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00:00:110Michele De Carli: Alright, so sorry. But
00:07:780Michele De Carli: no, we were here last time.
00:17:377Michele De Carli: so we have seen the they
00:28:970Michele De Carli: the multi-zone system with the rate coins. Okay, which are delocalized rate coins. And the.
00:38:290Michele De Carli: Now, let's see something that is
00:42:730Michele De Carli: has to be considered that not only for this page, but all cases. Okay, so basically, we are.
00:54:300Michele De Carli: we have to face a problem where we have different.
01:01:140Michele De Carli: We might have different okay, due to the different laws that we have in the different rules. And on the other side we might have different
01:13:750Michele De Carli: different fresh air flooring.
01:18:500Michele De Carli: And also it is. And and for this purpose it is very important to analyze the ratio between the
01:27:110Michele De Carli: fresh
01:28:400Michele De Carli: air flow rate and the overall air flow rate room by room. Okay. So I will go directly to the, to the example. And then we see the general rule. Because
01:40:262Michele De Carli: this, in this way, we can better understand. What is the problem? So let's imagine that in
01:49:690Michele De Carli: we have 3 rooms. Okay, I just can see the 3 rooms, basically the orange
01:57:111Michele De Carli: the orange arrow is representing the amount of fresh air flow rate that we need, which is
02:06:450Michele De Carli: 300 cubic meters per hour. In the 1st room.
02:11:950Michele De Carli: 500 cubic meter per hour in the second room, and 800 cubic meter per hour in the 3, rd in the 3rd
02:22:90Michele De Carli: for the different I mean, and these are the loads
02:26:860Michele De Carli: that we have to meet. Okay, I consider the summer loads
02:31:630Michele De Carli: so 1.85 kilowatts in the 1st room, 5
02:36:720Michele De Carli: kilowatts in the second room, and 7.55 kilowatts in the 3rd room, due to the 10 degrees temperature difference. Okay? And divided by dividing by the
02:50:536Michele De Carli: Cp of near which is 1,002 kg per kelvin, we get the
02:58:670Michele De Carli: the resulting, the resulting rates.
03:03:130Michele De Carli: Okay? So these 4 rates are the ones which are requested for getting 7.6 5 5 and 1.8 €5 in the 3 rooms.
03:14:850Michele De Carli: Now let's make this calculation, so let's consider room by room. The ratio between the required, the theoretical required
03:29:517Michele De Carli: prorate for the fresh air dividing.
03:32:750Michele De Carli: divided by the by the
03:37:800Michele De Carli: overall pro rate which is needed to meet the the load. Okay?
03:43:141Michele De Carli: So we can divide 300 by 500, 5,550, and we get.
03:50:360Michele De Carli: And we get for the 1st room 0 point
03:55:820Michele De Carli: 54. If we divide 500 by 1,500, then we have 0 point 3 3 and 800, divided by 2,250. Okay, here we have 0 point 3 6. Okay? Of course. Now.
04:15:460Michele De Carli: we, I want to remind you that the air heavy unit is serving all this.
04:22:230Michele De Carli: All these rooms? Okay? Which means that when we are recirculating the air we need to respect, we have to respect the
04:34:980Michele De Carli: indoor air quality, and
04:40:345Michele De Carli: which is the more, the the the strictest or the most strict condition in the for the rooms.
04:51:240Michele De Carli: Well, basically, the considering all these ratios, okay, 0 point 4 4 54 0 point 3 3 0 point 36.
05:02:330Michele De Carli: I would like to
05:05:270Michele De Carli: highlight that the flow rates are increasing from room one to 2. Room 2. Sorry and room 3. Okay.
05:15:520Michele De Carli: both in for the overall flow rate and also for the fresh air rate. But
05:22:760Michele De Carli: the 1st room represents the highest value of the ratio between the fresh air and the overall rate. Okay, that we need to supply. Which means that this is the 3, the the most strict condition. Because, when we
05:43:80Michele De Carli: recirculate all the air in the air handling unit. Okay, we need to. We need to satisfy the air quality in each
05:52:960Michele De Carli: room. And the strictest solution the, the, the.
05:58:810Michele De Carli: the the most critical condition is this one, because in that case we need half of air of the air, which is fresh and half of the air which is recirculated. Okay, if we consider this, or if we consider this doesn't matter, then if this is the the.
