Thanks for joining us today on the hvac school podcast eugene, thank you very much for having me brian. So this is a really big honor. For me, um we've talked over the years on and off about different things. Medit events, um i've read your books for years.

I've gone to your sessions and seminars, and so it's really cool to finally, have you here talking to the audience just to introduce yourself to the audience. Obviously, i think a lot of people already know you um from your work, but introduce yourself a little bit about your history. So those who aren't informed can know a bit more awesome uh. My name is eugene silberstein.

I have been in the hvac industry for over 40 years started out as a helper became a tech. I was a uh system designer consultant air balancer had the opportunity to own three service companies in new york, a retired teacher with 27 years in front of the classroom and have also been given the the wonderful opportunity to write and become the author and co-author of Over a dozen textbooks on hvac and with all of that experience in the industry brian, this is my first podcast, so i'm really really excited to to be here with you and i'm glad that i have the opportunity to come and hang with you for a little Bit yeah, it's fun, that's what we're doing just two guys hanging out and there's, like i don't know 40 000 people packed in the studio with us. That's all it is. You know just all of our best friends.

You know um so yeah. So this, what we're gon na talk about today is psychometrics, and specifically this relates to uh a book that you wrote a presentation that you've done, but the the concept is psychometrics without tears. So, even even the word psychometrics is overwhelming, so just to kind of unpack that a little bit. Why? Why do you think it's overwhelming and how can you kind of ease everyone's mind so that it's not so? No, not so many tears yeah there you go well.

Yeah psychometrics itself is really just a blanket term that really talks about the the physical and thermodynamic properties of air. So when people talk about psychometrics - and you hear a lot of engineers talking about psychometrics and when texts are talking - and you - and i are talking it's really all there is to know about air in our industry - we we all strive to become air conditioning experts and If any of your listeners read hebrew, we read right to left. So really. What is an air conditioning expert? An air conditioning expert is someone who's, an expert at conditioning air and if you want to become an expert at commissioning air, it's really important that we know a little bit about air and and that's what this is all about and and the psychometrics without tears book.

Actually is the second book in the series and the first one is pressure enthalpy without tears, and these are two topics that are really really um easy to understand. Once you unpack them and once you get down to the to the bare bones, so we really really need to start out and say what is air? Because if we're going to be an expert at conditioning air, we need to know what air is and and that's a difficult concept, because it's a hard issue to quantify. We know we know how water we know, waterways, we we carry bottles with us all the time we have refrigerant drums. We carry those from our trucks to the job oil.

You know all of these fluids, these liquids we can quantify. We could feel that they have weight and they take up volume and space and air is, is kind of different. We have air around us all the time and when we ask people - and i do this all the time i ask students - i ask technicians: how much does the air in the room you're in right now? Wait, and i do this at seminars. I do this when i travel to the ahr show where i'm doing sessions and these rooms are filled with engineers, contractors, technicians and students, and when i ask people what how much does the air in this room weigh the overwhelming response i get is it doesn't weigh Anything and that's a little disheartening when i get that answer from engineers and from teachers and contractors and technicians, i expect an answer from students, because it's you know it's something we take for granted.

We really don't understand what you know what air is and that it is a fluid that needs to be treated treated as such brian. Take. For example, you know everybody, maybe you're driving in a truck right now, maybe you're in your living room, maybe you're in your den but think about the size of the space you're in right now. Meaning i'm in my office at my house and and this room is, is uh 23 feet by 10 feet.

Uh, i'm sorry with a 10 foot ceiling 23 by 18 feet. So this room has a volume of of about 40 150 cubic feet. And if i took all the air in this room - and i put it on a scale that air would weigh about 300 310 pounds and that's assuming standard air and it's kind of neat. And if you have trouble visualizing that, if you do lawn work and you have a 50 gallon lawn lawn bag, you know a big garbage bag for long leaf.

