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00:04:250Michele De Carli: Okay.
00:21:630Michele De Carli: alright. So we started yesterday to analyze the the
00:30:346Michele De Carli: the full air systems. Okay.
00:34:626Michele De Carli: now, we have introduced the so-called environment or ambient line. Recta ambient in Italian. Okay? What does this line mean? As we have seen? Basically. Okay, it is the ratio between the
00:55:590Michele De Carli: the sensible the sensible power divided by the overall power. So basically, it depends on the indoor conditions which are fixed. So the a is fixed, okay, and what is
01:12:860Michele De Carli: And I. So the emission, okay, so the supply. So the internet and the conditions can be
01:20:900Michele De Carli: any okay in this line. Okay, so any point in this line is suitable in condition for your
01:31:170Michele De Carli: okay. Of course, you have to think about that. The closer you are to the point, a be greater
01:42:90Michele De Carli: will be the correct. Okay, all.
01:46:140Michele De Carli: In other words, the
01:48:960Michele De Carli: the the longer the distance between I and a, the lower the flow rate and the the volume volume. Okay, of the air entering the room.
02:06:700Michele De Carli: What does it mean? It means that if we increase.
02:14:50Michele De Carli: or if you
02:15:860Michele De Carli: increase the airflow rate, then that means that we need also to increase the electric power of the fan. Okay, the obsidian power.
02:28:811Michele De Carli: And of course, since we have a limit. Okay, in the velocity of the airflow in the the dots. That means that if we increase the maximum rate, we have also to increase the dimensions of the dots. Okay? So that means that the the greater the
02:48:780Michele De Carli: volume is much prorated day
02:53:690Michele De Carli: the more expensive will be the solution, because we need the and also the consequent electric power for driving the farm.
03:10:320Michele De Carli: So like, by decreasing this, the airflow.
03:22:618Michele De Carli: okay, so we have a cheaper solution. Okay, with also smaller costs for the ventilation.
03:45:390Michele De Carli: But of course.
03:51:810Michele De Carli: which is necessary to have to guarantee good quality of the air. Okay, so this is related.
04:06:370Michele De Carli: 1st boy, second point, okay.
04:16:310Michele De Carli: my greater
04:21:740Michele De Carli: the greater the Delta T, so the greater the temperature difference between the air and the air conditions
04:35:250Michele De Carli: turnover the efficiency. Because, for instance, if we are providing air at 30 degrees
04:46:589Michele De Carli: we can have a good distribution of the air temperature in the room. If we provide the air at 45 50 degrees. Okay, in heating, we might have stratification, because if we supply air at my temperature, and usually we supply gear on the top side. Okay, on the on the
05:08:870Michele De Carli: and on the top side of the of the room. Okay, we might have some expectation.
05:15:600Michele De Carli: Okay, so the greater the temperature difference, the lower the efficiency of radiation.
05:23:530Michele De Carli: And
05:27:420Michele De Carli: again, I want to remind you that if the in case of heating. We need to provide air at higher temperature and the lower humidity ratio
05:38:60Michele De Carli: for cooling. We need to provide air at a lower temperature and lower humidity. Okay.
05:45:220Michele De Carli: Now, which are the difficulty that we usually can expect in
05:54:380Michele De Carli: in heating conditions. Okay, but this is okay, this is what I have just written here. Okay? So by decreasing the
06:08:180Michele De Carli: by decreasing the the error, these things nowhere.
06:18:640Michele De Carli: You know what? That fixes explanatory. Okay? So the initial cost, okay, okay,
06:33:875Michele De Carli: So
06:35:460Michele De Carli: these are the usual ranges that have been only used in the past. You can see that here we we have a a potential range between 15 and 25 degrees. I have to remind that this is a quite old okay figure. Today.
06:54:700Michele De Carli: the best would be to be, let's say in between 5 to 15 degrees maximum. Okay? So the optimal solution is 10, what doesn't means that you should try to let the air entering at maximum 30 degrees. Okay? Which means that the air entering okay will mix up with the room air, and you will try to avoid as far as necessary or as far as possible. Okay.
07:25:835Michele De Carli: so 10 degrees is the best solution. Okay, so usually 10 degrees. C, okay. Also, you have to think about that
07:35:920Michele De Carli: in the past. You had larger heat heater power. Okay? And peak power, right? So you needed to provide air with a high Delta T. But if you decrease the peak power for heating the Delta. T, okay.