06:22:390Michele De Carli: if a 0 point 3 or 0 point 4 is the
06:26:980Michele De Carli: overall ratio between the fresh air and the overall pro rate. Then
06:34:180Michele De Carli: in this case we would have.
06:38:130Michele De Carli: okay, let's let's consider 0 point 4 times 550. Okay? So that means that the
06:46:80Michele De Carli: in this case Falling Fort is 220.
06:55:520Michele De Carli: You need this power.
06:58:570Michele De Carli: Okay, which is less than 300 per hour.
07:03:90Michele De Carli: while on the other side, if we consider 0 point 40 54,
07:09:280Michele De Carli: we satisfy the minimum requirements for the fresh air in the 1st room, and then we will increase the amount of fresh air. Okay, in the other rooms. And that is okay, they because we need to. At least we need to we need to supply the
07:28:530Michele De Carli: where the the Me.
07:32:588Michele De Carli: We need to satisfy the indoor quality purposes. Indoor quality purposes means that you need sufficient fresh air.
07:41:450Michele De Carli: So by considering 0 point 4 54, then we will have 300 cubic meters per hour. In this room we have to increase from 500 to 820 cubic meters per hour in the second room, and of course.
07:55:528Michele De Carli: so we will have an increase of 320 cubic meters per hour, and in the 3rd room we need to increase from 800 cubic meters per hour
08:06:390Michele De Carli: 1,230 cubic meters per hour overall.
08:11:510Michele De Carli: We had, in principle
08:14:680Michele De Carli: 1,600 cubic meters per hour as fresh air. But if we need, if we use this room, if we need to.
08:24:516Michele De Carli: If if we have to, as we have to
08:28:800Michele De Carli: have the recirculation of air in a central solution in the air energy unit, then we have to keep this
08:38:440Michele De Carli: ratio and the overall
08:42:429Michele De Carli: floor rate due to fresh air will increase up to 2,350. But in this case we are sure that in the most critical room we satisfy the indoor air quality. Okay?
08:58:220Michele De Carli: Which means 47% of increase of fresh air. Okay.
09:04:160Michele De Carli: the if you if we don't.
09:07:970Michele De Carli: There is someone smoking in the in the in the air inlet on the top of them. So
09:18:478Michele De Carli: because I don't see anyone smoking here. Okay, that's it.
09:26:740Michele De Carli: Okay.
09:30:90Michele De Carli: then, is it clear? Okay. So in order to face and to and to satisfy the the indoor quality per criteria. Then we need to increase the fresh air pro rate. Okay? And the the critical. The most critical condition is for the room which has the greatest
09:53:960Michele De Carli: value. Okay, between jf, J. External air. Okay, fresh air divided by the overall
10:01:130Michele De Carli: flow rate. And so that means that the we need to consider, then the maximum ratio. Okay. M.
10:12:550Michele De Carli: If this is the, if this is the ratio, the maximum one in the rooms that we have to
10:18:160Michele De Carli: supply with the air handling unit. This is the.
10:22:410Michele De Carli: the, the maximum, the the share between the fresh air and the overall flow rate.
10:29:350Michele De Carli: Okay.
10:32:610Michele De Carli: okay, so and this is not only for the rate coil. Okay, but this is true for all the
10:40:970Michele De Carli: different types of the full year.
10:45:850Michele De Carli: See things now. We have seen that we can.
10:55:296Michele De Carli: We can control the different conditions. Okay, room by room.
11:02:530Michele De Carli: by by adjusting the inlet conditions. So the temperature of air entering the room.
11:10:270Michele De Carli: We can also, okay, adjust the delivered or the required power in one room.
11:19:310Michele De Carli: Okay, so with the ray, the rate calls.
11:23:420Michele De Carli: okay. The different heat calls the localizer hit calls. We work on the Delta T, so we can adjust the
11:30:110Michele De Carli: power which is need. The load which is needed room by room
11:34:750Michele De Carli: that we can adjust with the temperature difference between
11:38:975Michele De Carli: the air, the ambient air and the inlet condition. Okay, there is another possibility. Okay, to model
11:47:580Michele De Carli: or to to to to have a partial load. Okay, considering
11:56:880Michele De Carli: or adjusting the flow rate. Okay. So of course, see.
