HVAC Techs Are Overcharging Heat Pumps in Cold Weather with Jim Bergmann | Part 2
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AC SmartSeal, the professional's choice. All right, so we're back with part two with Jim. And Jim goes on to talk about low ambient charging. And in this one, he talks about a little bit about how it's different from a TX valve charging a piston and how MeasureQuick has generated a workflow or a spot within the app that allows you to pick a

a piston for low ambient charging rather than a TX valve. So the conversation continues on low ambient charging. For a lot of techs, Canada, Northern US, other parts of the world, this is life. We need to learn how to do this and we need to learn how to do it right. So let's get back to it. This is the HVAC Know It All podcast. I

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Somebody from LinkedIn sent me a picture and it's got a refrigerant charging curve for cooling. Then there's a charging curve for heating. And then down the one side is the discharge temperature. And down the bottom, it's the ambient temperature. And they give you sort of a sweet spot to hit. What do you think of, have you seen those before or no? Yeah, I've seen those before. And those are just, but if you read the full installation directions, it'll tell you that like that's a wintertime charging process, but it's going to tell you you need to return in the summer and actually...

Dial it in. Like most heat pumps do have wintertime charging provisions, but they aren't designed to nail the charge exactly. It just gets you close enough to keep it going. The other trick with that is it's very, very easy to overcharge that heat pump, you know, because when it gets really cold, things take time. Like if there's any refrigerant that ends up in your accumulator outside, it's

There's no heat energy to help boil that refrigerant out. So like you're dumping a little gas in and you're dumping it into the true suction port. And if that true suction port's located before the accumulator, you dump that refrigerant, it hits the accumulator, and then there's no heat energy to really boil it out. And so it boils out very, very slowly and your charge will creep up over time. You'll end up with an overcharged system. So it does get really...

really really tricky this is where like if i had my druthers if life was perfect i'd take the gas out of the system out of everything you know and then charge it weigh it in exactly know what the know what the whole charge is and then put it on the nameplate so i knew what to charge it to going forward it's probably not practical but from a practical matter this is where superheat and sub cooling you know if you can mimic the right conditions are the best way in my opinion to charge it

So what about how this is all done within the MeasureQuick platform? So there, is there a way to, is there like a tab that says, okay, we're going to go into low ambient charging here? So it's a, well, it's a tool in the MeasureQuick platform. So you go into, you go into the toolbox and you, and you activate the charging. Okay.

And then when you activate the charging blanket, it looks at the outdoor air temperature because we're pulling in the weather data and it says, see, there's the right spot to put the charging blanket on or it's too hot or it's too cold. So it'll tell you, it'll pop up with a symbol of the charging blanket. It'll pop up with a different color temperature range.

to show you where to adjust it. Now, the cool thing is too, is we automated a whole process for fixed orifice charging too. So you can actually, it doesn't have to be just TXVs. We can actually, you tell it it's a fixed orifice that uses a whole different process where it basically looks at the return air wet bulb temperature, looks at the return air wet bulb temperature and calculates the target outdoor temperature to dial in a prescribed superheat to the system. So

It can work on fixed or TXV, which is pretty cool. Nobody's ever done that before. And it works just as well on either one. You just have to make sure that you pick the right metering device when you go to charge it. And what is the charging blanket you're currently using with all these tests and videos that you're showing? We're using AccuTools. Came out with a charging blanket, I don't know, maybe six months ago or so. We do a lot of work with...

Agitools and MeasureQuick. And so we've been using their product. It's a little less expensive than the ones that are out there. And then it's also really well made. But the key thing is we automated that whole process. So it was an interesting product. Charging buckets have been around for a long time, but they just weren't easy for people to use because it didn't really, I don't think anybody did a really good job explaining why you need to use one or when to use it and then

how to properly set it up and what target range to dial it into. So with all those features of MeasureQuick, we're able to really, I think, take an antiquated sort of clumsy process and make it something that was really slick and easy to use. So something to be talked about when it comes to low ambient charging, and I've forgotten to do this many times. You go to your truck when you're ready to charge and it's

bitter cold outside and you're like, my refrigerant is, how am I going to get my refrigerant into this system when the pressure is so low in the, in the tank? So tank, we obviously have tank heaters. There's different ways to heat tanks. I mean, I've got a yellow jacket, one that plugs right into the wall and it works. It works excellent. I mean, depending on how cold the tank is, it could take a while to heat up. So it's always suggested that you try to, as soon as you get to site, if you know you're doing low ambient charging,

get your tank warm. That's the first thing that you have to do. Now, please help me on this one because I've seen techs talk about filling up a bath of hot water and just throwing their tank in it unmonitored. And that to me speaks like it speaks to something bad waiting to happen. It sure can be, especially if your water is over 120 degrees. I mean,

