We talk with system and duct design educator Jack Rise about ACCA Manual J load calculation and Manual S system selection
Read all the tech tips, take the quizzes
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Read all the tech tips, take the quizzes
and find our handy calculators at https://www.hvacrschool.com/
This episode of the HVAC school podcast is made possible by our excellent partners, carrier and Mitsubishi comfort, also along the lines of today's episode, which is about Manuel J and Manuel s. I recently got a blower door from retro tech, as well as a duct leakage, tester from retro tech and I've been really impressed by these products, as well as the precision manometers that come with them like the gauges that come with them. You know we're just getting more into the building science building performance. You know in advanced measurement field at my company kalos and i'm surprised at how easy these tools make it to do.
I mean it really isn't that bad you go through their training, they have a good kind of pre training where they talk about the products and how they work and how to assemble them and disassemble them and keep them from breaking on you. But really I'm impressed by how rugged they are, how easy they are to use, and you know like doing a blower door test. I always thought that was a really big deal and we're finding. We can do a blower door test fairly easily.
It takes us about 20 minutes to do it so far, even and we're not even that good at it. Yet so big thanks to retro tech for making a great product, and also I want to mention test. Oh I've been using the 440 IAQ, which is a advanced air flow measurement and indoor air quality test kit that you can get with different, either Bluetooth or wired devices for measuring air flow, with a Hotwire mini vane. Large vein, anemometer a bunch of different attachments and I've been using that a lot for air flow measurement, a really nice tool and then the test of 4:40 air capture.
Hood is a just a nice light, easy to use accurate, airflow hood that you can. You can use in your company, even if you don't, you know, have it on every truck. You can get maybe one to serve the entire company and then that way, when you do a do a retrofit or something in your adding and some ducts or making a change to a duct system, you can go in and confirm or if you do new construction. You can also do balancing afterwards to make sure that you're delivering on the promise that you made to your customer that you would deliver to this amount of air these amount of BTUs into each room in the space.
The Exuma that second flame free refrigerant, fitting from Parker reduced, labor cost by sixty percent with no brazing no flame and no fire spotter discover how subhan can help you be more efficient and productive visit. Zum lot, comm for more information. There once was attack from the South who is always running his mouth. He started a podcast for his ego was vast, but he can't find another rhyme for South Brian.
Ah, it's been said of Henry Ford that he didn't like experts and whenever somebody would tell him that he should hire an expert or talk to an expert consultant than he would always poopoo that, because experts just know a bunch of ways that things don't work. But they don't think about ways that they do work and I think that's, I think, there's some truth to that. I think there's something to be said for for experts, people who have been there done that and can kind of point out some of the some of the challenges. But it's also good to try new things and to test things and to see do what works and see what doesn't work. So I will be the first to say that I'm certainly not an expert and today's guest Jack Rhys is the kind of guy. While he is a expert he's done it in his whole life and he's not afraid to he's not afraid to challenge the status quo, and I think that challenging the way that he challenges the status quo, even even codes and standards that he had a big hand. In creating is what makes me like Jack he's, a down-to-earth guy, a really smart guy and he's gon na talk to us today about manual, Jay and manual s. So that's the load calculation.
You know he gained. He lost on manual Jay, and the manual asked his system selection, oh, and by the way, this is the HVAC school podcast, and this is the podcast that's for Tex by Tex that helps you remember some things that you forgot along the way and also some things You forgot to know in the first place there we go Jack rise on manual, Jay and manual s. Alright, I'm pleased to announce that once again we have Jack rise with us, Jack rise of guide to manual D, fame and many other exploits in the HVAC industry. Thanks for coming on Jack, oh my pleasure always happy to be here bright today.
I wanted to kind of talk through Manuel J and Manuel s, which is the load calculation and system selection. Manuel J is one of those things that everybody pretends like they do, but very few do it properly. It's got like when you're sitting in I'm sure, you've been in these situations, Jack. When you go into a meeting, it's like who here does Manuel J and every hand goes up, and then it's like what software do you use and how exactly do you do it and everyone kind of looks around at each other right soft? I guess that's the source and you know what right soft they do it perfectly bill right.
God bless him and Hank Roth Kowski. The original author Manuel J sat down and bang that out until right, soft program followed Manuel J to the letter to the T and it's one of the only programs. I know of that follows it that closely and disabled Manuel D, I'm a big fan of rights off. Not only is it a well-built product from the standpoint of the accuracy of the report, but it's good software, it's just good, solid and user interface definitely is and don't hold out.
I mean I just made ten gram with that shameless plug. I gave I'm teasing. Of course, I need your connections. I know, Michael, like a marina, when I was with a big contracting company, we have hundred guys in the field.