12:02:970Michele De Carli: since the power is the the product between the
12:09:920Michele De Carli: measure, it and the temperature difference between air entering the room and the ambient air, we can.
12:20:640Michele De Carli: We have seen that with the rate coins. We work, or we, we use. Okay, we, we adjust the
12:29:640Michele De Carli: temperature of the inlet. Okay?
12:33:662Michele De Carli: But we can also work on the flow rate. So we can have a variable flow rate in order to okay,
12:43:100Michele De Carli: modulate the load. Okay? So we can reduce the flow rate.
12:49:270Michele De Carli: And we can face the load. Okay, according to a reduced flow rate, which also is beneficial, because in that case, if we reduce the flow rate, okay, we can also reduce the auxiliary power for the system. Okay? And that means that we can have energy saving also from the auxiliary point of view. So from the electrical point of view for driving the funds, because if we reduce the
13:19:400Michele De Carli: no rate, then we reduce also the power I would like to mention. I would like to
13:25:470Michele De Carli: remember you that the power
13:49:270Michele De Carli: there is the Delta P. In Pascal
13:53:180Michele De Carli: times the flow rate in cubic meter per second. Now Pascal means Newton 1st perimeter, maybe neither recycled
14:04:530Michele De Carli: 2 divided by second. Okay. So when we have the flow rate which is expressed in cubic meters per second, and we have the pressure. No, not the partial pressure? Sorry the pressure drop. Okay of our circuit, which is in Pascal. And usually we use Pascal. Okay for
14:23:690Michele De Carli: for their air distribution. System. Okay, then we have the power in well, soon.
14:35:190Michele De Carli: and usually
14:42:910Michele De Carli: the Delta P of the air distribution system is at least 400 500. It depends also on the, on the.
14:51:260Michele De Carli: on the size. Okay of the
14:54:120Michele De Carli: but wait for for full air system. Yes, we can have
14:58:30Michele De Carli: at least 500 600 K. Pascal as overall pressure drop. Okay?
15:11:300Michele De Carli: Okay. So
15:15:10Michele De Carli: that is the scheme. Okay? Or the near hand, the unit in this case, or or the the system. Okay, you can see you have
15:23:460Michele De Carli: the doctor. Okay?
15:26:727Michele De Carli: You can see that. Of course, once you have some air entering in the room. Then you have a reduction of this of the section of the of the docs. Okay? Because
15:37:330Michele De Carli: if they volume for rate reduces, okay.
15:42:250Michele De Carli: then also this section of the dust will reduce it. Okay? Because it's not needed to have large, or because that way we can save money. Okay? Because
15:56:145Michele De Carli: and of course, we will see how to which are the required velocities inside of the of the data. Okay.
16:04:830Michele De Carli: so how can you adjust the the volume flow rate.
16:10:890Michele De Carli: Well, usually the so-called air terminal devices Atv.
16:17:880Michele De Carli: Oh, oh, or air terminal units. Okay.
16:24:430Michele De Carli: the air terminal devices. Which are these ones here? Okay, they have a variable section. Okay? So the the area
16:37:340Michele De Carli: of these air terminal devices, okay, will be obstructed. Okay? Or will be opened, depending on the amount of flow rate which is needed in that room. Yeah, the thermostat which is controlling the
16:55:110Michele De Carli: the the engines. Okay? And in this case you have. You are modulating. Okay, the the flow rate by obstructing. Okay, the air terminal device, the Internet. Okay.
17:13:660Michele De Carli: Of course, you have to manage
17:18:349Michele De Carli: what you have to manage the pressure.
17:22:180Michele De Carli: Okay?
17:23:855Michele De Carli: And usually the best way to
17:27:640Michele De Carli: measure the pressure is to work or to measure the pressure
17:33:620Michele De Carli: in the farthest point. Okay, because this is the most critical point. So the point where you have the largest pressure drop in your in your system. Okay, the the, the ventilation system is an open sleep. Okay? So we have, as we see.
17:53:890Michele De Carli: we are, we have the email outside, that's sweet.
18:01:730Michele De Carli: Bring the air. We have the air and the unit, and then you have different branches. Okay.
18:16:260Michele De Carli: but I'm only secondary. And and then but in the end, okay.
18:30:740Michele De Carli: you take the air from the outlet. And you, inlet. Okay?
18:37:440Michele De Carli: And you have air entering the room. So it is an open circle.
