All right, so I want to show you quickly how you can use the enthalpy readings on the UE iHub smart kit, in order to calculate total system capacity. It's actually really easy to do so. First thing we're gon na do is we're gon na grab our two UEI whp ones. This is the hub to kit.

If you look here this entire thing, all together is the hub six, when you have the refrigerant refrigeration, smart probes and the two air probes to turn them all on. All you do, is you just open them, which is pretty convenient and as soon as you open them go to the app here, you click on the air side and then they're both connected. They connect really really quickly. So let's go ahead and put these in the ducts.

I warm them up on my hands, so I can figure out which is which easily alright. So this is the supply side, and then this is the return side put that in the return and now you're gon na start to see that the delta T begins to change begins to rise. It also gives you your target delta T based on the conditions in the return okay. So what you do is you hit this plus button, so you'll see on the screen right now that we have two different enthalpies or enthalpy is like total heat content, so the enthalpy of the return is twenty nine point one six.

Currently, the enthalpy of the supply is twenty-two point two seven currently and so your differential is your enthalpy split, so we're gon na. Let it run a little bit here and then we're gon na see what our enthalpy split is and we'll use that to calculate our total system capacity. You also do need to know the CFM of the system. You need to know how many cubic feet of air is moving through the system on this system.

We've already tested it, it's right about 730 CFM. Some of you may ask well how do you get that information? You can use a hot wire anemometer, which we've shown how to do in some previous videos. You can use the fan tables for the equipment and we also confirm the air flow on this unit by using something called the true flow grid which is made by the energy conservatory, which is a very accurate way of confirming system air flow. So we know that this system is it at about 730 CFM.

So now we have an enthalpy on the supply of twenty nine point, one three and the return of twenty-two point one three. We currently have an enthalpy split of seven BTUs per pound. So that's the differential right in there, so we have a little bit of change, but it's right at about seven beetee's per pound. Now we do the calculation total heat equals h1 minus h2.

So that's your split, which we know is seven times four point five times CFM so because the h1 is 29 in the h2 is 22 there's a 7 degree split seven times four point: five is thirty one point five times the CFM, which is 730, so the Total BTUs that this piece of equipment is putting out right now or that it's absorbing from the air in this space is twenty-two thousand nine hundred and ninety five BTUs per hour. It's actually really easy to remember. All you have to remember is enthalpy split times 4.5 times CFM, i'm brian with the hvac school podcast, thanks for watching.