07:55:160Michele De Carli: maintaining the same supply flow rate. Okay, the Delta Q will be smaller because of that. But ta is the temperature inside the room? Yes, 20 degrees
08:09:811Michele De Carli: in his name. Here, Anthony, okay, the emission, the inlet average.
08:16:180Michele De Carli: Right? So if you have a peak loan.
08:19:900Michele De Carli: and you have 20 degrees and 1030.
08:24:440Michele De Carli: Okay, and building the vicinity. So without insulation.
08:29:760Michele De Carli: we have seen that if you increase the insulation.
08:35:110Michele De Carli: Can you breathing?
08:37:120Michele De Carli: The power will be
08:41:520Michele De Carli: half of the power. Okay, or even less. Okay. But let's say half of the power that you you should need in the seventies. Okay, so 20 degrees means that in the air was 20 degrees. If you keep, if you keep the same airfare rate. Okay, that means that the Delta T is 10 degrees, which means
09:04:990Michele De Carli: actually 30, anyways, as supply. Okay, so by having the power, you have the record.
09:19:330Michele De Carli: if you if you keep the same.
09:21:960Michele De Carli: Okay? So
09:25:490Michele De Carli: it is not only a question of efficiency, but also of the distribution of data, but also the
09:32:820Michele De Carli: the new. Let's say, reduced.
09:36:970Michele De Carli: Okay.
09:42:430Michele De Carli: I just forgive you only for providing us. Okay, I'm I'm joking.
09:54:860Michele De Carli: okay, you can see you have a certain reach. But, as I told you.
09:59:990Michele De Carli: usually the minimum or sorry, the minimum temperature is 60 degrees. So the maximum delta T that you have, including is 26, the indoor temperature minus 16, which is the minimum temperature for inlet condition of the air, which means 10 degrees as Delta T between inlet and the air.
10:23:712Michele De Carli: So that's that's that's it. Okay, of course.
10:33:250Michele De Carli: No.
10:35:520Michele De Carli: What should you take into account? You should take into account that the there is on one side you have
10:54:260Michele De Carli: the dollar
11:04:660Michele De Carli: on one side, you have the sensible power. On one hand you have a day fresh here, alright.
11:16:240Michele De Carli: so depending, if you, if the fresh air flow rate for the room, he's senior.
11:30:330Michele De Carli: GA. Okay. So the amount of air that you need for
11:36:300Michele De Carli: for facing the big group. Okay.
11:39:470Michele De Carli: then you will just use fresh air.
11:48:50Michele De Carli: Okay, if let's say, if there is.
11:57:830Michele De Carli: that's minus 30% defense. Okay, you you use the fresh air. Okay?
12:04:103Michele De Carli: If the amount of flow rate that you need for the for the room is, let's say twice. Okay, 1.5 or 2 times or 3 times the fresh air needed by the room. Then
12:20:860Michele De Carli: you will.
12:24:480Michele De Carli: He really had it
12:31:00Michele De Carli: and recyclation?
12:54:900Michele De Carli: Okay? Good.
12:59:10Michele De Carli: Some pressure which we left.
13:02:760Michele De Carli: which will be okay. Replacing the question, could you? Could you see it or not? Because it no.
13:20:310Michele De Carli: what I want to say is that as far as the recirculation rate is 30% compared to the fresh air. You will just use fresh air. Okay.
13:30:30Michele De Carli: this is funny, Rahul, speaking.
13:33:300Michele De Carli: If it becomes more than 30%. Then it becomes, it might become suitable to have recirculation. Okay, so
13:42:700Michele De Carli: it's it's not a strict rule. Okay, it's just
13:46:490Michele De Carli: what you might have as reference to you. Okay.
13:56:116Michele De Carli: Of course.
13:57:570Michele De Carli: You might have also that
14:07:360Michele De Carli: the air in winter and summer, the fluids.
14:13:930Michele De Carli: they could be different. Okay, in the past. It was a problem because we work with the constant velocity. Okay? Times, okay, today is not anymore a big issue, because by using the brushes
14:32:70Michele De Carli: plans, okay? So by using, by adjusting the payment, the
14:39:760Michele De Carli: voltage and current. Okay, the the speed of the fast. You're you're able to. Let's say
14:47:00Michele De Carli: to the velocity, okay, the speed of the sound
14:50:540Michele De Carli: according to what is required. Okay, so this is not anymore a big problem. Okay? But in the past it was 30 40 years ago. It was a huge problem to
15:01:490Michele De Carli: to change the speed of the fact that not today's number.