18:41:500Michele De Carli: Okay?
18:43:719Michele De Carli: So in that case you have to consider the partner's point. Okay, with the greatness.
18:57:410Michele De Carli: with the largest pressure drop. Okay, that is what you usually do.
19:02:660Michele De Carli: In the past. Okay, in order to modulate the velocity of the fan. You had some
19:11:690Michele De Carli: equalizing dampers. Okay.
19:14:220Michele De Carli: which were opening and closing today is not anymore needed. Okay, you have a brushless engine, so you can modulate the flow rate by adjusting the
19:26:163Michele De Carli: the voltage. Okay of your unit. And then, of course, to control that once you are obstructing one section, the depression will increase, so you will reduce the speed of the fan in order to reduce the overall
19:43:130Michele De Carli: pressure. Okay, to then equalize all the pressures in all your you know, your, your.
19:51:910Michele De Carli: that works okay in all your in all your your your
19:59:150Michele De Carli: your week of that. Okay. Of course, remember, air is compressible. Okay, and in that case, air is let's say slightly more delicate than water. Okay.
20:19:889Michele De Carli: okay. Then rest of the
20:25:930Michele De Carli: and the unit is the same. What is important is that if you modulate the overall flow rate, you need to keep
20:35:400Michele De Carli: okay. The ratio between fresh air and recirculation. Air at this scene.
20:44:200Michele De Carli: Quantity that the one that you have seen before. So you have also to adjust
20:49:420Michele De Carli: in this case. Yes, these dampers. Okay, in order to has the fresh air.
20:55:590Michele De Carli: which is according to the Internet quality. So the amount of the the the
21:06:210Michele De Carli: amount of flow rate, the minimum flow rate will be on one hand.
21:12:710Michele De Carli: depending on the indoor air quality. Okay?
21:17:709Michele De Carli: And on the other hand, you cannot, I mean, reduce at 0%. Okay, usually, you need you can
21:27:740Michele De Carli: you can have 30% of the design flow rate. Okay?
21:36:140Michele De Carli: And that is because
21:38:20Michele De Carli: you can, you can control. You can see this is a damper. Okay? So we will see in detail these systems when we talk like 2 letters. Okay?
21:47:910Michele De Carli: And so you can see there is a kind of of this, okay, which is rotating, and by rotating will abstract more or less. Okay, the section, the cross section of the air. Okay?
22:15:323Michele De Carli: yes. So you cannot abstract the the section, and you cannot have 0% because of
22:26:180Michele De Carli: noise. Okay, when you obstruct too much you generate the noise and the noise disturbs people. Okay.
22:35:918Michele De Carli: okay. So more or less that these
22:43:564Michele De Carli: yes, what is important is that
22:47:370Michele De Carli: it's extremely important. Usually, if you want to do that, you need
22:52:540Michele De Carli: one system. Okay, so you cannot buy one technology from one producer, another from another producer, and so on. Because the control of the overall system is extremely important. It's complicated. Okay? So
23:08:272Michele De Carli: you have to
23:10:580Michele De Carli: to buy and use just one, let's say, integrated solution. Okay, so it's noted that if a plumber.
23:22:80Michele De Carli: an environmental, it would be the casual brain. Okay.
23:26:360Michele De Carli: okay, so I I do. I do that. I do that, and and and you will spend less. Yes, but then the the system will never work, because you're not able. Okay to control the effort.
23:41:115Michele De Carli: So you have to go to just one provider. Okay, which is able to modulate and to and to control the system. Okay?
23:53:128Michele De Carli: Okay? And then, of course.
23:56:770Michele De Carli: we can combine the 2 systems that we have seen. And so if we want to have a very
24:04:560Michele De Carli: a very a a perfect or good modulation of the
24:12:162Michele De Carli: of the of the loads. Okay, in a full air system, we can work on both technologies. So we can work on variable air velocity. Okay, Viv is called. I didn't mention that Viv is variable air velocity. Okay, the system that we have seen before.
24:29:680Michele De Carli: and also plus the red coins.
24:32:790Michele De Carli: Okay? So of course, you have to think about that. This will cost more because you have.
24:41:220Michele De Carli: You have electrical engines in all the air terminal devices. Okay?