Twelve salesmen, you know the whole deal. I needed a good software program and I didn't have one. I was using another brand time and it was the most popular brand at the time. I forget how I got led to rights off, but I ended up downloading the demo and I fell in love with it because I recognized so much in it that didn't recognize in the other program. In other words, it was speaking manual. J language to me was using the same terms when I did a duck design. It would do the friction rate formula available, static times, honor divided by the te elen and go wow. I just died and went to heaven.
You know so. This is something i can count on, so I called up Michael Moreno, the National Sales Manager, wonderful guy, I said, Michael, I got a dozen guys in the field and the demo was Washington DC weather. You couldn't change it, and I said, rather than by a dozen program, would be cheaper for me to move my company to Washington DC and rename it Joe's Heating and Cooling, because that was the other thing me is in there at the time he laughed and we Told me about different ways: you could do that with land systems and so on and so forth, and we became friends and I love the software so much that I recommend it wherever I go. I must send him a million dollars worth of business a year, because, even when I do my three-day dog and pony show in Washington DC for a CCA day, three is bright.
Soft in the afternoon. I'd usually do Manuel s or standard five, or something like that. In the morning, but I always I'm not going to let a three day class go unless they have some realistic way of applying what they learned in class. So I make them familiar with how the program works.
We use the free demos, it's just a wonderful program. It's two things: it is fast and it's deadly accurate. So you don't sacrifice anything. You can do a two story: building ductwork heat loss.
He came everything 20 minutes no big deal and I'm not talking about a guy that just does that all day long. He could probably do it in 10 minutes, I'm talking about the casual user. It's a wonderful program. It really isn't.
I don't get five cents for saying that. I say it because it's true and if you use it in your contractor, it's gon na save you money. It's gon na save you time. It's gon na make work for you, it's just a wonderful program.
I can't say enough for it and they are heading shoulders above any other competitor. Now that we're 5 minutes and 15 seconds into our commercial boom. This is obvious. We joke about it all the time in my Facebook group and it's a joke in the industry, but I think we need to answer it because I'm sure there's a good portion of the people out there who are listening or like blah blah blah.
Why do I need to do a manual Jay when I've already have a good idea? This model home does find it cools? Fine, it's no problem. Why do I need to do a manual Jay in the first place? Prove it does fine to say something works? Does it say anything, does this system work because you get air out of the that's? How efficient is it? Does it cost four times much topper, as that, could it be more comfortable? You have no basis for comparison when you say something works, and I understand that philosophy. My dad went through life that way, God blessed us, so he would tell you I've been doing this for 35 years and I don't have any problems and he didn't. He went home at night to mom my brother and I had two problems. I can prove to you by the mathematics and that's a nice thing about Manuel J and Manuel D. They can both be reduced to mathematics, so they are verifiable. They are repeatable. There's no question about it.
This science works. It would be to me, like I make this point in my classes when, at the end of the three days when we do the balancing my position is: don't do a great Manuel J and convert that into a great Manuel D and then pick your registers and Grills by hand and pick your equipment by hand, do everything perfectly and walk away from the job, because you know what you've ever learned anything. You may have a terrible flaw in your methodology. Maybe you're doing something wrong.
Maybe your guys are lining the ducts. When you told them to wrap them, maybe they're making mitered fittings. When you told them you use radius fittings. There could be a main things that go wrong, but if you can't verify that other than your opinion, your opinion is meaningless to me.
I want to see proof show me, you balance the system. Show me, you did the manual J show, because that's the only way, I can verify that you have in fact put the right piece of equipment by the manual j.lo calculation. Compare that to the manual last choice you make and manual s is a little weird in that regard to to some things in here that are, in my opinion, ludicrous and yet my name's in the front of the book. I was part of the committee, rewrote it, but there's some things that honestly shouldn't be in there and there's not a lot of stuff just one or two things that are annoying at me, because there's a better way to do it and the committee wasn't interested in Doing it that way, so life said: that's my new flesh, yeah, well yeah, and if you can't be grouchy about something, then what's life all about yeah, you got to have some reason to get up and get mad morning.
Let's talk about Manuel Jay first and then we'll kind of transition into system selection, which is Manuel s. What are some of the things this to me is probably the biggest thing. Is you have your salesmen who run all around and their salespeople? They want to sell equipment and their leadership, they tell them, they have to do a manual J because they don't want to be embarrassed when they go to their local akha chapter, but the reality is they go out and they do what they do. What are some of the most common things in your experience that people who are attempting to do manual J, get wrong or make errors in? I got to go back. You have to remember the manual J. Is it's a mathematical determination of the BTUs that are going to be lost in the winter or gained in the summer in a given structure, residence you're? Working on this? That heart I mean it's math. You learned in the fifth grade multiplication for godsakes the BTUs per hour. You're going to lose your game is equal to the reference area.
