Assistente AI
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00:00:00Michele De Carli: Okay?
00:01:180Michele De Carli: And of course, we come back to this point. So
00:13:660Michele De Carli: good.
00:14:980Michele De Carli: Then we got there. So there's a number.
00:25:490Michele De Carli: okay?
00:26:440Michele De Carli: And so.
00:39:480Michele De Carli: okay? So the typical clothing. Okay, are, I told you, we have a typical
00:50:426Michele De Carli: summer clothing is 0 point 5. Okay, growth.
00:55:850Michele De Carli: This is the summer typical clothing. Okay,
01:03:330Michele De Carli: of course, if you're naked, it's 0. Okay.
01:06:290Michele De Carli: 0 point 5 is the clothing that you usually have in summer, and one is the typical clothing. One cloth is a typical clothing of winter. Okay.
01:20:620Michele De Carli: so these are the 2. Let's say, reference
01:23:190Michele De Carli: protein resistances that you can take in design conditions. Okay? So on average, we can consider all we say, the standardized value is 0 point 5.1.
01:35:710Michele De Carli: And
01:37:860Michele De Carli: they, of course, as you can see, there are different ways to dress, and we might have some changes over the year. Okay, so you can see that.
01:52:326Michele De Carli: Well, I will skip this you might have different clothing resistances, so you might dress in a different way, depending on the time. If it's cold, it's mid season, or if it's warm. But let's say that these are the 2 different levels of clothing resistance that you can get. I will skip this slide
02:12:600Michele De Carli: so at the end, which are the which are the parameters that are affecting the heat balance, the heat balance. We said, we have the activity so that the metabolic rate we have the growth in resistance. So the way we dress.
02:33:280Michele De Carli: We have the
02:37:120Michele De Carli: real the air velocity. Okay? And the air temperature, because these are the parameters which affect the conductive heat transfer consumption. So
02:49:140Michele De Carli: and they they.
02:50:780Michele De Carli: The convection is related to the velocity of the air and the temperature of the air. Okay.
02:58:720Michele De Carli: so these 2 are for the convection.
03:04:164Michele De Carli: We have to consider, then, the way we
03:10:680Michele De Carli: exchange heat with the surrounding surfaces, and we will see how to introduce this? By means of the so-called mean radiant temperature. Okay, so mean. Radiant temperature is related to irrigation.
03:25:440Michele De Carli: infrarement, radiation.
03:27:710Michele De Carli: Okay?
03:29:380Michele De Carli: And we said that the relative humidity can be in principle neglected. Okay, with a certain, let's say, by simplifying the approach.
03:39:260Michele De Carli: Okay? So you can see, we have, let's say, 2 parameters which are related to one is related to the activity, and one is related to the way we dress. Okay? And we have at the end. 3 parameters. 3. Let's say physical parameters. Okay? So the 2 parameters, the affility, the energy metabolism, and the clothing resistance. They are related to. Let's say ourselves. Okay.
04:06:620Michele De Carli: we have, let's say, 3 different parameters.
04:10:510Michele De Carli: the infrared radiation. Okay, the the mean, radiant temperature. We see that. But it's mainly related to the the way we or how much energy we exchange by infrared radiation and convection. Okay, so these are the parameters that we have to get in. This
04:29:360Michele De Carli: basically is the temperature of the surface of the surroundings where and they are responsible of our infinite exchange.
04:39:720Michele De Carli: Us? Okay,
04:45:860Michele De Carli: So what I want to mention is that
04:52:430Michele De Carli: we can avoid or include the direct availability. Okay? So we can make the equation. I told you
04:59:980Michele De Carli: at the beginning, we can write
05:03:700Michele De Carli: a set of equations. Okay, we don't write it because it takes a long time. But so we can write set of equations. And this set of equations
05:13:360Michele De Carli: can be at the end. Okay, can be summarized into this 5 or 6 parameters. Okay? Which are air, temperature, air, velocity, temperature of the surfaces. Let's say, relative humidity. We can. We can even neglect it. And we can include the metabolism, the activity and the closing.
05:37:160Michele De Carli: So we can, we can set okay the equations so as to reach
05:45:250Michele De Carli: a a certain let's say, and to check which is the thermal balance in this moment between the human body and the surroundings.
05:55:983Michele De Carli: Of course.