You know, you got to make sure if you're going to put a refrigerant in a warm, a warm water bath that, you know, keeping that water below 100 degrees is ideal Fahrenheit. Or monitoring the pressure too, just to make sure. Yeah. Monitoring the pressure in a tank too. Absolutely. Yeah. You know, sometimes water can come out of commercial kitchen or something at, you know, well over 120 degrees. Yeah.

And water has a lot higher specific heat than air does. And so when you immerse a tank in water, it's a lot different than putting it in air. Warm air is just going to not have the amount of heat energy that hot water has. So it can heat up very quickly. And I don't think I've ever ruptured a cylinder in my entire life. I've had one rupture in the back of a truck when I wasn't in there. But I wouldn't want to be standing there holding the tank when all of a sudden that high-pressure relief lets loose. That would be...

Yeah, I'd have to clean out your shorts probably. Yeah. I've had a piece of copper pipe explode right in my face that was filled with refrigerant. It's a long story, but I mean, it was my mistake too. Oh yeah. I saw the one you posted the other day with the hydrostatic force of the discharge line bend in the copper inside where it wasn't fully brazed in. Was that? No, that wasn't me. That must've been somebody else. Okay. All right. Yeah. They were just showing how refrigerant just got an oil hydrostatic on the inside of the line and it was

basically collapsing the discharge line from the inside because it wasn't braced properly. Oh, I, I, sorry. I've shown pictures of that back in the day where, yeah, there was like little pockets where liquid was getting trapped. Right. And then as that liquid expanded, it would turn to vapor and it would actually blow the line apart. I've posted about that before. But it's probably more hydrostatic force to just slamming, slamming that liquid in there. Could be, yeah.

could be liquid doesn't compress yeah there's a lot of things we always wonder what happens inside of a system yeah i was just going to say that the time that i had the line explode on me myself and the apprentice we were i was just a young technician like i was it was it was very dumb of me to do this but we were it was cold outside we were trying to move some refrigerant into a tank and the tank pressure wasn't coming up we're like well let's just heat heat this line up with our torch we're trying to heat it up and we didn't realize the valve was closed

to the actual tank. We didn't even open it. So we're heating up this line and the line, the copper just buckled and blew apart. And whatever was trapped in that section blew at us and knocked us back on our, on our asses. And it could have taken our eyes out. It was, it was, it was just a quick flash. We both fell backwards. My apprentice's hat blew off of his head. It was, it was quick. It

There was no reaction time whatsoever. It was this and then that. And it was all because we had that refrigerant too warm and pressurized in that pipe. Yeah. Wow.

Yeah, that kind of stuff can be dangerous. And overall, like low ambient charging isn't dangerous, but you got to consider, you know, like you said, you got to consider multiple things. The same thing with your vacuum pump. You want to make sure that your vacuum pump go inside and get warmed up because your vacuum pump oil doesn't work well. Vacuum pumps don't work well when they're cold periods. What I usually do is take the vacuum pump in, like in the house, and I'll plug it in and just let it run without a load on it. Just let it warm the oil up before I take it outside. And then...

The other really important thing is, you know, if you're going to do low ambient charging, obviously, you're probably you're doing an evacuation before you do the low ambient charge. So I do a couple of things. Number one is I'll turn on the furnace if it's got a furnace inside and run hot air across the evaporator coil. That helps raise the temperature up inside. But then all you got to do is just close your eyes for a minute and imagine like, well, where would the moisture go if there was moisture in the system? And the moisture always goes to the coldest place.

So while you're evacuating, you got, you know, whatever line set you have outside that actually sometimes if you can warm that line set up or even warm up the service valves, like take your torch up and just gently warm the service valves up, it'll help drive that moisture out. Because if you're cold outside, especially really cold outside, all the moisture will go to the coldest place. And then if you drop the pressure really quickly, you could

turn that moisture into liquid and then you have to deal with sublimation, which takes a long time for a good evacuation. But you can pick that up with a decay test, but you can avoid it all the way around by just warming things up a little bit. Supplyhouse.com is your shortcut for part shopping. They have thousands of HVAC parts from all over the world.