24:48:36Michele De Carli: Or in the in the, in the final branch. Okay? And you have also the rate choice. Okay? So you have to invest more, but sometimes it might. It might be necessary. Okay? Or it might be, you have to do a cost effective, sorry.
25:05:520Michele De Carli: a cost benefit analysis in order to check. If the increase in cost that you have
25:11:250Michele De Carli: for this solution will okay, prevent additional cost for running cost or programs during the lifespan of your
25:20:490Michele De Carli: of your system. Okay?
25:23:960Michele De Carli: Of course, in this case, first, st you work with the flow rate
25:29:660Michele De Carli: and then you adjust the load by the rate. Okay? Because.
25:36:840Michele De Carli: okay, what I told you okay, these slides ago is that by reducing the flow rate you will reduce the electricity due to oxygens. Okay? Which is very beneficial for your running costs. Okay?
25:52:470Michele De Carli: And of course, if you need to modulate more and you're not able to to to go below a certain flow rate, then you can adjust the power of your
26:04:400Michele De Carli: of your room by adjusting the inlet temperature. Okay, so these more beneficial to work on the prorate, because in that case you you save money
26:15:20Michele De Carli: and you save energy. Okay? Because the electricity of the fan will be lower.
26:21:380Michele De Carli: Okay? And then to work with the rate.
26:26:800Michele De Carli: Okay? So these are more or less the the the 8 sorry, the full air systems that are available today. Okay?
26:37:630Michele De Carli: There are some
26:42:960Michele De Carli: archaeological, okay, systems. Okay, I want just to mention them because you might meet them. Okay, in in your
26:52:830Michele De Carli: New York.
26:54:619Michele De Carli: In your experience. Okay? They are not used anymore. They were used up to the eighties. Okay? Because they were really poor from the energy point of view. They were poor solutions. Okay? So they were an efficient solution from the energy point of view. Okay? So
27:16:80Michele De Carli: the 1st system, they are similar in the political. Okay
27:19:600Michele De Carli: in the operations principle. The the 1st system is the dual planning system. Okay? What is this? Yes, basically.
27:30:58Michele De Carli: You can see, there is not the the air handling unit. Okay? So you have just the pressure and the recipient air. Okay, you have the fan.
27:40:790Michele De Carli: And then you have 2 platinums. Okay.
27:43:990Michele De Carli: I told you the platinum is a kind of box. Okay, you can imagine it's 2 large chambers. Okay.
27:51:880Michele De Carli: in macro sheets. Okay?
27:55:380Michele De Carli: And in this case you can see you have some
28:01:554Michele De Carli: couple dumpers. Okay, here, with, of course, 3 elect electrical breathing down
28:10:570Michele De Carli: where you you had a cold planning and a warm planning. Okay, so well, how were this landing
28:19:200Michele De Carli: work it?
28:20:896Michele De Carli: If we incurred the call? Planning was all there just taken outside from outside.
28:27:810Michele De Carli: And your plan you heated this year. Okay, at the 45, th 45 degrees 50 degrees. Okay.
28:36:535Michele De Carli: and in summer
28:39:210Michele De Carli: the warm planning was outdoor air and the cold planning was the humidified and the cold air. Okay? And then you mix up them in order to have the
28:49:960Michele De Carli: what would require the temperatures.
28:52:430Michele De Carli: So it was very cheap solution. But of course. Here you can see you have
28:57:200Michele De Carli: no heat recovery at all right.
28:59:480Michele De Carli: and they were poor solution from the energy point of but yes, thing, you adjust their entry
29:13:60Michele De Carli: by having mixing the cold air outside there with the warm air at 60, 50, 60 degrees.
29:20:910Michele De Carli: The the one plan was at 6 liters, let's say.
29:24:410Michele De Carli: but at that time, who cared about the temperatures?
29:27:530Michele De Carli: Boilers can pumped up to 90 degrees. Okay? So you should even have 70 degrees in the Wall plan. Okay? So you could adjust the inlet air entering. Okay, by mixing the cold air with the warm.
29:42:730Michele De Carli: Okay? The same in in summer. Okay,
29:47:290Michele De Carli: and and you can see you have these days. You have the from the core plan here on the one platinum you have a dot which is going below the platinum. Okay, you can see, these are dot lines, which means that here they go below the plan. Okay, here you have a curve.