The square foot of wall ceiling floor window. Whatever is you're looking at times the? U value for that particular material times. The difference in temperature across them, it's simple, the math gets a little more complicated when you get into ma FRC type one days and that kind of thing, but it's manual J, is not hard people. Just look at the current edition, the 8th edition manual jack.
It looks like the Manhattan yellow pages, it's a thick book and they start flipping through it and you've got to solve for the sign. They see all this complicated mathematics and they get afraid they run it and hide somewhere, and then somebody says: hey, try the red sauce program and they use the right soft program without any background information on how heat flows, what a lobe calculation is things like that And once in a while, we even take a classroom writes often once in a while, unfortunately writes off as people teaching the classes about the computer program, and there are experts in a computer program. But they don't know one end of the unit. The hot air comes out of it's like a catch-22, but at the end of the day, they've looked back or at the end of the year and they say well, I didn't have that many complaints and I guess what we're doing is okay and that's where the Opinion comes in it's not hard to do a load calculation, it really isn't.
The hardest part is taking their time to measure the building. But if you've been through a J and a D class and you're using a good program like right, soft, it's a cakewalk to put it into the program, put it into the system. In fact, I know contractors that hire kids right at a trade school. They send them to like a class like mine, a three day class on JD and so on, right, soft and then they put them in the field and all they do is measure buildings for them and then bring the loads back, and somebody puts it into write.
Soft, so these salesmen really doesn't get involved with sizing the equipment it's done by other people, but it's done correctly. That's one way of doing and then they're paying these guys minimum wage. It's not like it's hard to use a ruler. I want to do it right.
I don't care if it's a 1,000 square foot, two-bedroom retirement cottage or it's a 2 million dollar house, like my daughters on the Gulf of Mexico, with all glass and skylights and everything and I'm what I've done right. I don't do bad work. I refused to do it. I told my wife that years ago, when I started this, I said: hey, I'm gon na be the best there is or I'm not gon na. Do it at all. I'm gon na go broke so you win. She said yeah you're, stupid, I'll, follow you. The question was a general one about what are some things that people get wrong, but I think what you're pointing out is, if you have somebody who's doing a manual J and they're, not really focused on getting it right.
They're not really focused on that they're more focused on the sale, whatever their motivations are sideways, then maybe that's the challenge, if they're just pencil whipping it and not taking the time to do it correctly sure and I'll tell you how I learned heat loss. He came. I'm sixteen seventeen years old one day it occurred to me what we were doing was expensive, I'm looking at the invoices coming in for the equipment we stocked. That kind of thing.
So I said to my dad pop what how come we put a hundred thousand BTU furnace and mrs. Jones's house? Why don't we put eighty thousand and he said? Oh, I did a Galatian. I said what I'm 16 17 years old. The only thing I'm thinking about is girls, so he says length you take elected a building times the width times the ceiling height times 8.
Now my dad quit school in the 11th grade back in 1943 42, something like that. One off to fight in World War. Two and never went back to school again, so he limited he didn't know length times, width, I'm assuming I it was volume. He always said black ties wit time, high time 8 for heating length times, width, I'm height 4 times 3 for cooling Wow, I'm empowered where you get the 8 into 3 from pop, oh they're factors, Wow factors, holy cow, hey why'd, you put 24 by a duck In that 3 ton unit well right here takes out a slide rule duck calculator.
You see where it says, recommended residential setting. Well, just put the volume 2 CFM see. What's a opposite, the point 1 look gives you two round ducks I've secured a rectangular block, sighs Wow, that's it! That's all you got ta know, that's all he knew so that's all. He could teach me and I went off on my own.
I tried that no in complicated buildings and I ate my shorts and my father - wouldn't take those jobs. They did the big house on the beach pop. We had all that glass and everything on the ocean man. He said now.
I stay with you get in trouble in those buildings well, but he never had a problem length times. Width some times ceiling height times 8 there's got ta, be better technology. You've got to think there's something better out there a way to do it. That's more accurate and more technical.
For god sakes, you can't just look at a building and say, and I've seen guys contractors that have for an 800 square foot building you put in a two-ton and for a 1200 it's a three-ton and for 1600 for time. Anything over 5,000 is a five-ton. What do you do when you get over 5,000 square feet? What do you do that? If that's the only thing you know what's out, there is sad, and you know what's really sad about it. It's not that inherently it's just doing it the wrong way or anything like that. It's that the guys that do it that way, you're competing against the guys that do it the correct way and in a situation like that everybody looks bad, the guy that's getting the right price for the job that he should be getting because of his investment in Technology and good equipment and good men, and so on he's got to compete with the guy. That's doing this out of a back of a station wagon, the whole industry looks bad, the guy, that's getting it asking. The high price looks like a crook in the gon na test and a low price. They can't trust him he's too far off, but they want to pay that price.
They just don't want his product. It's like having a champagne taste on a beer income. It's crazy anyway, I'm talking too much ask me something I can answer okay here we go. Here's the question that I have legitimately and I'm not trying to put you on the spot here anything but the two areas of manual Jay.