50 gallons. If you fill up two of those with air, those 250 gallon bags, 100 gallons of air, that weighs one pound, that's one pound of air and, of course, that's assuming standard conditions which you know, sea level, 70 degrees, atmospheric pressure, fun things like that. But it's really really important brian, that we that we understand a little bit about air and it's something we take for granted. We don't really.

We think we don't really think about it. It's interesting because i think we don't you're exactly right. We take it for granted. We're air conditioning technicians, we condition air and yet the air part is scary to us.

We look at a psychometric chart, it's like. Oh, my gosh. This is such a confusing thing right or we start to do the math related to air or even figuring out what all goes into the standard air equation, and it becomes this like really scary thing. But why is that? Why do we as technicians look at everything else in the system other than the air part of the system? And really that's exactly what we said.

We we tend to look at the refrigerant side, because we think about compressors and pumps and again because we're moving refrigerant, we're thinking about cooling. Unfortunately, a lot of us have the mentality that, oh, if a little bit of refrigerant cools a little bit, a lot of refrigerant is going to cool a lot better and what we typically don't understand is we we go out on a service call and old school Technicians, i'm one i've been in this industry since i'm 14 years old. The first thing we always did was we put our gauges on a system. We wanted to see what the operating pressures were and we diagnosed the system based on those operating pressures, and what a lot of people don't understand fully is the readings that you get from a system the operating pressures, your saturation pressures - they mean nothing if we don't Have proper airflow through our evaporator coils and condenser coils, and it's difficult to understand something.

We can't see smell, taste hear touch and we can't do that with air. We could feel a moving air stream, but for most people it's it's invisible. So we concentrate on what we can see. We see the compressor.

We could hear the compressor. We could take amperage readings of the compressor which is moving refrigerant to the system, but the air side for many has been a been a mystery and it's it's been my goal to to quantify air, and when i do my sessions, i i come. I come equipped with a bolt and i pass this bolt around then you might have seen it and the bolt weighs exactly 1.2 ounces, and i pass this bolt around at the beginning of my session and say what does this have to do with air and 1.2 Ounces is exactly the same as .075 pounds, which is the weight of one cubic foot of air at standard conditions, and it allows individuals to quantify and realize that wow hold it. This is a real thing.

This is something we have to take into account. This is something we need to account for, and another thing i like to do when we're on that. You know on that. Topic is to have people think about a blower on an air conditioning system and let's assume that blower is moving 2000 cfm.

So, roughly a 5 ton system with if you use the old nasty 400 cfm per ton rule if we have a blower, that's moving 2000 cfm and that blower is left on for 24 hours. Well, if you're moving 2 000 cubic feet of air every minute - and there are 64 minutes - i'm 60 minutes in an hour and 24 hours in a day that blower is moving 2 million 880 000 cubic feet of air every day and using that 1.2 ounces or 0.075, pounds per cubic foot you're, looking at a blower, that's moving 216 000 pounds of air a day or 108 tons, and i've done this when i was in the field when i was younger and a blower is making a little noise. So you take a little piece of wood and you and you wedge it under the blower mount. Oh, it's just a blower.

I could you know, put this little piece of wood under there to to get the noise gone over the years when i started realizing how much weight these blowers are actually moving in air. It's really really important that we as technicians and people in the field, really look at it and say wow. This is a major air. This is a major system component that is moving massive quantities of a fluid, so it's actually kind of neat.

So in my sessions in my books in my trainings, i always try and and make it easier for people to to visualize aaron, quantify it and realize that it is a very important aspect of air conditioning system, refrigeration system operation in some senses. It's even more important than the refrigerant side. If you have a small refrigerant flow problem, the system will still cool air flow problems magnify. So you can have a small airflow problem and it's going to cause the system to malfunction and often we target right onto the refrigerant side.

You know how many times have we well. None of us have ever done this ever we've gone to a job gauged up on a system and saw the operating pressures were low, so we immediately ran to the truck got to the tanker, for you know, got went to the truck, got the tank of refrigerant And started dumping refrigerant into the system trying to force refrigerant into the system. You're, opening your manifold refrigerants flowing in closing your valves gauges, the gauge ratings aren't changing. Ah, this system must be really really.

