This episode of the HVAC school podcast is made possible because of generous support from our sponsors, rector seal carrier and Mitsubishi comfort, and also I've talked about this a lot. You can find a lot of the a lot of the products. A lot of the tools I talked about by going to true tech tools, comm and you can find my entire list, my entire tools list of products that I think that you should have on your truck and then it's it's really based on the types of tools We use and then also some feedback that I've gotten from technicians. Obviously you know everybody's got their opinions about what tools the best and you can make your own judgments, but you can find that by looking on our home page, you go to HVAC our school comm.

There in the resources tab you can find it there at the tool list is what it's called and we've got links there to everything. A lot of them go to true tech tools. You can get an 8 % discount by using the offer code. Get school to check out is actually coupon code down there at the bottom left and you can actually find a wide range of retro steel products there as well, just a whole bunch of different recreational products, including the new rector seal Pro fit flaring kit.

So that is true tech tools, comm and thank you to our sponsors carrier, rector seal and Mitsubishi comfort. When we exhume lock the 10-second flame free refrigerant, fitting from Parker reduce labor costs by sixty percent with no brazing no flame and no fire spotter discover how Siouxland can help you be more efficient and productive visit. Zoom lot comm for more information and now your host, the guy, who checks the air filter of every single hotel room right when he walks in, but still can't change his own filter. When he's supposed to Brian or yes, I'm actually going with my wife to Savannah Savannah it's one of my one of my favorite cities, Savannah and Chattanooga are two of my favorite cities.

I like Nashville, those are Asheville Asheville. Okay, so I like a lot of cities in the south anyway, so I'm going to Savannah with my wife and we're gon na be staying in a bed-and-breakfast, and I can assure you that if I pass a filter back return, air, grille or a piece of equipment That I can check that air filter by golly I'm gon na. Do it, I think, for those of us in the trade. I think you understand that you know we're always looking at equipment and looking at you know whether or not maintenance is being done, but but by golly on my own house.

It is hard for me to remember to do my own maintenance, and it's just I guess it's just when you're at home. You just don't feel like doing the things that you do all day long. I don't know what it is exactly. Maybe it's just laziness.

It's probably just laziness anyway, thanks for listening to the hvac school podcast, i am brian, and this is the podcast that helps you remember some things that you've forgotten about the hvac, our industry as well as helps you remember some things you forgot to know in the First place and today we're gon na talk about reach-in, coolers and freezers with Eric Mele, and I think this is a really important episode. We really jump right in and it's it's a little bit of a winding road, but for those of you who find yourself in the position that you do air conditioning, but you have to do a little bit of refrigeration now and then I think this is gon Na help give you kind of a flavor of that, certainly not a deep dive, but it'll give you a nice introduction to reach in freezers and coolers. So here we go Eric Mele well today, on the podcast, I'm happy to have Eric Mele. He brought up the idea of talking through reach in boxes and walk-in, freezers and coolers, and all that sort of thing.

But today we're gon na focus on regions because that's sort of a topic in and of itself. And actually it's a topic that my own staff and one specific technician: jeff kraebel so Jeff. If you listen to this, I'm thinking of you in this podcast. So Eric he's expert knows all this stuff and is the super tech and top experts top expert? Not a expert at anything by any means, but at least we can get people thinking about what they might encounter and a starting point.

Basically, because I've surely not seen every type of reach-in box. Let's start with sort of the basics. What are some of the different types of reach-in boxes that you can work on? What are some of the differences? Well, basically, the main ones you'll see our coolers freezers and then ones that are specific to wine or the three different things you're trying to achieve three different conditions shall we say I mean there may be even more than that, so specific to wine would be higher Temperature and controlled humidity yeah generally, wine is looking for 55 degrees at 55 percent, relative humidity whites, a little colder Reds a little warmer, but generally, if you're, keeping both in the same 55 55. Is it.

I hate to put rules of thumb out there, but it's like a general design condition for wine, okay and then no so we're gon na do quick design, temps average design temp. So what are the other two then coolers and freezers, so a cooler is usually gon na be between 35 and 40. Ideally I mean you can run them a little colder, but you don't want to go over 40. The health department does not like when your box is over 40 and you're, storing perishable food and a freezer, usually we're keeping them more towards zero degrees.

If you need to keep ice cream hard, you want to be like zero to minus ten. If you're, looking at like there's some blast freezers, I've worked on that are meant for like hardening the ice cream right after they make it. Those go down to like negative thirty really fast, but those are kind of a special application. Alright, so you get coolers freezers and wine wine being the warmest and also with wine - and I mention this, but the relative humidity part is really important with wine because of the maintaining of the corks right exactly if the humidity gets too high.

The corks that can swell if it gets too low, they can dry out none of that's good. Some of the places I work. Some of these people have quite the wine collections, and it's amazing to me because most of the wine split wine room unis, I see setup - are very poorly commissioned and designed, but that's for the next podcast on the actual walk-in boxes. Alright.

So there are wine regions as well. What type of controls do you see in a wine region that would affect the relative humidity? Actually, the critical sizing is what they do in wine rooms, whether they're, reaching or walk-in in my area, I'm in South Florida. So if you're in other parts of the country, you might have a humidifier, I don't deal with them here. We got plenty of humidity.