That still seem like a guess to me and there's a couple others. But these are the two primary are leakage of the envelope and leakage of the duct work, and so obviously there's this big push in building performance to do testing to get things down to a particular standard. But when you go into retrofit applications and that's the world I live in, so that's the world I think about, if you're a company that does residential new construction, I'm assuming you already have a some way of dealing with all this, even though you may not be Doing it properly, but in retrofit, that's where this really gets missed. So what are your thoughts on that as it relates to manual Jay? Well, I think manual Jay handles those areas very well.
As far as leakage there's three ways you can do it manually and they cover and my estimation the whole gamut, especially in a new building or, let's say an existing community and existing tracks, something you're familiar with, but especially in new construction. You can use the calculation. The chart method Table five area. I believe you go to where they give you the air change rate per hour based on the square foot of the building and how tight it is, whether it's tight, semi tight, loose somewhat loose la blah blah they have like seven or eight different categories.
That's one way: that's kind of the standard is stagnant way. The other is the system component method, and you would want to apply that methodology where you have, let's say, an old existing building where somebody came into the building, like I'm thinking, upper montclair, new jersey for all the new jersey fans where they have these turn of The 19th century homes that are upgraded very often it'll be a tall, steep three-story home. A lot of people cut off the third floor. They improve the windows in the building and everything else is pretty much the same, no way it was in the 1920s or whatever 1910. The third way is the blower door test that really covers the whole field. If it's an existing building, of course, you're gon na want to do a blower door. If you can, if you have that ability, if you've invested in that kind of technology, you're gon na know exactly what the leakage rate is, there's no doubt about it. You can do the component method where you have a mixture where you can't say I have one actual air change rate in this building, because everything is equal.
If you have really good windows and everything else in the building is bad, then you won't do the component method. Then you always have the table table 5a, ABCD and Manuel J. I think that cover that very well that was 100 duct leakage yeah. I think they do a pretty good job on that too.
There's a whole thing. I do at the end of day, one when I'm doing manual J, where we calculate the duct leakage, it's really a combination of duct sealing and duct insulation. That is the way Manuel J looks at it and they look at it pretty carefully. There's quite a few calculations - and I usually say at the beginning of that section that this is the point in time in class where everybody goes running out of the building with their hands over their ears.
Saying stop this man from talking at me because it gets pretty detailed and, as a user of right, soft, all you have to know is to be aware of. What's important to put in the machine. Just have the broad strokes of how that I want to say methodology, I'm using that word too much, but how that works for ductwork and what's important to know what's important to put into the Machine and then the Machine takes it and runs with it. Does all the complicated next way to me? There's no excuse for anybody, not knowing Manuel Jay Manuel de and rights off it's too available.
It's too accessible, Wow right soft! If I buy two residential sweet, it's right, J right, the right draw. It's gon na cost me eleven twelve hundred hours. You can't afford not to have it as a contract. Twelve hundred bucks come on.
You can't afford not to have borrow the money you can't afford. Not to have a good computer program apply for a loan at the bank of Jack rice he's giving out free money. Everybody do budget I'll finance it for you, don't say that Jack thirty percent interest. Okay.
Ah really we got a New Jersey loan going on here. Yeah, I know the big piece of this is you can have the confidence of the field or you can have the confidence of the office, and you don't really want to have you either of those you want to have the confidence of actually knowing that you've done? The right thing, which is a combination of both so the confidence of the field, would be a guy who says I don't need to do all that crap. I know how this all works and I know what size equipment this needs, and I know my ductwork is well sealed and I crawled through that attic. So I know what type of structure that is. That's the confidence of the field without the confidence of the office. I'm doing air quotes here because of course you can do these calculations in the field, but generally it's done by people who are sitting in front of a computer. I don't need that pencil pusher to help me and meanwhile the person in the office knows all the calculations, but if there isn't an actual field arm to what they draw up or what they design or what they specify then, like you mentioned, if the field doesn't Represent what's being designed or being created, then you don't end up with the result that you want, even if it's not within one particular person within an organization, you have to have that accountability on the design side and then also on the field side, to ensure that When you're saying that the ductwork is tight, that it's actually being installed that way, it's actually being sealed that way right, you even made it sound a little more complicated because any one person can do that writes off was written from a milepoc company. So his manual check, where dad's at in the field all day long - and this is what I grew up in my watch and my father do this is a he would be in the field all day.
Long and it maybe came home did the paperwork, but while he was in the field, he measured a house or to Darna thames and he came back at night and he did his length times width i'm ceiling at times 8. Nowadays, he would come back and put it into write soft, which makes his life easier, which gives him more time with his family and his life is better because of that yeah. You got to have both components. Somebody has to know how to measure a structure, and somebody has to know how to put it into a computer today or to do too low calculations by hand, but even one of the very first pages in the current edition.