Then you start dumping refrigerant and dumping refrigerant. The system is choking. It's telling you, i don't want refrigerant, but you're, forcing it in there and you finally get the operating pressures a little bit and then you go well, that's as good as it's going to get the system's old. This is what it needs, and now you get ready to leave the job and you say: oh, let me just check the air filters and you open up the filter, grill and you're.

Looking at the filter and it's three inches thick, the the homeowner has 14 cats. Two dogs, two ferrets and a squirrel living in the house and the filter is three inches thick, so you go to take the filter out and you're pulling the filter and the filter is pulling you back in. You finally put your foot up against the door and you're able to pull the filter free and also you hear that whoosh of air sucking right into the system and that's when it strikes you now you go back out to your truck at your gauges. Put your gauges back up on the system and those pressure readings are, are super super high now, so it's really really important that we we attack and we address the airflow issue first before we look at the refrigerant site.

So again, in my sessions in my books, i'm always trying to to change the way people look at things and you've been to some of my sessions, one of the first slides that i always address i always have on my special. My sessions is, if you change the way you look at things, the things you look at change and we really do need to look at air a little bit differently than the way we've been looking at it in many cases, up to now, yeah start by looking At it at all, i think is a nice starting point um, so yeah. It is interesting because you talked a little bit about the weight of air. You talked about the you know, kind of cfm, 2000 cfm and a five ton unit.

That's sort of the rule of thumb that we've used for a long time, a 400 cfm per ton, which we're learning to to not rely on that as much as we used to. But what's interesting is is that we always talk in terms of cfm, which is a volume flow measurement cubic feet per minute right, it's boxes of air. You know one one foot by one foot by one foot square boxes, but yet what really matters to the equipment? Really is the weight of air? How much air are you moving by weight? So that's like a mass flow rate, type of um equation or calculation. So talk a little bit about the things that can affect the weight of air because that that .075 pounds per cubic foot.

We use that as sort of standard air, but there are some things that can actually pretty drastically affect the weight of air per cubic foot. Yeah and - and there are a lot of things that one thing - that's really really cool and you - and i have had this discussion almost ad nauseum about you - know what affects the weight of air and you know we could throw it out there really quickly. I mean air has moisture in it and you know i always send this question out and you and i have joked about this for years and we know water is heavier than air, so i always ask people, technicians, teachers, students, as we humidify air. What happens to the density or the weight of air and across the board? You know the answer is well, as you add moisture to air, the air gets heavier and it's we started out and and brian you and i both have done this and we get people to buy into as we humidify air it gets heavier and it's because the Mentality is the thought is that water is heavier than than air, and, and the fact of the matter is that, as we humidify air, the density of that air actually goes down.

And and when i say that i've seen your classes and when you say that people's jaws drop and and the fact of the matter is that when we humidify air, the density of that air goes down and we need more air to make up a pound. And and getting back to to what areas mean air is primarily nitrogen and oxygen right. Air is made up of 78 nitrogen 21 oxygen and not to get too deep into the into the chemistry. But a molecule of of nitrogen weighs what we call 28 atomic mass units, which are you know, units of mass at the atomic level again.

Reading hebrew is a great thing and in an oxygen molecule it weighs 32 atomic mass units. So these these molecule weights are between 28 and 32 units. A molecule of of water weighs only 18 atomic mass units. So it's a fraction of what a molecule of nitrogen or oxygen weighs and one of the key elements to think about.

When we talk about psychometrics - and we talk about air - is we're always assuming constant pressure and when we talk about constant pressure, it's kind of a no-brainer, because if i have high pressure in the room, i'm in right now and low pressure in the room. Next to me, air is going to move from my room to next room, either through cracks or under doors or through an open, uh passageway, when the pressure is constant. The number of molecules in that space is constant, so this is a key. We can't change the number of molecules if the pressure is going to remain the same, so with the assumption that the pressure is the same as we humidify air.

