WEBVTT - TechStuff Goes to the Ice Rink 0:00:04.480 --> 0:00:12.120 Technology with tech Stuff from half staff works dot com. 0:00:12.119 --> 0:00:14.440 Hey there, and welcome to tech Stuff. I am your host, 0:00:14.560 --> 0:00:18.319 Jonathan Strickland. I am a producer executive at how stuff 0:00:18.320 --> 0:00:22.000 works dot com and I love technology and that's why 0:00:22.040 --> 0:00:24.919 I've been hosting the show for as long as I 0:00:24.960 --> 0:00:30.280 can remember. No, I seriously love tech, and recently, due 0:00:30.360 --> 0:00:34.840 to the hard work of Ramsey the Wonder producer, I 0:00:34.880 --> 0:00:38.919 was able to have a discussion with some people up 0:00:38.960 --> 0:00:41.480 on the rooftop click click click of the Pont City 0:00:41.520 --> 0:00:45.959 Market where we have an ice rink. Now, now, when 0:00:46.000 --> 0:00:48.120 I actually had this conversation, the ice rink had not 0:00:48.200 --> 0:00:52.200 been completely installed. There was a distinct lack of ice, 0:00:52.560 --> 0:00:55.760 for example. But it got me to thinking about doing 0:00:55.800 --> 0:00:59.840 a full episode about the technology then makes ice rinks 0:01:00.000 --> 0:01:04.440 possible in areas where it is not below freezing. I mean, obviously, 0:01:04.480 --> 0:01:06.560 you can have a natural ice rink if you happen 0:01:06.640 --> 0:01:09.480 to live someplace where it gets cold enough for a 0:01:09.600 --> 0:01:12.720 pond to freeze through thick enough where it's safe to 0:01:12.800 --> 0:01:16.160 do that. But as for indoor ice rinks like hockey 0:01:16.280 --> 0:01:20.320 ranks and ice skating rinks in general, you have to 0:01:20.560 --> 0:01:23.080 have a system there in order to make it work, 0:01:23.240 --> 0:01:25.520 So that's why I'm really going to explore today. Now, 0:01:25.560 --> 0:01:29.119 I'm not really familiar with this from a personal level, 0:01:30.120 --> 0:01:34.560 and that's because I live in Atlanta. I grew up 0:01:34.720 --> 0:01:38.480 essentially in the Atlanta area. I am a Southerner. We 0:01:38.520 --> 0:01:42.160 are not well known for our winter sports. We did 0:01:42.240 --> 0:01:45.360 once upon a time have an NHL hockey team called 0:01:45.400 --> 0:01:49.320 the Thrashers that got sold off to Winnipeg. But I'm 0:01:49.360 --> 0:01:53.080 not going to spend this entire episode grousing about how 0:01:53.120 --> 0:01:56.600 we don't have the Thrashers anymore. I could do that, 0:01:57.440 --> 0:02:01.960 but I won't. We do have a few temporary ice 0:02:02.080 --> 0:02:05.480 rink seasonal ice rinks that pop up during the winter, though, 0:02:05.720 --> 0:02:09.040 and I've never actually been on an ice rink. The 0:02:09.120 --> 0:02:12.919 closest experience I've had would be roller skating, and that's 0:02:13.000 --> 0:02:17.720 obviously similar but not the exact same thing as ice skating. 0:02:18.040 --> 0:02:21.520 But I do know I'm terrible at roller skating. I mean, absolutely, 0:02:23.000 --> 0:02:27.400 hilariously not graceful on roller skates, so I'm pretty sure 0:02:27.400 --> 0:02:30.480 i'd wipe out instantaneously on an ice skating rink. But 0:02:31.040 --> 0:02:33.679 I did want to learn more about how those are 0:02:33.680 --> 0:02:38.480 created and how they're maintained, particularly in places like here 0:02:38.480 --> 0:02:41.280 in the South where we have some of these outdoor 0:02:41.639 --> 0:02:45.120 ice skating rinks. And in case you weren't really familiar 0:02:45.160 --> 0:02:48.560 with us, our temperatures rarely dip below freezing, so it 0:02:48.600 --> 0:02:50.960 takes a lot of engineering to make sure that ice 0:02:51.040 --> 0:02:54.320 rink stays nice and icy. The tech to make an 0:02:54.360 --> 0:02:57.639 ice rink is pretty cool, pun intended, and a big 0:02:57.680 --> 0:02:59.960 component of it is essentially the same sort of tech 0:03:00.200 --> 0:03:04.840 that makes refrigerators or air conditioners work, only on a 0:03:04.840 --> 0:03:08.360 way bigger scale, but the same basic principles apply. So 0:03:08.360 --> 0:03:11.320 we're gonna talk a lot about the refrigeration cycle, and 0:03:11.360 --> 0:03:14.360 we're gonna talk a lot about heat exchangers. But first 0:03:14.760 --> 0:03:18.480 let's get some basic physics under our belts. Now, we've 0:03:18.520 --> 0:03:21.359 got to talk about thermal physics, as in the physics 0:03:21.400 --> 0:03:25.840 that are all about heat, and heat itself is a 0:03:25.880 --> 0:03:30.800 physical process. Heat is not something that is necessarily possessed. 0:03:30.919 --> 0:03:37.760 Heat is technically the transfer of energy from something of 0:03:37.800 --> 0:03:41.320 a high temperature to something else of a lower temperature. 0:03:41.800 --> 0:03:45.680 That process, that exchange, is in fact heat. So a 0:03:45.680 --> 0:03:47.600 lot of this stuff i'm gonna talk about you've probably 0:03:47.640 --> 0:03:50.440 heard plenty of times in basic science classes. But if 0:03:50.440 --> 0:03:52.360 you're like me and may have been a very long 0:03:52.400 --> 0:03:55.560 time since you've had a physics class, and you might 0:03:55.640 --> 0:03:58.200 need the refresher. And I always feel it's important to 0:03:58.240 --> 0:04:01.640 start simple and then you build from there. So first 0:04:01.640 --> 0:04:04.760 things first, heat always moves from an area of high 0:04:04.800 --> 0:04:08.040 temperature to an area of lower temperature within a system. 0:04:08.080 --> 0:04:10.400 That's how you do not have heat move from low 0:04:10.440 --> 0:04:13.080 temperature to high temperature. That would be crazy. It only 0:04:13.120 --> 0:04:16.520 goes high to low. That's just how our universe works. 0:04:16.560 --> 0:04:21.239 You cannot transfer the other way around. So any object 0:04:21.240 --> 0:04:24.279 that has a higher temperature than its surroundings within a 0:04:24.360 --> 0:04:29.080 system will gradually transfer heat to those surroundings and its 0:04:29.080 --> 0:04:33.880 own temperature, assuming there's not something actually generating the heat 0:04:34.040 --> 0:04:39.360 within this object will decrease until both the object itself 0:04:39.400 --> 0:04:43.440 and its surroundings will reach an equilibrium, that meaning they 0:04:43.520 --> 0:04:47.040 reach the same temperature. Similarly, if you have an object 0:04:47.040 --> 0:04:50.600 that has a lower temperature than its surrounding environment within 0:04:50.640 --> 0:04:54.200 a system, it will gradually warm up. Now this is 0:04:54.240 --> 0:04:58.040 not to say that cold is leaking out or escaping. 0:04:58.200 --> 0:05:02.960 Cold does not transfer. Only heat transfers. Heat from the 0:05:03.080 --> 0:05:07.640 environment moves into the object, ject gradually increasing its temperature. 0:05:07.680 --> 0:05:11.440 Until again it reaches an equilibrium. Now, in the real world, 0:05:11.720 --> 0:05:14.960 we would typically call this room temperature, because the systems 0:05:15.000 --> 0:05:17.599 we operate in on a day to day basis are 0:05:17.640 --> 0:05:21.719 these rooms and basic environments. So if you have a 0:05:21.800 --> 0:05:24.120 hot cup of tea and you leave it sitting on 0:05:24.160 --> 0:05:27.120 the counter for several minutes, it starts to cool because 0:05:27.160 --> 0:05:29.880 it's releasing that heat. That heat is transferring to its 0:05:29.880 --> 0:05:32.960 surrounding environment that is at a lower temperature than the 0:05:33.000 --> 0:05:36.240 hot cup of tea. Uh. Likewise, if you have a 0:05:36.320 --> 0:05:40.039 nice frosty beverage and you leave it on the counter, 0:05:40.279 --> 0:05:42.360 it will start to warm up. It'll start to absorb 0:05:42.400 --> 0:05:44.960 heat from its environment as it transfers in, until again 0:05:45.000 --> 0:05:48.920 it reaches that equilibrium. From a macro level, we could 0:05:48.960 --> 0:05:52.800 say that the heat is this flow of energy, So 0:05:53.400 --> 0:05:55.880 just keep that in mind. Generally speaking, if you want 0:05:55.920 --> 0:05:59.920 to make the base of an ice rink colder, technically 0:06:00.760 --> 0:06:03.880 this works for anything, but we're gonna use ice rink 0:06:03.920 --> 0:06:07.000 specifically because that's what this episode is about. If you 0:06:07.040 --> 0:06:09.360 want to make the base of an ice drink colder, 0:06:09.440 --> 0:06:11.680 you have to expose it to something that has a 0:06:11.680 --> 0:06:17.039 lower temperature than the rink base. So here in Atlanta, 0:06:17.360 --> 0:06:20.600 it's in I think the low sixties right now on fahrenheit, 0:06:20.800 --> 0:06:23.120 and we want to get the temperature of the base 0:06:23.120 --> 0:06:26.640 of that ice rink below the freezing temperature of water, 0:06:26.720 --> 0:06:29.640 which in fahrenheit would be thirty two degrees. It means 0:06:29.640 --> 0:06:32.479 that we have to expose that base of the ice 0:06:32.600 --> 0:06:37.000 rink to a temperature that's actually significantly lower than the 0:06:37.040 --> 0:06:39.560 freezing point for water in order to make this happen. 0:06:40.480 --> 0:06:44.000 Then the rink base will transfer heat to that lower 0:06:44.040 --> 0:06:47.480 temperature object, in other words, whatever we're using to cool 0:06:47.680 --> 0:06:51.279 down the base. Technically, what's happening is that the base 0:06:51.400 --> 0:06:55.520 is actually transferring heat to that system, and thus it 0:06:55.520 --> 0:06:59.040 will grow colder. Now, on principle, that's pretty simple, right, 0:06:59.120 --> 0:07:01.880 It's not a very amplicated thought. You just have to 0:07:01.920 --> 0:07:05.800 get something that's colder than what you're working with and 0:07:06.080 --> 0:07:08.640 move them within the same system, and then it will 0:07:08.680 --> 0:07:11.120 gradually make the other thing colder because they'll start to 0:07:11.160 --> 0:07:15.000 absorb the heat from that other thing. That's not that complicated. 