05:58:20Michele De Carli: what is important to say is that well, that is something that I have already already mentioned. The severe climates. Okay, of course, we have to think about that. We
06:10:580Michele De Carli: we, we can set the parameters, and we can make the. We can solve the question, the the system.
06:22:60Michele De Carli: But do we know if we are comfortable or not.
06:26:690Michele De Carli: are we able to state if we are comfortable or not? Or
06:30:590Michele De Carli: so, we basically finish all the discussion about the physical language.
06:36:700Michele De Carli: Okay, physical and physiological approach.
06:39:130Michele De Carli: And we have seen the way we are we. Our activity is involved. The way we dress. Okay? So we can.
06:47:480Michele De Carli: we can end up with the the energy, that is.
06:52:550Michele De Carli: let's say, going outside our body.
06:56:450Michele De Carli: Is this energy or power is leading to comfort or to or to uncomfortable conditions.
07:04:10Michele De Carli: Most probably. Yes, most probably sorry.
07:09:800Michele De Carli: Probably means
07:16:550Michele De Carli: taking account. All the the people on the
07:21:890Michele De Carli: okay. So that is a good point. So taking into account
07:25:930Michele De Carli: people means that we have to ask people if in this session conditions they're comfortable or not.
07:33:80Michele De Carli: So what has been done exactly in the sixties, seventies, and eighties was to expose people.
07:40:860Michele De Carli: Okay, panel of people to the different parameters. So by changing one parameter per time, okay, by changing the temperature of the air by changing the temperature of the surfaces by changing the way they cross. They were addressing the activity. Okay? And they they put them in a room
08:00:840Michele De Carli: and they had to rate if they felt if they felt comfortable or not.
08:06:580Michele De Carli: So that is the psychological and the statistical approach. Okay? And for doing that, basically, we can. Let's say, introduce. Let's say, 2 parameters. Okay? And they are linked. They are linked. I will start with the the 1st one, which is okay. The Ppd, the percentage of people dissatisfied.
08:30:260Michele De Carli: How many of you are uncomfortable here?
08:34:990Michele De Carli: 1, 2,
08:37:340Michele De Carli: raise your hand, 2, 3. Okay, so there are 3 persons, 4 of you. Okay, maybe you are 20. So 4 divided by 20 is
08:51:170Michele De Carli: 25%, right? 1 5, th more or less.
08:54:950Michele De Carli: Hope. She paid the same button
08:57:160Michele De Carli: 4 to 5, 30%. Okay?
09:01:210Michele De Carli: So the percentage of people dissatisfied is made one under the person inside of the room. The percentage of people this that are or not so satisfied.
09:13:400Michele De Carli: This is a way to see. It's quite simple by. If you have quite rate of people dissatisfied in the room, the room will be most probably not be comfortable.
09:25:630Michele De Carli: Okay, but there is one thing, 1 1, let's say informationism.
09:36:160Michele De Carli: which one you remember when I, when I show you the
09:42:400Michele De Carli: take 2 pictures feeling cold, feeling warm.
09:47:980Michele De Carli: Yeah, I mean, we don't know if you just ask people, are you discomfort or not? We don't know if they're feeling cold, or if they're feeling warm.
09:56:30Michele De Carli: Okay? So by knowing in order to know if they're feeling cold or warm, we need a two-scale approach
10:03:980Michele De Carli: where negative means that you're feeling cold and positive that you're feeling warm.
10:09:248Michele De Carli: So that is the approach of the Pmd scale.
10:14:220Michele De Carli: Okay? So the Pmv scale is a scale between minus 3 and plus 3. Of course, the extremes. You should not go there. Okay, so minus 3 means
10:25:100Michele De Carli: severe cold conditions, plus 3 severe hot condition and 0 means 0 trouble.
10:31:930Michele De Carli: Okay? So neutral is, let's say, the optimum, the comfort sensation. What is the comfort at the end is the minimum work for your
10:43:280Michele De Carli: epobalance. Okay? So it's the minimum work that you have to do for adjusting the heat balance of your body.
10:53:250Michele De Carli: Okay, so if you have no stress
10:57:570Michele De Carli: from the camera point of view, then this is a comfortable condition. But of course we have to check. If what is the
11:08:630Michele De Carli: then?
11:09:540Michele De Carli: Which is the average.