That means, as we add water molecules to the air, then some molecules have to leave. So if we introduce water, which has a an atomic mass of 18, we have to push other molecules out and chances are the molecules we're pushing out are going to be either nitrogen or oxygen. So we have a space, we have a room that has 78 nitrogen 21 oxygen with molecular weights of 28 and 32, and then we add molecules that only weigh 18 water and we push out the heavier molecules. The weight of the air in that space actually goes down so when we humidify air, the density of the air actually goes down and to move a pound of air.

As you were talking about mass flow rate, that blower needs to move more cubic feet of air. To actually make that happen, so the the argument is often well. If i have a a fish tank and the fish tank is empty, it weighs a lot less than what i fill that fish tank with with water and that's absolutely true, but how many more molecules of water are in that fish tank when it's full, then there Are molecules of air, so, yes, a molecule of water lays weighs less than a molecule of nitrogen and oxygen, but per volume. There are magnitudes more molecules of water, which is why water air quote weighs more than uh.

Well, i'm sorry where water weighs more than uh air, so kind of an interesting concept, yeah for sure, and we get this stuff all mixed up in our brains. When you start to think about uh latent heat, i used to have this entire mythology that i would that i believed about how this all worked before. I actually understood anything about it that i made up about how well yeah it is it's heavier and that heavier air. That's the reason why there's uh there's more heat in the heat content in the air and that's latent heat and this whole like weird thing, but we, when we mix up ideas like this, we get we get really confused, which is where really understanding the psychometrics behind It understanding that, yes, more humid air is actually less dense and it does have more latent heat content.

That does impact the evaporator coil differently, but that's a completely different thing, because now you're changing the state from vapor to liquid and just lots of really interesting, interesting. Things like that. Yeah and everything that you need to know about air is on the psychometric chart and, and one of the main problems is whenever you look at a chart and you look at the piece of paper and there's more ink on the paper than in white space. It's very very intimidating, and there really are only a few things on that chart.

You know, there's you know your humidity scales, your absolute humidity relative humidity, your wet bulb. Your dry bulb your enthalpy so and your specific volume, you know your your volume per unit weight. So there really are only a handful of factors on that chart and if you take a short amount of time it doesn't take long to understand or or or learn the components of that chart. But with that chart, there's nothing.

You can't figure out. So this whole concept of humidifying air and making it lighter you can prove it on the psychometric chart. You literally just have to pick any point and go up and if you look at the point before and look at the point after you're going to see that your second point after you humidify has a higher specific volume, which means you need more cubic feet to Make a pound and as the specific volume goes up, the density goes down, so you could really really become a master of air by by becoming a master of the chart and becoming a master of that chart doesn't take hardly any time at all. So whether you've learned about it or not in school, whether you've learned about it or not in the field, it's an investment in yourself, so you will be the one with the answers when, when faced with a problem uh on that chart, you could plot out a System, you could plot out what that air conditioning system is doing and you can determine what the capacity of that system is again.

That's down the road. It's a little bit more involved, a couple of formulas here and there, but literally by taking a couple of temperature readings at an air flow reading, you can determine exactly how many beats you use per hour. That air conditioning system is, you know, is you know, absorbing from the airflow yeah. It is incredible, and it's it's a huge eureka moment when you actually take the time to do it and, like you said it doesn't actually take as long as you think it would so.

Many of these things seem horribly overwhelming, but it's only because you haven't taken the time to sit down for a couple hours and read up on it and figure out how to do it. The psychometric chart itself. A lot of people will nowadays point out and say well, but you can do this nowadays with calculators. You know, munters has a great app and there's these great apps and i am a huge fan of apps and calculators.