0:07:15.040 --> 0:07:17.240 But then when you start actually looking at practical applications, 0:07:17.240 --> 0:07:19.400 you realize, all right, we've got to solve some pretty 0:07:19.440 --> 0:07:22.400 big problems. Requires a lot of engineering So, for one thing, 0:07:23.160 --> 0:07:25.880 if you want the ice rink to remain ice even 0:07:25.960 --> 0:07:29.559 if the surrounding temperature is above the freezing point for water, 0:07:30.080 --> 0:07:34.200 for example Atlanta, Georgia, and the winter tends to be that, 0:07:34.880 --> 0:07:38.000 you'll have to continuously chill the base of that ice rink. 0:07:38.040 --> 0:07:39.920 You can't just get it cold and leave it. You 0:07:39.960 --> 0:07:42.200 have to keep it cold. And since the base of 0:07:42.200 --> 0:07:45.880 the ice rink will continually transfer heat to that colder object, 0:07:46.280 --> 0:07:49.360 that colder object will eventually warm up. So whatever the 0:07:49.400 --> 0:07:51.840 system is that you're using to chill the base of 0:07:51.840 --> 0:07:55.160 the ice rink, it's absorbing heat. That means it is 0:07:55.200 --> 0:07:57.480 warming up. That means you have to have a continuous 0:07:57.520 --> 0:08:02.040 way to to keep that that's system more cool, to 0:08:02.400 --> 0:08:05.440 chill it, to use a chiller if you will, that's 0:08:05.440 --> 0:08:11.480 what they're called. Uh So these are actually pretty complicated. Now. 0:08:12.520 --> 0:08:15.680 I keep saying colder object because not all ice rinks 0:08:15.720 --> 0:08:18.880 are equal. They're not all exactly the same. They use 0:08:19.000 --> 0:08:22.680 the same principle, but the actual application is different. So, 0:08:23.680 --> 0:08:27.520 for example, if you wanna hockey rink, like a standard 0:08:27.520 --> 0:08:31.200 hockey rink in HL hockey rink, you're talking about typically 0:08:31.400 --> 0:08:36.080 a a base. There's a concrete base under which you 0:08:36.160 --> 0:08:40.960 have a network of steel pipes, and the steel pipes 0:08:41.080 --> 0:08:44.960 carry an extremely cold liquid, something that's below the freezing 0:08:44.960 --> 0:08:47.280 temperature of water. We'll get into that a little bit later, 0:08:48.160 --> 0:08:52.400 and that in turn pulls heat away from the concrete base, 0:08:52.480 --> 0:08:55.560 making it colder than the freezing point for water. You 0:08:55.559 --> 0:08:57.920 can then add water on top of the concrete base 0:08:58.040 --> 0:09:01.360 and start building up layers of ice. Others are a 0:09:01.400 --> 0:09:03.439 little bit different. The one that's up on the rooftop 0:09:03.640 --> 0:09:08.960 of our building actually has a series of plastic tubes 0:09:09.000 --> 0:09:12.320 that are carrying an extremely cold liquid in them being 0:09:12.360 --> 0:09:15.720 pumped underneath the surface of the ice rink, and that's 0:09:15.760 --> 0:09:19.280 what allows the water to freeze even in temperatures that 0:09:19.280 --> 0:09:23.080 are above the freezing point for water. And essentially pour 0:09:23.160 --> 0:09:26.440 water on top of this or otherwise distribute water on 0:09:26.480 --> 0:09:29.079 top of it. It's a little more precise than just pouring, 0:09:29.760 --> 0:09:35.640 and you get your ice rink. Uh So, generally speaking, 0:09:36.240 --> 0:09:41.880 same approach, just slightly different applications. Now we have to 0:09:41.880 --> 0:09:44.640 create a system that will hold a temperature below the 0:09:44.679 --> 0:09:47.680 freezing point of water. Now that presents itself with a 0:09:47.679 --> 0:09:49.679 few challenges. First, you have to figure out, all right, 0:09:49.720 --> 0:09:52.720 what substance are we going to use. Clearly, we can't 0:09:52.800 --> 0:09:56.000 just use plain old water because if we did the 0:09:56.040 --> 0:09:59.640 water in our system to try and absorb heat, that 0:09:59.679 --> 0:10:02.160 would freeze and then you wouldn't be able to move 0:10:02.160 --> 0:10:04.439 it through your pipe system. So you can't just use 0:10:04.520 --> 0:10:07.320 plane old water. You would need to have a liquid 0:10:07.320 --> 0:10:10.440 that has a lower freezing temperature than water does. So 0:10:10.559 --> 0:10:12.600 one way you could do that is by adding stuff 0:10:12.840 --> 0:10:16.040 to water in order to lower its freezing point. So 0:10:16.360 --> 0:10:20.040 salt is a good example. Saltwater has a lower freezing 0:10:20.080 --> 0:10:23.520 point than freshwater, and that freezing point is dependent upon 0:10:23.640 --> 0:10:29.200 how much salt concentration there is within that water mixture. 0:10:29.280 --> 0:10:33.839 So some hockey rinks will use a briny mixture, meaning 0:10:33.840 --> 0:10:36.720 they've got some salt content in the water to lower 0:10:36.760 --> 0:10:40.720 that freezing temperature. Um if you have fresh water that 0:10:40.800 --> 0:10:45.040 freezes at thirty two degrees fahrenheit or zero degrees celsius, seawater, 0:10:46.000 --> 0:10:48.480 which obviously is not the same thing as being used 0:10:48.480 --> 0:10:52.360 in hockey rink systems, uh seawater freezes at twenty eight 0:10:52.360 --> 0:10:57.000 point four degrees fahrenheit or minus two degrees celsius. So 0:10:57.040 --> 0:11:00.720 seawater has a salinity that's salt content of about three 0:11:00.760 --> 0:11:04.360 point five percent. That is not as salty as water 0:11:04.480 --> 0:11:07.960 can get. Though. You can keep adding salt into water 0:11:08.080 --> 0:11:09.880 up to the point that the salt makes up about 0:11:09.920 --> 0:11:13.400 twenty three point three percent of the weight of the mixture. 0:11:14.080 --> 0:11:16.640 So at that point you reach what's called saturation. You 0:11:16.720 --> 0:11:19.960 cannot put more salt into that mixture. It will never dissolve. 0:11:20.520 --> 0:11:24.520 So at twenty three point you hit that maximum salinity. Now, 0:11:24.600 --> 0:11:28.040 at that concentration, saltwater would have a freezing temperature of 0:11:28.120 --> 0:11:32.320 minus twenty one point one degree celsius or minus five 0:11:32.320 --> 0:11:36.800 point nine eight degrees fahrenheit, So very different. Right, You're 0:11:36.840 --> 0:11:41.760 talking about a vast array of temperatures there, and again 0:11:41.800 --> 0:11:44.040 it's all just based on the amount of salt in 0:11:44.080 --> 0:11:47.120 that water. So a lot of ice ranks, like I said, 0:11:47.120 --> 0:11:49.480 a lot of hockey ranks, use a briny mixture as 0:11:49.520 --> 0:11:51.839 the cooling mechanism for the base of the rank. And 0:11:51.880 --> 0:11:55.360 now the ice itself that's on the the rank, that's 0:11:55.440 --> 0:11:59.360 pure ice. That's just water that doesn't have any salt content, 0:11:59.400 --> 0:12:01.840 and at all, the only thing that has the salt 0:12:01.920 --> 0:12:06.280 content is the system underneath the rink that is at 0:12:06.320 --> 0:12:08.920 a lower temperature in order to allow the ice to 0:12:08.960 --> 0:12:12.400 form the one that's actually being or one that's in 0:12:12.559 --> 0:12:14.840 use now on the rink. When we went up to talk, 0:12:14.880 --> 0:12:17.800 they were still putting this all together. Doesn't use a 0:12:17.840 --> 0:12:21.720 briny mixture. Instead, it uses glycol, which is a type 0:12:21.720 --> 0:12:25.600 of alcohol, and glycol also has a lower freezing point 0:12:25.600 --> 0:12:29.319 than water. In fact, glycol will remain a liquid until 0:12:29.320 --> 0:12:32.400 you hit about negative seventy four degrees fahrenheit, which is 0:12:32.440 --> 0:12:36.079 about negative fifty nine degrees celsius. So if you can 0:12:36.200 --> 0:12:39.880 cool glycol down well below waters freezing temperature, but still 0:12:39.880 --> 0:12:43.640 above the freezing temperature of glycol itself, you're in business. 0:12:43.679 --> 0:12:46.760 You can keep pumping liquid glycol that's at a very 0:12:46.800 --> 0:12:49.720 low temperature at the very base of your ice rink, 0:12:49.840 --> 0:12:53.440 and that will provide the heat sink to pull heat 0:12:53.480 --> 0:12:56.520 away from water and allow it to freeze. But this 0:12:56.640 --> 0:12:58.960 leads us to our second big problem to solve. How 0:12:58.960 --> 0:13:02.400 do you get the cooling liquid to that low temperature. 0:13:02.520 --> 0:13:06.800 How you keep your glycol or your briny mixture, and 0:13:06.920 --> 0:13:10.120 they'll temperature lower than the freezing point for water. If 0:13:10.160 --> 0:13:13.839 the water you are adding is constantly transferring its heat 0:13:14.160 --> 0:13:17.319 to the system, how do you then get rid of 0:13:17.360 --> 0:13:21.040 that heat, because if you don't do that, you're cooling 0:13:21.080 --> 0:13:24.240 pipes will gradually warm up and then your ice rink 0:13:24.320 --> 0:13:28.560 will just become a very shallow swimming pool and people 0:13:28.559 --> 0:13:31.920 will not have very much fun. That is where the 0:13:32.000 --> 0:13:34.800 chillers come in. Chillers are all about transferring heat, so 0:13:34.840 --> 0:13:38.520 as you can siphon it away from one area and 0:13:38.679 --> 0:13:43.480 dump it in another area. You cannot destroy energy, but 0:13:43.600 --> 0:13:47.000 you can move it from one place to another. So 0:13:47.240 --> 0:13:50.200 you can't destroy heat, but you can pull it from 0:13:50.240 --> 0:13:55.079 one location and disperse it into a different location. Chillers 0:13:55.120 --> 0:13:58.320 do this by taking advantage of thermal physics. And there's 0:13:58.400 --> 0:14:02.160 several different types of killers that use slightly different approaches, 0:14:02.240 --> 0:14:05.480 some of them dramatically different approaches, but they all have 0:14:05.679 --> 0:14:09.400 essentially the same end goal, which is to facilitate heat transfer. 