11:14:590Michele De Carli: Right?
11:16:130Michele De Carli: That we might have at 0. Okay, made by the persons by changing one parameter per time. Okay, so doing this research in the
11:28:890Michele De Carli: 10 years. Well, 50, 50 years ago. Okay. It was possible to, let's say, establish
11:36:510Michele De Carli: a a correlation between the different parameters and the conversation.
11:45:280Michele De Carli: Here, okay, you see the different set of equations. So and what is this? You can see that
11:54:930Michele De Carli: this is the saga. Okay? So it is possible to let's say rate.
12:01:220Michele De Carli: under the different. You can see that there are the different parameters here. Okay?
12:08:317Michele De Carli: You can end up by setting a different conditions. Which is the Pmv
12:15:996Michele De Carli: value that you can get into a room. This is the farthest equation. And and
12:24:310Michele De Carli: I don't open it right now because my computer has problems. But you may find there is an Excel file in moodle where this equation are implemented. Okay? And you can play with the different with the different parameters in order to check the Pm.
12:43:393Michele De Carli: Of course, Pmd and Ppd. Are strictly related. Okay, so there is a strict connection. There is an equation, or there is a strict correlation between the Pmd and Ppt, okay, so this, you get the same results.
13:03:790Michele De Carli: But of course, working with Bnd, we know the thermal sensation. If feeling
13:12:520Michele De Carli: colder or warmer than the neutral condition, what can we see in this picture here?
13:26:320Michele De Carli: Okay, so you can see that. Pmv, okay, the use your regular.
13:35:420Michele De Carli: They, I mean, historically, 8% of people dissatisfied of 10% was
13:45:280Michele De Carli: a good or still acceptable okay for comfort conditions.
13:51:290Michele De Carli: So 10% of Ppd means that you can have either minus 0 5 or 0 5
13:59:950Michele De Carli: for 0 point 5 spnd. So the people easy, comfortable. If we stay that
14:08:210Michele De Carli: 10% of people dissatisfied is a good percentage or acceptable percentage for the comfort level. We can say that either you're feeling slightly cold or slightly warm. Still, in a very limited range of 0 between minus 0 point 5 0 point 5. That is an acceptable coach.
14:31:670Michele De Carli: Okay?
14:38:950Michele De Carli: what happens if we have a P and blue.
14:46:330Michele De Carli: you can see that we will have always 5% of people complaining.
14:52:710Michele De Carli: That is really important from from our side. Because if you design a system, even a current system, and there are a few people complaining.
15:01:720Michele De Carli: it's okay.
15:04:360Michele De Carli: Okay. So it might happen sometimes that people they are feeling called the world a certain environment.
15:14:290Michele De Carli: And few people are feeling all the warm.
15:17:550Michele De Carli: And if that value sometimes okay, that
15:25:140Michele De Carli: in order to satisfy these persons.
15:29:400Michele De Carli: The heating and cooling system were completely destroyed. Okay? Because, then, or it was impossible to manage that the thermal comfort inside of the room. Okay? So it is very important. You you will almost never okay, satisfy the 100% of people.
15:47:630Michele De Carli: And this is extremely important from your side. So it's a safe. It's a guarantee that you you when you design. You know that even someone is complaining. It's not really
16:01:460Michele De Carli: a major issue. Of course you have to limit which are the limits there I go back to. Oh, sorry I I had to go back to the previous slides, so usually for new buildings.
16:15:720Michele De Carli: we can allow to have minus 0 point 5 plus 0 point 5, which means Ppd of 10%.
16:25:950Michele De Carli: This is the maximum dissatisfied amount of persons that we might have. There might be, some say, critical environments
16:35:530Michele De Carli: where we should be more restrictive. Okay, so you can see minus 0 point 2 plus 0 point 2.
16:44:540Michele De Carli: Which means.
16:46:640Michele De Carli: okay, here, about 7% of people dissatisfied. So it's very narrow range. It's really complicated this issue. But for some environments, the Ppd could be even lower. But let's say that on average, for most of the
17:03:935Michele De Carli: of the new buildings. Okay, you have to set. You have to satisfy the 10% of maximum percentage of people be satisfied.
17:12:680Michele De Carli: Okay, in existing buildings, which means buildings which have been lived before 2,010 more or less so
17:21:119Michele De Carli: for buildings that are older than 1520 years.