15:04:910Michele De Carli: It's November.
15:06:903Michele De Carli: Of course
15:10:610Michele De Carli: you are sizing the system for rather for facing the peak load coefficient. So the maximum power heat for the cooling.
15:20:320Michele De Carli: You have to think about that in practically okay, especially winter time. The design conditions are really, really okay, are really harder to to meet. Okay.
15:35:280Michele De Carli: as your experience that minus 5, we have learned ahead minus 5 here in in
15:40:940Michele De Carli: in this winter. Okay, and imagine that the design conditions are constantly at minus 5 in cooling. Yes, we might have more than one day as a high resolution, or even worse conditions.
16:00:120Michele De Carli: And so what you have to think about is not only on one side, you have to size the system according to the peak load in the peak conditions. But on the other side, you have to think about how to make the system. Okay.
16:17:950Michele De Carli: how to allow the system to module. Okay, to modulate. Okay, the the the power according to the actual. Okay.
16:31:290Michele De Carli: But we'll come back to this point later. Okay.
16:35:340Michele De Carli: so now, how can you? Let's say, let let's look. So this is, let's say what you
16:43:580Michele De Carli: estimate. Okay in terms of the rate and in the condition for the
16:50:540Michele De Carli: now, how can you distribute the air inside of the different rooms? Well, the easiest way is to use this solution, so the so called the single duct solution. Okay, so single duct solution means that you have one ductor providing air in all the rooms that you have.
17:13:420Michele De Carli: And of course, in this case you might have different flow rates in the different rooms, but the inlet conditions will be the same. Why? Because, as I told you the handling so the the processes which are related to the air cooling divulification. They are inside of this box of the air handling unit. Okay? Which is a centralized box where you are heating
17:42:910Michele De Carli: could have everything defined. And in this human defined also, okay.
17:49:665Michele De Carli: so you might have. So the air conditions are the same because the the air gets out at the temperature high
18:00:740Michele De Carli: and specific under humidity ratio. I, okay. And of course, H. Enthalpy, I okay.
18:10:70Michele De Carli: from the or less outlet of the air handling unit.
18:15:840Michele De Carli: Okay, so the inlet conditions are the same for all the rooms.
18:20:908Michele De Carli: What is changing or what might change is that one infrared. So you don't have to need the central rate in other rooms. Okay? You might in one room
18:32:130Michele De Carli: 2 times the flow rate of the other room. Okay, so let's say, ABC, so okay, let's say, ABC, okay, they can have the same air flow rate. But you might have also that room A has twice the flow rate of room 2, which has 3 times the flow rate of room. C, okay, so we don't care what is changing, then, is the dimension of the ducts. Okay.
19:02:80Michele De Carli: that is what we are going to see at the end of the of this section of this fact here on the duration. Okay? But let's say that from the I mean from the inlet, conditions are the same. Which means the inlet conditions. Okay, they are
19:19:890Michele De Carli: the environment or ambient line. Okay? So which means that the
19:28:557Michele De Carli: see, the conditions are the same. It means that the rules they have to be to have the same encryption, the same line. Okay? So basically, they, they are similar in terms of.
19:41:820Michele De Carli: okay. What does it mean? It means that basically, if you have, like a building, which is.
19:54:790Michele De Carli: imagine that this is a sketch of an aerial view. Okay, imagine that this is a corridor.
20:02:700Michele De Carli: for instance. And here you have a glass, a glazed window. Here, for instance, is east, and this is West.
20:12:888Michele De Carli: That means that you have one area. Okay, which might be subdivided into different rooms. Okay, if this is one floor, this is one floor. So imagine that you have more floor. Okay.
20:26:860Michele De Carli: so imagine that this
20:31:917Michele De Carli: you have 3, 4 rooms in each floor, and you have 3 floors. So you have 12 rooms facing east and 12 rooms facing west. Okay? So in that case, if you want to provide air full air with this system.
20:46:970Michele De Carli: then you will have 2 healthy units, 2 system, one which is cooling and eating the east zone. Okay all day. 12. Face east and the other one, which is which is instead providing air and heat and cooling in the West. So because if you if you have different.
21:11:570Michele De Carli: we load okay in Eastern orientation and West orientation, because the maximum peak will be different. And you you should adjust that in the inert condition
21:23:442Michele De Carli: which might be similar for Easter, and they are, but they are completely different from the green road that you have in the rooms west. Okay, so this solution can be done can be used.