0:14:10.080 --> 0:14:12.760 We're gonna look at a general approach and talk about 0:14:13.160 --> 0:14:15.480 the types of chillers you're likely to run into if 0:14:15.480 --> 0:14:19.040 you were, I don't know, going to an ice rink 0:14:19.400 --> 0:14:22.640 or installing a massive HVAC system for an office building. 0:14:23.560 --> 0:14:29.840 So think of chillers as three loops that are adjacent 0:14:29.920 --> 0:14:33.360 to one another, but they don't connect to each other. 0:14:33.800 --> 0:14:36.960 So almost like three rubber bands that are very close together. 0:14:38.280 --> 0:14:41.840 Within one loop, you have the chilled liquid. That is, 0:14:42.000 --> 0:14:45.360 this is the stuff that is creating the heat sync, 0:14:45.480 --> 0:14:48.080 that's pulling the heat away from whatever it is that 0:14:48.200 --> 0:14:50.680 you want to cool down. This might be an air 0:14:50.720 --> 0:14:54.440 conditioning system, or it might be again the basis the 0:14:54.520 --> 0:14:59.800 foundation for your ice rink. Uh. So you've got that, 0:15:00.040 --> 0:15:03.080 You've got the second loop that takes the heat gathered 0:15:03.120 --> 0:15:06.040 from the first loop. So that first loop starts to 0:15:06.080 --> 0:15:08.640 heat up as it's absorbing this heat. You've got to 0:15:08.680 --> 0:15:10.920 find a way to remove that. You've got to find 0:15:10.920 --> 0:15:13.600 a way to dump that heat someplace. There's a second 0:15:13.600 --> 0:15:15.880 loop that it essentially does that. It takes the heat 0:15:15.920 --> 0:15:18.920 from the first loop and then finds a convenient spot 0:15:18.920 --> 0:15:22.400 to dump it. And then you have a third loop 0:15:22.480 --> 0:15:25.160 that is your refrigerant that kind of acts as the 0:15:25.160 --> 0:15:28.600 facilitator between loops one and two. In fact, it's the 0:15:28.640 --> 0:15:32.200 most important component of the entire system, is your refrigerant 0:15:32.800 --> 0:15:38.320 uh loop. Now there are four different pieces to the 0:15:38.440 --> 0:15:41.480 chiller system. Within that refrigerant loop then make all of 0:15:41.560 --> 0:15:45.640 this possible. You have a compressor, you have a condenser, 0:15:46.120 --> 0:15:49.520 you have an expansion valve and you have an evaporator. 0:15:50.320 --> 0:15:53.200 And this leads us to another element of thermal physics, 0:15:53.200 --> 0:15:57.080 which is if you crank up pressure on a gas, 0:15:57.360 --> 0:16:02.640 for example, you not just increase the pressure of that substance, 0:16:02.680 --> 0:16:06.520 you also increase its temperature. And it also means that 0:16:06.560 --> 0:16:10.479 you can push up the boiling point of a substance 0:16:10.560 --> 0:16:13.560 by putting it under pressure, which is also a great 0:16:13.600 --> 0:16:15.920 song with Freddie Mercury and David Bowie. So if you 0:16:16.000 --> 0:16:20.160 take a gas and you pressureize it enough, you can 0:16:20.160 --> 0:16:23.760 convert that gas into a liquid, even if the temperature 0:16:23.880 --> 0:16:28.080 of the substance is above its normal boiling point at 0:16:28.560 --> 0:16:32.760 regular air pressure. So it will end up condensing into 0:16:32.800 --> 0:16:35.920 a liquid, whereas it would normally evaporate into a gas 0:16:36.000 --> 0:16:39.400 under that under a normal pressures, as long as you're 0:16:39.440 --> 0:16:42.440 cranking up the actual pressure of the gas. So here's 0:16:42.440 --> 0:16:44.840 how I think about it. On a molecular level, it's 0:16:44.880 --> 0:16:48.720 really easy to understand the behavior of solids, liquids and gases. 0:16:49.240 --> 0:16:52.760 A solid substance has its molecules pretty much locked into place. 0:16:52.920 --> 0:16:56.200 I mean, there's always some little movement, but it's more 0:16:56.240 --> 0:16:59.320 or less locked into place. They hold their positions relative 0:16:59.360 --> 0:17:02.680 to each other that keeps a solid consistent. But a 0:17:02.720 --> 0:17:05.600 liquid has molecules that can move around more freely. They 0:17:05.640 --> 0:17:08.359 spread out a bit, they get to wander around, they 0:17:08.400 --> 0:17:11.159 test their boundaries because the liquid always is going to 0:17:11.200 --> 0:17:14.520 take the shape of whatever container it is in. Then 0:17:14.520 --> 0:17:18.320 a gas goes even further with molecules spreading out even more. 0:17:18.800 --> 0:17:20.880 But if you do put that gas under pressure, you're 0:17:20.880 --> 0:17:24.760 effectively forcing those molecules closer together as if they were 0:17:24.800 --> 0:17:27.199 in a liquid. So if you do that enough, the 0:17:27.240 --> 0:17:30.160 gas condenses into a liquid. You push those molecules together 0:17:30.280 --> 0:17:32.760 enough to convert it into its liquid form. So how 0:17:32.800 --> 0:17:36.119 does a chiller take advantage of this? All? Right, this 0:17:36.200 --> 0:17:38.199 is gonna be a little tricky to describe without the 0:17:38.280 --> 0:17:40.480 use of visual aids, but I'm gonna do my best. 0:17:40.880 --> 0:17:43.359 So let's just imagine the system as simple as we 0:17:43.400 --> 0:17:47.480 possibly can. Imagine a rectangle, and it's wider than it 0:17:47.600 --> 0:17:50.240 is tall. So you've got a wide rectangle. Now in 0:17:50.280 --> 0:17:53.280 the center part of the base of the rectangle, that 0:17:53.440 --> 0:17:58.520 bottom border of the rectangle, just imagine a circle right 0:17:58.560 --> 0:18:00.320 in the center of that. That circle is going to 0:18:00.359 --> 0:18:04.200 represent our compressor. Now at the top of the rectangle, 0:18:04.359 --> 0:18:07.720 opposite of our compressor will draw a little triangle, and 0:18:07.720 --> 0:18:11.160 that triangle is going to represent the expansion valve. So 0:18:11.200 --> 0:18:14.320 you can think of these as two gates. They keep 0:18:14.359 --> 0:18:19.080 the pressure different on either side of the gates. On 0:18:19.119 --> 0:18:22.080 the right side of this rectangle, we're going to imagine 0:18:22.119 --> 0:18:25.480 that's the condenser, and on the left side, we're going 0:18:25.520 --> 0:18:30.080 to imagine that that is the evaporator. So refrigerant moves 0:18:30.200 --> 0:18:35.159 from the evaporator side through the condenser side via the compressor. 0:18:35.920 --> 0:18:39.800 So you have the refrigerant moving from evaporator into compressor 0:18:39.800 --> 0:18:43.479 where it gets compressed, thus the name, and then pushed 0:18:43.480 --> 0:18:46.840 over to the condenser side. So we're going to take 0:18:46.880 --> 0:18:50.000 a journey with the refrigerant to understand how this works 0:18:50.000 --> 0:18:53.440 from a technical perspective. From the evaporator side, just as 0:18:53.440 --> 0:18:57.040 you get to the compressor, that refrigerant before it goes 0:18:57.080 --> 0:19:01.600 through the compressor is a low pressure arm gas. Typically, 0:19:02.040 --> 0:19:06.240 the compressor then compresses this gas so that the output 0:19:06.320 --> 0:19:08.679 on the other side, on the condenser side is a 0:19:08.760 --> 0:19:14.159 high pressure hot gas. This hot gas then moves through 0:19:14.280 --> 0:19:17.919 the condenser and that's typically a long length of pipe 0:19:18.000 --> 0:19:21.040 or tubing that folds back and forth on itself. If 0:19:21.080 --> 0:19:24.119 you've ever looked into the back of a refrigerator or 0:19:24.160 --> 0:19:26.440 in an air conditioning unit, you've probably seen this where 0:19:26.440 --> 0:19:29.000 you've seen these these pipes that do these tight s 0:19:29.080 --> 0:19:32.359 curves over and over and over again. Well, that's the 0:19:32.400 --> 0:19:36.560 way it's laid out. In a condenser. The high temperature, 0:19:36.680 --> 0:19:39.840 high pressure gas moves through this length of pipe and 0:19:40.000 --> 0:19:43.480 it can start to transfer some of that heat. Some 0:19:43.560 --> 0:19:46.359 of it gets transferred straight through the pipe, some of 0:19:46.400 --> 0:19:50.640 it typically gets transferred through fins that are uh connected 0:19:50.640 --> 0:19:53.679 to the pipes so that it can draw heat away 0:19:53.720 --> 0:19:58.520 through conductivity. It's it's conducting the heat and you then 0:19:58.600 --> 0:20:02.800 have um a fan typically that blows air across the 0:20:02.920 --> 0:20:06.400 system that uses convection to pull heat away as well. 0:20:07.760 --> 0:20:12.159 So this gas starts to lose some of that temperature. 0:20:12.200 --> 0:20:15.560 As it's moving through this series of s curves, it's 0:20:15.600 --> 0:20:19.080 transferring heat to the air around it. Now, the higher 0:20:19.119 --> 0:20:22.080 pressure means that as this happens, the gas begins to 0:20:22.160 --> 0:20:25.640 condense into a liquid. As it makes its journey through 0:20:25.640 --> 0:20:29.800 this part of the loop, the liquid is still under 0:20:29.840 --> 0:20:33.600 a lot of pressure that you can't really pressurized liquid 0:20:33.600 --> 0:20:36.040 the way you can with gases, but it's still under 0:20:36.080 --> 0:20:39.000 a great deal push, you could think of it in 0:20:39.040 --> 0:20:43.080 that sense, um, but it's reaching more of a regular temperature. 0:20:43.560 --> 0:20:46.080 At the end of the condenser side, you have that 0:20:46.200 --> 0:20:50.440 expansion valve which leads to the evaporator side. Now, the 0:20:50.480 --> 0:20:53.119 reason its valve is so that it can again create 0:20:53.160 --> 0:20:57.199 this partial seal. It's sealed. Whenever it's shut. You have 0:20:57.240 --> 0:21:00.000 a low pressure side on the other on the evaporate 0:21:00.080 --> 0:21:03.680 raator end of this loop the circuit, if you think 0:21:03.800 --> 0:21:06.399 of it that way. So you have high pressure on 0:21:06.480 --> 0:21:09.320 the condenser side, low pressure on the evaporator side. That 0:21:09.440 --> 0:21:12.960 expansion valve allows for one way travel, so it goes 0:21:13.040 --> 0:21:16.760 from condenser to evaporator, and pressure, like temperature, is all 0:21:16.800 --> 0:21:20.359 about moving from areas of high concentration to low concentration. 