30:10:410Michele De Carli: So this
30:11:900Michele De Carli: shadow here. Okay, is representing the curve. Okay, that you have imagine that you have a duct, or usually they, we have rectangular ducts. Okay for large applications.
30:23:100Michele De Carli: Okay, we have seen that in residential application we have
30:26:890Michele De Carli: secular that's usually in in, in.
30:30:550Michele De Carli: in a commercial application or large application, we use
30:35:310Michele De Carli: the rectangle of that which are and cheaper.
30:41:300Michele De Carli: And here you go on, the others on the bottom of the call planning. And then you have the this planning. Okay, the mixing, planning environment.
30:52:730Michele De Carli: The same there. Okay, see? On the other side, you have another doc, which could be another room.
30:59:400Michele De Carli: In that case you have take the air from the one planning. And here you take air from the cold planning. You go at the bottom part. Okay? So you go below the planning.
31:10:970Michele De Carli: There is a curve.
31:12:470Michele De Carli: Okay? And then the.is going today.
31:16:660Michele De Carli: It's implement them there. Okay, so
31:23:860Michele De Carli: they are not used anymore. But you can have this
31:27:820Michele De Carli: type of system. Okay? Usually, that solution was kept for let's say, relatively small solutions. Okay.
31:40:612Michele De Carli: for larger solutions. Okay, you have this
31:45:121Michele De Carli: system. Okay, the the concept is similar. Instead of having a a plenum, you have a duct, you have a warm duct
31:53:560Michele De Carli: and the core doctor. Then you have mixing days. Okay? Or mixing boxes. Okay.
31:58:530Michele De Carli: in your buildings mixing with air. Okay? And having you.
32:04:920Michele De Carli: Okay.
32:09:790Michele De Carli: There are still buildings working with this
32:13:440Michele De Carli: ventilations. Kind of thing, of course, the ones which have been built
32:17:510Michele De Carli: in the seventies and in the eighties
32:20:982Michele De Carli: which means that the regulation system is running since 50 years. Okay? Which is.
32:31:510Michele De Carli: it's not okay. But it's it's cheap. It's cheap. It's cheap not to intervene. But it's not cheap as as Bill. Okay, as you can imagine today.
32:41:230Michele De Carli: And okay. So
32:45:437Michele De Carli: then there are some. Yes, remember, one important issue. Is that for when you consider.
32:55:750Michele De Carli: I mean, this is in general. Okay, when you consider the air.
33:01:80Michele De Carli: Okay, the air the outlet, the the fresh air intake. Okay, you have to think about
33:07:880Michele De Carli: that, I mean, in our condition, in our climate is not a problem. But you have a severe if you have a severe cold climate. Okay, you have to really take care about the icing problems, okay? And and
33:25:920Michele De Carli: slow entering and so on. Okay, so there are some particular strategies to to be considered in severe cold climates. Okay? Okay. And that is, and what I want to mention is that also in the past, okay, for cold climates.
33:48:240Michele De Carli: you might need the humidification. Okay? Because the of course, the colder the outdoor air, the the
33:59:120Michele De Carli: drier will be the other, the the air, and also the resulting air in the in the room.
34:06:350Michele De Carli: Okay, I I mean, here you have some comments about this system, but I don't want to spend time on that, because they're quite old. So it's not.
34:15:420Michele De Carli: They are not relevant anymore.
34:18:469Michele De Carli: Okay? Now, in the last decade. Okay, in the last 10 years, 15 years.
34:26:790Michele De Carli: let's say, from 2,010.
34:31:150Michele De Carli: There was a new perspective about the ventilation, the full air system. Okay, and in this case.
34:47:100Michele De Carli: So the the identification system with it, which has
34:52:70Michele De Carli: and constant air flow rate is called the Cav. Okay. Constant air volume. Okay.
35:01:40Michele De Carli: This is.
35:02:690Michele De Carli: for instance, what you use in case you have an air and water solution. Okay, in case of the air water solution, you can use a constant air volume, but constant air volume, where
35:16:895Michele De Carli: system were also used in fuller system. Okay, especially in the past.
35:22:140Michele De Carli: Then around the nineties, 18 nineties.
35:27:420Michele De Carli: the concept of Vav, the reliable air velocity
35:31:830Michele De Carli: since then have been introduced. Okay?