21:41:690Michele De Carli: Buildings in general can be used for or can be used for a certain, a certain. Okay,
21:54:470Michele De Carli: this solution, okay, is actually what you can use in this code.
22:01:150Michele De Carli: There, hey, Walter.
22:05:860Michele De Carli: solution, air and water solution, like in this case here, okay, in this case, usually in air and water solution, basically.
22:17:760Michele De Carli: here is almost at neutral temperature, neutral temperature.
22:27:74Michele De Carli: So basically, the workers terminal units are used to control the temperature inside the cave.
22:38:300Michele De Carli: What you need from the air is just to control the air quality and the the balance. Okay? So the the relative humidity. So basically, the you can put in the rooms. The, this is limited condition. Okay, so in this kind of system in the
22:58:970Michele De Carli: air water solution, mixed air water solution. Usually you use a simple one, doctor, single doctor solution for the distribution of the okay. And usually you use the fresh air as
23:15:30Michele De Carli: air flow rate. Okay? Because the the power needed for which is which has water inside water in summer and cold and hot water.
23:29:900Michele De Carli: One person.
23:32:140Michele De Carli: Okay, right?
23:34:890Michele De Carli: Yes.
23:38:940Michele De Carli: You said that we need a tool for different locations. This is like, for example, in different platform, or also in a residential
23:52:910Michele De Carli: okay? No. I mean, if you talk about residential buildings and you want to keep autonomous the different residential building. Usually we have one area unique.
24:09:820Michele De Carli: here we talk about. Let's say, commercial meetings, maybe. Okay. For commercial meetings. Usually you might have in the in the.
24:21:290Michele De Carli: in the large buildings. If you want to use 2 layer system, you're not allowed to use a 2 layer system, but you can do that. You cannot have 100 400 unit per zone. Okay? Of course it depends. It depends on the building. I mean, imagine an airport. You have a huge.
24:40:610Michele De Carli: a huge building. Okay, where you, you have separating the building in different sub areas of volumes. And each sub volume has its own area.
24:52:790Michele De Carli: Usually the airports. Each unit is okay located in where you have
25:00:391Michele De Carli: just to give you an overview.
25:05:450Michele De Carli: or they can be on on top of the of the service.
25:10:860Michele De Carli: But let's say that this is so it depends depends very much. But usually, if you have to provide
25:20:80Michele De Carli: air with more than 100 unit is that you need huge amount of air. Okay, so large buildings and or buildings with a lot of people inside. Okay. So for instance.
25:35:770Michele De Carli: in a in a lecture room right here. Okay? Or in a large letter room you might have okay
25:45:780Michele De Carli: or in a.
25:53:640Michele De Carli: But if you have rooms with 200 300 people. Okay, then you will have. It is
26:01:420Michele De Carli: possible that you might have one parent unit. Because, okay.
26:08:600Michele De Carli: Now, let's see a little bit. Let's have a look at what happens inside of a near handy unit. Okay? And then
26:19:250Michele De Carli: we are going to look at the
26:22:430Michele De Carli: air handling units more in detail about the technologies in the next lecture. Okay, so this is how an air handling unit is can be can be.
26:37:640Michele De Carli: can be. I mean, drone, okay, this is the fresh air. Okay?
26:44:650Michele De Carli: And this is the recirculation. Okay, the recirculation of the air. Okay, you don't. If
26:55:350Michele De Carli: if needed. Okay? So if there is circulation, so fresh air. And that's okay. In case you have a circulation. Okay? These are. These are some dampers. Okay, dampers are brilliant. Okay? So equalizing dampers are.
27:19:800Michele De Carli: And Italiano green Jack
27:28:360Michele De Carli: Equilizot reach. No.
27:31:625Michele De Carli: Hey?
27:33:604Michele De Carli: Okay? So they can be. They can be. They can be adjusted once, just once. Okay, the beginning. When you have to. Let's say,
27:53:750Michele De Carli: you have to check the amount of flow rates, recirculation, and in and fresh air, or they can have an electric engine. Okay? Which which is allowing to, let's say, modulate to different flow rates. Okay? By closing and opening the developers. Okay, the use of the developers. Okay.
28:18:50Michele De Carli: right?
28:22:150Michele De Carli: Serrande motorizate in Italian. Okay? So Serrande motorizate Cerrande motorizate. Okay this is in
28:32:800Michele De Carli: with the engine with electric engine. Okay?
28:37:930Michele De Carli: Notorizate.