0:21:20.480 --> 0:21:24.760 So the expansion valve allows this pressurized substance, this refrigerant, 0:21:25.000 --> 0:21:29.440 to pass through into that low pressure side, the evaporator side, 0:21:29.440 --> 0:21:32.240 and when it does, it suddenly finds itself with a 0:21:32.240 --> 0:21:35.560 lot more room to spread out than on the high 0:21:35.560 --> 0:21:39.080 pressure side. Right Suddenly it doesn't have that high pressure 0:21:39.119 --> 0:21:42.879 to cram it together, and so the molecules of the 0:21:42.920 --> 0:21:45.520 refrigerant end up spreading out and as a result, the 0:21:45.560 --> 0:21:48.840 temperature begins to drop, so at the beginning of the 0:21:48.880 --> 0:21:53.359 refrigerant journey around the evaporator, it becomes a low pressure 0:21:53.560 --> 0:21:56.520 cold liquid, and as it moves through the evaporator, it 0:21:56.560 --> 0:22:00.040 starts to absorb heat from the system. Whatever it is 0:22:00.119 --> 0:22:02.080 you're trying to cool. In this case, it would be 0:22:02.520 --> 0:22:05.840 the the stuff that's running underneath the rink, whether it's 0:22:05.880 --> 0:22:10.120 the brine or whether it's glycol, that would be tangential 0:22:10.600 --> 0:22:14.560 to this refrigerant system, and the refrigerant would be absorbing 0:22:14.600 --> 0:22:18.159 the heat from there, and as a result, the refrigerants 0:22:18.200 --> 0:22:20.879 starts to boil off, it starts to evaporate, thus the 0:22:20.960 --> 0:22:24.080 name of operator. In air conditioning systems, this heat would 0:22:24.119 --> 0:22:27.240 be from the air of whatever area you were trying 0:22:27.240 --> 0:22:29.520 to cool, But in the case of the ice rink 0:22:29.680 --> 0:22:31.679 on the roof of our building, the heat is in 0:22:31.720 --> 0:22:34.880 that glycol that's running through the tubes that are under 0:22:34.920 --> 0:22:38.880 the rink itself. The refrigerant boils as it moves through 0:22:38.920 --> 0:22:42.320 this part of the loop and evaporates, and that turns 0:22:42.359 --> 0:22:45.640 into the low pressure warm gas that we started off 0:22:45.720 --> 0:22:48.040 with when I began talking about this refrigerant in the 0:22:48.080 --> 0:22:51.200 first place. That low pressure warm gas that immediately moves 0:22:51.200 --> 0:22:55.160 through the compressor and becomes the high pressure, high temperature gas. 0:22:56.280 --> 0:22:59.040 So we're back at the beginning, and we just keep 0:22:59.040 --> 0:23:01.600 going through. It's a close system, so it doesn't go 0:23:01.640 --> 0:23:04.879 anywhere else. The refrigerant does not mix with any of 0:23:04.880 --> 0:23:08.280 the other loops. It just continuously goes through this process. 0:23:08.600 --> 0:23:12.040 Now the glycol again access that separate loop, comes into 0:23:12.080 --> 0:23:14.800 close contact with a refrigerant, but it never actually shares 0:23:14.880 --> 0:23:17.760 a common line with it, so you never mix them together. 0:23:17.840 --> 0:23:20.719 The glycol will transfer heat over to the refrigerant, and 0:23:20.800 --> 0:23:24.560 because it's transferring heat, the glycoal itself becomes colder as 0:23:24.560 --> 0:23:28.160 a result, or if you prefer, the temperature decreases due 0:23:28.240 --> 0:23:31.160 to this heat transfer. The glycol then moves through its 0:23:31.160 --> 0:23:35.920 own pump to travel underneath the rink through lots of tubes. 0:23:35.960 --> 0:23:38.200 I mean there were hundreds of these tubes underneath the rink, 0:23:38.600 --> 0:23:41.439 and it absorbs the heat from the environment as it 0:23:41.480 --> 0:23:44.040 moves through until it gets back to the heat exchanger 0:23:44.119 --> 0:23:47.480 part of the loop, and then again transfers heat to 0:23:47.520 --> 0:23:50.480 the refrigerant and goes all the way through it again. 0:23:50.520 --> 0:23:53.560 So again closed loop systems. It's just pumps moving liquid 0:23:53.560 --> 0:23:56.480 through at this point. Typically you then would have a 0:23:56.520 --> 0:23:58.600 third loop, and this is the one that picks up 0:23:58.600 --> 0:24:00.600 all the heat that was pushed out from the condenser 0:24:00.720 --> 0:24:04.119 side of that refrigerant when it was that high pressure, 0:24:04.200 --> 0:24:08.720 high temperature gas. So there's some that are air cooled, 0:24:08.920 --> 0:24:11.040 but a lot of them end up being water cooled, 0:24:11.119 --> 0:24:14.840 so you have this water loop again on that side 0:24:14.880 --> 0:24:17.520 of it. You can use water in this particular system 0:24:17.520 --> 0:24:20.000 because you're not you're dealing with temperatures that are well 0:24:20.040 --> 0:24:22.560 above the freezing point of water. You just have to 0:24:22.560 --> 0:24:24.320 make sure that the water is at a lower temperature 0:24:24.359 --> 0:24:26.919 than the gas going through the condenser, because again, heat's 0:24:26.920 --> 0:24:30.159 going to only move from high temperature to low temperature. 0:24:30.400 --> 0:24:33.000 So if the water you're using is high temperature and 0:24:33.040 --> 0:24:36.160 the condenser is at a high temperature, it's not very efficient. 0:24:36.240 --> 0:24:37.959 You need the water to be cool enough to actually 0:24:38.200 --> 0:24:41.560 pull heat away, or rather to accept heat that's being 0:24:41.560 --> 0:24:46.080 rejected from the condenser. This water would then typically be 0:24:46.160 --> 0:24:48.359 pumped up to some sort of cooling mechanism like a 0:24:48.359 --> 0:24:51.080 cooling tower, and these are the big things you see 0:24:51.080 --> 0:24:53.480 on top of buildings that often emit enormous amounts of 0:24:53.520 --> 0:24:56.480 steam on cold days. If you've ever seen that. That's 0:24:56.520 --> 0:24:59.560 typically a cooling tower on the top of a building 0:24:59.600 --> 0:25:01.920 that's part of the HVAC system. The hot water will 0:25:01.920 --> 0:25:04.600 go into the cooling tower. It drips down over fins 0:25:04.680 --> 0:25:08.000 that are inside the cooling tower. You typically have a 0:25:08.040 --> 0:25:10.080 fan or maybe a couple of fans at the top 0:25:10.200 --> 0:25:13.639 of the cooling tower that is drawing air into the tower. 0:25:14.080 --> 0:25:18.000 Their vents along the side that pull air in. The 0:25:18.080 --> 0:25:20.960 air moves over these fins that have the hot water 0:25:21.080 --> 0:25:23.919 on them, thus cooling the water, some of it evaporating 0:25:23.960 --> 0:25:27.840 away and then ejecting out the top of the cooling 0:25:27.840 --> 0:25:30.000 tower being pushed out through that fan. So it's kind 0:25:30.000 --> 0:25:34.119 of like a vacuum cleaner, but instead of sucking up dirt, 0:25:34.240 --> 0:25:38.000 it's sucking up heat and air from the water, or 0:25:38.240 --> 0:25:41.199 heat from the water, but air in general, and blowing 0:25:41.240 --> 0:25:44.280 it up through the top. The cooling water ends up 0:25:44.359 --> 0:25:47.840 dripping down these fins, typically collects at a basin at 0:25:47.880 --> 0:25:51.200 the at the base of the cooling tower and then 0:25:51.320 --> 0:25:54.800 drains back down into the system. Uh and then back 0:25:54.800 --> 0:25:58.199 down to the heat exchange, your part of the chiller 0:25:58.359 --> 0:26:00.960 that I was just talking about. So that's your basic 0:26:01.040 --> 0:26:04.040 parts of a chiller. And again it's the same principle 0:26:04.119 --> 0:26:07.520 that's working with things like refrigerators, it's working with air 0:26:07.520 --> 0:26:11.000 conditioners and also ice skating rinks. Now I've got a 0:26:11.000 --> 0:26:14.600 lot more to say about the technology behind ice skating 0:26:14.680 --> 0:26:17.640 rinks and maintaining them, but before I do any more 0:26:17.680 --> 0:26:20.560 of that, let's take a quick break to thank our sponsor. 0:26:27.200 --> 0:26:28.879 All Right, So we've talked about how to get the 0:26:28.880 --> 0:26:31.159 temperature down low enough to freeze water and keep it 0:26:31.200 --> 0:26:35.879 at a temperature where you still have solid water a k. A. Ice. 0:26:36.320 --> 0:26:39.960 But how do you fill up the ice rink. The 0:26:39.960 --> 0:26:43.080 answer is that you do it very carefully, or if 0:26:43.080 --> 0:26:46.760 you prefer, meticulously and slowly. So a large permanent ice 0:26:46.840 --> 0:26:51.119 rink typically will have that concrete foundation, and underneath that 0:26:51.200 --> 0:26:53.240 you have a network of pipes that carry the cool 0:26:53.320 --> 0:26:57.360 liquid that keep the concrete foundation nice and chili. The 0:26:57.440 --> 0:26:59.639 concrete will be at a temperature that is below the 0:26:59.640 --> 0:27:03.000 freezing point of water. Uh. You fill up the rink 0:27:03.080 --> 0:27:07.159 by spraying it with a fine mist of water onto 0:27:07.160 --> 0:27:10.119 the concrete layer to start off with the temperature of 0:27:10.160 --> 0:27:13.760 the concrete so low that those tiny water droplets pretty 0:27:13.840 --> 0:27:16.520 much freeze as they make contact with the concrete, it 0:27:16.560 --> 0:27:18.399 doesn't take along at all for it to freeze to 0:27:18.440 --> 0:27:22.320 the surface. The first couple of layers of ice are 0:27:22.359 --> 0:27:26.200 always extremely thin, So for a typical hockey rink that 0:27:26.320 --> 0:27:30.520 uses this concrete approach, you're talking about an inch thick, 0:27:30.640 --> 0:27:33.960 which is about point eight five millimeters, and once those 0:27:34.040 --> 0:27:39.000 layers are down, you paint it. So most ice rinks 0:27:39.000 --> 0:27:41.960 will lay down a layer of paint on those first 0:27:41.960 --> 0:27:44.920 couple of layers of ice. This helps do a few things. 