17:26:801Michele De Carli: Then you can allow to have a slightly greater temperature range.
17:33:940Michele De Carli: So that means between minus 0 point 7 and 0 point 7, which means which means Ppd, less than
17:47:490Michele De Carli: 15%.
17:49:600Michele De Carli: Okay, so these are the 3 ranges. Let's say that for the new design.
17:59:289Michele De Carli: Think that most of you feel cold. So it might be that will be round about minus 0 point 8. Okay.
18:28:458Michele De Carli: but it's fine, so you can have your your more.
18:33:140Michele De Carli: You can you? You're not allowed to fall asleep, so that helps you in in keeping the the the attention high.
18:46:420Michele De Carli: Let's see, okay, now.
18:51:740Michele De Carli: let's go. And let's go ahead. Okay, so we have seen that basically we can. Let's say.
19:02:500Michele De Carli: yeah.
19:03:530Michele De Carli: we have seen the physical approach. And we have seen that based on this approach we can get, we can have an a, a suitable response of people or expected
19:16:960Michele De Carli: answer. People, whether they are feeling
19:20:540Michele De Carli: comfortable or not. Slightly warmer, slightly folder now.
19:28:110Michele De Carli: I introduced, but I didn't define the so-called mean, radiant temperature. So the mean, radiant temperature concept is a concept that is, let's say, expressed in this picture here.
19:42:990Michele De Carli: So on the left hand side, you see what is the real condition. Okay, in the room.
19:49:190Michele De Carli: Basically, you can consider just the larger surfaces.
19:56:90Michele De Carli: Okay, like windows, the walls, the floor and the and the roof. Okay?
20:02:30Michele De Carli: And in this case your your body is exchanging by infrared radiation. Okay?
20:10:924Michele De Carli: With their surrounding. Okay? So
20:16:680Michele De Carli: the mean, radiant temperature is the equivalent temperature of a black body.
20:35:370Michele De Carli: Did he rigor?
21:15:830Michele De Carli: Yeah, yes, you have questions.
21:20:640Michele De Carli: I didn't understand what the issue was.
21:25:860Michele De Carli: The regulation changes only by the position, but not the the objects inside there?
21:34:700Michele De Carli: Well, the object these objects are, let's say, are not affecting that much, the mean, radiant temperature, basically your your exchanges with the greatest service. So with the floor, with the walls, the roof.
21:50:290Michele De Carli: the ceiling okay, and the windows not like furniture
21:57:120Michele De Carli: in preschool. You can make like the furniture and other stuff.
22:00:100Michele De Carli: Okay?
22:01:596Michele De Carli: Of course, you have to think about that.
22:05:840Michele De Carli: The the the equivalent temperature. So the mean, radiant temperature. Okay.
22:11:630Michele De Carli: is actually combination of the surface temperature that you have
22:18:330Michele De Carli: and also the view factor. So the way
22:42:235Michele De Carli: you can see that in in this case, okay, you can have different different
22:51:90Michele De Carli: view factors depending. If you're city, if you're standing, if you're
22:55:700Michele De Carli: closer to a window or closer to a certain
23:24:793Michele De Carli: rather than rather than going.
23:32:60Michele De Carli: father. Okay. And if you, if you, if you are far away from the fire.
24:00:550Michele De Carli: he said, leads to the the same
24:07:960Michele De Carli: heat exchange that you have in the real environment with the real surfaces. Okay?
24:16:450Michele De Carli: Oh.
24:32:840Michele De Carli: current surfaces and the adventure of the surfaces. Okay?
24:37:820Michele De Carli: And
24:39:690Michele De Carli: so the mean, radiant temperature. What what is the benefit of the of having a mean, radiant temperature? The benefit of the mean, radiant temperature is that we don't really have to care about the
24:53:590Michele De Carli: the real temperature of the different surfaces. But we have to, let's say.
25:14:770Michele De Carli: for the infrared foundation.
25:19:830Michele De Carli: So I want to remind that we have then the 4 parameters
25:25:930Michele De Carli: before physical parameters are near temperature, wave temperature, wave velocity, and we have seen that the relative humidity.
25:50:50Michele De Carli: The temperature in the gross Guildina is ease of
25:54:760Michele De Carli: responsible for the connectivity change. Now we can even consider
26:07:720Michele De Carli: We can even consider sorry that velocity. So we said, air temperature mean radiant temperature.
