want to make sure that we're testing in the flu draft testings one of the first things we do when we're doing combustion analysis. We want to make sure that we're gon na ventilate those products up the stack so a lot of times before I go in while do is punch a hole in there make sure I have some draft make sure things are gon na go up the stack you Sometimes you won't have draft, especially if the chimney is cold, but it's important to realize what you're walking into when you when you, when you do this type of work, so you want to make sure that we're going to make sure we have some drafts.

So, let's talk about the function of the draft to it is the draft hood actually separates the appliance from the draft. So if you look here, I've got this broken into right here and a draft hood. What the reason they invented. The draft hood was fires.

Okay, if you have, if you have properly burning appliance all you're going to get, is carbon dioxide, water, vapor and heat right? Just carbon dioxide is a it's a pollutant, but it's not gon na. It's not going to kill you. We have. You guys burn your oven in your house.

You burn your stove in your house right all these things produce carbon dioxide, water, vapor and heat it's when we get the intermediate conversion from carbon dioxide to carbon monoxide that we have an issue. So what they did here is, if you ever seen a movie backdraft right, the the doors are closed, the fires burning in the room and as soon as you open up the room, the flame comes out, and it's looking for air right starving for air. What would happen is we've blocked off an appliance, the the flames that come out the front looking for oxygen, looking for something to debris, the flame is a living breathing thing right and it needs it needs air. So, as a flame rolled out the front of the boiler, the furnace that would catch the wiring on fire burn up everything, and that was not such a good idea.

So people were getting killed by by fires back then. If you go back and look at a lot of why appliances were built the way they were built and why we have an electronic code, it's because fires, everything was catching on fire back in a day right. I mean it was pretty pretty darn common, so if we separated the appliance from the draft that this became blocked right, if the chimney became blocked, then the blue gaskets could youcould to come out and just spill into the space and the carbon dioxide, water, vapor and Heat was a lot safer than a fire, because the odds are that as long as the boiler is burning correctly, you just realize you had high humidity in your house. A lot of people don't realize if you walk in a home and they're complaining about high humidity.

All the time you better start looking at the at the large appliances for for dumping, flue gasses into the home, so the drafter burger the whole idea of it here and, let's see if this I can't work Joe's at the same time as mine, is that when The fire burns it creates a natural drafts, so when the fire goes up there, the warm air rises and as it rises, it goes up and it just goes up into the area and low pressure right pressure, always flows from high to low. So if you were to actually take and measure right here - and you were to measure your your draft here - it'd actually be a positive pressure. There's actually positive pressure in that part of the of the breaching right. There there's negative pressure here where it's tied to the chimney positive pressure right here.

The positive pressure is going to flow up in this area and because there's a negative pressure here, it's just going to pull those flue gases in along with dilution, air up that hood right. So when we have our air come in, there's all the secondary air that comes in and these are actually once you start testing older appliances. You think all these are going to be really really inefficient and you look at the excess air readings you can see. They're actually running really really low excess air.

Any excess air is very, very well controlled because these appliances took air in at exactly the same rate that they went out. It's just natural draft drawn that up in there now what happens when we get a bird and the chimney on there right we get spillage, and if everything is working correctly, we get carbon dioxide, water, vapor and heat. That's not that's not going to kill anybody, but we don't it's a pollutant. We don't want to have that in our home in there, but when we have carbon dioxide, water, vapor heat and co, and that's when we have a problem right and so that's what we're trying to avoid at all cost than their draft has got to be established Within the first five minutes of starting the appliance, you've got to make sure that it's running it could spill for a few minutes when the chimneys cold, especially like the first part of the year, you go out and it's been a no heat and it's been uncomfortable.

For hours and hours and hours you could get a little bit of spillage, especially if you're talking a concrete or masonry chimney. That's where you'll probably see that on metal, it's going to warm up right away and you'll establish draft very quickly, but on concrete chimneys, which we have a lot of up north, it could take up to five minutes. You want to check across the entire length of that for my pickup another mic here. It just seems like it went up out all sudden.

Alright, you want to go across the entire length of the draft hood here check for spillage. This is a little wind indicator here. It's just producing a little bit of smoke. We're gon na go across the entire front of this, and we're gon na check for spillage on there to make sure that we're not spilling flue gas.

When you see these get rust up on top here, it's not because the manufacturers made bad metal. Yes, because it's it's getting flue gases that are spilling and they're, causing that there's acids and flue gases and those acids are eating that metal up there so that when you ever, you see rust or anything up on the top here, that's an indication you have spillage. That's an indication you have a system that has a very serious problem. You need to look into.