However, it is nice visually to do it on a piece of paper at least a couple times like, maybe maybe nowadays, when you're out in the field, you probably aren't going to pull a chart out and get a ruler and use a pencil you're likely aren't going To do that, but having done it a few times gives you a clarity about the fact that this is not magic. This is science, and it is very easy to do. Willis carrier had some really good thoughts about all this when he first came up with the term air conditioning and that's where a lot of these a lot of the original psychometric charts come from but brian, let me let me throw this out there all right. I have a a very, very good friend and he's in the hvac industry and he's not a service tech.

So he cares nothing about superheat sub cooling airflow, but he is a a tin knocker and he has been doing duct work for decades and he knows how to install ductwork, never laid out ductwork, but he could install it. His company recently decided that they were going to manufacture their own ductwork and they got a plasma machine. So he learned how to lay out duct work on a computer. He was okay.

I need a piece of duct work. 18 by 24, 48. Inches long punches it into the computer hits send and there goes the plasma cutter and it cuts out the pieces and he would take the pieces and they would bend them and fold them and knock them together and - and i had asked him at one point - i'm Like listen, i would love to have my students come over because at that time the college that i was teaching at. We did not have a a duck job, so i said i would love to bring my students over so they could learn how to fabricate a section of ductwork and he goes ah that'll be great.

We go over there and he goes to the computer enters a piece of duct work in and there it cuts. I'm like. No, no. I want my guys to learn how to lay out the duct work with with rulers and sharpies.

Oh, i don't know how to do that. So, yes, brian, there are tools, there are instruments, there are apps where you can enter return air conditions and enter supply, air conditions and enter air flow, and it will give you results absolutely, but that is not learning. In my mind, that's using so if your phone discharges does that mean you can't do the work? If my buddy's plasma machine fails, does that mean he can't create ductwork? You still need to know how to do it manually. There are great instruments out on the market.

Now are smart, manifolds that calculate superheat, calculate sub cooling and help diagnose the system. Awesome equipment, awesome instrumentation, but it's important for the technicians to understand where those numbers came from. So yes, you can plug numbers into a psychometrics app. You can absolutely do that.

I do it now too, i'm still old school. I like to do it pen and paper just to check myself but gaining that knowledge on how things work. Why things work it's important to not only know what to do, but why you're doing it and that's going to separate the atex from the btex, the guys that know how things work and why they work? Those are the ones that are going to be successful. Yeah.

There's so many um versions of that in our trade, i think about electrical basics. You know there are. There are people who are even good at reading a wiring diagram but still have no understanding of what each component does you know, so you could say well. This wire goes here, and i can see that because it's on the diagram but understanding what the purpose of this device is or how the sequence of operation works.

So there's so many different things like that, where you really want to understand, not only the how but the why and i couldn't agree more. Let's touch on a couple kind of common things that relate to psychometrics that are very field applicable. That might kind of maybe set a light bulb off in somebody's head. So, let's start with talking about like humidification and gas furnaces.

What's up with that, why wha? What is what is it about gas furnaces? I mean do these gas furnaces, do they do they burn the the moisture out of the air? I mean what's going on there, that you know what probably that that that's so funny, because when i was teaching a heating course - and this was a heating course for for technicians and and i throw this question out - and it was like okay. So when you sell a customer new gas furnace, what do you always also sell them and they said oh well, we always sell them a humidifier as well, and my question is well. Why do you sell a humidifier with the furnace and the answer i get almost 95 of the time is the humidifier puts back the moisture that the furnace takes out takes out. So i said okay, so that means that the furnace takes humidity out of the air and i follow along, i joke and i'm like okay.

So if the furnace takes moisture out of the air it shouldn't, there be a drain line coming off a gas furnace and it's eugene that's stupid. Why would there be a drain line coming off the furnace i'm like? Well, you said the moisture gets pulled out of the air from the furnace and they go yeah, but you don't realize eugene that the furnace is hot, so that moisture gets evaporated. So i'm like okay, so where does it go? It goes. Oh, it goes through the ductwork back to the space, so i said so basically you're saying that the furnace is pulling moisture out of the air, but then it's putting it back in well, if we're pulling it out and putting it back in then we're really not Taking anything out - and we really need to understand that we're not dehumidifying we're not pulling moisture out of the air, but what we're doing is we're simply heating the air and when we heat the air, we're increasing the air's ability to hold moisture.