So typically, here it's just critical design. You want to size the unit properly and then you usually trim it with fan speed like they run on a TV typically and you can increase or decrease fan speed to adjust your humidity as required. Ok, so you've mentioned AV. You just went there.

Let's talk about AE v because I think I've only worked on maybe three automatic expansion valve systems in my career and that's what we're talking about here right yep, I haven't seen one on a reach-in wine box. A lot of regions are still cap two, but we'll get into it anyway, because you might see one on the bigger reach-in, but typically I've only seen them for wine and it's basically a TX V is regulating superheat and a XV is regulating suction pressure. If we want to really generalize it down - and you have a whole podcast on TX fees, that people should watch if they really want to know how TX keys work, but ax V only cares about suction pressure, you set it and that's what it does. So.

The challenge there, with an automatic expansion valve is yes, you're, going to get the evaporator temperature exactly as you want it to be, but as load changes, that's going to potentially run very high, superheat or very low superheat all the way down to zero superheat. Those are the reasons why that setup doesn't work so well, and while we don't see it that often because you can have some consequences on the equipment itself, unless you have a very, very stable environment, which my understanding is, that's why it's used in wine is because, Generally speaking, in a wine cooler, you're going to have the condenser in a very fixed temperature environment, fixed conditions and the evaporators in very fixed conditions, and so once you kind of get it set and you get it pulled down to temperature. There's not a lot of variation, sometimes you'll see condensers outside for that actually a lot of times, but they recommend an accumulator for sure because, like you said if your superheat gets too low, but they just want to keep that evaporator from freezing that's their strategy for Not frosting, they run a 35 degree, typically with whatever refrigerator, using you're running about a 35° coil saturated temperature. That's what you set your axv to and just let it ride, essentially by using an automatic expansion valve you're sort of eliminating the need for an evaporator pressure regulator.

I mean you can do the same thing with the TXV and evaporator pressure regulator, but this is just sort of a more simplistic way of doing that right. I suppose I mean I've seen where every real dedicated wine room unit I've seen has been using an ax v, not to say that I've seen them all, but you could accomplish similar results with EPR valve. Typically, those are on like multiple evaporator applications, but you could do different things, there's weird stuff. When you get into refrigeration and regions and small BTUs like I did a split BTU system for a wine room, a split system and it was two thousand BTUs.

So you're talking real fractional equipment. At that point, I remember doing one probably the only real wine cellars. I know we're getting off on wine and you didn't want to do that, but just quickly, oh, no, it's fun. It was a ductless air handler, like a high wall unit, could tied into a medium temperature ation condenser.

That's all I remember about it. It was new construction. It was like when I was totally green and I didn't know what I was looking at, but even at that time I was like what on earth is going on here. I've seen one like that too, and I'm like this does not seem any kind of right and I still question the design of some of these that I've seen but yeah.

We are kind of getting into split remote, condenser stuff we're getting a little off-topic, but it's fine. I mean it's gon na tie into the other podcast anyway. What are the other differentiations, then that you see between different types of regions as far as metering devices yeah? Just go through your list. Basically I'm trying to guide you down the list.

A lot of the stuff I'm seeing right now is cap 2. I know that as regulations change, stuff's going to digital controllers, but a lot of the stuff you see around has been around a while and they try to keep it around and it's really simple cap tube stuff, even on freezers, so reach-in stuff you'll, see TXV. I should probably clarify, for the purposes of this podcast we're talking about like packaged regions not like when you're in a gas station, and you have like a whole wall of reaching doors, so we're talking about like small packaged regions. Yeah a lot of them are capped.

Tube, some of them will start to get TXV as they get bigger. The blast freezers that I've worked on are TXV. Okay, we're talking about self-contained equipment; basically, yes, primarily when we say reach in, but there are a couple distinctions because you can have products that are reach-in that are on a parallel rack system in a grocery store. That would be the extreme version, but then there's sort of an in-between version too.

You could have a reach in that has a remote condenser, that's just for that unit like a gas station, three Doors or whatever. That would be a convenience store exactly, but here we're primarily talking about regions that have self-contained compressors. They have the refrigeration cycle within them. They have the compressor, condenser metering device and evaporator all within that device.

And so let's talk about that real, quick, we're the in general when you go to a convenience store, you go somewhere and it has a self-contained unit. Where are the different components generally located for a technician who walks up is like? Where do I start on this? If you're lucky, the condenser will be on top of the unit and you have to work off a ladder, but you'll quickly find that it's a lot easier. Sometimes the condensers are going to be underneath the unit and they'll actually be accessible. Underneath the unit to where you don't have to move them, but then there's also cases where the condenser is tucked in and it actually has like a spiral of refrigerant tubing behind it.

And you actually slide it out of the machine to work on it. And those are the biggest pain so to even do any testing on it. You've got to slide it out pretty much first thing before we go too far in like cooking up any sort of like pressure gauge is definitely going to be the last resort on these boxes. You want to verify that everything else is clean, especially condensers.