0:27:44.960 --> 0:27:47.920 For one, it hides the base of the ice rink away, 0:27:47.920 --> 0:27:50.320 so you're not looking at clear ice and seeing a 0:27:50.480 --> 0:27:53.840 concrete floor, or in the case of the ice rink 0:27:53.880 --> 0:27:56.040 that's on the roof of our building, you wouldn't see 0:27:56.080 --> 0:28:00.640 a series of tubes that are pink because call has 0:28:00.720 --> 0:28:03.280 a the glyde call they're using has a pink tent 0:28:03.480 --> 0:28:07.199 to it, so you would otherwise see just lines and 0:28:07.240 --> 0:28:09.720 lines and lines of pink tubes. So they paint the 0:28:09.720 --> 0:28:12.919 ice that it obscures that. It also will allow for 0:28:13.000 --> 0:28:16.200 good contrast with any logos or words that you want 0:28:16.280 --> 0:28:18.800 to paint on the ice rink. So, for example, with 0:28:18.840 --> 0:28:22.320 hockey rinks, you would typically paint the name of the 0:28:22.359 --> 0:28:24.960 hockey team on there, maybe put their logo on, maybe 0:28:25.000 --> 0:28:28.640 a sponsor logo could go on there. But you want 0:28:28.680 --> 0:28:31.679 there to be good contrast, so that's why you have 0:28:31.720 --> 0:28:35.439 that white base. Also, it creates great contrast for the 0:28:35.520 --> 0:28:38.600 puck in hockey because you want to be able to 0:28:38.600 --> 0:28:42.360 see that if you're a player or or an observer. Really, 0:28:43.080 --> 0:28:46.280 So after that layer of paint would come another layer 0:28:46.280 --> 0:28:48.760 of ice. This one is a little more thick. It 0:28:48.880 --> 0:28:52.040 is one of an inch thick, that's about one point 0:28:52.120 --> 0:28:55.959 six millimeters, and that acts like a seiler for that 0:28:56.080 --> 0:28:58.800 layer of paint that was just laid down, and then 0:28:58.840 --> 0:29:01.360 you could put more paint down on top of this layer. 0:29:01.640 --> 0:29:04.640 So this is where you would paint logos or the 0:29:04.840 --> 0:29:08.840 lines and circles and arcane symbols that make up the 0:29:08.920 --> 0:29:11.360 rules of hockey that I never got a chance to 0:29:11.520 --> 0:29:15.000 understand because Atlanta's team was taken from us before I 0:29:15.000 --> 0:29:18.560 could ever get a full grasp on the rules. And yeah, 0:29:18.560 --> 0:29:19.920 I know, I said I wouldn't talk about it, but 0:29:19.960 --> 0:29:24.000 I'm still angry about it. Anyway, after that you would 0:29:24.000 --> 0:29:26.120 add your final layer of ice on top. But this 0:29:26.200 --> 0:29:30.040 actually would happen in several stages, so it's one solid layer, 0:29:30.120 --> 0:29:34.520 but it's done in phases. This is the actual surface 0:29:34.600 --> 0:29:38.480 that people would skate upon. Now. Typical hockey rank, which 0:29:38.520 --> 0:29:41.320 again is much larger than the one that we have upstairs, 0:29:41.600 --> 0:29:46.720 would require between twelve thousand and fifteen thousand gallons of water, 0:29:47.440 --> 0:29:51.360 that's forty thousand to fifty seven thousand liters. Most of 0:29:51.360 --> 0:29:54.880 that water gets added in that final layer. The overwhelming 0:29:54.920 --> 0:29:57.800 majority of the water is added in that last layer. 0:29:58.240 --> 0:30:02.080 And whereas the early layers get added as a fine missed, 0:30:02.120 --> 0:30:05.160 the final one is a bit less delicate. They typically 0:30:05.160 --> 0:30:08.800 will just use a flooding hose to pour water out 0:30:08.880 --> 0:30:10.960 on top of the rink, and we're talking about ten 0:30:11.040 --> 0:30:14.560 thousand gallons of water at a rate of about five 0:30:14.640 --> 0:30:17.520 hundred to six hundred gallons per hour, which means it 0:30:17.560 --> 0:30:19.719 can take about twenty hours or so to add that 0:30:19.800 --> 0:30:22.720 final layer to the rink. And according to Don McMillan, 0:30:23.000 --> 0:30:26.440 whom hell Stuff Works, interviewed for an article on how 0:30:26.520 --> 0:30:29.960 ice rinks work, most rinks will allow each five hundred 0:30:30.080 --> 0:30:33.120 or six hundred gallon amount in that hour to freeze 0:30:33.160 --> 0:30:36.720 completely before they start adding more water. So again in phases, 0:30:37.000 --> 0:30:39.240 and that helps maintain a really good quality of ice 0:30:39.320 --> 0:30:41.520 and ice quality is really a thing. You can have 0:30:41.560 --> 0:30:44.080 good ice and you can't have bad ice. If your 0:30:44.080 --> 0:30:49.400 temperature isn't right, you're gonna have some issues. So for example, um, outside, 0:30:49.680 --> 0:30:51.880 if you don't have the right temperature, it's gonna start melting. 0:30:51.880 --> 0:30:54.320 You'll have some slushy ice at the top, and that's 0:30:54.720 --> 0:30:57.680 not great for skating. Um if you have really high humidity, 0:30:57.680 --> 0:30:59.720 you're gonna end up with a lot of fog over 0:30:59.720 --> 0:31:02.200 the ice, which happens here because we have a lot 0:31:02.240 --> 0:31:07.280 of humidity in Atlanta. And uh, it's pretty spooky looking 0:31:07.440 --> 0:31:10.000 in the morning to walk up to Pont City Market 0:31:10.080 --> 0:31:14.480 and see the the the mist pouring off the top 0:31:14.520 --> 0:31:17.800 of the building. Professional ice skaters tend to like their 0:31:17.840 --> 0:31:22.520 ice at a relatively warm to twenty degrees fahrenheit at 0:31:22.520 --> 0:31:26.080 the surface. That's minus three point three three to minus 0:31:26.120 --> 0:31:29.560 two point to two degrees celsius. Hockey players like it 0:31:29.640 --> 0:31:32.960 a little colder because the ice is harder, it's more resilient, 0:31:33.120 --> 0:31:36.680 doesn't grip the ice skates quite like the softer, less 0:31:36.800 --> 0:31:39.800 cold ice does. They prefer the surface to be closer 0:31:39.800 --> 0:31:42.480 to twenty four to twenty six degrees fahrenheit or minus 0:31:42.520 --> 0:31:44.880 four point four four to minus three point three three 0:31:44.960 --> 0:31:47.400 degrees celsius. Now, I had a chance to chat with 0:31:47.440 --> 0:31:49.920 the project manager for the ice rink installed on the 0:31:50.000 --> 0:31:52.120 roof of our building, and we cover some of the 0:31:52.160 --> 0:31:54.240 stuff I just mentioned, but I think it's a pretty 0:31:54.280 --> 0:31:57.400 interesting discussion, including all the work that was required to 0:31:57.520 --> 0:32:00.480 install an ice rink on the roof of a nine 0:32:00.560 --> 0:32:03.680 story building in Atlanta, Georgia, and just the amount of 0:32:03.760 --> 0:32:06.880 sheer effort it required to do that. So here's what 0:32:06.960 --> 0:32:09.239 he had to say. Oh and just so you guys know, 0:32:10.120 --> 0:32:13.120 we were talking up on the roof on a windy days, 0:32:13.480 --> 0:32:16.440 so it was also during while you know, construction, they 0:32:16.440 --> 0:32:18.320 were still playing the ice ring together, so the audio 0:32:18.400 --> 0:32:24.880 quality is a bit atmospheric. But here he goes, so basically, 0:32:24.960 --> 0:32:28.360 you got to have a level surface. Obviously, if you're 0:32:28.360 --> 0:32:30.240 gonna make guys it's greight water, you can have it 0:32:30.320 --> 0:32:33.680 running downhill. So we were fortunate enough to already have 0:32:33.760 --> 0:32:37.240 a basically a perfectly leveled deck up here. So then 0:32:37.240 --> 0:32:40.520 we put in foam insulation over that deck, uh, and 0:32:40.600 --> 0:32:45.200 then a biscuen plastic and then we put these mats together, 0:32:45.520 --> 0:32:50.600 and each of these tubes is a circulating system that 0:32:50.720 --> 0:32:55.040 will run the glacoll pump pressurized probably minus ten twenty 0:32:55.080 --> 0:32:59.320 degree claike all through and as the glacoll is running 0:32:59.320 --> 0:33:03.320 through it and freezing, you basically take your standard garden 0:33:03.360 --> 0:33:06.280 host and start missing water. And as soon as the 0:33:06.320 --> 0:33:10.440 water hits that minus twenty degree glycol to being, it 0:33:10.520 --> 0:33:13.240 starts to freeze. And so you start building that that 0:33:13.320 --> 0:33:17.200 base of ice. And they'll basically take it from from 0:33:17.240 --> 0:33:20.040 below the glacoll t being that you see here to 0:33:20.240 --> 0:33:23.440 about a half inch above it, and then they'll paint 0:33:23.440 --> 0:33:27.280 it white so that you don't see everything all this 0:33:27.760 --> 0:33:30.720 pink glacol underneath. So then they'll put after they've got 0:33:30.760 --> 0:33:33.600 that basecoat of white paint on it, then they'll put 0:33:33.640 --> 0:33:35.760 another layer of clear ice on it. So it looks 0:33:35.800 --> 0:33:38.719 just like any other ice skating rink in America, hockey 0:33:38.800 --> 0:33:40.640 rink that you would see on TV. And if we 0:33:40.680 --> 0:33:43.000 wanted to, you could paint lines, or we could have 0:33:43.040 --> 0:33:45.680 a sponsor, we would have a how how stuff works 0:33:45.680 --> 0:33:47.640 out there, and you know, logo in the middle and 0:33:47.840 --> 0:33:51.360 everybody skating would be skating over it, and that's pretty 0:33:51.440 --> 0:33:53.800 much that. That's you know, that's the the end of 0:33:53.800 --> 0:33:58.040 the process, and it's pretty simple. It's what happens prior 0:33:58.080 --> 0:34:01.760 to that where all the engineering comes into play and uh, 0:34:02.240 --> 0:34:05.480 all the hard work happens. So in order for us 0:34:05.520 --> 0:34:09.520 to create this on the roof, a lot had to happen. 