Hey this quick video is on a topic that I've already talked about a few times, but the reason why I'm doing this video is because I received a comment I think it was on Facebook. I haven't been able to relocate it, but where somebody criticized me rightfully so, because they said that I missed out on the best way to remember the relationship between super heat, subcooling, dew, point and bubble point. But before I give you the secret, I want to first remind you what dew point bubble point are so first off. If you don't already have the refrigerant slider app by Danfoss, I would suggest that you download that so that you can follow along with exactly what I'm doing, but I'm gon na use our 22 and our 4:07 sea as ways of demonstrating this.

So if you take a look at our 22 on the refrigerant slider app and you plug in 68, point 5, 4, psi or 40 degrees, saturation you'll see the two correlates. So sixty eight point: five four psi correlates to 40 degrees Fahrenheit and on the refrigerant slider app you can see up top next to choose refrigerant. There is no option for switching between dew and bubble, so that can't be changed. The reason is is because r22 is a single component refrigerant, and so it does not have any Glide.

So it is what is known as an azeotropic refrigerant. It has no Glide. Now really an azeotrope would be a blend that has no Glide. R22.

Is a single component, so it has no Glide, so don't get the terms confused there, but its glide less. It's got no Glide right. You look at something like r410a r410a. If you take a look here, it only has point 1 degrees of glide at 40 degree and at 40 degree of Aperta quote between dew and bubble point.

But let's talk about what do in bubble point are so imagine that you're looking at on the horizon - and you have the ocean down below and you have the sky up above. That line that thin line would be what we would call the saturation line and that's the line at which, if the refrigerant is boiling or condensing changing state from vapor to liquid, it will be at that temperature. So long as the pressure is the same now, unlike a horizon, that's always at atmospheric pressure generally about 14.7 PSI, a is atmospheric pressure within an air conditioning system that pressure changes, and so again this metaphor isn't perfect, but it just gives you a way to envision That line when we say saturation, that is the line where refrigerant is changing state and that temperature remains the same. So it's a thin thin line just like a risin line.

Now, if you have a zeotropic refrigerants, the atrophic means that it has glide. That would be something like our 407 C that we're gon na use here in the example now there's this range and that's represented by the fog so now, instead of there being just a line of the horizon now the horizon is represented by a fog in between The ocean and the sky - and so it's not when it's in the fog, it's all in saturation, it's all changing State, but it changes state from a range. It starts off at bubble point which is a lower temperature, and then it slowly works its way up to dew point, and so, when you have refrigerant going into an evaporator coil, it starts off at bubble point in this case, you can see that it is a Lower temperature than the dew point, so in the case of our 407 C, which is the example that we're using here, you can see that it starts off at bubble. Point at twenty eight point: nine degrees, if you're using 63.8 PSI, that's pretty low, we're just gon na use this as an example, because then, when you, by the time you get to do, which is forty degrees, but by the time you get to the end of The evaporator coil, which is dew point at that point when it's fully boiling off when it's just that last little bit of vapor now it's at forty degrees.

So if you want a 40 degree outlet on your evaporator coil, then you would have to have a twenty eight point. Nine degree Inlet on your evaporator coil. That's that range! That's that range of saturation when you have glide on a blend refrigerant, which is what we call azeotropic refrigerant on for 10a. Well, it's only that little tiny amount.

We call that a near azeotrope, so that means that it's near has nearly no Glide at all, and so we're used to working in air conditioning with r22 and then with 410 a so, we haven't used a lot of glide. Now, when you go into a lot of these blends or a lot of the modern refrigerants you're starting to find more glide, so you have to learn how to deal with that. So you have the temperature that it starts boiling at and then you have the temperature that it ends boiling at. But here's how you can remember, which is used for sub cooling, which is used for superheat very easy.

So it's Bubba cool bubble. Point is used for sub cool, so all you have to do is remember. Bubba cool dew point is used for superheat, so all you have to remember is duper heat de W per heat. So it's like super heat, but duper hate V.

At the point, all right now, that's the those were the words that were given to me in the comments. It really is a great way to remember it, and so, if you're ever working with the refrigerant blend and you're having to measure superheat use dewpoint to measure sub cool, you use bubble point and that's easy to remember, because it's Bubba cool and / he'd and just Remember that that Glide is like having a wider horizon. It's that boiling or condensing temperature is now a band, unlike a single component refrigerant or an azeotrope, where that is just a single line. A single point at which that condensing temperature or boiling temperature occurs at that pressure.

Hopefully that makes sense. Remember Bob cool and duper heat thanks for watching.