26:34:320Michele De Carli: And we are not doing hard work. Okay?
26:39:459Michele De Carli: But for sedentary activity, like, we are here, okay or in the house. Usually. We can try. We can you see, okay, tomorrow, okay, that when we have
26:56:664Michele De Carli: when we are in cemetery activities we have to keep the air velocity.
27:19:520Michele De Carli: then the velocity would be increased. But if you are almost quiet, okay, you're not moving. Okay, then the air velocity should be kept under a certain level. We will see that tomorrow I can. I can. I can. We can say that the velocity of the air should be below 0 point 2 meters per second. Okay, so in these conditions, the
28:02:700Michele De Carli: interactivity, then. So the air velocity should be
28:07:360Michele De Carli: neglected. Okay, so now, the only 2 parameters that we have to take into account are the mean radiant temperature and the air temperature.
28:17:560Michele De Carli: and it can be demonstrated that
28:23:330Michele De Carli: the in a moderate environment. So in the in the environment, which is not too cold or too warm. Okay, they
28:50:670Michele De Carli: Hc, are similar. Okay.
28:53:860Michele De Carli: We can in principle state that the
28:59:140Michele De Carli: we can consider instead of the mirror temperature and air temperature, we can consider the average temperature of this
29:26:260Michele De Carli: environment.
29:27:710Michele De Carli: So actually, if we have just
29:33:50Michele De Carli: they. If we consider just comparative temperature, we have just one parameter. Okay.
29:38:780Michele De Carli: to be satisfied. And this parameter is is combining
29:45:670Michele De Carli: the heat exchange due to convection and infrared radiation between the human body and the surrounding.
29:52:960Michele De Carli: So the periodic temperature is the design temperature. So is it the temperature that we have to that we have to
30:01:660Michele De Carli: to and to guarantee in a certain environment.
30:24:828Michele De Carli: The combination of these of the thank you.
30:33:480Michele De Carli: The the different cup different
30:38:280Michele De Carli: values of media temperature than temperature. We come to this point tomorrow.
31:02:455Michele De Carli: Basically, we can measure. Okay, you can measure
31:10:150Michele De Carli: the air temperature and the media temperature with the global thermometer. Okay? So it is like here, like sphere about 12
31:21:600Michele De Carli: between 10 and 15 cm diameter. Okay? And
31:40:780Michele De Carli: pleasure to meet me, Richard. Okay.
31:44:00Michele De Carli: with this system here, and their temperature can be measured by yeah, thank you. Say so
31:51:820Michele De Carli: this year, which is
31:55:590Michele De Carli: and and of course, you measure the media temperature, the air temperature, and the average of these 2 temperatures, the operative temperature.
32:02:990Michele De Carli: This, let's say, elliptic sensor
32:08:360Michele De Carli: is has more or less the same shape of the human body. Okay, so basically, with this type of sensor here, you're able to measure the
32:20:340Michele De Carli: right directly. Instead of using team sensors.
32:23:880Michele De Carli: It costs a lot, so is more. It is cheaper to understand this one, but in principle it is, I mean a specialized system or special device to measure the operative temperature. And of course, you can measure this depending.
32:43:40Michele De Carli: you can lay this to different, let's say, orientation. So vertical is for standing position of incline is for seated and horizontal is for is for let's say,
33:01:510Michele De Carli: line. Okay,
33:20:750Michele De Carli: have to take into account that.
33:23:223Michele De Carli: There could be also problems in the in the clothing. Okay. Okay. Now, sorry.
33:37:250Michele De Carli: What if all 3 positions which
33:59:280Michele De Carli: in the best, or you take care of the people working there.
34:04:460Michele De Carli: It's a compromise.
34:06:840Michele De Carli: But let's say that in in this year, for instance.
34:10:190Michele De Carli: you are the person who had to be comfortable because you're seated. So you're it's supported. You're seated. Standing usually.
34:37:699Michele De Carli: Okay. So this is the the the condition. So looking at this, let's see who's like.
34:48:870Michele De Carli: So you can see here the different different sets of parameters and different comfort that you might have. Okay, so we can. Let's
35:16:80Michele De Carli: you can see that with the 0 potency, the is always 50%. Okay? Because we say, we don't care about okay. So you can see that by.