Dirty condensers are the most common problem, you're gon na run into with these, and that will cause cap tube restrictions if they get too severe and run for too long like that, so I mean the hooking up gauge. Is this kind of the last resort? You have to do it, but you kind of don't want to have to ask. So why does a dirty condenser cause a capital restriction again, a lot of heat built up in the system and it starts to break down the oil. You could hire the normal head pressures everything's running hotter.

These things already run high head pressures. I mean, if you look at some of the performance ratings on these units, they're like four and six seer or EE R, I should say not seer they're really low. They have really small condensers they're, really not worried about peak energy efficiency, at least as of the time of this podcast. I'm sure they're going to be more worried about it in the future, but a lot of the stuff you see is really really inefficient.

Cleaning is obviously a really big piece of it, but let's say you go to a case and again whenever we have a system, that's not working something electrical isn't functioning at all and that's sort of where our attention goes. So we're not going to focus on that. We're gon na say you walk up to a case and it's just not maintaining temperature and let's say it's a cooler or refrigerator and the temperatures are rising above 40, so 45 46 degrees. So very simple application.

What do you generally do? First, first of all, like it's making your condensing unit run because you could have a bad control. That's obviously not bringing your condensing unit on which is not gon na meet the box. But if you're past that point, what you probably are then you're gon na have to hook up gauges to it and see what's going on now. These are very small refrigerant charges, so you're not gon na want to hook up a manifold if at all possible.

I know there's guys out there that aren't using like testo, smart probes and stuff. Well, if you insist on using an analog gauge, you're gon na have to get a stub adapter for an analog gauge and dedicate it for that kind of stuff. So you're not losing a bunch of charge every time you hook up to it, and some of these don't even have access ports and those are even more annoying, but sometimes you have to tap into them. So you walk up to a unit, that's not maintaining temperatures, but it's the first thing you're gon na do, and you already mentioned this - is you're gon na check all the cleaning items right I mean you're gon na make sure that there's nothing.

That's blocking the condenser and then you're gon na make sure the condenser is not dirty and clean that, if that's the case and are there any other sort of maintenance housekeeping things, you check on a reach-in before you go to the step of either using the port's That are there or putting in some ports to attach evaporator cleanliness to, but just those are the basic things to check, make sure your condenser and evaporator clean, because that can really pack those systems. A lot of people don't take time to clean off the fan. Blades adequately and if you're gon na hook up gauges to shut it off before you hook the gauges up, because if they run low, they can easily be in a vacuum on the low side. And you really don't want to start pulling air in.

To hook up gauge, if you can avoid it, let's focus on this idea of test ports and connecting gauges, because, obviously Jim Bergman and I talk about this all the time - we don't want you connecting gauges unless you have to. But if you have to - and there are no ports, then what do you typically look to like what is your hierarchy of how to install ports on a system? How do you approach that these are kind of hated in the industry? I'm sure guys have seen them before the mechanical access ports that you can clamp on that pierce. The lines and they'll be fine when you put them on that day, but they tend to leak later on down the road, especially if you put it on the high side. So if you have to tap it, you have to tap it and that's the easiest way to verify yeah do I have a problem, but if at all possible you want to remove those and removing those would look like raising in a stub and recovering all the Charge raising in a stop at that point, so I guess in that strategy, if you're planning on removing them and then you're, basically connecting with in your accounting on the fact that you're gon na have to recover the whole charge anyway.

What about those like stubs, that you can pinch as pinch off tools and then you can add in a Schrader there yeah! That's another method. You can do they're, usually gon na, have process stubs, sticking off these units that were pinched and braised already when they started them at the factory. So if you put your pinch off tool where it was already pinched and you cut it and put a stub in there and braze it, then you can put a flare block or they actually have a rerouting block. That's basically a flare block without the countersinks in it and open it up, and then you have a test port, that's braised! In so that's another option.

You basically have to purge the air off the top in that situation, or you can just like you set it straight up. If there's no gas in it, you can just basically braze them in at that point. The mechanical access fittings are a quick, cost-effective way to verify, there's a charge issue, and then you can proceed from there. You just got to use your best judgment of when to use them.

I also imagine that in a reach-in application, weighing the charge in and out is probably a really good who, similar to in the automotive world a lot of automotive mechanics. If they want to see if a charge is right, they just weigh it out and see how much comes out and then wait back in again. I imagine that that would be a more realistic method to use in this world than it is in the regular air conditioning split world. Well, here's the problem with that, though, when you try to do that.

You're gon na have losses due to your connections of your recovery equipment and your condenser of your recovery machine. I mean it's kind of hard to calculate exactly how much refrigerant gets lost in transmission between all of that right. Good point it's doable, but it would be very tedious to figure out what you could reasonably expect to lose when you're talking to system. That might take seven ounces of refrigerant, it's kind of hard to say, you'd, pretty much know you're gon na see a lot lower than expected head pressure.

These things run like condensing temperatures. Thirty to forty degrees over ambient is not uncommon. You'll basically know that it's not working right if it's a cap tube system by that, and if you have a restriction and then I imagine you can also probably watch you or discharge temperature in order to have some indication. If you know that the condenser coil is clean in decent shape and the fan spinning and all that, I imagine if you watched your discharge temperature on your compressor, you could have some indication of whether or not you have a charge problem.

