All right, so, yes, this is a short episode of the HEC school podcast and actually today's Thanksgiving I'm sitting here in my home office and I wanted to get out a short episode. So that way we keep the schedule you had to keep the schedule on radio. The show must go on as they say: we've got 65 people coming over today, three and then we've got 45 coming tomorrow and my wife is thrilled that I'm sitting here in my office talking to you in this short podcast, but it just shows how committed I Am to you okay enough chitchat, because this is a short episode and first I've got to thank our sponsors now back in Navajo Bolcom carrier carrier, calm, air Oasis at air, Oasis, calm, Forge /go, refrigeration technologies. Thank those guys for all of their support, and I also want to mention solder, weld we're pleased to announce that the Johnstone ware group in Central Florida has brought on some solder oil products for those of you who are in Central Florida to try.

So thank you to them. Thank you to blacks supply also for doing that here in Central Florida, but if you are not able to find it on the shelves where you are right now, then I would suggest that you have your local supply house contact products by pros products by proz.com. In order to get solder weld on the shelf, it's great stuff, you will love it. Today's episode is on our value and you value our value and you value, and I think these are things that we tend to ignore in general as technicians, but if you're ever gon na do a load calculation, these can come up pretty quickly, and I know I Was confused by it because some things have our values listed on them? Some have you values listed on them and it gets silly confusing, but we're doing this class with Jack Rhys, and he reminded me of something that frankly, I had forgotten, and that is that our values and you values are really the same thing.

So I'm gon na tell you how you can do the math and the math is pretty easy, but if you forget it, this is the sort of thing you don't have to memorize. You can look it up really easily. The main thing to know here is that our value and you value are really just inverse coefficients. Who cares what that means? But here's the point.

So our value is a value of resistance to heat energy moving through conductance, and it's important that we establish those through conductance because you can have radiant gains and radiant gains very depending on how much Sun is coming through a window. Something like that. But conductance is molecule to molecule through an actual solid materials, so you can only have convection in fluids, but conductance happens molecule to molecule, and so, if you're thinking of a wall, for example, you will use a wall because that's the easiest way to think about this. The temperature difference across the wall, so there's a heat difference across the wall and, of course, hot goes to cold moves through the wall.

You have an R value, which is the value of resistance to the heat moving. But then you value is just the inverse of that. That is the coefficient of heat transfer in very simple terms. The higher your r-value is the higher your resistance to heat moving, the less heat energy is going to move through the wall and the lower the? U value the lower the coefficient of heat transfer, the less heat is going to move to the wall.

So if you're thinking in terms of insulation, lower, u value is good. Higher r-value is good, but the truth is is that the two are essentially identical, because you can find your R value from your? U value by dividing your! U value into one, so you take 1 divided by, u equals R or you can convert? U value to our value by doing 1 divided by R equals? U value so different materials tend to be categorized in different ways and in fact, and a lot of your load calculation stuff you may have to enter a u value you may have to enter in our value and if you have the other one, you can easily Convert one to the other, all right, so let's look at another kind of useful thing. You can do this, which is really what your manual J programs are really doing. They're just doing it for use of the way you don't have to do all the math, but you wanting to calculate our heat gains and heat losses.

Primarily when we're talking about that side of things I mean this is useful in other arenas of what we do. As well other than doing a manual J, but probably menial, J is the most common case that you would use, are new values or you've run across them, and that is that BTUs per hour equals square feet times the? U value times the delta T. I actually posted this on Instagram and Facebook, and some of you asked what is that? U value mean - and I thought my gosh it'd be easier for me - just do a podcast. So that's why I'm doing this short episode? Actually, it's kind of the inspiration of it, but it's BTUs per hour equals square foot times: U value times, delta T and each one of those are actually pretty simple on their own, so square footage! That's just the square to the surface area.

Again, we're talking about conductive gains, actually heat transferred through the material. We can't count windows where there's glass and there's light coming directly through radiant, but BTUs per hour equals the square footage, so figure out your square footage and then you forget your temperature difference cross. So if you had a 75 degree inside temperature 95 degree outside temperature, that would be a 20 degree difference across and then you figure out GU value. If you have an r-value, you can convert that easily to a u value by dividing the? U value into one.

So one divided by: u value equals our value or vice versa, but we're solving for u value here so square footage times? U value times delta T that equals to BTUs per hour, which, for us is what we're trying to find we're, trying to figure out how many BTUs, how many energy units are we moving through this surface and so very practical stuff and another thing that we need To mention real quickly is that some products are rated. They have a rated. U value that you can't use because they may just be rating a part of it and not the entire assembly. So Jack was talking about this.

How you have some windows where the manufacturer rates the window and they give a? U value, but that's just the glass and not the frame and not everything else. So it may not be a whole. U value! So you have to make sure when you have a surface or some sort of component that has diversity in it, where it's not all. Just one thing that the entire thing is rated now obviously you're talking about a block wall.

There's not gon na, be a whole lot of variation within that block wall, because it's a block wall, but something like a window, a door. There can be some variation and you would need to make sure that that is averaged out over the entire surface and there's, I think it's called the national fenestration council. Fenestrations just means openings, they rate openings and they'll, take the entire thing and rate it appropriately, and then that gives you an accurate rating. But Jack was mentioning that some manufacturers, when they rate their own products with you value, may not be quite accurate because they may just be rating a portion of it there.

You have it anyway, our value and you value you can convert them to each other. Our value higher is better higher means. Lower heat transfer you value lower, is better. Our value is a resistance value and you value is a coefficient of heat transfer.

So there you go. You are now an expert when it comes to our values and you values. Thanks for listening to this podcast, I appreciate you, you can find all of the great shows and the blue-collar roots Network by going to blue-collar roots comm. If you haven't downloaded the app yet the HVAC school app is available on both the Android and the iOS app stores you can download it.

There. Listen to the podcast, see all the daily tech tips and also use some of our calculators that we have there. If you haven't tried that out yet I would suggest that you go give it a shot and give me a zero star review if you hate it. Alright, thanks for listening, we will talk to you next time on the HVAC school podcast.