You don't want that flue gas spilling in there. So look for evidence of rusting stain in and evidence evidence of spillage. Draft on a hot water tank again must be established within five minutes of starting so many guys walk in they test the furnace. I have seen more hot water tanks, making large amounts of CO than I ever have furnaces.

Hot water tanks are a huge potential source of CO. Anybody know why who puts in hot water tanks. Homeowners do yeah and that's the problem right, because they don't have tin snips to cut their flue pipe down. They just shove.

It all the way to the back of the chimney and it's hitting the back of the chimney and it's not venting it anywhere, but in the house you'll see issues where they, where they don't use a backup wrench. They torque on the gas valve now the burner sitting sideways in there you'll see rust that piles up inside there because their kids constantly taken. You know they have two daughters at home and they're running the hot water down empty all the time and it's rusting and dripping inside there. So hot water tank should always always be tested again all the way around the draft hood to make sure that we don't have spillage on there.

We're going to look for evidence, a rusting staining the same thing: melted plastic plugs in a water line. So a lot of a lot of what we do in combustion analysis is not just about the combustion analyzer, but using your eyes and use a little common sense. If you don't start noticing these things - and you start talking yourself, I'm looking at them you're going to miss some serious problems. This is probably one of the most common ones.

I see out there today because we're common venting appliances and I used to when I was teaching classes. I taught a cog about my career center for 12 years and I what I did is I had on my I had a metal bestest chimney. On top of it, I put a big draft inducer motor, a power power vent on the top of it. To put a rheostat on it, so I'd start to furnace up with the kids that have the draft going on there just like normal and then what I do is to just decrease the draft and walk over.

There say test test, draft and I'd, haven't, checked the furnace and they go through and they test everything and they say yep, it's all. It's all working good and then I'd say you're done and they say yeah, it's a good. You just killed your customer and then look at me like what what the heck you talking about. I'm like come over here.

We walk over and we'll walk over the hot water tank and all the flue gases for the hot water are spilling out from the furnace or spilling out the hot water tank, because there was no place for it to go in the chimney. This is very common when people undersized chimney liners or undersized chimneys that, as you start that furnace up and it's running it's it has draft initially, but as the flue gases fill up the chimney, it starts to back up in there and the draft starts to decrease To the point where we get spillage in the chimney chimney liners right chimney liners collapse. I think I got a slide. That's no! It's not on this one.

The chimney liners collapse chimney liners, fail, chimney, liners aren't put in correctly guys, don't pay attention, and this whenever you see common, vented appliance, you need to make sure that when this appliance is running that you don't have, oh there's a chimney liner right there in the Bottom corner of it, so that that is a very common problem when you walk in a lot of you guys, don't realize part of the International fuel and gas code and part of the National Fuel and gas code is actually inspecting the chimney. Whenever you go out there and they do a service on there, so you're supposed to actually take take the chimney. Apart. Take the take the stack off take a look inside there.

This one was absolutely full of aluminum full of aluminum beads top to bottom, because what happened was the this is a masonry chimney liner, the masonry is cold. They didn't put a sleeve on there to protect it from condensating. The condensate collected on the inside of the liner, you know again it's an acid in there that acid ate the aluminum, and then you end up with a rotted outline or sitting there right. So these are our common problems that we see out in the field.

All the time, but this one here is one that's near and dear to my heart, because I've seen this happen more times than one well the why you can have the white on there that helps divert the flue gases in the right direction, but if it builds Up and it backs up it's a problem - it doesn't matter what you know. Why is the correct way of doing it? So normally we'd have like a three four five or four five six, you know and and you'd white in, but the problem is, is when it goes up. If the pressure builds up, it's static pressure right. It just built up a pressure in there and it's just got to have somewhere to exhaust itself, so it exhausts out the hot water tank and that's that's what most common problem.

When you see those things melt it out there all right. So now we get. We just went through a whole bunch of visual inspections. We made sure we got draft, we made sure the flue gases are going up the stack and let's talk a little bit about setting manifold pressure.

All right. First thing we got to understand is that every single appliance is engineer a lot of guys to get they get. They get crazy when you start talking about working on a gas appliance, and we talk about setting gas pressure and we talk about changing offices on the gas appliances or whatever. This is the business that we're we're in we're in a HVAC business.