In addition to checking your suction temperature right, it's weird because a lot of these little cap tube systems, they're gon na, have the suction line and the liquid line, or even the cap tube, like touching each other inside of the insulation. Don't quote me on why they do this? I think it has a lot to do with not getting liquid back and trying to use it kind of as dropping the temperature that liquid going into the machine may be assuring both at the same time. But you'll see that a lot so yeah. It's a quick and dirty way of dropping your liquid temperature and increasing your suction temperature.

Simultaneously, it's a little energy saving hack that they can use yeah. I think it has to do with energy saving and not getting liquid back because of these cap tube machines. They don't have receivers or accumulators, so I guess they're trying to do that to assure that they don't get liquid coming back and, like you said, the energy efficiency aspect of it, whichever one is more, I think they're doing it for really both reasons, but you'd have To talk to a manufacturer to see why so, it's really hard to look at a suction temperature and see anything that you're used to seeing and there's also like cold wall boxes that don't even have an evaporator fan. So you're gon na see really weird stuff going on on the low side of systems like that, because there's no airflow whatsoever by design just from a practical standpoint, do you find when you're dealing with maybe an application that you hadn't worked on before? So I'm thinking specifically, I was just doing a recovery on it, but it was a floral case at a grocery store and self-contained floral case.

You know I wouldn't know exactly what the design temperature would be for that or what the design temperature difference on the evaporator coil would be. Do you find that you look at manufacturer specifications a lot, or what do you do in applications like that? Where it's a piece of equipment that you may not be very familiar with, oh yeah, if I'm not familiar with it and I'm having trouble with the problem. Like anything else, I have tried to consult manufacturers they're, usually pretty good, about answering their phone and helping you through stuff. So you can definitely gained a lot of ground by getting all this tech support numbers in your phone and once you have a good idea of what to look at giving them a quick call, but I mean the cases are usually pretty simple.

I don't know about a floral case. I can't say that I've worked on one, but these like what we're talking about here is they're, pretty basic they're captive systems. The restrictions become a pretty evident pretty quickly. Alright bear with me for a second, because I'm gon na talk to you about acid away and acid away has almost become it's almost like Kleenex and you use it when you're talking about an acid inhibitors or an acid neutralizer, and there are different products on the Market that do different things - there's acid scavengers, which isn't what I'm talking about here.

I'm talking about specifically the acid away product made by rector sale and I is the product that we use in certain cases caveat because I know a lot of you are gon na get upset when you hear that we use it because you a lot of you, You know abide by the strictly refrigerant and oil approach. I agree with that approach in general. That's what we want in the system, but also keep in mind that you know the simplicity of refrigerant oil and the old mineral oil in a world that we used to live in with our 22. That's not even how it works anymore, even the brand new systems.

There are additives in systems right now, it's even even brand-new ones. Did you get their additives that are being at it? As you know, I've talked about this in the past. When carrier had the issue with some of their expansion valves sticking, they actually suggested an additive which was the old, zero lice product rebranded. So it's not like manufacturers, aren't using additives or don't understand the effects.

Obviously, in general, we would like to have perfectly clean equipment that never fails and there's never any issue with it, but from time to time that can become a challenge and that's where this these products come in, and so the first thing to understand is that a Sit away what it does is it actually interacts and neutralizes the acid, but it creates a salt okay, so it actually creates another substance that still needs to be removed. It's not like you can add acid away, and it's just as magic magic substance that you put in a solves all problems. What it does do is it interacts with the acids. Neutralizes them creates a stall assault and then that salt is caught in a filter dryer.

So when you have a compressor burn out, the first thing you need to do is follow all of the proper procedures you know performing flushes, using suction liquid line dryers of the proper type and of the proper size. But sometimes - and you know this when you, when you test - use an acid test kit and you test, you can smell the oil, you can see the black oil and somebody wants to salvage a unit. That say say every unit: that's eight years old, 10, 11. 12 years old residential cases - and somebody wants to install a compressor - sometimes it just makes sense to use a neutralizer, because you know you're not going to be able to get all of that acid out and making multiple trips can be very expensive for the customer.

So so this is a great product for that, and what I specifically want to talk about about this acid away product is acid away Pro. If you haven't seen this yet it actually uses a copper injector, as opposed to a can that you dump in because those are always super awkward like how exactly do you get that in there just kind of make a mess of it? But these new acid away injectors are really nice, especially if you're, if you're coming it up to a system, and you did the burnout protocol and now you're still seeing acid. You know. Obviously you got to change your dryers, but then you can also use this product.

You can eject it in the suction line. Using you know your liquid pressure to force it through. It's just a really nice delivery method. It works with all oils.

It works with. You know mineral and piauí being the most uh, most common, but all types of refrigerant oils, and - and I really I really like it - it's it's product that we use at Kalos at my business in those applications. So it's not the sort of thing that takes the place of other protocols, making sure that you're, following all the proper procedures, testing for acid suction dryer, liquid line dryer properly sized dryers, removing them from service. Once all the asset is taken care of.