The 8th edition Immanuel J says: don't trust. Do this by hand by the way there's 21 worksheets 21 worksheets. You have to at least peruse if not fell out completely before you can go to the trifle to do a manual J load calculation by hand. The 8th edition was not designed to be done by hand manually.
It was designed to be done with a computer. In fact, I tell the story talking to Hank about that. I said: what's the right after the 8th edition came out, I said Punk. What's the 9th edition gon na look like, and he said it's going to be one page I said yeah: what's it gon na say he's gon na say getting computer? I'm tired! I didn't want to do all that.
I did the 8th edition, but the people that were in charge of ACCA at the time said we want a manual type of program and it just had been too many changes too many advances too much. Information became aware to our industry between the 7th and 8th edition. There was just no way it could be done by hand anymore and be accurate, so you need to have computer assistance. So, let's transition into talking about equipment, selection system selection. Now so you go through the proper procedure for resonance, is to go through and do the load calculation either if you're designing a whole new duct system or if you're, building a new home, they're gon na do a room-to-room. A lot of us end up just doing block loads and a lot of cases when we're doing change outs, but we need to select equipment. That's going to be able to deliver the promise that Manuel J sets forth. So, let's talk through that, I'm interested in finding out what your grapes are with Manuel s, but let's just go through some of the broad strokes.
What does it take to select a piece of equipment properly? That's an easy process once the load calculation is done. Let me just talk generally about Manuel s: there's only three chapters you want to read and it's n1 n2 and n3 all the rest. Those are the normative chapters. If a state New Jersey adopts Manuel s, they adopt n1, n2 and three all the rest of that book is just information.
It's informative. It's best practices that kind of thing, but the specifications are n1 n2 and three chapter n1 defines all the terms target value selection value all that junk right and a lot of it is really obvious. It's very easy reading. That's all in n1, n2 is the chapter you're going to be using most of the time.
That's where all the minimum and maximum capacities are for every type of equipment, gas, heating, hot water, heating, air conditioning air, dare heat pump water? Dare he pump all that kind of thing, they'll give you the mens of maxes. That's chapter 2. N2. N3.
Normative 3. I don't know why we spent any time on it. You will never use it. I promise you, I don't care if you live to be 200 years old, you'll, never use it.
It's a scenario where you would take, let's say, carrier blower and a Trane coil, alright, and you would put them together. You would then go into the field. According to the way, n3 is written and somehow you become a laboratory and you'd be able to determine the actual output of the equipment, heating and cooling mode, both latent and sensible. You would measure the seer rating, the HS PF.
It was a heat pump. The co pay if it was a heap of so on and so forth. You with me on this you're going to submit all this data to the two different manufacturers. They are both going to give you a letter saying that that is an acceptable combination.
Okay, you know how committees are it's whatever you set out to do, doesn't look anything like the end result when the committee's done. What do they say? An elephant is a dog that was made by a committee. It's got a year's, it's got a tail, but it doesn't look anything like the dog. We tried to design that's the thing so n1, n2 and 3, the rest of the stuff. It's good information, I'm not saying, there's anything bad there. The problem I have with it is n2 allows a furnace to be doubled in size simply because you need a larger blower and I have no problem with that world. We live in Florida. That net was my objection.
I wanted to make that rule Geographic. I wanted it to be a regional requirement that if you were in a hot damp climate like wearying, where we need a lot of cooling, both laitanan sensible and you had a very short winter, we're in the middle of a terrible winter in Florida, one of the Coldest on record - and I haven't turned my heat on five times yet. Why would I give a damn about over sizing the heating equipment? It's not an issue, so in Florida, that's an important rule, but not in New Jersey, not no hi. Oh certainly not Michigan.
That's crazy, the thing it's going to cause and mark my words: it's been too soon now he can't see the effect yet, but eventually the inspectors in northern climates are gon na say who cares about a heedless? You can double the size of the equipment. For god, sakes, because you say you need a bigger blower and the cooling side go ahead, put in whatever you want, I don't care. It's gon na cause a problem. It's we didn't solve anything.
By doing that, I couldn't. There was only one of the guy in the committee Jana what god bless him. He works for Eastern meaning Council in New Jersey, and it knows the problems we have there with oversizing heating equipment and how terrible that can be from a comfort standpoint. In a climate like New Jersey, I'm talking any four-season climate where you have a cold winter and a hot summer, oversizing the heating side.
Just you have terrible discomfort, dryness bloody noses. I mean furniture cracking it's just horrible and no matter how much humidity you try to throw in the air, it's never enough to compensate for it. It's extremely dry inside and that's extremely uncomfortable. I can't relate where I live, but when I went to Colorado on vacation last time holy smokes, I don't know what the relative humidity was, but it was probably in the single digits inside the place we were staying and it really is awful.