35:30:290Michele De Carli: you can have different combination of clothing and metabolic rate, and you end up with an
35:50:470Michele De Carli: so they better.
35:52:930Michele De Carli: And chapter 5, is that the idea that so in summer.
35:58:910Michele De Carli: okay in this room the ideal temperature would be one 24.5 degrees.
36:06:625Michele De Carli: What happens if you increase the metabolic rate and increase the protein resistance.
36:29:610Michele De Carli: or by increasing the relative, you will increase the heat exchange. Okay? And also you're addressing.
36:39:856Michele De Carli: you have greater metabolic rate. And you have also, you're dressing more. you are increasing isolation. So
36:50:720Michele De Carli: by increase.
37:07:930Michele De Carli: you can see in this diagram, here, what is the this diagram? Well, this diagram is providing the growth and resistance.
37:20:380Michele De Carli: Okay?
37:22:880Michele De Carli: And and we have different metabolic rates. So the metabolic rates are these lines here? Okay? So you can see, this is the line with 0 point 8 metabolic rate this is with.
37:37:450Michele De Carli: I don't see anything.
37:39:130Michele De Carli: Okay, this is one. Okay, this is one. This is 1.1. And this is 1.2. So we are interested. We said, we are interested in a 1.2. Okay, 1.2 meant.
37:50:380Michele De Carli: it's the the average that about creating sedentary activity.
37:56:740Michele De Carli: So let's see, what can we expect from an ignorant? Okay, so let's consider. You can see that we neglect the velocity. We neglect the the relative humidity. And and okay, that's it.
38:15:260Michele De Carli: No, we say that.
38:18:130Michele De Carli: Let's start with wintertime wintertime. The clothing resistance that we can consider as a reference is one.
38:26:660Michele De Carli: Okay? So this is the reference, protein resistance for for winter. Okay, now I will. Highlight in blue.
38:36:580Michele De Carli: No, in green.
38:38:100Michele De Carli: The metabolic rate of at 1.2.
38:42:70Michele De Carli: Okay.
39:03:860Michele De Carli: across between the one metabolic. Sorry. One scroll and 1.2 at metabolic rate.
39:12:430Michele De Carli: Okay, now, what we can see here is the optimal optimal temperature.
39:24:780Michele De Carli: Okay, which is more or less 22 deals. Okay, so 22 degrees is the operative temperature.
39:41:00Michele De Carli: So 22 degrees in wintertime is the optimal temperature for reaching Piebu noon.
39:48:970Michele De Carli: But we said that we can.
39:52:220Michele De Carli: I asked, minus 0 point 5 plus 0 point 5. So how can we state the range
40:01:240Michele De Carli: that above or below 22 degrees, which is the optimal temperature so we can go slightly below slightly below
40:08:490Michele De Carli: light, remove 0 point 5 light below minus 0 point 5 spmv.
40:14:180Michele De Carli: so this is, this can be seen in this dot line here. Okay.
40:21:620Michele De Carli: and here you see that is written plus minus 2 degrees.
40:26:300Michele De Carli: So that means that we have the range of comfort is 22 plus minus 2 degrees.
40:33:700Michele De Carli: Okay?
40:35:100Michele De Carli: All right.
40:36:620Michele De Carli: So the dot lines that are here are
40:42:210Michele De Carli: expressing the temperature range, the Delta T, that you can go above and below the optimal temperature, but still being in a Pmd of minus 0 point 5 plus 0 point 5. So 10% of people dissatisfied.
41:00:830Michele De Carli: And this can be, let's say, 24 degrees as upper temperature and 20 degrees C for
41:10:460Michele De Carli: mean as minimum allowable package.
41:13:960Michele De Carli: Sorry.
41:15:270Michele De Carli: How can you decide to do this?
41:17:860Michele De Carli: Because the the line, this line here I will highlight in yellow. Okay, this line here
41:27:440Michele De Carli: you are close to this point.
41:29:830Michele De Carli: And here you have
41:31:970Michele De Carli: plus minus 2 degrees. Okay, so the dot line, which is closer to the to, the or the the upper one. Okay, is the one
41:41:430Michele De Carli: which is is the is the delta that you might have.
41:47:180Michele De Carli: Yeah, what does it mean that in wintertime you're allowed to be in between 20 and 24 degrees?