In fact, anybody here Duke work on propane bunchy, guys right, you guys, don't really panic over change in orifices. Do you right you guys, so you have to go out and convert natural gas appliances, the propane all the time for guys that are in classic gas markets that never convert appliances out there on it. Maybe guys have seen for years. Oh, it's 3.5 inches! It's got! Instead of 3.5 inches, what does that say right there, manifold pressure? 3.0, 23.8 inches.

That's on a 90 Plus furnace at my daughter's house right, it's an ICP product carrier product. Now it's saying that there's a range of adjustable pressure: it's not just 3.5 inches! It's a range of pressures on there and you'll, see this more and more as people are making sure that you get the input correct on furnaces. So here I'm just setting up the fuel pressure on the furnace, and now we get the fuel pressure set. Now we want to the meter.

This is a step that almost nobody does. If you and every single furnace manufacturers manual there's a section on cocking the meter. This, in my opinion, is the most important step on making sure we're getting the appliance setup right. If you think about it, there's not too much we can adjust on a natural gas, gas appliance.

In fact, there's only two things: what are the two things we can adjust on a natural gas appliance input, gas pressures one and what's the other one blower speed? That's it right guess which two things don't get set correctly and most appliances, gas pressure and air flow right. That's the stuff! Everybody forgets about and clocking. The meter is a step that we learn about in school. We think it's like a some kind of theory that we should clock the meter, but nobody does it and a meter is probably.

This is one of the most important steps now, here's. Why and here's why you don't ever adjust a furnace with a combustion analyzer, a lot of guys say I'll, just put it in there, I'm gon na just go to adjust the gas pressure till I get fifty percent excess air you'll hear that in the industry. You don't want to do that. This is called woab index and what that is, it's a measure of the interchangeability of fuel gases.

What it's showing is here is that there is different heat content so anywhere from 1035. 10. 30. 99.

1041. 1019. 1035 heat content varies of natural gas across the country. In Florida they have a lower heat content of gas than we do up in Ohio and a lot of times what the manufacturers do is they actually add in other gases like propane in and they get the heat content where they want.

It. They'll trim the gas on their problem with this is is the heat content if you were to, if you actually have a counter imager and again si si Labs went down there years ago. The heat content varies not only hour by hour, but almost minute by minute. The heat content is going up and down to the gas, and so the big problem is, if we don't set it up for average heat input, we don't know whether the heat content is high or the heat content is low.

When we're adjusting that appliance, you need to make sure that you're setting it up o'clock to get your average heat content for your area set your appliance up for the average heat content, because that fifty percent excess air is designed to make sure we always have enough Air, if the heat content of the gas increases right, so the heat content of the air goes up, need more oxygen, that excess air is making sure that we don't make carbon monoxide and we want to make sure we get that input correct on there. So what we've got here is I'm clocking a meter, and one thing you can tell me: what can you tell me about a gas meter? There's something really important about gas meters that can assure us that they're that they're accurate it's the same thing to go to the. When you go to the go to the butcher, you know look at a scale or you go to the gas station and you look at the meter. What can you tell me about there there's always a what on there some kind of a sticker certification yeah? These are utility grade meters.

Okay, now there they are they're very accurate, they're, also temperature compensated. A lot of them are temperature compensated now to 68 degrees, meaning that it's always going to give you a precise reading of the input of natural gas. So here I'm just clocking a meter on there and then there's a scale here that simply tells you, when you clock the meter here, how many seconds it took for the meter to clock and then what your input is now there's different dial sizes 1/2 on one Foot in the two foot, but the key thing here is that the table assumes a thousand BTUs per cubic foot. So whenever you the meter, whenever you look at the manufacturers, things are going to tell you that.

There's an assumption made for the heat content of the gas and you actually have to mathematically correct that and the way that you correct it and we'll talk about that in just a minute on the next slide. Here, I'm gon na hear a clock that at 48 seconds there - and at this point here we got to determine - is the input correct. Do we have to change the fuel pressure? Do we have to adjust the the orifices change orifices? What do we have to do? Right so in this case here at 48 seconds, I'm at 75 thousand BTUs input and I might have to correct that for my heat content. So let's talk about that.

If your suppliers, we give me a thousand 25 BTUs per cubic foot and your charts and a thousand all you do - is just a thousand 25 divided, a thousand multiplied it times 1.05. So if you had 86,000 on your chart times 1.0 to 5 would be 88 150 right. It's just a correction for the heat content of the natural gas and it could be a multiplier that makes it higher or makes it lower, depending on what your supplier heat content is on that chart. This is really slick, and I I found this if you ever want to.