28:40:60Michele De Carli: Okay, cool. You got it, usually. But I mean, it's okay.
28:44:570Michele De Carli: Okay. Well, you got the means that they are working only okay.
28:49:510Michele De Carli: even if they don't work a company. But it doesn't matter. Okay? And okay.
28:56:473Michele De Carli: so then you have. You have the
29:02:640Michele De Carli: I mean, this is the usual scheme, the the classic scheme. Okay, usually you have a heating a printing coil. Okay?
29:14:845Michele De Carli: Then you have a humidifier. Okay, this is especially true. If you are using atomizing of the humidi humidifiers. Okay, we will see them. When we talk about the air handling unit and then you have a a
29:35:170Michele De Carli: and
29:37:70Michele De Carli: you have a well local separator. Okay? Then you have the cooling coil here. Okay, 5 and 6 red coil. Red coil is called also Bateria di postaneto. In Italian. Okay. Post riscaldoneto
29:56:400Michele De Carli: is ready for Austria.
29:59:737Michele De Carli: Is is a rate called in English. And then you have the phone. And then usually, you have the silencer. Okay, in order to reduce the noise of the phone okay towards the rooms. Okay.
30:19:240Michele De Carli: so this is the scheme of an unit. And let's see how this system operates. Okay, which are the transformation. I think you should know that. Okay, but let's say that you you have already seen them right in previous courses.
30:35:40Michele De Carli: What? Also the or in your students?
30:47:780Michele De Carli: Okay, good.
30:49:680Michele De Carli: So just to make a recap, then very, very quick.
30:53:204Michele De Carli: If this is the inner condition, and this is the other condition, the mixing condition depending on the ratio between the 4 rays would be the end point. Okay? Then you have the preheating point.
31:05:610Michele De Carli: M to DI want to remind you that heating is just sensible. Okay, so it's a horizontal line from N to d the the point is is, is the the exiting point. D will depend on the required
31:25:813Michele De Carli: humidification level that you need. Or let's say, the Delta X that you need from C to D, okay, so the amount of of humidity. That you need to provide to the. And then you have the rate coil from C to I. Okay.
31:44:10Michele De Carli: And that is that is how you can enter it.
31:48:629Michele De Carli: Of course, if you use a heat recovery unit.
31:53:730Michele De Carli: Okay? So the heat recovery unit will make possible to recover the heat of the fresh air. Okay? If it is 70%. And we might have today 70% of heat recovery unit, because efficiency, you can see that instead of minus 5, the air will enter in the mixing
32:18:350Michele De Carli: in the or will meet the risk linear, not anymore at minus 5, but 13
32:27:470Michele De Carli: 13 degrees. So at this time, you don't need anymore. Okay? So you just need to get out at the mixing condition. Okay? And then in case you can. You cannot provide the humidification with the optimizing humidifier. And then you have the rate coil from C to I, okay.
32:55:450Michele De Carli: this is just an example. Okay, I want to remind you.
33:02:920Michele De Carli: This is with the atomizing humidifier. Okay with atomizing humidifier you're making like a kind of form which is humidifying the air passing through, but also cooling the air. Okay? But if you use vapor, okay, if you use vapor, then you will have a, as you know, in almost a constant temperature. So it's called also isothermal humidifier. Okay? So in that case.
33:30:130Michele De Carli: then, the recoil will need less power, because the Delta T that you have to cover will be less than the Delta T that you have here.
33:38:450Michele De Carli: Okay, so this is this is what you have. I would like us to remind that if you're using a ice, the fire.
33:50:240Michele De Carli: I mean you don't. You're not. I mean, you can install it everywhere. Okay? So in any position
34:01:800Michele De Carli: in principle. Okay, if you're using a optimized, you need to locate this between the predict call or before direct call.
34:11:940Michele De Carli: Okay?
34:13:239Michele De Carli: Now, in the summer. Okay, this is what you get. If you have no heat recovery, we are considering that 35 degrees and 50% of the humidity quite high, slightly higher conditions than you have this design condition. Okay? But similar to what we have here.
34:34:753Michele De Carli: So again, in the in the mixing point, you will get the M point between circulation and supply fresh air. Sorry, then you know that when you are.
34:52:70Michele De Carli: when you have a a a cool call. Okay, a cooling call your
35:07:690Michele De Carli: point, m, okay? And the and the equivalent temperature.
35:22:960Michele De Carli: The condition from the corinko oil
36:50:414Michele De Carli: We have lost the Anna. We're still in registration