Like didn't sleep right, I got sick, oh yeah, you can't turn on a light switch without a spark. It's not healthy. I have a lot of sick sore throats things like that. It's nothing good about this Comfort and what we sell in this industry is comfort.
We don't sell duct work or great service or carrier lennox or train. We sell human comfort, people want to be warm in their homes in the wintertime and they want to be cool in the summertime and we have every way there is to supply that to them. And if we're not doing that, shame on us, I think you hit on something when you talk about some of these standards and the need for some regionality. A perfect example of this is like ASHRAE 62 point to the ventilation requirements. There's going to come a time. I think when some of these standards are more regional and in the meantime, I think a lot of contractors and local municipalities start to understand where they can maybe bend the rules a little bit in order to be a little bit more regionally thoughtful. In order to kind of match the heart of the rule, without necessarily complying with every single detail, there is some of that, but you do have to look at all this and when it comes to manual s, this isn't something that you do specifically, I mean you Do it in manual s, but when you wake up to the fact that the sensible and latent capacity and sensible heat ratio matching that more carefully to the seasonal states that exist in your particular market, and not only just thinking about setting everything up for peak but Also setting your equipment up properly in the field, and this is a field setup thing - it's not only knowing what it should be when you match up the equipment to what you're getting from manual Jay. It's also looking at all right what are my shoulder seasons and how can I set up this equipment in such a way that we are maintaining the sensible load? Obviously sensible is what turns the thermostat on and off, but dealing with that latent load.
So that way, we don't have discomfort in the shoulder seasons and when the spring comes around it's rainy, but it doesn't have nearly the heat load. Are we setting up the equipment appropriately so that way I can deal with that and those are things that are good for even the technician to be really aware of, even if you're not designing equipment and remember Brian, that was the aim of the committee. We sat down, and we said a handful of us when we first the guy's enacted Glen Horan myself here, but on profit. We said manual last should say you just did a look.
First thing you have to do using manual says you have to have done a manual J. If you didn't don't bother with manual s, it's not going to help you so once you've done a manual J load calculation. Now, let's go find heating and cooling equipment without over sizing it any more than we need to based on the low calculation. So I did a calculation, the building it came out.
Ninety-Eight thousand BTUs I'm gon na go out and trying to find a furnace with 98 thousand BTU output. With that I may have to take one - that's a hundred, but that's not grossly over sizing, but I sure, as heck don't want to take the 120. I just went up another size unnecessarily, that's what we set out to do and what you got was the dog or the elephant, not the dog, but it's not bad. I'm not saying manual eyes is bad.
It's not! I just think some of the leeway is way too big that one particular thing about the furnaces that just shouldn't be, but that was our intention understand that we wanted to stop oversize and we knew that making people comfortable involved, giving him the right size equipment. That was step one step two was giving a right size, ductwork, making sure all the BTUs got out of the furnace and where they needed to go. That was our intention and that's. The trifecta in residential is obviously there's more than just that. There's a lot more akha standards than just those three, but the typical trifecta in residential is manual j. Then you go to manual s, then you go to manual d right and then, if you test imbalance as well at the end, but we've made progress because I know the company that I used to work at before. I started my company and even when I started mine, nobody was thinking about system selection. In this way I mean nobody was thinking about Layton and sensible.
We just quoted 400 CFM per ton, like that, was what everything she and now we've at least gotten to the place where we realize in our market Florida, market 400. Cfm per ton is not what we should be hitting in most cases, it's a nominal just like 12,000 BTUs per ton. Well, what's a ton of cooler? Well, 12,000 BTUs an hour! What's that mean what is it? A ton of cooling is defined as two hundred and eighty eight thousand BTUs per day. It's the amount of heat necessary to melt a ton of ice in a 24 hour period.
So what do we do? We take two hundred and eighty eight thousand. We divide it by 24 hours in the day we get twelve thousand BTUs per hour and we think it's written in stone. Wait a minute hold on that's twelve two house: that's okay! That might be the way the ice melted, but of that how much was sensible? How much was late huh? What what are you talking about? This is the history we live in man. Most people can't define a ton of cooling, they'll, tell you it's 12,000 BTUs per hour and you ask him what that is? They don't know what the hell are.
You talking about, I'm complaining, I guess I'm sorry it's funny. They were talking about this because I just did that class yesterday with my people, the 288,000, like we just, went through that and me at none of them knew I mean I've had guys have been in the field five years, and they don't know that. I think it's a good thing because we're starting to think in ways that we didn't think before an example would be. You may have a space now with the new ventilation requirements we're in Florida.