There's all these steps you have to take, but in some cases using this product can help you get there to where you have no acid in the system, so that is the acid away pro from rector seal, all right now back to Eric. So now, let's just talk through some of the controls and some of the other accessory components that might be inside some of these different types of regions. Yeah, a lot of the smaller ones are gon na have just basically a lot of times. It's called a cold control.

It's gon na be a little dial that usually just says one through nine and colder will be pointed to arrow and then there'll be an off position on it at times, and that's just going to be shoved into the evaporator somewhere and there's typically like there's a Straight type and a spiral type, so if you're gon na keep them on your truck, keep them one of each is good and those are just gon na stop the compressor when the coil reaches a certain temperature and then start it again when the temperature rises enough. In Dick was saying that generally five degree, temperature swing is pretty standard, it's kind of hard to say because you're looking at this dial - and it really just says one through nine on it - I haven't actually specifically looked at temperature rises, though controls all come with different Specs and obviously you should try to get one really close to what you're taking out or the same one, if possible, but yeah. You can crank the control down and go colder with it, but it's they're, not very precise. You know what I mean: they're, not any sort of digital controller they're, just using like a charge and a bulb to operate a switch to operate an electric switch, so simplicity's the name of the game.

Here I always tend to overthink this stuff. But if you're trying to set one up so say you replace a cold control, then are you just essentially setting it back to the same setting that the last one was or are you sitting there and kind of watching the on and off cycles of it and Monitoring the temperature of the box at that point. Basically, the easiest way to see when those are going bad is your box is not meeting your temperature and your condensers not running, and you turn that thing all the way to coldest and it's just not running the condenser enough to bring the box in. That's a telltale giveaway that it's your cold control, that's causing the problem, so you can cross-reference it with your application or with the exact control and get one in a similar setting like the cooler ones, we'll cut out and the temperatures around the teens and then cut Back in or I don't have offhand in memory exactly where they're gon na do it, but the freezer ones are obviously gon na be lower, and you were mentioning on some of these more simple regions that they're just manual defrost, which that's something I mean.

I think of an old manual defrost refrigerator that you've got a shutoff and defrost every once in a while. Is that what we're talking about here? There's these cold wall cases and these cold wall boxes and some of them are meant for like for displaying and serving ice cream out of like. If you go to an ice cream shop, we actually have an account that has a few and a few different stores and there's no evaporator fan. In these cases they run off a cold control and by their nature, it's a freezer.

So it's gon na freeze up ice is gon na coat the walls of it where the tubing is running until it just not effective at refrigerating anymore. So I think it's like once a week. They recommend that you take everything out of it and let it completely thaw and there's actually a drain plug that you unscrew and let it route it to a floor drain interesting. So then, that just becomes part of the customers like it has to be part of their regular practice.

Otherwise, the thing will become a big giant chunk of ice, exactly it will just form so much ice on it that it's just not effective at keeping the product where they want it, and actually the blast. Freezers that I work on to the manufacturer does recommend, even though they have defrost timers and defrost cycles, the manufacturer does recommend actually de-icing them once a week as well. So it's going to be manufacturer specific. I guess it only makes sense.

Then these would be in applications that are not in constant duty use then. So the idea is you're displaying some ice cream here, but then you're taking the ice cream and putting it back in some other type of storage, long-term storage and the same thing is true of a blast freezer. It's like you're, not using it all the time, and so we can use this strategy more. Obviously, if it was for constant duty use that wouldn't really work yeah, it's just kind of the nature of the design of the case.

Maybe you can get really fancy ones that have defrost but, like I said most of the stuff, I'm seeing is pretty basic. There's a couple things I see with digital controllers on them, but a lot of it's very, very basic, ok and so then in defrost you're. Pretty much with regions, traditional regions, you really don't have much in the way of hot cast. It's either weird fan defrost or it's got manual defrost like you mentioned, which would be more rare but then commonly especially in freezers.

You're gon na have electric defrost, then yeah you'll have electric defrost on those. Some of them have actually I've seen time clocks in them, but a lot of them have like a little dick cell controller in there. That does basically everything it has a couple sensors and it basically runs the whole box and it has defrost built in they actually have aftermarket generic replacements. You can replace a lot of the controllers with those dick cell controllers and even use the same sensors that you already have interesting.

No, that's good to know, because I didn't even think about that. But could you also use a controller like that say you were having a trouble with an older reach-in and maybe the defrost wasn't working as efficiently as you'd like and maybe having trouble keeping it to temperature, where you could actually install one of those aftermarket controllers with The sensors, in order to do that, I mean, is that something that people will ever do you can retrofit it to that type I mean it would all depend on the customer. I don't know if you'd have an advantage if it had like a time clock in it. I don't know if you'd have to advantage as long as your time clock is working, because you could always play with your defrost there.

Usually, if you're having defrost issues is because you have a heater out, do you test a heater with an ammeter, or do you test it just by like it's warming up or not warming up? How do you check that it's hard? Some of these heaters don't draw a lot of current and you actually have to do the old touch test on them. I've actually had a drain heater on one of those blast. Freezers go and I called the manufacturer, and I was asking them like what is the resistance on this heater, because you couldn't get an amp draw on it and they gave me the wrong resistance and I checked the resistance and it seemed fine. But then I had to call them back again and they said.