If you ever want to learn a lot about our industry, you got to learn it from the debt from Dan Houlihan would say, is the dead men that came before us right. Things have gotten so commonplace in our textbooks today you know you go out. You buy a copy of refrigeration, air conditioning technology. You won't find this formula anywhere in there that it tells you that if we know our current input and a current pressure, we can calculate what our new manifold pressure should be based on our desired input.

It's a formula that comes out of a book from 1920 when they were, it was called installing gas burners in coal boilers right. So it was all about setting up coal on there. Now these formulas are things that are lost because we as an industry, we don't talk about gas, burners iana, retrofitting appliances anymore, and this is what we use in measure quick, this exact formula to calculate out what the pressure should be. So if we had ninety thousand BTUs equals 88 150 divided by T P 2 divided by 3.5.

I can calculate out if I want to have 90 thousand BTUs output. What my P 2 should be is three point: six, five inches of water column, so we can set it at six point five. It just allows us to correct for the gas pressure on there. So when they're saying 3.0 to three point: eight, that's what this is! All about it's getting correct input on the appliance right now measure, quick.

What we do is we simply the meter you'll notice that there's a couple of different things here that are pretty important here number one is we have the heat content of gas and pretty quickly we're going to use your geolocation on there to pull this heat content In off that EIA website, you guys just saw so you want to have to set this it'll just do it automatically for you and here's just three examples here, so we clocked it at 38 seconds and tells you that, because it's 2.7 4 inches of water column Is the target it tells you that we need to downsize that orifice and recaulk the meter, because at 2.7 4 we're below 3 inches of water column, so that's too low. So we need to downsize the orifice in this case here the targets for 4 inches of water column, so we need to increase the orifice size in this case. Here it falls in the range. So now I'm gon na do is just set it at three point: six, eight inches, so they'll tell you all those things that runs all the calculations in the background, so you don't have to do it by hand on a propane system.

It's there's a couple different things you can do. One is get a sublet meter for propane and install it in line, and it might be the it's a one-time thing when you're doing a propane installation you just take. What I did is take two flexible gas lines. Connect the propane meter in line literally o'clock in the basement, which is sort of a nice get the input correct on the appliance propane is a it's a son of a gun to because you get a lot of different heat content from different propane manufacturers.

So you got a call, I'm asking what the heat content of their gases and then the appliance is engineered for natural gas. It's retrofitted for propane, so sometimes you're not going to get the performance out of that appliance on propane that you would on a natural gas installation and it's it's it's it's just the way that appliances are built, but input on propane is absolutely critical, because if you Don't get the input correct, you're gon na have issues with carbon monoxide with sitting it's. It can be a nightmare, there's probably more if you see a furnace that suited or have bed installations, typically a propane installation more than natural gas, because somebody didn't do something: the conversion correctly right. So you know a sublet meter you can buy.

You can go on Amazon and buy a sublet meter and that's the easiest way to to test that so on a 90 plus furnace - and this is depends on the efficiency, your furnace, if you have an 80 plus furnace, not a big deal. If you have a 90 plus furnace, it's a huge deal because the difference in getting the input correct the only way you can adjust the only way you can adjust the amount of air going into that appliance because there's no there's no shutters or anything else. The only we can judge the change the amount errors might getting the input correct. So whenever you have a in orifice a gas orifice and any fire gas through it, it'll it'll, actually in Trane air and the proportion of velocity of the gas.

So, as the gas pressure goes up or down it's going to get exactly the same amount of fuel gas mixture in the in the primary air all the time, that's why we can run a furnace down to one point: seven inches on low fire up to 3.5. On high fire, because the Bernoulli effect is just going to train the right amount of air in well, what we can't control is the amount of secondary air and secondary years, the air that goes in around the flame. So what happens is by it? We're going to pull an air we're gon na pull in gas-right gas and heat. So when the flame is too small, we have a high amount of secondary air going in because there's just no gas does this place that no fuel does to displace it.

And what happens? Is it dries out the flue gasses? So, in my case in my house, I had an input and correct at a 94 % full modulation, Rheem furnace put the combustion analyzer and it's running 90 % efficient like why the heck's this thing running so low. Why isn't it running closer and I pull off my condensate drain? I have no condensate drawing it out of that drain. Well, I have 75 80 percent excess air, a huge amount of excess air that excess air dries out. The flue gasses right there you go well.