So the relative humidity is dropping and it's kind of neat, because when we have air at you know steady state air right now. Molecules of water in that air are constantly evaporating and condensing and they're, evaporating and condensing at the same rate, when we heat air, more evaporation is taking place than condensing. So now we have less liquid water in the air. So our relative humidity drops because now that air can hold more moisture and we need the humidifier to raise what we call the absolute humidity, we actually have to put more moisture into the air to avoid dry skin cracking furniture, cracking paint.

So what you know an example that i that i often give to to my students is: is that of a parking lot. So, let's assume we have a a two layer, a two level parking garage and the second level is closed and cars start parking in that. First level - and let's say there are a hundred spots in the first level and uh well, make it let's say: 50 spots 50 spots on the first level 50 spots on the second, as those cars fill that first level, that parking lot becomes more and more full. So let's say we have 40 cars on that first level.

Now that first level is 80 percent full. So let's say those cars represent moisture and the number of spots represent the capacity or the ability of that parking lot to hold cars. That parking lot is now 80 percent full, but now what if the second level opens now? I have 40 cars in a 100 car lot. Now the lot is only 40 full.

I didn't change the number of cars in the lot. I just changed the ability of that lot to hold cars so when we heat air, the capacity of that air increases, the ability of that air to hold moisture increases. So the relative humidity, the fraction of how much moisture is in the air to its ability to hold moisture decreases and that's when we start getting dry, skin cracked furniture, cracked paint fun things like that and and that's kind of the same concept of our barometer. When you watch the weather report and the meteorologist says, oh, the barometer is rising well when the barometer is rising.

That means we're going to be due for some warm dry air, some good weather, because if, as the barometer rises, that means the atmospheric pressure rises. So the atmosphere pushes down heat can't rise out of our atmosphere. It traps it gets hotter and as that air gets hotter, its ability to hold moisture increases less likely to rain warm weather. You know hot temperatures dry, whereas if the barometer is falling, then what happens? Barometric pressure drops the pressure in the atmosphere.

Drops. Heat can rise out now we're going to get cooler, damper air cooler, damper weather. So all of these things, you know the your your weatherman talks about dewpoint. So all of these things, all of these concepts are all right there on that psychometric chart.

So i mean we could take it off. I mean go off on a deep end here, but all roads point back to that psychometric chart all roads, point to the basic concepts of air and and the more you understand about air, the more you will understand about a lot of other things you encounter in Your daily lives - absolutely i mean even just thinking about the effects of altitude on how a system operates. I mean there's so many different things that we see regionally and and all that and a lot of what we're talking about um up to this point on the humidity side is a lot of the confusion comes in because people don't understand the difference between absolute and Relative humidities, so they they, when they say relative humidity, they think that's humidity. They just think that relative immunity means humidity.

So would you mind speaking to that for just briefly to kind of help anchor your uh? Maybe the technician's thoughts on the difference between those two things: yeah awesome yeah and we touched on it just before you know. Absolute humidity refers to how much moisture is in the air. That is, you know, that's directly related to dewpoint again, if you're looking at a psychometric chart we're not going to get into that right now, but absolute humidity is how much stuff. How much moisture is in the air, the relative humidity, it's a relative term and it's how much moisture is in the air compared to how much moisture the air can hold? So if you think about it, if, if i have a a sponge, think about a perfectly dry sponge - and i take two drops of water and put it into that sponge - i have two drops of water in that sponge.

My absolute humidity or my the moisture content of that sponge is two drops. How many drops of moisture can that sponge hold that's my capacity. So if i look at the relationship that the moisture content to the capacity of that sponge, that would be relative. The amount of moisture relative to the size of the sponge, if the size of the sponge changes, then the relative moisture content is going to change.