0:34:09.719 --> 0:34:13.000 We had a hundred and twenty ton chiller that we 0:34:13.080 --> 0:34:16.880 had to crane to the roof, and so that was 0:34:17.160 --> 0:34:19.839 we had a three hundred foot crane basically that we 0:34:19.920 --> 0:34:24.000 hooked that up to. But before we did that, you 0:34:24.080 --> 0:34:28.560 just can't set pounds plus another three thousand pounds of 0:34:28.600 --> 0:34:31.960 glycol on a roof. It has to be engineered. So 0:34:32.360 --> 0:34:36.560 we did structural engineering analysis and then built a platform 0:34:36.640 --> 0:34:39.960 that would handle the weight the distribution, because not only 0:34:40.040 --> 0:34:43.360 is it weight, you also need a little shock absorbers 0:34:43.360 --> 0:34:46.239 in there to handle any of the vibrations because once 0:34:46.280 --> 0:34:49.640 you tie into the columns and the beams, you don't 0:34:49.640 --> 0:34:53.400 want the neighbors below hearing or feeling any any vibration 0:34:53.440 --> 0:34:57.040 and rattling. So we isolated that system, craned up the chiller, 0:34:57.480 --> 0:35:00.600 and uh and at that point we're running six inch 0:35:00.840 --> 0:35:05.479 steel pipe from the chiller up to the rink here 0:35:05.680 --> 0:35:08.800 and it's a closed system. So it's just a massive 0:35:08.920 --> 0:35:14.120 circulation of glycol. Because we had to locate our chiller 0:35:14.400 --> 0:35:18.520 UM further than about twenty feet from the rank. We 0:35:18.560 --> 0:35:21.359 had to put a massive pump on it too. So 0:35:22.160 --> 0:35:26.719 the chillers themselves have a limited pressure capability for runs, 0:35:26.719 --> 0:35:29.040 but our run was so long, we we put a 0:35:29.200 --> 0:35:32.760 huge pump on it so that we get the constant 0:35:32.840 --> 0:35:36.080 pressure that we need and UM and that we maintain 0:35:36.120 --> 0:35:39.840 our ability to keep this thing frozen. We're lucky that 0:35:39.880 --> 0:35:42.759 we're under a tent. If we were outside in Atlanta, 0:35:43.280 --> 0:35:45.000 you know, we we don't have a lot of days 0:35:45.040 --> 0:35:49.400 of constantly below freezing here and in the sunshine it 0:35:49.520 --> 0:35:52.160 would probably melt the ice at some of the some 0:35:52.239 --> 0:35:56.080 of the other outdoor rinks struggle with that. UM, we 0:35:56.200 --> 0:35:58.960 will not have any issues. I'm told by the experts. 0:35:59.520 --> 0:36:02.440 Without rect sunlight on our rank that we should have 0:36:02.480 --> 0:36:06.480 a great surface. We could probably do it all year round, 0:36:06.520 --> 0:36:09.400 believe it or not. UM. I know that this company 0:36:09.840 --> 0:36:13.920 UH does things worldwide and they have outdoor outdoor skating 0:36:13.960 --> 0:36:17.360 in San Diego, so and they say to run that 0:36:17.400 --> 0:36:19.560 in the summertime there. So you just have to have 0:36:19.640 --> 0:36:22.719 a you know, it's all about your how big your 0:36:22.800 --> 0:36:24.839 chiller is, and how big your rank is. In order 0:36:24.880 --> 0:36:27.359 to to make that happen, and then all the six 0:36:27.440 --> 0:36:30.640 inch piping of course had to be highly insulated. Uh. 0:36:30.680 --> 0:36:32.920 You don't want to lose any of your value, your 0:36:32.920 --> 0:36:36.560 temperature values. You know, steel obviously would would bleed out 0:36:36.560 --> 0:36:41.480 and into the ambient air temperature. So we've got about 0:36:41.520 --> 0:36:45.960 the two inches of insulation around all the piping. Uh. 0:36:46.120 --> 0:36:51.840 From an electrical standpoint where four naty volts three phase uh, 0:36:51.920 --> 0:36:54.279 so lots of lots of juice to run all this, 0:36:54.960 --> 0:36:58.640 as you're probably aware, you know, the bigger equipment, anything 0:36:58.680 --> 0:37:01.040 that involves heating and cool really it's gonna pull a 0:37:01.080 --> 0:37:03.120 lot of amps and it's gonna need a lot of 0:37:03.160 --> 0:37:06.960 a lot of voltage. So we we actually ran additional 0:37:07.040 --> 0:37:10.200 power up here on the roof in order to make 0:37:10.239 --> 0:37:13.279 that happen. Can't just plug it into the outlet on 0:37:13.320 --> 0:37:17.680 the wall, regrettably, because running power from the west side 0:37:17.680 --> 0:37:21.480 of the building to over here is it's it's pricey 0:37:21.680 --> 0:37:24.200 at at the thirty bucks a foot just for the 0:37:24.520 --> 0:37:27.000 just for the wire, just for the cable. So they 0:37:27.239 --> 0:37:31.080 the power was was a disappointment. My landlord has been 0:37:31.160 --> 0:37:34.680 very helpful with with helping us out on some of that. 0:37:35.320 --> 0:37:38.440 So basically what we're looking at here for for people 0:37:38.440 --> 0:37:41.320 who may not be aware of how this all works, 0:37:41.320 --> 0:37:44.440 we're looking at essentially a heat exchanger. You've got your glycol, 0:37:44.480 --> 0:37:46.960 which has a lower freezing point than water, so you 0:37:47.000 --> 0:37:49.759 can lower that temperature of the glycol much lower than 0:37:49.800 --> 0:37:52.840 the freezing point of water. You run that through the system, 0:37:52.960 --> 0:37:57.840 water hits it. Obviously, the heat transfers into the glycoal system, 0:37:57.880 --> 0:38:00.200 which is so cold and so massive and being up 0:38:00.280 --> 0:38:04.120 so quickly that it's not effectively raising the temperature of 0:38:04.160 --> 0:38:07.239 glycol enough for it to affect uh. But it's not 0:38:07.280 --> 0:38:08.600 like you're going to have one part of the rink 0:38:08.640 --> 0:38:10.960 that's slushy, whereas the rest of it's all all nice 0:38:11.000 --> 0:38:14.120 and solid. It goes, pumps through the system, hits the chiller, 0:38:14.840 --> 0:38:17.200 reduces the temperature of the glycol back down to what 0:38:17.280 --> 0:38:20.240 you wanted at the top, goes right back in because 0:38:20.239 --> 0:38:23.360 it's a closed loop, and just continuously pumps through to 0:38:23.440 --> 0:38:26.880 keep that water at that that below freezing temperature, so 0:38:26.880 --> 0:38:28.800 that you have anice solid rink. Is that more or 0:38:28.880 --> 0:38:32.640 less what we're looking at. That's exactly what we're looking 0:38:32.680 --> 0:38:36.399 at here, And and In fact, the chiller has got 0:38:36.400 --> 0:38:38.960 it the sensors on it, and it will monitor the 0:38:39.000 --> 0:38:42.080 pressure and it will also monitor the temperature. So it's 0:38:42.120 --> 0:38:44.680 kind of a smart system in order to be efficient 0:38:44.719 --> 0:38:47.120 to tell itself exactly what it needs to do to 0:38:47.280 --> 0:38:50.160 maintain the conditions that we're looking that you just described 0:38:50.200 --> 0:38:53.000 out here. Well, that's great because this is exactly the 0:38:53.040 --> 0:38:56.319 same sort of principle that you would see on things 0:38:56.360 --> 0:38:59.759 like air conditioners or a refrigerator, just on a much 0:38:59.800 --> 0:39:02.720 more are massive scale. And it temperature is far lower 0:39:02.719 --> 0:39:04.759 than what you would I mean, I like a nice 0:39:04.840 --> 0:39:09.800 cool man cave, but minus twenties is low even for me. Yeah, 0:39:09.880 --> 0:39:11.800 you know, it's not something you want to walk around 0:39:11.800 --> 0:39:16.480 barefoot on in the garage or in your cave. So 0:39:16.560 --> 0:39:20.160 that's great. About how long would it take to go 0:39:20.360 --> 0:39:24.920 from from dry to full rank? Uh? Knowing that this 0:39:25.000 --> 0:39:27.400 is going through phases right once, once we're at this 0:39:27.480 --> 0:39:29.640 point where the system is set up, the grid is 0:39:29.680 --> 0:39:32.719 laid down, and once we flip that compressor on within 0:39:32.760 --> 0:39:35.440 an hour, we're gonna start making ice. As soon as 0:39:35.480 --> 0:39:38.520 we reach the right tempts that are circulating through the system, 0:39:38.680 --> 0:39:42.120 we're gonna start spraying down that that first coat of 0:39:42.120 --> 0:39:44.680 water in order to uh to build up that ice. 0:39:44.760 --> 0:39:47.640 So it should happen very quickly. Uh, you know, we 0:39:47.800 --> 0:39:51.000 probably will. It'll take hours, of course to build up inches. 0:39:51.120 --> 0:39:54.080 Will probably get to about three inches of ice out here. 0:39:54.640 --> 0:39:57.880 That may take some time. But again, because we're not 0:39:58.000 --> 0:40:01.640 interact sunlight, we're and it is cool at night. So 0:40:01.680 --> 0:40:04.200 if we start this in the afternoon and work into 0:40:04.200 --> 0:40:07.799 the evening, we should have a solid rink within a 0:40:07.840 --> 0:40:10.320 matter of four or five hours up here to skate on. 0:40:10.560 --> 0:40:12.680 That's incredibly one of the do you happen to know 0:40:12.760 --> 0:40:15.200 the dimensions of this rank? Yes, this rank is fifty 0:40:15.200 --> 0:40:18.959 by seventy, so we're right at suare feet here, So 0:40:19.239 --> 0:40:24.200 just five hours or less for that much that much 0:40:24.239 --> 0:40:26.600 square footage is really impressive when you sit there and 0:40:26.600 --> 0:40:29.560 you think about the energy requirements, as you were saying, 0:40:29.600 --> 0:40:32.439 just for the equipment is incredible, but if we're talking 0:40:32.440 --> 0:40:35.799 about just physics, the energy requirements to remove that much 0:40:35.840 --> 0:40:38.920 heat so that you can convert water into ice for 0:40:39.040 --> 0:40:43.319 that much square footage, it's it's phenomenal and it's an 0:40:43.320 --> 0:40:46.480 elegant solution to I'm sad that my listeners won't be 0:40:46.520 --> 0:40:48.880 able to see this. Well, we'll share some images on 0:40:48.960 --> 0:40:51.719 social as well to kind of get a look at 0:40:51.719 --> 0:40:54.160 how this works. But when you see it and you 0:40:54.200 --> 0:40:58.120 see the solution that was proposed, from an engineering perspective, 0:40:58.719 --> 0:41:04.040 it is simple and elegant and yet incredibly effective to 0:41:04.120 --> 0:41:06.640 be able to turn that much water into that much 0:41:06.680 --> 0:41:10.440 ice that quickly. Um Again, when you start looking at 0:41:10.480 --> 0:41:12.600 it from a physics perspective, like that's a that's a 0:41:12.640 --> 0:41:16.359 lot of energy that you have to take into consideration. 