Hey this is a short episode. I guess you probably knew that because you saw that right in the title. This short episode is about the three things that the condenser does. The evaporator only does two things, but the condenser.

No, no, it doesn't do two condenser. Does three so so we're gon na talk about today, but first we're gon na talk about our excellent sponsors, those sponsors, our refrigeration technologies, at refrige, tech, comm makers of all sorts of grates chemicals for the HVAC industry, and if your supply house doesn't sell them well, Then ask them: why not and tell them to get you a price anyway. Tell me you wan na see refrigeration technologies, Viper products on the Shelf, at your local supply house, Aero, Asus makers of the bipolar and Nano whole home purifiers uei in the hub, smart kit, the thermo hygrometers pressure, probes and temperature line, probes and wrs scales from uei Mitsubishi Electric cooling and heating carrier, and also I want to mention my friends from retro tech makers, of excellent excellent blower door and duct leakage, testing equipment, retro tech, that's retro and then Tec. There's no H.

I always want to add the H whenever I look it up online, but it's just retro tech with a/c alright. So here we go three things that the condenser does. First off: let's just compare to the evaporator, so the evaporator coil we have boiling, they can call flash gas whatever, but it's changing state from liquid to vapor and then you have super heating, but in the condenser you have three things. So there you start by de-superheating.

That's the first thing that happens in the condenser and that actually happens in the top couple passes of a condenser. So if you imagine it starts off as fully vapor and then as it travels down, it becomes liquid. So if you think of gravity you have vapor up high and that eventually it travels down and becomes liquid down at the bottom. So if you look at a typical condenser, you'll notice that the discharge line goes into the top of the condenser and the liquid line comes out of the bottom of the condenser, that's pretty Universal.

The reason why it has to be superheat first is because, when refrigerant comes down the suction line, it's already superheated, it's already fully of vapor. So you have the superheat that's in the suction gas and then you have the heat in the compressor from the motor and then you have heated compression as well via friction and everything else going on inside that compressor, that's also adding heat. So you have the superheat that was in the suction gas to begin with, and then the additional heat added in the compressor from the motor and heated compression, and it comes out of the discharge line pretty hot. If you measure average discharge line in average conditions, you're gon na see discharge lines, temperatures vary quite a bit, but you really don't want to see a discharge line.

Temperature get up above 220 degrees under normal circumstances. In fact, it should be quite a bit lower than that for a typical summer here in Florida, our discharge lines are gon na be 150 to 170 degrees in that range on average, and so you have this higher temperature than the saturation temperature. At that point, if you look at your gauge, you look at your liquid line gauge highside gauge and you look at your saturation temperature and your condenser condensing temperature. If you will it's another name for it, you look at that temperature you're, going to notice that the discharge line is much higher temperature than that condensing temperature.

So let's just use some round numbers here so we'll say we have a condensing temperature of 100 degrees. We'll say, and we have a discharge line, temperature of 160 degrees, so in that first part of the condenser you have to drop sensible temperature. So you have to drop that discharge gas. It's fully vapor from 160 degrees down to a hundred degrees, because that's the condensing temperature at that pressure.

I just arbitrarily picked that but we'll say that's what our gauge was showing us right. So the first thing that condenser has to do in the top of the condenser is it has to de superheat has to reject that sensible heat in order to get it down to the condensing temperature. That's called d superheating, so that's thing one: if you're thinking of dr.seuss here, that's thing 1. That thing condenser has to do is reject heat to get down to the condensing temperature, and so, if you were to track the temperature of that line in the condenser that first pass and the condenser, let's say it's a single pass condenser just for sake of imagining And it comes out of the discharge line and it's going to be 160 degrees.

It's going to slowly drop in temperature, 160. 159. 158. 157, all the way down until it hits the saturation temperature, and in this case we said that that's 100 degrees so hits that saturation temperature.

Now it's going to stay the same temperature through the bulk of that coil. The reason it's going to say the same temperature and it's still rejecting heat is it now it's going through a phase change and that's what we call latent heat, so you're transferring heat from that refrigerant in the condenser to the air, moving heat out of that condenser. Putting it into the outside air as it blows over that condenser coil, so now that heat is going to changing temperatures, not going to drop the temperature anymore. Now it's going to change the state, so it starts off at a hundred degrees, 100 percent vapor and then it slowly starts to become more and more liquid.

So it starts off at a hundred percent vapor. Then it goes to 99 percent vapor than 98 percent vapor 97 percent vapor all the way down hundred degrees, same temperature, the whole way through that condenser coil. If you were to use the laser thermometer pointed at it, laser thermometer infrared thermometer to be exact, pointed at it and measure all the way down through you're gon na notice that the temperature stays consistent and that condenser through that middle portion. So the second thing that it does is it changes the state it condenses that condenser condenses.

That's pretty obvious. These superheat is number one thing it does in the top of the condenser. Condense is what it does in the center of the condenser changes state at the saturation temperature at that condensing temperature, and once it's become a hundred percent liquid. Now it can start to sub cool, so now can start to drop temperature again below 100 degrees.

In this case, so this would be a common circumstance where you'd see something like this, if it's 85 degrees outside we'll say, and so you have a hundred degree, condensing temperature, that's 15 degrees over the outside temperature. That would be like a high efficiency system. So now it's gon na go from 100 to 99 to 98 to 97 to 96 to 95, and so let's say we measure at the liquid line and it's 95 degrees, that's five degrees of sub cool, five degrees below the condensing temperature. So the third thing that the condenser does is it sub cools first thing: is D: superheats drops the temperature from that high discharge temperature down to the condensing temperature.

Then it condenses that's what most of the condenser does and then at the very end it starts to sub cool it and in general, as you know, we see sub cools between 8 and 16 degrees depending on the equipment, and so it's gon na drop that down Below that condensing temperature, I'd say 8 to 14 is probably more common. I've seen a little higher than that, but anyway you get the point. So you drop that down below the condensing temperature in that sub cooling. So that's the three things the condenser does and that's a lot of things for just a coil to do I mean condenser doesn't have much going on for it's just a coil with some air blowing over it, but it does three.

Things beats the pants off of the evaporator coil, so that's it. These superheat, condensed sub cool there. You have it alright. Hopefully that's helpful thanks Alysa.

We will talk to you next time on the HVAC school podcast.