It's only 4 %. Well, if my gas bill, you know over the course of a year, let's say up in Ohio, I might spend you know - maybe just shy of a thousand dollars a year on gas, 4 % of that right. 40 bucks a year over 20 year period is substantial, so getting that input correct right. The first time is going to save you anywhere in it from 4 to 7 percent, on your on your gas, long-term and and you're gon na get the appliance running the way.

It's designed to run, I mean that's. The other thing is: if you don't make condensate a lot of times what you'll do is: you'll pull flue gasses backwards up the secondary heat exchanger, there's a trap in there and that trap has got to have water in it and if it doesn't have water it. The induced draught motor is going to pull because it's on the collector box pull backwards up and then then we have some serious problems on there. So you want to make sure if it's a condensing appliance, it's actually condensing you'd, see high excess air yeah I or high oxygen.

I typically when I'm looking at a point. So a lot of guys watch co2, they're, older oil, guys i watch excess air excess air. You know what I have it anywhere from about thirty five percent to fifty percent excess air when it's set up properly on a first stage on our plane. It's like, if you're talking about a two stage appliance, you could easily have a hundred one hundred fifty percent excess air because we can't control the the the secondary r-right.

Now. Here's the other thing that a lot of guys don't understand. Two-Stage appliances. Do not save you! Any money at all right: they don't save you any money.

In fact, your appliance runs worse on the low stage and running around the 90 percent efficient range versus ninety seven percent. Let's say on the the high fire: the only reason we have modulation and we have two-stage appliances, there's for comfort, that's it. It provides us comfort, so you're, getting more comfort, you're, sacrificing efficiency. Okay, so, like my full modulation furnace, it runs at 90 percent, a good part of the year right, the only time it comes up in the high fires when it early in the morning when it's - and I have the house set back it warms up - fills the Trap up keeps so I don't pull water up the secondary heat exchanger, but most of time it's running in this in a slow fire, but it's like having a gravity furnace in my house right.

I knew it wasn't as efficient, but I wanted the comfort of having that out there, whatever setting up an appliance here. What we're trying to set it up for is the highest efficiency with it's a certain amount of safety here. So what we're always going to set up the appliance so we're in this zone here this is what we call stoichiometric combustion. This is when you have excuse me when you have just the right amount of fuel and just the right amount of air.

So if you look at the bottom here, there's there's no excess oxygen. There's no excess fuel! There's no excess air right! That's stoichiometric combustion! We want to be in here when we have some excess air. Now here's the thing you got to remember is: even though you have excess air, you can still have carbon monoxide. Keep pumping that crazy thing.

You can still have carbon monoxide on there. So, just because we have excess air doesn't mean we don't have CO on there, and so what we want to set the appliance up for is this. Is this range here which is typically and again at 30 to 50 percent excess air range on the appliance? So this is what we see when we're graphing. This is actually off of a testo analyzer.

You can do the same thing off of a off the active Tools. Analyzers is a graph of combustion analysis. This is typically what we want to see. So we start the appliance up.

If you look here, this is efficiency. This is oxygen, the green is co undiluted and this is stacked. So if you, if you just start with us with the o2 here right, we start at 21 % oxygen. We start the appliance up and we see this dip right here.

Why do you think we see this dip right here? What happens when I first started on appliance up and warm up, and we also have a lot of gas right. We're feeding a lot of gas in because the igniters starting to glow igniter is going the open, the gas valve up and there's going to be this little bit of gas that goes through, and it's sort of whoop right when it lights off. It's got a lot more fuel than it needs initially, so we see this dip in oxygen right here right. We see this dip in oxygen notice.

We also have Co right here because we have excess gas and we have X. You know we're pulling the o2 down, but almost immediately that o2 starts to rise up. This is only minutes here, so this is a minute after Inlet and within a minute and a half here, the up the o2 starting to stabilize the co air free drop down to zero right, the stack temperature slowly rising. Why does the stack tender? Here's one that people say well study, state efficiency of a furnace is when the stack temperature stops rising.

The stack temperature will never stop rising. Why not return airs rising yeah as a return? Air rises, just act, temperatures going to rise and then here's our efficiency. So it started off here higher and you notice the efficiency is also dropping off. Why would our efficiency drop off because the return air is going up right? He'd either goes to places in the house or out the stack so again as it runs, are going to have a small drop in efficiency, but overall, let's run it right in at 80 %.

Efficient range now contrast that to this, this is an appliance under duress. This is actual points I went out on. This was at a Lorraine, metropolitan Housing Authority. Oh two, on the bottom right.