Oh, no, that's wrong. It's supposed to be this resistance and I'm like all right, Pat heater, and I said they should feel warm to the touch. I mean that's very subjective, though, especially with calloused hands and you've been working in a freezer for a while, and you basically have no feeling left in your hands. So I imagine a thermal-imaging camera would be handy in that application.

Yeah. That's not my short list of tools that I really need to buy completely off topic, but I've seen people get into trouble on water source systems with blockages in the pipe that were pretty much undetectable without a thermal imaging camera. And you start to think you have problems in your unit and it's a blockage in the pipe. I think thermal imaging cameras.

I've always been opposed to missions. I'm opposed to. I just think they're generally misused infrared guns. I think they cause more trouble than they're worth, but infrared cameras, thermal imaging cameras.

I think you have a lot of applications that we haven't considered and I think there's a case to be made that every diagnostic technician would be able to use a thermal imaging camera and I think about all these different applications with say you have even a reach In that, maybe the door seal is having an issue if you've tested everything else, and you think that it could be related to that. Do you think there'd be an application there, or is that more just common sense? As far as a door seal goes, you'll probably see it, but I mean it's a great tool. You don't think about using them until you have it and you use it. You pointed it's tough and I don't have one to point.

It's tough but I've seen where people can just point it at things and get an idea of. What's going on just more data that you can use to your advantage. I've been on back-and-forth about one. I just really don't know which one I want to buy and I just want to make sure if I spend a lot of money on a tool that it's gon na be the right tool, especially one that costs as much as those can.

So that's why I haven't ended up with one yet, but I think they're a great tool. So obviously we've already talked a lot about. I don't want to go too much into defrost because we covered a lot of the defrost topics and the previous podcast with dick yeah. Maybe we talked about a lot of that, but you have to have some form of it's either time termination or you have some sort of sensor base termination and then some sort of failsafe and or I guess is what I'm saying you have to have some way Of saying hey it's time to come out or something's wrong and it's got to come out because it's been way too long kind of a situation.

Is there anything else there that I'm missing or that we missed in the podcast about defrost? No, you didn't miss a thing. Your podcast about defrost, but one thing I've noticed about some of these reach in coolers is a Woma digital controller. I saw actually not running the fan continuously and without getting too far into it. I don't know if they're sensors that deal with that or not, but you might see that a lot in the future, as digital controllers become more available, maybe they're running a coil sensor and they're not running the fan full-time.

So that's something to look out for I've. Seen it happen and there's also usually a door switch on the equipment. That's not gon na run the family, the doors open, just another thing to check, so you because in a cooler refrigerator and a medium temp, you need to run the fan in order to defrost. If you're expecting air to defrost stead of ever to coil, the fan obviously has to be running, whereas in a freezer it's the opposite.

The fan needs to be off in defrost. Otherwise it's gon na when that heater comes on it's gon na blow snow. All over the place, you'll definitely know it. If you have a box where the fans coming on too soon, because they'll usually be ice forming around the ceiling around the fan, it usually sticks right there, because the coils are usually mounted right against the ceiling, whether it's a cooler or a box like a reach-in And then, in addition to that, you've got drain heaters.

In some cases you have door heaters, you see a lot of door heaters and I imagine you do in freezers, region, freezers, yeah, you're, gon na have door heaters in a lot of the cases to keep an eye on and see if they're working and it's pretty Obvious when they don't, your door starts to ice, shut indication that they're not working is door, doesn't open exactly and then, if you do have a system that you have to defrost if you're having a defrost issue, what strategy do you generally use on a reach-in? If you have to de-ice the coil yeah, if you've got something, that's a like manually, yeah, it's a big bowl of ice. If it's on wheels, I like to take it outside and use a hose. If it's not on wheels, then it's more complicated. I mean usually a pump sprayer and a shop vac, and it's tedious.

I prefer not to do it. I prefer to just put it over by a floor drain and prop the door open and come back if the customer is okay with that just unplug it but yeah, it happens sometimes where you have to just di stuff and it's not fun. Your hose is the fastest, but it makes a mess that you have to be able to be by a really good floor drain or be outside cool. What else will be missing as it relates to regions? Well, one thing we kind of skipped over on my list here is: most of these boxes are meant to hold a product at temperature like some of them are not.

Some of them are designed like the blast freezer designed to take a product. That's warm and pull it down, but it's something to keep in mind like how the customers using it, if they're, putting like hot food in there and expecting it to pull it down. You really got to check with the manufacturer to see if that's what its intended for and most likely, it's probably not they're, just doing that and not to say it doesn't work depending on how much you put in there at a time, but just keep that in Mind is these boxes are designed to hold a product at temperature and just beat it could be conveniently located, not necessarily designed to take like warm product and stuff it in there and expect it to pull it down right exactly, and so let's say you do that: Let's say you take a reach-in freezer, that's designed to maintain temperature and you just jam it full of a bunch of hot meat, freshly slaughtered steak. What are some of the things that you might see? You're gon na have poor performance because you're gon na basically overload it with BTUs.