So when we talk about relative humidity again, if you read hebrew, it's humidity that is relative relative to what relative to the capacity of that air to hold moisture and the ability of that air to hold moisture is going to change based on temperature. When we cool air right, when we air condition the ability of the air to hold moisture decreases. So if you think about an air conditioning system that dehumidifies and cools, if you took readings of the air, the supply air right after the evaporator coil, that air is going to be close to a hundred percent relative humidity, because that air is cold. But once that airstream reaches the occupied space now it gets heated as it mixes with the air in the space and then that relative humidity drops back down again.

But in the interim we've pulled moisture out of that air and you guys know it it's the condensate. That's that's dripping down the side of somebody's house, hopefully not through their. You know sheetrock in florida. That seems to be the case very often.

Unfortunately, we don't have humidity where i am so lucky, yeah, yeah and so sorry to make you kind of beat a dead horse there, you kind of had to reiterate a couple times, but that, but that issue there, if, if technicians, can get their head around that Now again, you still got to understand the psychometric chart to make sense of all these moving pieces, but just getting your head around that alone helps solve so many questions that you get. I mean the first time and i do this uh when, when i'm teaching classes, i you know hand somebody a psychometer for the first time, they're like oh, this is cool, we're going to do some delivered capacity calculations and i have them. Stick that thing in the supply, duct and say: what's the relative humidity and you just watch their eyes like what is going on here. This thing must be ruined.

You know something's wrong with the system, because it's actually putting humidity in the air and uh, and it's that it's not understanding that concept that leads to that thought and that eureka can really help. You understand this a lot better, yeah and again that's right from the psychometric chart air when, when you cool air you're moving from right to left on the psychometric chart - and you can see that the relative humidity of that air increases and again it's it's a relatively Simple chart: i guarantee that if, if you sit down with that chart for no more than 30 minutes, it doesn't take even that long, you could get a really good grasp of what air does and if you have a solid understanding of what air does that's going To make you a stronger technician, it's going to give you a a broader understanding of air as it surrounds us how it behaves what it does why it does what it does you know if you know it's a mystery, if you don't understand something, oh, why do Things happen: oh it's magic, but yeah. If you understand the hows and whys there there's very little magic. You know, there's always a a rational explanation, all right as to why certain things happen and why things are the way they are and again that's.

That really is the first step in in becoming an air conditioning expert. It's that expert at conditioning this fluid known as air yep, how how it behaves, how much of it you need in order to do the job. All these things become really important and so yeah. I would suggest to everybody, take a look at psychometrics without tears.

You can actually find it. It's it's published through esco press um. You can find it on escogroup.org. That's a great website for all the stuff that we're talking about here today.

Um also eugene is the co-author. I guess on the rack manual kind of the the heading up that project and there's a lot of information in racked as well on the topic um. So, if you're reading through that gigantic tome of a of a work, you know, but i'm always amazed by it honestly, every time i look at the newest edition, it's uh, it's really the book for our industry. It's a tremendous tremendous resource, but not quite as focused on psychometrics as psychometrics without tears, what other resources could? Maybe people find? Is there some maybe in the in the e-learning is? Is there some information available there as well through escope group yeah on on the esco? Has a uh uh, an e-learning network, it's called the hvacr learning network and on that learning, on that platform there are over 200 uh solutions.

There are different courses, different webinars recorded uh, a lot of it's free. I mean some of it's subscription based, but i mean every day new stuff is going up there, so i would definitely recommend you know, visiting eskogroup.org and clicking on the e-learning tab. Uh i mean literally stuff is going on there all the time yeah i work at the company and i go in there every day, i'm like oh, when did that come up. When did that come up, so you see stuff, you know popping up there all the time and you know and the psychometrics without tears book it.