There you'll see that the o2, when the this is not when they applying to starting it's just running, OH, is all over the place right and you can see there is that appliance is running. The the CEO is down at zero parts per million, but then all the sudden, when it Oh to hit in the 8 percent range, the CEO went through the roof right straight up. This is a characteristic, most guys, don't understand. With gas appliances.

Co is like a hockey stick, you have. You have air and fuel going in everything looks good. You keep trimming down the o2 trimming down the o2 and, and everything looks good. You can be right at zero parts per million, but you literally cross half a percent of oxygen and it'll go from no co2 Co through the roof notice that where that's at that sealant diluted of over 3,000 parts per million.

Now I pulled my stack out at that point because I go. I was watching this thing run and I saw my analyzers are gon na get pegged so I I pulled the probe out of the stack. That's why my o2 went back up to 21 % right here, and then I put it in here. Anybody have an idea.

What could cause something like this, and this is where again everybody I went out. This is a little Lorraine, metropolitan Housing Authority. It's a beastmen boiler, sealed combustion bringing in air from outside - probably probably a million Btu boiler right, big boiler. This is a weird case of events out here.

What could cause something like that? Right everybody's out there, the pressure, there's a pile of pressure switches on the floor right because it's got to be a bad pressure, switch right. This is actually from an elevator right. What was happening is every time the elevator would go up or go down. It was creating a plunger effect on the building because they had gone and taped off part of the elevator shaft.

That was a ventilation for the shaft. So when the elevator would go up, it would depressurize the the room and the elevator to go down, and what you're looking at is the elevator going up and down a couple stories versus the elevator going to the sixth floor. The reason we saw this is because we're a graphing errata combustion analyzer and we're going what in the heck is going on and I'm listening and hearing the elevator going up and down and sure as heck that's what was depressurizing the space now. Here's what I want! You understand this is a sealed combustion appliance, sealed combustion, so it's exhausting outside bringing air from outside.

This was overcoming this. This pressure was overcoming the sealed combustion that appliance. This is actually when we tested it cuz. The other thing they did was they abandoned the chimney.

In the building the abandoned the chimney altogether, this is probably a 10 story building huge chimney. The pressure in the chimney was negative. 50 Pascal's. So we had it open boiler space with an open chimney in there sucking the air out.

We have this plunger effect of the elevator shaft going up and down. We have all these perfect series of events that are causing all these problems here and you can see. This is a definitely combustion under s. If you weren't test ins with a combustion, analyzer you'd, never see this stuff happening measure quick, we just incorporated in the gas heating and here's the big reason why, when I first bought a combustion analyzer, it had all these readings on it, and I had no idea What all those readings meant or what they were for right, because we have stack temperature, we have Oh to co2, we have excess air readings.

We have you know, efficiency readings. We have Co air free readings. We have you name it there's, probably about a dozen readings that the analyzer I'll make on there one of the things we did with measure quick was we tried to tie targets to all these, so you can actually see if they're, in a safe zones, if they're In a high efficiency and low efficiency, if the inputs in the correct range or not very, very visual and we've built that all into the product and that's all working well, there's a set of tools. We recommend with that and what we're trying to do now is, instead of looking at the appliance measurement by measurement we're looking at the entire appliance at once.

Furnaces are dynamic and here's a problem if you're not looking at everything at once, if you're not watching things, you miss things right because again, here's we're talking about that gas appliance. It's hooked to a distribution system to get the air out where it's got to go. It's got a ventilation system, it's got a gas supply system right. There's things that happen.

You know you're standing down there if you're not watching your incoming gas pressure, how many guys have seen furnaces lockout on intermittent flame failure right you go out there you're clean igniter, you do all kinds of other things. How many of you guys have constantly measured your incoming gas pressure and notice times when the gas pressure dropped too low for the regulator to regulate, and now we got a flame that is not working correctly. Somebody turns on gas logs. Somebody turns on the dryer.

Somebody turns on something else, if you're not watching incoming gas pressure at the same time, you're watching your manifold pressure, you're missing a problem that could be potentially happening if you're not watching your temperature split at the same time, you're missing things that could be happening if You're not watching your combustion you're missing things that could be happening, that's what we with all the bluetooth tools that are out there. We recommend you know in this case here I got four manometers hooked up. People think sometimes I'm crazy, but this is what differentiates a technician that catches problems versus something that that misses them consistently and walks away. This is about you know, it's a small investment in tools, if you think about where we come as an industry, that's like the best time ever is an industry, because the cost per point of measurement is just dropped down next to nothing right now, it cost of One manometer they're not expensive anymore, but now you can see these things in real time as they're happening right.