35:35:310Michele De Carli: And we have seen, okay, the basic principle which is to
35:41:662Michele De Carli: to modulate the rate. Okay in the air terminal devices and the final branches, and to adjust the speed of the phone. Okay.
35:52:830Michele De Carli: but let's say that from 1015 years.
35:55:950Michele De Carli: but from 2,010, more or less.
35:58:783Michele De Carli: We had also the 2,015, maybe. We had the the new concept of DC, the demand control ventilation. Okay? So the demand control ventilation
36:12:350Michele De Carli: is basically a did which also is considering. Not only so, the did usually is adjusting the flow rate according to the
36:26:190Michele De Carli: thermal load of the rooms. Okay, to, according to the actual load required by the rooms. Okay? So the variable air volume systems are
36:38:740Michele De Carli: there are
36:40:90Michele De Carli: changing, or change the rates according to the required load of the room, and if you have a reduced load of the room, then you can
36:52:310Michele De Carli: adjusted can reduce the fluent in the room.
36:56:370Michele De Carli: The Dcv is not only acting on the load, the variable load, but they are also working according to the required indoor conditions. Okay? So they are not working, only looking at the loader, the partial loader.
37:17:560Michele De Carli: Okay.
37:20:71Michele De Carli: or the load factor, let's say, but they are also adjust the ventilation flow rate according to the air quality that we have in the room. Okay? So so they are. So that means that basically they will, or they. They are controlling the volume flow rate
37:43:644Michele De Carli: according to the thermal load, and also to the required ventilation rate, according to the indoor air quality. Of course, in order to do that, you have to, let's say monitor the indoor air quality in inside of of the rooms, and usually you, you have
38:05:900Michele De Carli: the Co 2. Okay, the dioxide as marker in order to measure the air quality that you have in the rooms. Okay, as we have seen.
38:17:642Michele De Carli: So in this case you will adjust the volume. Flow rate according to the
38:22:610Michele De Carli: comfort to the external room. Okay to the thermostat, but also, according to the indoor air quality. Okay, you, you can have a look in this room right now, we are maybe 20% okay of of, let's say, 25% of the
38:39:890Michele De Carli: people which could be expected here. Okay, so and we are providing 100% of ventilation. Okay, we are in. We are in a cost center room.
38:48:960Michele De Carli: Okay?
38:50:406Michele De Carli: Imagine how much you could save in terms of energy if you could modulate at 30% of the boiling flow rate. Okay.
39:00:690Michele De Carli: during, for instance, these hours, or sometimes, okay. And and this is what this is what you can do. Okay, so the idea is that you can modulate. Okay, so this is the
39:17:620Michele De Carli: the, the reference, constant prorate. Okay, here you see the.
39:23:260Michele De Carli: the, the modulation according to the load. Okay, so if this is the full load of the room, and this is the load that you have during one day. Okay, you can adjust the volume flow rate according to the
39:38:60Michele De Carli: load required. Okay, which is which can be met. Okay, just 1 h per day.
39:45:560Michele De Carli: or okay, according to the Co 2 sensors, you can have maybe a full
39:54:118Michele De Carli: presence of people inside of the room for the 1st 2 h
39:59:570Michele De Carli: for 3 h, and then you have
40:04:70Michele De Carli: nobody, and then you have 20%, then you have 40%. Okay? So imagine
40:09:660Michele De Carli: by modulating. Okay, the the velocity. Of course, you cannot also, in this case go below 2530% of volume flow rate. Okay, with the maximum flow rate. Okay. But imagine how much energy you can save. Okay from the thermal point of view, and also from the
40:29:250Michele De Carli: auxiliary point of view. Okay? Because in this way, okay, you will work. With the the electricity, with the with the fan. Okay, at the at the limited electric power or energy through all the okay in this case, and of course, by according or according to the Co. 2, you can.
40:54:620Michele De Carli: You can check if the room is full or not. Okay, the new rooms? Well, you will not. I don't know if you will experience them. Okay. But the new rooms, the new, the new lecture halls in in the
41:08:820Michele De Carli: the hub. Okay, it's close to the theater.
41:12:110Michele De Carli: They are working with the DC, okay, they have the control of indoor airport. Okay?
41:19:980Michele De Carli: And it is planned that also the other the other rooms. Well.