What we're learning is that ER v's energy recovery, ventilators aren't generally gon na keep up, even if you're bringing your ASHRAE required fresh air through an energy recovery ventilator for a good sized home you're, still generally not going to keep up with the latent load of that Air and so you're gon na hit dewpoint you're gon na have some issues, I'm not gon na, say the M word, but you know some of the issues that you can potentially have yeah it's a four letter or more yeah. Exactly it's four letter M word yeah. So we don't say that word, but anyway, it causes some nasty problems and we're seeing it let alone, if you're, just taking outdoor air and just dumping it straight in the returned, which is what a lot of people are doing. We see some real fun stuff on townhomes in that segment, so now we're starting to realize. Okay, maybe ventilating dehumidifiers - maybe the best way to do this. So not only does it ventilate and can deal with the outdoor air, but it can also is your primary dehumidification method for the indoor space, how the hell do we get here? Why do we make a building so tight that we have to bring outside air and in order to have enough for respiration, did we just make a stone bigger than we can roll? Are we not in a stupid position? We shooting ourselves in the foot every time this ventilation issue comes up, I go we're doing it to ourselves. We put the tie back on and we see if we take the hammer and screwdriver and shove its insulation material, around the gaps between the window and the frame and the door and the frame you cook fish in there in June. You still smell it in September.
Why did we build a building so tight that it doesn't breathe? Naturally like it? Should that's the shame of it. You can't tell me this efficiency in there anytime you've got to bring outside air in and he can cool it and dehumidified. You just lost them anything. You gain by insulating the building or making it that tight.
I just think it's a catch-22. I really do. I feel like I'm on an infinity figure-eight all of my listeners who are in the building science community. First, they pulled all their hair out and then they stab themselves committed harakiri.
They said this jack rise guy you're right. Let me speak to this real quick, because I think this is an interesting. Yes, oh I'm, sorry, this is your podcast, I'm just a guest. There's an interesting thing: Brian: what's your favorite color! If I'm interviewing you can you talk about your favorite book? Please they quote this well Jack.
Thank you for asking. Let me quote something here know it. We have put ourselves in an interesting position because in our marketplace this is a perfect example. If you look at Holmes, cracker houses that were built prior to air-conditioning, they were built completely differently.
I actually owned one that had a gigantic gable and vents on the attic, and it was nice in the Attic. Do you go in the attic and it was nice and then you'd have these big breeze ways and that you could open all the doors and it would just flow right through and a lot of this stuff is prior to drywall, to you know, open construction and So you didn't have places for the four letter M word to grow, and there just wasn't as much of that at those problems. Balloon framing. Remember that I would go into crawl space in a two-story building and I could look up into the attic balloon framing. There was no plate between the first and second floor. It was wide open all the way and then we say well, we don't like. What's growing, we don't like how things smell. We don't like all this stuff, so we just start sealing up more and more, but an interesting thing is because I've talked to a lot of building science, people Building Performance people, for example, cooking odors.
You brought that up, you cook fish and you smell it for a month, it's true, and so they say. Oh you know what one of the worst VOCs is. One of the worst sources of VOCs in a home is volatile. Organic compounds cooking, so people who cook you're bringing dangerous toxins into your home.
Well, how long have people been cooking in their homes, yeah, thousands or millions of years, depending on your worldview, you know or, however, of any long, it's been. We've been cooking in our homes forever well now, because we have these homes that are so tight now that even presents a challenge. Well, so now we have to exhaust to the outdoors okay, when you exhaust to the outdoors that puts the homeowner negative pressure because it's tight. The challenge is: is that we're not going to give up control because that's what it takes? The only way to change the paradigm is to go back to not having control and just flowing with the seasons.
Opening your windows sitting on the porch swing drinking iced, tea with Aunt, Bea and Andy, which, by the way, I'm a huge fan Tiger fan. So I kind of wish for those days, but that's the challenge. We've gone past this point now, where we can't take these homes that we already have and treat them the way that we were treating home so now, we've got to think differently. Well, you can always do what I do when it comes to making food make reservations.
That's all you know. I have nine kids. I don't know if you're aware of that, do you really Dan yeah wow, that's great! What a nice family, my sister-in-law is seven yeah! That's wonderful. I like big families.
My mother was one of nine. Her mother was one of eleven. I mean we got big families in our history, that's great yeah! So with nine kids, I can't afford to eat out. So we cook a lot in our house and I have an air particulate sensor that measures VOCs and every time we cook the thing just turns all colors units.
It's not happy yeah, I'm sure about that, but we even have a big range hood that exhausts outside, but anyway before we got all distracted. What I was gon na say about ventilating dehumidifiers, because, as we go down this road, where we build tighter and tighter, what happens is this now you can rely if you size the dehumidifier right and you look at your latent load. You can design the dehumidifier to deal with your latent load on all seasons and then you only need to size, your air-conditioner to deal with sensible and you can set up the airflow. So that way, your coil largely stays. I'm not above dew point but near dew. Point it doesn't need to get nearly as cold at that point, which then can result in a lot better efficiencies, because when you shift to higher air flows, you get much better sensible capacity and efficiency. So now you've bumped up effectively the seer rating of your equipment. You don't have to worry about the stroller seasons and over cooling, and so you don't worry about driving down the dew point of the house, which even further reduces issues with mold and all that and indoor air quality.