There's really not much. You can do about it, except tell the customer not to do that sort of thing. Just tell him it's very naughty. Yes or you could have them just pack.

It full of dry ice, then what would happen good things, I'm sure just pack, it full of dry ice, and then it solves all the problems, the human aspect of people that don't know about the equipment working on it kind of create some more the headaches too, Because I've seen a situation and this was with a walk-in cooler or every Monday, the cooler will be frozen up and there's an attack out and he'd be ice. It and check it and everything would be fine and they had to eventually install a camera. And what was happening is when Sunday night, when the cleaning crew would come in to clean the walk-in cooler, it was too cold in there for them said prop both the doors open. That's not a good idea.

No, but yeah you'll see stuff like that. Though I mean never rule out the human interface of people that are working with your equipment, because I've seen it before I've seen the display freezers where they're holding ice cream and there's pulldown little plexiglass lids, and they just leave them up. It has that there for a reason, it's designed to help, keep everything in there cold. So you got to kind of be a detective, sometimes with some of the stuff, and unfortunately that's just things.

That'll happen is some of the people that are working around the equipment. Don't understand that hey you shouldn't prop the door open on this for hours at a time and also maybe not even realizing some of the other ramifications like the moisture as well. You know that you're gon na have copious amounts of ice, so that frosting problem that occurred a day later could very well have something to do with that night. Before that you left it propped open for an hour or whatever.

The case may be exactly it's tedious. At times to deal with got it one thing I want to briefly cover and you will see it on some of these boxes. The only thing I see on my list that we didn't cover is pump down. You'll see it a lot more on walkins, but some of the bigger regions will have it where, when you're condensing unit satisfies temperature, a solenoid will close and it'll pump down, and I mean your large refrigerant charge, you're pumping it into a receiver instead of letting it Go where at once, because if it does go where at once, then it's gon na go to the evaporator and when your compressor starts back up, it's gon na flood it out.

So you will see control strategies where all your thermostat does is cycle. A solenoid and the condenser just reacts based on pressure, so they'll actually be no interconnecting control wires between the condenser and the evaporator or not necessarily any, unless it's a freezer and then that time clock can be wherever they put it. But it's just something to keep in mind. You might not be familiar with pump down and why things pump down.

But that's the reason we don't want all the liquid to migrate to the evaporator in the off cycle and then flood out the condenser when it starts back up, I've actually seen a entire grocery store. I'm not going to name the grocery store where the air conditioning system was set up in that way and we're talking a massive system. I think it was probably 40 tons, something like that and that's how it was set up. So you had two condensers and they had low pressure switches on them and when it was time to cycle the equipment off, all they did was shut down, pump down solenoids and they pumped down until the low pressure switches took them out.

Needless to say, the a failed low pressure switch was not a good thing on that store because it would just sit there and run all day long. It's the problem. It's not the worst control strategy in the world, but yeah. It's definitely you don't want to failed pressure.

Switch I've seen plenty of systems running on that. I think that's actually I mean we're going off into air conditioning now. Well, when you start to get into long line sets one of the first things they want is a crankcase heater. I can't remember the order, so it's crankcase heater pump down solenoid an accumulator, and I can't remember which order goes in it's probably specific to manufacturers yeah.

That order makes sense, because the crankcase heater is easy to do hard. Shutoff TXV is another strategy. That's often employed or just a very simple way of managing some of the migration in air conditioning. It's a slightly different situation, because in that case, it's more likely that you're gon na have the refrigerant set in the compressor crankcase.

As that evaporator coil warms up wears in a box, the evaporator is in a very cold location, so you're gon na have all that liquid refrigerant, condensing inside that evaporator coil. So it's slightly different but yeah. It's a strategy. That's used, it's not a bad strategy, but it does have some possible ramifications, but that's something to watch for.

Obviously in refrigeration equipment is, you do have more of that. It should be running on pump down if it has TXV and a decent-sized refrigerant charge, and I actually saw one the other day that didn't and it was a cooler and it was built up. So that was the installers fault, but yeah destroyed the compressor it destroyed. The valves in it not a good thing, and so, when you mentioned, when you have a TXV, it's because when you have a TXV, then you also likely have a receiver.

And when you have a receiver, then the system can hold more charge. And when the system can hold more charge, there's more charge that can be stored in the evaporator coil when there's more charge that can be in the evaporator coil, the more likely you're gon na flood out right exactly well. Refrigerant charges are getting bigger, they're wanting and then they have to use a TXV. That's when they're gon na put a receiver on there, because they don't want that refrigerant to be able to migrate, make sense for technicians if you get thrown into something like this.

My biggest advice would be just to take your time. Slow down, understand the equipment. Look up some manufacturers information on it, see if there's any on site, understand how the equipment works and don't start just like yanking, wires off and doing all kinds of crazy stuff, because you're, probably gon na make it worse. You spend a little time get to understand this particular product.

What type of metering device it has where the evaporator is. I look over it from a cleaning standpoint and, more often than not, I think, you'll probably come out ahead, even if you don't have a lot of experience with them, yeah pretty much don't go by that old adage of when in doubt jump it out. Alright. Eric thank you so much.