41:58:330Michele De Carli: So we need to. Let's say we need to to have combination. We have to combine
42:08:520Michele De Carli: on one end the comfort temperature for comfort resolutions, on the other hand, and did you see?
42:15:710Michele De Carli: Okay, so in winter time, which is the temperature which allows you to have.
42:22:960Michele De Carli: And it's your saving 2020 degrees. So 20 degrees is still an acceptable temperature.
42:31:680Michele De Carli: That is the minimum temperature. And this is the best interaction in order to meet
42:37:700Michele De Carli: or to combine the travel, condition, and energy saving.
42:43:230Michele De Carli: So 20 degrees is the design temperature in winter time in summer.
42:51:590Michele De Carli: In summer, we said, I will. Highlight in blue. Okay.
42:55:310Michele De Carli: in summer we have 0 point 5. The metabolic rate
43:00:310Michele De Carli: is the same. So we don't change activity. Okay.
43:04:250Michele De Carli: so with the 0 point 5 clue.
43:10:900Michele De Carli: Now, the optimal temperature is here. Okay.
43:21:490Michele De Carli: believe me, it is 24.5. Okay, so the optimal temperature in summer
43:31:140Michele De Carli: 24.5 degrees C, and plus minus 1.5 exactly
43:43:420Michele De Carli: plus minus 1.5. So that means
43:47:680Michele De Carli: that the comfort. Condition in summertime can be between 26 degrees and 23 degrees.
43:57:300Michele De Carli: Now, which is the contract which leads to minimum energy
44:03:520Michele De Carli: 26. So 26 is the design temperature, because it's a combination. It's a good compromise between comfortable condition
44:12:430Michele De Carli: and not excessive energy power. Okay, for designing the system.
44:20:870Michele De Carli: I want to remark
44:22:760Michele De Carli: that in this case I don't know if you will get it, but I will tell you
44:28:660Michele De Carli: it doesn't really matter if the mean, radiant temperature is greater or lower than the air temperature. Okay.
44:36:10Michele De Carli: so this 20 degrees can be met in with the
44:45:770Michele De Carli: let's say, with a mean, radiant temperature of 21 in the near temperature of 19 degrees C, or
44:55:830Michele De Carli: with, let's say, 19 degrees C, with medium temperature and 21 degrees of air temperature, which is the difference?
45:05:770Michele De Carli: Will not?
45:07:740Michele De Carli: Yes, it. But let's say it depends on the type of initial system that we.
45:13:370Michele De Carli: So the convective initial system like this system, they don't work. But if they would work, okay.
45:20:560Michele De Carli: convective systems is heating here. And here. That means heating. Okay, or are facing the
45:31:440Michele De Carli: lower temperature due to the surfaces.
45:35:750Michele De Carli: Okay, so with these systems, you will have an air temperature which is greater than the mean temperature.
45:42:890Michele De Carli: But if you have an underfloor heating system.
45:46:450Michele De Carli: then the media attention will be higher than the attempt.
45:50:270Michele De Carli: Okay? But basically, from the thermal point, comfort point of view. Okay, at the end, you need to have.
45:58:570Michele De Carli: Okay. So it doesn't really matter if you work with the connective system or the written system from the physical problem
46:06:970Michele De Carli: this way.
46:08:310Michele De Carli: But opposite in summer. Okay, yes, I understand why, in summer it's possible. And
46:18:430Michele De Carli: because in summer you need. I mean in summer you have less messy.
46:26:600Michele De Carli: So the range is no limit, because the if you increase the way you dress.
46:36:990Michele De Carli: the temperature will be lower, but also you have greater regional temperature that you can allow. If you dress less. Then the the the temperature range across the Pmv, okay, is more limited.
46:53:550Michele De Carli: Okay, okay.
47:01:490Michele De Carli: okay. I think it's all for today. There might be problems in the recording
47:08:440Michele De Carli: that you are here. Okay? So you, the, the, the video will be available. Okay, so
47:16:240Michele De Carli: that's it. So we need tomorrow. One thing important next week.
47:22:940Michele De Carli: I will not be here but there.
47:25:550Michele De Carli: So it might be that either we have no lectures at all, or we have a lecture next week.
47:36:390Michele De Carli: Okay, I will let you see. Okay.