So as we start to think about this, traditionally we would say all man, it's so much more expensive to put in this dehumidifier, but once you realize you can downsize the equipment you can increase. The output you're gon na have less crap growing on and the inside of that air handler, which is going to result in less maintenance. There's all these things that when you're creative, you can start to design for that, and previously we wouldn't have even thought about make sense to me why sorry, I just talked to it. Here's why I'm in this position, because I installed a RV on my house when I built it two years ago and it's not doing what it needs to do.
We have open cell foam on the roof deck, so it's a pretty tight house and oh you go up into that. We have a finished attic and it is just humid up there as all get-out. So that's the strategy I'm gon na go to and then I'm gon na end up having oversized equipment, but then at least I can increase the airflow and get a little more efficiency out of it. So you think about encapsulating the attic.
No, it is that particular attic is encapsulated, it's all encapsulated and it is and it's hot yeah, because a stack effect - and this is something I didn't fully understand until recently, but you do get this moisture driver up in that space. I still don't fully understand it. Waymon, are you communicating? Is there an opening between the attic and the occupied space of living? Yes, that's the problem. It's not an encapsulated attic! Okay, when you say encapsulated, you meant completely sealed.
Okay, that's what you're saying completely encapsulated yeah we'd go to a COS website. The technical bulletins Luis Escobar engineer, who until just recently work track, I wrote the Bible on it's an excellent read. In fact, I could send it to you if you want on encapsulated Alex. So when you said encapsulated, I didn't know what that meant.
So yeah I'm interested in find out more about that. Oh yeah, 95 degree day outside vana davic is 140 and on Bendix 150 that capsulated avoc 85 on a 95 degree day. Man. It takes a half a ton off the cooling off, depending on the size of your second-floor IRA, appreciated Jack.
Anybody wants to find your books and all that stuff. Where do they go? Let's point them there to wrap it up. You can get them in Amazon, but the cheapest place to get them is right from a cat, a CCA org and go to the online bookstore and it'll be in. There sounds good well. Thank you for taking the time to talk to me. I always appreciate it. I'm sure we'll get a chance to talk again sometime. If it's up to me, I hope so.
Brian take care of yourself stay well and kiss all your sons and daughters, spelling the 11 puppy I'll. Try to remember that thanks jack, hey thanks for listening! Thanks for being part of the HVDC school and the blue-collar roots, family you're part of the family, hopefully your your the good part of the family and not that weird uncle Randy who's, always talking about things that he shouldn't in front of the kids seriously uncle Randy Calm down anyway, so I thanks to Jack for being part of this thanks to write software making great software, I actually just want to mention. I want to mention that again because if you want education on manual Jay, specifically one of the best ways to do that is to pick your software and then get some education from that particular software manufacturer and write soft has a tremendous amount of education that you Can get so if you, if you in the market for some low calculation, software or design software manual estimate you'll, be even on the commercial side? Whatever your wanting, I would suggest that you take a look at write. Soft and again they are not a sponsor.
They just happen to be the best product on the market. Currently, I also want to mention real, quick, our friend Jim Bergman. In case you didn't know this. The red fish meter is now part of the sub-code family and so Jim's partnered with the sub Co, and they now have a new app out.
That's a really really nice application. In fact, let me Stephanie look at me. Look it up real, quick on my phone here. Let's see here, it is the echo team in the app.
So I found this called tech link, tech link, bicep CO and it's one of really the first HVAC diagnostic meter. So it if you, if you, connect your red fish meat here to this cefco app, you can do a lot of really cool things with it. It gives you a lot of tests and education along the way, things that you may not have even thought about testing. So flame, rectification of ground testing, capacitors under load flame run, current furnace temperature rise, thermocouple tests, voltage drop tests, all kinds of different stuff.
I mean it's all available by going to the sub Co tech link app. Alright, that's it for today. One thing that happened to me recently is: I got, I got pulled over by a police officer and he ran my ran. My tag remote license and came back and said well, son looks like you've got quite a police record and I said officer I beg to differ, it's actually a sting CD either you get better you don't.
If you don't it's, not it's not worth getting. Alright. Thanks for listening, we'll talk to you next time on the HVAC school podcast.
I've been waiting for this one.
I've been waiting for this one.
I just got Resload J, not regretting that decision. I have a builder that requires a calc for every house.
I've been waiting for this one.
I've been waiting for this one Service area Kanata??
I’ve been waiting for this one.
I’ve been waiting for this one.
I’ve been waiting for this one.