It really does start at the very very basics it it takes that psychometrics chart and breaks it down into all its skeleton pieces or every line. What does the line mean? What does this line mean? What does this line mean? Then we ultimately put them together and you have the chart and um. I mean it's the kind of book that once you pick up, you can put down and that's primarily because i coat every book in in gorilla glue. So literally once you pick it up, you physically can't put it down, and, and hopefully you won't try - i mean it really does break the the topic down into bite-sized pieces and and again engineers, even like it, because it's the without tears and i've had engineers come Up to me and go, i've never had psychometrics, explain to me in that way before and that's kind of cool coming from an engineer because by trade i am an engineer, but i'm a tech at heart.

So so it's kind of nice to get the nod from technicians and teachers, but also from from engineers just approaching it a little bit differently. Oh yeah and there's no shame in in you know. If, if at some point you realize you don't understand something as well as you could well, there's no better time than now to understand it and - and i think there's a lot of that sort of thing in the trade where people say well, you should know this. It's like well, it doesn't matter if i showed or shouldn't i don't and so uh so now's the time to just spend a little bit of time and get to know it, and once you know it, it's like riding a bicycle.

I mean it'll come back to you pretty quick. I feel that way. Every time i pick up the psych chart, i look at it as like. Okay hold on a second.

What am i, what am i looking at here again, you know and then it's and then it just comes back to you again. So it's a nice thing to to at least at one time spend some time get a grasp on it and i think you'll find it pace, really great dividends. And i don't think there's a better book in our industry for this topic than psychometrics. Without tears and again that's eskogroup.org, as we mentioned in our promos and everything you can find out a lot more about hvc excellence, esco group, all that the hvc excellence conference is coming up soon, i'm going to be there a bunch of uh, really great people like Eugene are going to be there giving classes and, if you're, in the kind of education space, that's a really great uh conference for you to go to in fact, probably really changed.

My course when i first went to the hvac excellence conference, when it was in orlando kind of opened my eyes to a lot of things that i wasn't uh previously aware of and kind of changed a lot of what we've done here at hvac, school and and Kind of put my head on straight, so the type of conference, if you're in education, that you definitely want to consider uh attending what else am i missing eugene? I i think you nailed it at the uh at the hvac excellence conference. I will be doing uh. My my two favorite sessions and one is psychometrics without tears and and one's pressure enthalpy without tears, so at that event i'll actually be doing both of those. So those are my two favorites, because those are the two ones: the air side of the system and one's the refrigerant side of the system and yeah those those are my two go-to's.

Those are my favorites whether this is airing before or after ashrae, i'm doing psychometrics without tears at ashrae as well or have done psychometrics at xray, depending on when this makes it out, but but yeah. No, the the e-learning network, hvac learning network has something for everyone. You know no matter what part of this industry no matter what sector you find yourself in in this industry. There's this content from industry-leading teachers, industry-leading manufacturers, presenters organizations from refrigerants to equipment manufacturers, so yeah.

If you go, it doesn't cost anything to go and poke around and see what's out there. So we definitely uh definitely want you to go check it out and uh. Like i said, a lot of the stuff is free. You know you still have to set up an account, but it's free to set up an account and you could uh check out a lot of the uh.

The training options there yeah so get out there and do it. For goodness sake and they've got ta. They uh they, they inked a relationship with rses. So if you're used to a lot of the kind of rses content, that's been out there, a lot of that is combined in there and it's just a lot of really great stuff.

So you're not gon na you're, not gon na, be sorry by taking a look and and seeing what is available, especially if you're a contractor, and you know you need to provide some training to some of your techs and you kind of feel guilty about it. I know a lot of you are out there feeling that way. It's like gosh, i don't know the training isn't available, or i don't have time. This is a great way to kind of get started.

You can do a little bit of low-hanging. Fruit. Take care of some of these issues that you know your techs are having get them some training, you know, get them through some courses and by golly it will make you feel good and it'll make your text feel good, too so yeah, and even if you're, even If you're an engineer, ashrae is now uh adding a lot of their e-learning content to the hvac learning network as well. Well, eugene, i think uh.

I think we did it. I think it wasn't as scary as uh as maybe you thought it would be being on a podcast the first time i don't know it's very cool, all right all right. Thank you, brother. We'll talk again soon, all right man.

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