I appreciate it and we're gon na have Eric back on soon to talk about walkins as well. I think this has been helpful. I know you have a youtube channel. If anybody wants to find you on YouTube, how do they go about doing that? My youtube channel, it's bad because I have been on there so long.

I don't post much anymore, but it's Eric M HVAC and I'm also on Instagram. Actually, I think I'm on YouTube is just Eric M, but just to be forewarned everybody there is some adult language on my stuff. So don't listen with your kids around just to be warrant. Don't let your three-year-old go on to Eric M's YouTube channel, because they're gon na be appalled, shocked and appalled, shocked, appalled and I'm definitely were active on Instagram than YouTube.

Although I just did post some of that stuff about that 1959 York unit, I'll be at a very brief video that thing's kind of cool, alright we'll go check it out. You can encourage him to get his a YouTube channel back up and kick-started if we just inundate his channel with traffic HVAC school army and all of the mighty minions attack Eric's YouTube channel there we go, then I could monetize it and I can quit my job Retire right, have you ever noticed that everything's, a nation everybody has a nation? It's not enough that I'm just a goofy podcaster here sitting in front of my microphone talking about air conditioning, I got ta have a nation HVAC school nation, HVAC school podcast, nation podcast on fire nation explosion army. Sorry, there we go alright thanks Eric! Thank you. Hey thanks for listening to the to the podcast.

I am I enjoyed this one. I think we're gon na do more and more in refrigeration as we go, you know generally on HVAC school, we really focus on fundamentals, so we focus on again, like I always say those things that you might have forgotten or forgotten to know. In the first place, it really about the fundamentals, the stuff - that's very core to the trade, but there's a lot about refrigeration that seems alien to AC tanks, but it's not complicated. It just requires a new perspective and just a few, a few things to remember so we're gon na do more in refrigeration.

I also have been begging Jim Bergman, to get back on, we've been talking about doing a combustion analysis and furnace commissioning podcast, but he's so busy right now that he just you just keep standing me up. So if you, if you have Jim's email, you could shoot him an email tell him to come on the podcast so that it's that you've been waiting with bated breath to come on, because I think that of you that'll be a really good episode. So keep watching for that in the coming weeks, if you haven't been to HVAC our school comm ever or for a while, I would I would recommend doing that. We we're starting to build up a lot more resources.

We have some great calculators. We have a calculator there to show you phase and balance if you enter the different voltages of a three-phase system. It'll show you your percentage of imbalance and, if that's a problem, we have a new nitrogen pressure, calculator so showing how nitrogen changes pressure with temperature. Depending on when you, you know, you set it at one temperature and you come back and if it's at a different temperature, your pressure will be different.

So it allows you to calculate what that difference will be, and we have some other things there as well. So if you just you know, click around the website, I think you'll find some useful things. There do a dad joke, I'm just I'm just fresh out of dad jokes. Okay, and I think my sense is, is that everybody? You know you want to share it with your friends but you're like man.

I don't I don't know, there's those dad jokes in the end. That's gon na you know Brian's gon na make a fool of me, but but I want to make a fool of somebody: Jordan, Cummings. So Jordan, if you listen to this, I don't know if Jordan actually listens to my podcast or not. Jordan was was one of my besties on the HVAC school Facebook group which, by the way, if you haven't been there, you need to go to the HVAC school Facebook group.

That's the best way to interact with me and with the whole crew of our happy admins. A lot of people send me very, very technical, in-depth questions via messenger or via email, and I really don't have time for that anymore. I mean if you, if you have things about the podcast, you know little quick, hit questions, that's great, but in-depth stuff. I really don't have time to respond to most of those anymore and I would love to, but it just it's just too much at this point, but if you post it on the Facebook group, it's very likely.

You may get a response from me, but you'll certainly get a response from some other smart people and again you know. Obviously, it depends on who's once went what what the quality of the response, but you know, we've got 19,000 people in the group now, but there's a lot of really smart text there who can help you but anyway, so Jordan Cummings is a guy who I've interacted With and he was a tech in the field now he got a fancy-pants job with a fancy-pants company, doing fancy-pants, vrf work and I'm kind of jealous of him. But I got to meet Jordan at the HR conference and he mentioned that he's been listening with bated breath to see if I mentioned his name so here we go Jordan, Cummings, Jordan, Cummings, Jordan, Cummings, Jordan, Cummings, Jordan, Jordan, Jordan, Jordan, coming Cummings all right there we Go but a great meeting, you, Jordan and I look forward to look forward to finding a way to meet all of you, I'm looking forward to doing a some in-person meetups around the country. Maybe some events that sort of thing - I think that's gon na be fun when the time comes for it, but now we're we're getting.

We just had this ridiculous cold that cold snap opposite had this ridiculous hot snap in Florida, it's like 88 degrees here and it's February. I know a lot of you're like you're seriously complaining about that. But for us we got super busy, and so I got kind of wrapped into that and my two primary things that I that I have to do after I have to continue running kalos have to be here for for that, and then I have to do this.