So here's a couple things we want to do with metric quick. We got a profile, a system. Profiling is the most important part when you're doing combustion analysis and by the way you don't have to have a single digital tool to use measure quick for combustion analysis or any other thing. Alright, because one of the things I did is it built it so that you can there's input boxes here, so you can tap on these boxes input your temperatures input your pressures right.

So if you don't have for manometers, you can input stuff by hand and still use all the diagnostics and everything else measure quick does. But the key things here are: we want to profile the system profiling. The system is telling me what type of a system - I guess you just can't see that one profiler system is telling me what kind of a system it is. Is that a ninety plus is an eighty plus? I need to know what to expect.

Obviously, the stack temperature under 90 is much different than a stack temperature on an eighty right after we profile it we're going to make sure our temperatures are in the right range. This is resupply err return. Air temperatures can can return air temperature be too cold to actually set up the appliance correctly, absolutely right, yeah. Absolutely.

It can also be too high what about an 80 degree day in Florida? Would you want to run the furnace? No, it doesn't work right. It's not engineered for that. So there's, every single reading we make has a target. This is probably one of the things I'm most passionate about in our entire industry is used to never ever make a measurement.

Unless you know what buicks you should expect right. Honestly, if you, if you're, if you're, making a measurement - and you don't know what to expect, why are you making it if you making it just to put a check in a check sheet to say: oh here's, the gas pressure was or here's what the co was Right and how guys have you guys, seen sitting in her truck on on on on Tuesday, when they got to come in the office filling out their paperwork right and it writing down 118-pound suction 350 pound high side 9.2 degrees is superheat. Ten point: seven degrees of subcooling right. How do they know all this stuff because they're there they've memorized it from all the jobs? No, they.

You know. Those are the readings their boss isn't going to question right. So if they just write those readings in they'll be good to go so dope tummy doesn't happen, I mean I've seen it over and over again right, and so they get tired of you know. Tech support guys.

This is a. I talked to the guys that Jake carrier Trane Lennox Goodman. They get guys on the phone. What's your super heat? Oh it's ten degrees.

What's your suction pressure? What's your suction line, temperature? Okay! That's not ten degrees of superheat right! You need to know what your measurements should be, and this is what a big part of what we're doing a measure quicker, making sure the temperatures are right. The pressures are right. The inputs right on that appliance, we're making sure it's breathing okay. Does it have enough oxygen? Is that input correct on there and then, if you have a question what's up here right and what we got here is just a target inside of range.

If you tap on any one of these targets, it'll tell you what that? What that reading is they'll tell you well about it, and it's a lot of times will tell you what to do about it. So now you know, you know, step by step what to do so. Everything on there is calculated out, so you can. You can do that all right combustion testing gas furnace very important on here when you're testing, multiple cell appliances, like an old 70 percent of fish and furnace on here, you're gon na, have to do three combustion tests.

Every single cell is its own little combustion chamber. They're they're not tied together again that what's the job of the draft hood is to separate the appliance from the draft, so you're gon na test each cell and the undiluted flue gas, undiluted flue gas is an important term. We never want to test the flue gas once it's gone through the once it's gone through the the dilution error, hood or draft to it on there, because that flue gas is highly diluted. We want to test it when it's coming out of the out of the combustion chamber itself verify the base pant seal.

This is this is again that CO poisoning bill and I ran across years ago, 90-plus furnace. They actually condemned that it was a comfortmaker furnace, cracked, heat exchanger, reasonable standard of care. The guy shut, the appliance off suddenly got a cracked furnace. Let me get a new furnace out here, we'll get it put in.

Take the old furnace out put the new furnace in they reuse. The existing venting system right three inch. Exhaust vent going out, went from a single-stage appliance to a two-stage appliance. Well, Lennox furnaces on these required an exhaust accelerators, so they didn't put the exhaust accelerator on and so now they got a furnace, that's making carbon monoxide and it's exhausting it outside, which was all good except it's, exhausting and underneath and overhang for a gas fireplace.

That's got a ventilated soffit because it didn't have the velocity they carried out from the house that pulled it back in decided to in the home through the ventilated soffit. Well, how did it do that base pan on the furnace on the bottom? A lot of these furnaces come with a either removable base pan if you're going to use it with the bottom returned or none at all, and you got to pay on your own return under there. That base panel is loose depressurized in the basement. So now I got a negative pressure of my basement.