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And the evaporator bundles had heaters wrapped around it. So we turned on the bundle heaters for the condenser and then the evaporator. And then we also made sure the crankcase heaters were all powered up.

during evacuation and it really helped. Oh yeah, it helped big time. Yeah, there's a lot of little things we can do and we just don't always appreciate them. But here's what people we got to realize is you spend a hundred bucks to buy a charging blanket and what you got to realize is what's it cost to go back on that job, right? Because truck rolls are very expensive. So if you can avoid having a secondary truck roll and having to go back out there in the spring or whatever, it's

Number one, you can focus on selling more systems because your service techs aren't tied up, you know, charging everything you put in this winter. And number two is you're going to just have the savings of the secondary truck roll, which could be anywhere from, depending on your overhead costs, your company could easily be $400 to $1,000. So, you know, you may not be able to use a charging blanket year round, but like in Ohio, it increases our days that we could charge by typically two-thirds.

So, you know, like this time of year, we're going, oh, it's cold, it's cold, it's cold. And yeah, we have like a week or two that are not sub-zero, but below 30, below where you can use a charging blanket. But then we get a lot of days that are in that 30 to 70 degree range that are ideal for using a charging blanket and charging.

you know, a lot of companies are sending techs home this time of year because there's like, you know, there's no heating load, there's no cooling load, there's no work to do. It's like, this is where charging blanket can expand that, that cooling season and allow, you know, you know, even like in tune-ups, you can use it to check the charge and lower ambient conditions. So,

which makes it a lot easier for younger techs to get the charge right than it does, you know, when they're out there and they're seeing super low suction pressure because they have low head pressure because there's not enough load to make the TXV work properly. Right. I mean, it's just,

Solves a lot of problems. So it's, it's a good tool to have on your truck. Cool. Uh, before we head out, I seen a bit of a rumor, not really a rumor. It was, it was, uh, Ben and Yi at AHR walking by a big sign that said measure quick and NAVAC, something like that. You guys are working together now with NAVAC?

Yeah, NAVAC finally came out with some digital tools that are Bluetooth equipped. Yeah, new probes, and we've got their gauges tied in already. We'll be working with more products with them. Yeah, so NAVAC is going to be coming on board here soon, and we're just wrapping up the final details of that. But they're starting to command on larger following than I've, you know, I mean...

It's pretty amazing how that brand went from zero to where they're at today in such a short time. Zero to 100 in a couple seconds. Yeah, I mean, they have some really cool products. So it'll be interesting to see how they compete in the digital world. I'm sure they'll do pretty well because they seem to constantly be innovating. I don't know. I've never seen a company come out with products as fast as Navi has. I mean, they're...

And for the most part, they're flooding the industry with really some decent products. So who is in the Measure Quick umbrella as far as test tools go? Pretty much everybody that's the main players, right? Testo was the first one. And then Field Peace and Energy Conservatory, CPS, UEI. Yellowjacket's new, right? Oh my gosh, I have to look. Yellowjacket's in the mix. Sourman's in the mix.

Sporlin is in there. And we have about 10 or 13 manufacturers. Navec's now in there. And it just depends on the manufacturer what tools we have in there and to what about the integration we've done. JB is another one we've been doing a lot with JB. They'll have some pretty cool products here with some pretty cool features we're working on with them. So I think they're going to be interesting to see.

But yeah, there's a lot of great manufacturers we're working with and we're sort of becoming the, like the universal app for all these brands. And what's neat is like not a single manufacturer has every single tool that you need to, for the full ecosystem and measure quick. So yeah.

That cross compatibility, being able to use multiple tools from multiple manufacturers is really slick. And then the other thing we're doing that I think is really exciting to me is we're delving into the world of AI. But instead of trying to make a better troubleshooter, we're actually handling things like data input. So you can just take like three or four photos, you know, outdoor condenser, indoor furnace, indoor coil, filter, etc.

And it'll automatically do the whole profile for the system and the AI. So it's like taking a piece of work that nobody wanted to do and doing that with AI versus, you know, trying to make a trouble, a better troubleshooter or something like that. Inadvertently, it did that though, because with a better profile, we also get better diagnostics. But, you know, we're looking for ways we can make MeasureQuick easier for technicians to use, you know, all the time. Perfect.

Cool. Well, I appreciate the conversation today, Jim, on a holiday for both of us, really. Hey, yep.