0:41:16.600 --> 0:41:19.360 And of course that's before anyone that tries to manage 0:41:19.560 --> 0:41:22.759 a triple axel out here. I will not be one 0:41:22.800 --> 0:41:25.320 of those people. I might try my hand at skating, 0:41:25.440 --> 0:41:29.600 but considering my lack of grace just on roller skates, 0:41:29.719 --> 0:41:34.319 I suspect spectacular white belts would be to followed so 0:41:34.960 --> 0:41:37.160 well when they when that ice has finished and ready 0:41:37.200 --> 0:41:39.480 to skate on, you're gonna hear me tap out at 0:41:39.480 --> 0:41:42.240 the other sides and turn it over to another group 0:41:42.239 --> 0:41:44.480 of people to handle it from there on out. You know, 0:41:44.560 --> 0:41:47.680 to your point, the amount of energy and and everything 0:41:47.719 --> 0:41:50.200 that goes into this, you know the I think only 0:41:50.280 --> 0:41:53.680 mother nature really does it better than what we're doing here, 0:41:53.719 --> 0:41:56.080 and it is it is when you start to think 0:41:56.120 --> 0:41:59.239 about the the energy and the physics involved, it is 0:41:59.480 --> 0:42:02.440 h s daunting really sure. Yeah, yeah, And as you 0:42:02.520 --> 0:42:05.399 we were pointing out, just the just taking into consideration 0:42:05.440 --> 0:42:09.239 and how they handle the weight is an enormous undertaking 0:42:09.280 --> 0:42:13.600 because you're on we're on the rooftop of an existing structure. Obviously, 0:42:14.160 --> 0:42:17.960 Uh one, the rooftop was not necessarily intended to hold 0:42:18.640 --> 0:42:24.040 a ton chiller plus a rinkfull of solid water, uh 0:42:24.200 --> 0:42:27.040 not dimensional people on top of it. But that's incidental 0:42:27.080 --> 0:42:30.319 compared to everything else. Uh So yeah, having to take 0:42:30.360 --> 0:42:32.279 that into consideration and look at and how is the 0:42:32.280 --> 0:42:37.319 building built, how does that weight distribute already? Love would 0:42:37.320 --> 0:42:40.040 you need to do in order to offset that in 0:42:40.080 --> 0:42:41.920 any way? If there's a point where you think, well, 0:42:41.920 --> 0:42:44.960 we'd love to play it here, but the roof literally 0:42:45.040 --> 0:42:47.520 can't support it there, There's a lot of things you've 0:42:47.640 --> 0:42:51.160 taken into account, and I imagined the whole process took 0:42:51.239 --> 0:42:53.640 quite some time before anything was laid down at all. 0:42:54.000 --> 0:42:57.040 We we should really started visioning this over a year 0:42:57.080 --> 0:43:01.640 ago and started to kind of analyze the hurdles that 0:43:01.680 --> 0:43:04.719 we would have in front of us, and uh, structural engineering. 0:43:04.800 --> 0:43:07.800 Of course, it was our first consideration, can we handle 0:43:07.880 --> 0:43:10.720 the pounds per square foot up here? What's the rating 0:43:10.760 --> 0:43:13.319 of this ice gonna be? And how well is our 0:43:13.360 --> 0:43:16.120 deck engineered? And and so we had to bring in, 0:43:16.320 --> 0:43:18.920 you know, the brainy acts to help us out and 0:43:19.000 --> 0:43:22.360 figure out exactly what we could handle up here, because 0:43:22.480 --> 0:43:24.799 it's not just ice. We have wind load up here, 0:43:25.000 --> 0:43:27.399 and then we're gonna have a human load as well. 0:43:27.600 --> 0:43:30.480 So if you really start to factor in all of that, 0:43:30.600 --> 0:43:33.759 and the math kicks in. And we were fortunate that 0:43:33.800 --> 0:43:36.759 we have very robust engineering up here and that we 0:43:36.760 --> 0:43:39.919 were able to to pull this off. But uh yeah, 0:43:40.080 --> 0:43:42.440 almost at every turn of the project we were we 0:43:42.440 --> 0:43:46.640 were surprised by the complexity of it and surprised because 0:43:47.440 --> 0:43:49.279 this was a little bit out of our wheelhouse. This 0:43:49.360 --> 0:43:51.240 was a new venture for us, and so the learning 0:43:51.239 --> 0:43:53.439 curve was steep. Well. To me, those are the most 0:43:53.480 --> 0:43:56.759 exciting projects to work on. I've always said that my 0:43:56.880 --> 0:43:59.400 job is one of the best I can imagine because 0:43:59.840 --> 0:44:02.400 I get to learn new things every single week, and 0:44:02.440 --> 0:44:05.080 that you know, that challenge is what I feed off of. 0:44:05.480 --> 0:44:09.400 At times, it can obviously become so challenging as to 0:44:09.440 --> 0:44:12.719 be frustrating, but the fact that we're looking at a 0:44:12.800 --> 0:44:16.920 project that's so close to being ready for the public 0:44:16.960 --> 0:44:21.600 to see. I'm very excited to actually get a look 0:44:21.600 --> 0:44:23.560 at the rink once it's all finished. Being able to 0:44:23.560 --> 0:44:25.600 see that in this state is actually really cool for 0:44:25.640 --> 0:44:28.680 me because it's something that I typically would never have 0:44:29.239 --> 0:44:32.520 been able to see, you know, outside of just images 0:44:32.680 --> 0:44:35.320 or maybe some videos. So having this opportunity is fantastic. 0:44:35.520 --> 0:44:38.279 I really appreciate it, and I can't wait to see 0:44:38.280 --> 0:44:41.840 this chiller I've heard so much about. Well it was. 0:44:41.960 --> 0:44:44.040 It was a beast and and to see it come 0:44:44.040 --> 0:44:47.520 off of a huge flatbed truck and have the crane 0:44:47.800 --> 0:44:50.920 and of course you just don't latch onto it. You 0:44:50.920 --> 0:44:53.799 can imagine, you know, even a five mile an hour 0:44:53.920 --> 0:44:56.640 breeze as you're craning something hundreds of feet into the 0:44:56.680 --> 0:45:00.160 air can get a little bit dicey. So they just 0:45:00.160 --> 0:45:02.720 just watching the crane set up, it's booms and it's 0:45:02.719 --> 0:45:06.240 it's weight distribution. That was a whole another engineering lesson 0:45:06.239 --> 0:45:10.880 in itself. Again, the physics involved in every phase of 0:45:10.880 --> 0:45:14.239 this was really amazing, and and yeah it was. It 0:45:14.360 --> 0:45:16.200 was an enormous amount of fund for me to be 0:45:16.239 --> 0:45:18.720 a part of this, To go through the learning curve 0:45:19.080 --> 0:45:22.040 and I can now speak in in some languages of 0:45:22.120 --> 0:45:25.240 physics that I couldn't have before we started the project. 0:45:25.440 --> 0:45:27.360 You never know, and that's gonna come in handy on 0:45:27.480 --> 0:45:30.880 the future projects. And that's also well, thank you so 0:45:30.960 --> 0:45:33.440 much for showing the rink. I really appreciate it. I'm 0:45:34.239 --> 0:45:36.160 I really can't wait to see this one. It's ways 0:45:36.160 --> 0:45:39.440 ago well as a pleasure having you up here. And uh, 0:45:39.480 --> 0:45:41.160 I think we'll force you to get into a pair 0:45:41.200 --> 0:45:42.759 of skates and get on the ice when we're done. 0:45:43.080 --> 0:45:45.399 I think I have to. At this point, I want 0:45:45.400 --> 0:45:48.160 to thank Mr Brett hole Ride for inviting us up 0:45:48.200 --> 0:45:51.400 and taking a look at the ice rink in progress. 0:45:51.520 --> 0:45:54.840 It was pretty awesome, not just to see the rink 0:45:54.960 --> 0:45:57.640 itself and how it was laid out and with all 0:45:57.640 --> 0:46:02.080 those tubes of glycol underneath, but also just that massive chiller, 0:46:02.200 --> 0:46:05.680 hundred twenty ton chiller on the roof of this building. 0:46:06.520 --> 0:46:09.600 It was enormous, along with the huge pump that was 0:46:09.680 --> 0:46:12.839 necessary to actually move the glycol through the system, and 0:46:12.920 --> 0:46:14.719 we never would have had a chance without it. So 0:46:14.760 --> 0:46:17.120 thank you again, Brett. And I got a little bit 0:46:17.120 --> 0:46:20.720 more to say about maintaining an ice rink. But before 0:46:20.719 --> 0:46:22.919 I go into that last section, let's take another quick 0:46:22.920 --> 0:46:32.399 break to thank our sponsor. Alright, I thought it might 0:46:32.440 --> 0:46:34.640 be fun to end this episode with a look at 0:46:34.760 --> 0:46:39.879 ice resurfaceers. Typically, folks would refer to these as a Zamboni, 0:46:40.280 --> 0:46:43.719 But just to be clear, Zamboni refers to a particular 0:46:43.800 --> 0:46:47.480 brand of ice resurfacing machines. It's just that most folks 0:46:47.640 --> 0:46:50.160 use that brand name to refer to the technology in general, 0:46:50.760 --> 0:46:53.239 much the same way that some people will refer to 0:46:53.400 --> 0:46:56.880 any copy machine as a xerox. Now, the purpose of 0:46:56.920 --> 0:47:00.040 these machines is to repair and polish the surface of 0:47:00.080 --> 0:47:02.719 ice rinks as they experience wear and tear, and it 0:47:02.760 --> 0:47:05.360 does not take very long for metal ice skates to 0:47:05.440 --> 0:47:08.560 carve up that nice, pristine surface of an ice rink. 0:47:08.840 --> 0:47:10.839 And once in a while you need to fix things 0:47:10.920 --> 0:47:13.560 so that they're more attractive and to avoid situations where 0:47:13.560 --> 0:47:16.279 a skater goes topsy turvy after hitting a particularly big 0:47:16.360 --> 0:47:20.120 divot cut out of the surface. Now, in the good 0:47:20.120 --> 0:47:23.120 old days, and by that I mean the awful old days, 0:47:23.280 --> 0:47:26.440 this was all done by hand. People would actually venture 0:47:26.520 --> 0:47:31.080 out onto the skating surface with tools to physically chip 0:47:31.120 --> 0:47:33.560 away at that top layer in order to get as 0:47:33.600 --> 0:47:36.640 smooth as surface as possible. They would use shovels to 0:47:36.640 --> 0:47:39.240 shovel up any of the ice shavings that they created, 0:47:39.280 --> 0:47:43.200 either from skating or