I've got carbon monoxide and I've got a path to that carbon monoxide to get back in the house and that's exactly what happened on there right. These things are perfect chain of events, so you got to look at the entire appliance and make sure that we're doing it right - excess air 31, the 91 % on this type of appliance, Oh 2, reading 5 to 10 %. You know each one of these, and these are all laid out in the combustion guide on there sort of step by step, how to do that so I'll flip through these and we'll get through this quickly. So Brian, don't yell at me: understanding combustion efficiency versus AFUE.

This is probably one of the most important things you guys are going to buy a combustion analyzer you're going to go out there you're gon na. Stick it in the stack of this old piece of junk appliance you're going to go. Oh, this is burn pretty good. It's almost 80 % efficient and it is burning pretty good, but you're not considering is all the standby losses of that piece of equipment.

A combustion, analyzer measures, combustion efficiency, not appliance efficiency. So here I've got a draft hood. That draft hood loses 10 % of my of my efficiency, my appliance because it's constantly sucking air out of my home, whether I'm burning or not, pilot standing pilot loses 10 %, uninsulated cabinet losses so yeah. I got 81 % combustion efficiency.

The draft hood, the standing pilot, the insulated cabinet - that's a little bit more representative, the fue that appliance so consider when you're looking at an appliance - and you look at that combustion efficiency that that only tells part of the story right. How do we get think about the evolution of furnaces as we go? We went to an 80 % efficient. We eliminated the draft hood first, the you guys. Remember.

We had 80 pluses with standing pilots. Any of you guys remember those right. Then we eliminated the standing pilot right. We got rid of the standing pilot, then we saved more gas by putting in a secondary heat exchanger in it and getting secondary heat exchanger, so a 97 % a if you, a replacement, actually does increase a 41 % efficiency.

So that could drop that $ 1600 gas bill down to 656, all right the rest of this just going over different spots on combustion tests on here. This is all in the guide. You can download that a couple other things on differential temperature testing. Second, most important thing on appliance: you want to be in the center of the range on there.

You don't want to be either end of the high end and the low end, because we can either cause condensing and a non condensing appliance or we can. We don't leave any room for the filter and load up with dirt right so again, combustion analyzer can be used for that to measure the differential temperature with a couple of nice field. Piece contain thermometers, all right boilers again make sure you're testing and the undiluted flue gas below the draft to it on there and then we're going to test the rise of the water on a non condensing appliance. We don't want to see that water coming back at less than 140 or we're gon na get condensation in there.

Oh, the old book. I'd have to look it up. I honestly don't remember what the name of the book is. It's a series of small books that were it was it's.

It's called installing gas burners underneath coal boilers. I think it's the name title of it, but I'll. Look it up I'll. Look it up I'll, put something online on it, yeah.

So what they do is they have a 3 inch flue pipe. They neck it down to 2 inches and it's just for a short range of spans, so think about it's a lot like evacuation when you're when you're an evacuation, the larger diameter tube causes the a decrease in friction. So if we just neck down the the exhaust, just at the end of it there, it doesn't cause a lot of friction where the for the with a pipe becomes a problem. It just accelerates the exhaust speeds, it up, increases in velocity and throws it away from the house.

So that's common on Rheem. Does that Lennox? Does that you'll see a lot of 90-plus appliances where they you got a 3-inch and then it necks down the two-inch when they exhaust it out of the home it'll work with back Rex. If you got the QR code, it'll scan a QR code and bring the readings in off the Bacharach, so it'll work with and and you can also input the readings by hand in there, but yeah everything we do and measure quick is set up. So you can you can input the data by hand if you need to combustion, is combustion so for the most part, wheelies try and get the right amount of fuel the right amount of air in there? That's why both all the targets in all the different appliances? That's when you ask how important it is that that's the profile, so we've got to make sure we get a right profile put in.

So we know what we expect coming out. The biggest thing that changes is your oxygen reading in your stack temperature right, your stack temperature can be anywhere from 90 degrees up to 600 degrees, and it all depends on the appliance in your o2 could be anywhere as low as, let's say, 30 % all the Way up to 150 percent, depending on the appliance so yeah, it does have a more of a wide range of anticipated outcomes. You're gon na shut me down now, yeah, no more questions all right. This could go all day.

This is just like the podcast, but I can't get a word in edgewise. There's good reason for that. Everybody, Jim Bergman, thanks for watching make sure to follow measure quick and a key tools on social media to find out more with what they have going on. Really nice tools and really great software, so go check them out on YouTube.

Facebook, Instagram they've got accounts all those places and stay up with all the latest with measure quick and a key tools. Thanks for watching.