just scraping that top layer of ice, 0:47:43.560 --> 0:47:45.640 and they would use water hoses to pour out more 0:47:45.719 --> 0:47:48.880 water to replace the ice lost from the whole process 0:47:48.920 --> 0:47:52.319 as well, and they'd use squeegees and towels to help 0:47:52.360 --> 0:47:55.279 spread the water in a thin layer across the entire 0:47:55.320 --> 0:47:59.400 surface to get that nice shiny appearance and make everything 0:47:59.440 --> 0:48:02.839 clean and beautiful again. And the whole process would take 0:48:02.920 --> 0:48:08.320 several hours of backbreaking work. Then in you have a 0:48:08.400 --> 0:48:12.560 visionary named Frank Zamboni who decided to tackle this problem 0:48:12.560 --> 0:48:15.120 and find a better way to resurface an ice rink. 0:48:15.440 --> 0:48:18.080 He and his brother Lawrence had opened up an ice 0:48:18.200 --> 0:48:21.600 rink in California, Southern California at that and they had 0:48:21.600 --> 0:48:24.240 been using a tractor that was outfitted with a large 0:48:24.360 --> 0:48:29.560 blade to scrape that top layer before manually shoveling up 0:48:29.560 --> 0:48:32.120 all the ice shavings and pouring hot water from a 0:48:32.160 --> 0:48:35.120 hose onto the rink and then squeegeeing it by hand 0:48:35.200 --> 0:48:39.080 across the surface. The whole process, even with the tractor, 0:48:39.640 --> 0:48:41.480 meant that it would take about an hour and a 0:48:41.480 --> 0:48:45.520 half to resurface their ice rink, which was not an 0:48:45.640 --> 0:48:47.600 enormous rink. It was a It was a decent size 0:48:47.640 --> 0:48:49.360 one is bigger than the one that we have upstairs, 0:48:49.760 --> 0:48:51.799 but not the biggest one in the world. And so 0:48:51.960 --> 0:48:54.040 Zamboni thought, there's gotta be a better way to do this. 0:48:54.160 --> 0:48:57.320 His solution was to create a new type of vehicle 0:48:57.520 --> 0:49:00.360 that could do as much of this work as pile 0:49:00.440 --> 0:49:03.400 all by itself. And he worked on this concept for 0:49:03.520 --> 0:49:08.480 nearly a decade and created a truly terrifying Frankenstein's Monster 0:49:08.680 --> 0:49:11.640 of a vehicle out of parts that included stuff like 0:49:11.680 --> 0:49:14.120 there was a cylinder from a plane, there was a 0:49:14.200 --> 0:49:16.840 jeep engine driving the whole thing. There was an oil 0:49:17.000 --> 0:49:25.440 derec chassis. So this invention first debuted in nineteen forty nine, 0:49:26.920 --> 0:49:32.240 it obviously went through lots of different evolutionary processes until 0:49:32.320 --> 0:49:35.880 it was refined into the sleek, sexy vehicle we all 0:49:35.920 --> 0:49:38.080 know and love today. And of course, there's more than 0:49:38.160 --> 0:49:41.680 justice Amboni ice resurfacing machines out there at this time. 0:49:41.719 --> 0:49:44.799 There's all sorts of ones that are out there. But 0:49:44.880 --> 0:49:49.200 here's what a modern ice resurfacing vehicle actually does. So 0:49:49.400 --> 0:49:55.000 underneath the vehicle there's a blade that is positioned inside 0:49:55.080 --> 0:49:59.640 an overall structure that's called the conditioner. This you can 0:49:59.640 --> 0:50:03.000 actually raise and lower underneath the zamboni, so when you're 0:50:03.000 --> 0:50:04.880 just driving it onto the surface of the ice, you 0:50:04.880 --> 0:50:07.080 can raise it up so nothing is dragging, and when 0:50:07.080 --> 0:50:10.120 you're ready to start, you lower the conditioner down and 0:50:10.160 --> 0:50:13.960 then you typically have a control that can put the 0:50:14.040 --> 0:50:17.040 angle of attack for the blade at such so that 0:50:17.080 --> 0:50:20.200 you can cut exactly the amount of ice you want 0:50:20.239 --> 0:50:23.200 off the top surface. For hockey rinks, it's a very 0:50:23.320 --> 0:50:27.320 very thin layer, but other rinks it might be a 0:50:27.400 --> 0:50:30.959 little bit more more severe, depending upon what they're trying 0:50:31.000 --> 0:50:34.880 to do. So the blade is typically somewhere between seventy 0:50:34.880 --> 0:50:38.279 seven to ninety six inches in width, which is about 0:50:38.280 --> 0:50:43.279 a hundreds and it cuts that top layer of the ice, 0:50:43.360 --> 0:50:46.560 the very top layer, removes any protrusions, helps level out 0:50:46.560 --> 0:50:50.040 any big divots. Uh. There are a pair of augers 0:50:50.040 --> 0:50:53.680 that catch all the shavings, the the ice chips or 0:50:53.719 --> 0:50:56.800 the snow and they move it into a snow tank. 0:50:56.880 --> 0:51:00.960 Augers are are essentially large screws, so you rotational force 0:51:01.040 --> 0:51:05.359 to move those shavings around. There's one that's horizontal and 0:51:05.480 --> 0:51:08.319 it ends up pulling all the ice shavings, are really 0:51:08.360 --> 0:51:11.560 pushing all the ice shavings into the center back portion 0:51:12.200 --> 0:51:15.840 of the zamboni. Then there's a vertical auger that lifts 0:51:16.040 --> 0:51:20.120 from that central packed mass and moves it up to 0:51:20.320 --> 0:51:23.120 the snow tank, this waist tank that's typically on the 0:51:23.160 --> 0:51:27.680 front of the zamboni or ice resurfacer, i should say. 0:51:27.760 --> 0:51:30.319 And then typically one of these machines will pour hot 0:51:30.360 --> 0:51:35.960 water onto the ice. Behind this there's maybe it's warm, 0:51:36.000 --> 0:51:38.160 not hot water, and helps level out anything that the 0:51:38.200 --> 0:51:41.279 blade wasn't able to get. There's a squeegee that is 0:51:41.400 --> 0:51:44.000 right behind this hot water that then allows that to 0:51:44.040 --> 0:51:46.600 get sucked back up into the system so that it 0:51:46.640 --> 0:51:50.520 can be recycled. And then there's another hot water emitter 0:51:50.640 --> 0:51:53.719 at the very back of the zamboni just before you 0:51:53.800 --> 0:51:57.759 get to the the extreme rear of the vehicle where 0:51:57.760 --> 0:52:01.360 there's a flap. It's essentially a towel at the very back, 0:52:01.880 --> 0:52:05.919 and so hot water drips out and the towel then 0:52:06.040 --> 0:52:09.480 spreads the hot water against the surface of the ice 0:52:09.960 --> 0:52:13.320 ice free surfacers use hot water instead of cold water 0:52:14.080 --> 0:52:17.200 because the hot water, when it makes contact with the 0:52:17.239 --> 0:52:20.560 ice rink, will start to melt that surface ice just 0:52:20.640 --> 0:52:24.760 slightly before it begins to free freeze into a solid layer. 0:52:25.320 --> 0:52:28.800 If you were to use cold water, cold water freezes 0:52:28.840 --> 0:52:31.919 so quickly that you end up more like very thin 0:52:32.120 --> 0:52:36.120 additional layers on top, and those chip way very easily. 0:52:36.239 --> 0:52:39.600 So if you're doing some sort of fancy ice skating 0:52:39.800 --> 0:52:43.000 or you're doing you know, playing hockey or something, you 0:52:43.080 --> 0:52:45.799 end up getting these big chips that fly up, and 0:52:45.840 --> 0:52:49.840 that typically is not really preferred. So that's why they 0:52:49.920 --> 0:52:52.160 use hot water. It it melts the top surface of 0:52:52.160 --> 0:52:54.800 the ice just a little bit before it all refreezes 0:52:55.160 --> 0:52:59.360 and makes it more of a solid layer of ice. Often, Um, 0:52:59.480 --> 0:53:02.000 you'll have a couple of other elements, like there might 0:53:02.040 --> 0:53:05.279 be another brush. It depends upon the vehicle. Some of 0:53:05.280 --> 0:53:08.600 them run on natural gas, some of them run on 0:53:08.880 --> 0:53:14.080 battery power. Um, if you're looking at a full size 0:53:14.160 --> 0:53:18.000 zamboni with a full tank, these things are heavy. They 0:53:18.040 --> 0:53:23.439 weigh about eleven thousand pounds or four thousand ns. These 0:53:23.440 --> 0:53:28.000 are massive, heavy vehicles. So running across that ice is 0:53:28.000 --> 0:53:30.520 no joke. And they also tend to have a metal 0:53:30.560 --> 0:53:33.239 studs on their tires to give them enough purchase to 0:53:33.320 --> 0:53:36.640 be able to actually move across the ice effectively. And 0:53:36.680 --> 0:53:41.000 according to Car and Driver, operating a zamboni isn't exactly 0:53:41.080 --> 0:53:45.319 like driving a sports car. The report said, quote, visibility 0:53:45.400 --> 0:53:48.640 from the elevated left rear position is poor, the abrupt 0:53:48.760 --> 0:53:51.960 throttle tip in takes some getting used to, and the 0:53:52.080 --> 0:53:57.720 vague steering is totally seventies Cadillac end quote. But it's 0:53:57.760 --> 0:54:00.799 still kind of like to ride on one, though, And 0:54:00.880 --> 0:54:04.440 that's our show about ice rinks. I'm still not likely 0:54:04.520 --> 0:54:08.000 to get on one anytime soon unless I just decide 0:54:08.040 --> 0:54:10.520 that a few nice weeks in traction would be a 0:54:10.560 --> 0:54:15.840 really good vacation. But like many Southerners, I really only 0:54:16.000 --> 0:54:19.400 trust ice if it's in my t That wraps up 0:54:19.400 --> 0:54:22.200 this episode. If you guys have any suggestions for future 0:54:22.280 --> 0:54:26.320 episodes of Tech Stuff, whether it's a particular technology company 0:54:26.400 --> 0:54:29.120 that's been important in tech, or a figure that's really 0:54:29.160 --> 0:54:30.920 important in tech, or maybe there's someone you would love 0:54:30.920 --> 0:54:33.560 me to interview or have on as a guest host. 0:54:34.160 --> 0:54:37.080 Any of those suggestions, I welcome them all. You can 0:54:37.160 --> 0:54:40.000 write me the email address for the show is tech 0:54:40.040 --> 0:54:43.239 Stuff at how stuff works dot com, or you can 0:54:43.320 --> 0:54:46.200 draw me a line on Facebook or Twitter. The handle 0:54:46.239 --> 0:54:49.400 at both of those is tech Stuff hs W. 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