41:24:770Michele De Carli: we are going to retrofit all the other lecture halls. Okay, here in the
41:34:760Michele De Carli: day. Okay, and also in m. 1 and M. 2. They will have also this curve. I I hope they. DC, okay, so you can see here the
41:46:580Michele De Carli: electrical power. Okay? So you can see here. The difference between a constant air volume
41:55:50Michele De Carli: prorate and the DC. You can see that with a constant air volume flu rate. Okay.
42:01:325Michele De Carli: you can work. Okay the whole day, the whole year at the year, let's say, but would be also half year also depends. Anyway, the electric power.
42:14:620Michele De Carli: Okay. With respect to the full Lorraine, you will work 100%. Okay by having this
42:24:500Michele De Carli: consumption. If you work with the constant air ball, sorry with the Vcv.
42:30:750Michele De Carli: you will adjust the amount of your rate according to the required.
42:36:840Michele De Carli: into the Co 2 levels, and you can adjust the flow rate in cubic meters per second, and you can and you can also adjust the the electrical
42:51:20Michele De Carli: power. Okay, power by hours. Which means the electrical energy. Okay, so which are the
42:58:670Michele De Carli: buildings which are more suitable for a Bcd, okay? Well, of course, buildings where you have people inside.
43:09:316Michele De Carli: Like, conference centers, auditorium or lecture halls. Okay?
43:16:85Michele De Carli: It might be also suitable for offices, restaurants, theaters schools. Okay? And so.
43:23:920Michele De Carli: of course, the greater the variation of the load.
43:27:720Michele De Carli: the larger the larger the energy saving. Okay because of the
43:33:110Michele De Carli: reduced flow rate that you have.
43:36:100Michele De Carli: Okay?
43:38:622Michele De Carli: Yeah, you can see an example. Okay, you have 2 examples. These are not.
43:45:437Michele De Carli: are, are works okay? Taken from the literature. Okay?
43:51:981Michele De Carli: they are both in the
43:57:160Michele De Carli: northern Europe countries. Okay? So you can see that. This is
44:06:280Michele De Carli: before and after the retrofit of the building. Okay? By working on the ventilation system. Okay, you can see that. The heating energy to supply air has been reduced. Okay.
44:19:654Michele De Carli: of course, because of the greater.
44:23:570Michele De Carli: Okay, heat recovery efficiency. Okay?
44:28:810Michele De Carli: The electricity for fun was also reduced. Okay? And on the other side they had to. They had to supply cooling. Okay, you can see that cooling is also needed. Okay, in the northern countries. Okay, because
44:43:370Michele De Carli: offer they increased. Well, being of people. Okay? Also because
44:50:10Michele De Carli: they have, anyway, a lot of solar addition. Okay, during summer. Okay, you have almost 18 h of sunny conditions. Okay? Which means that you have solar addition entering the room. And you have.
45:03:60Michele De Carli: And you need to in the rooms. Okay, as you can see.
45:08:690Michele De Carli: And also another example is here. Okay?
45:12:548Michele De Carli: You can see that there.
45:15:790Michele De Carli: this is another office administrative office of the University of I don't know why.
45:20:510Michele De Carli: Okay, well, I should know where. But I was not allowed at that time to
45:26:873Michele De Carli: to tell you where or to tell people where. So I I don't remember exactly right now where people pause in Sweden. But I think it's
45:34:900Michele De Carli: multiple utility. Okay, okay, so
45:41:20Michele De Carli: so now, so what I want to, highlight is that today? Okay, it is possible, okay, to have
45:52:230Michele De Carli: or to yes, to to promote or to propose
45:59:50Michele De Carli: efficient solutions also for full air system. Okay? Which, of course, make the fuller system less energy intensive than in the than in the than in the past. But still, but still
46:19:220Michele De Carli: Still, the water-based solution. Okay, are
46:23:50Michele De Carli: are better than fuller system. But of course, again, if you have
46:29:30Michele De Carli: a huge amount of person in the rooms, okay, crowded spaces.
46:34:170Michele De Carli: Okay, the most suitable
46:36:690Michele De Carli: technology is fuller system. Okay? And by using the Dcv, you can, let's say, save a lot of money. Okay? Again, I want to remind you that for a Dcv, okay, exactly like for a Viv.
46:51:310Michele De Carli: you need a system integrator. Okay, so you need to have
46:58:100Michele De Carli: technology. Okay, you have to have just one provider. Okay, you have just to work with one company which is dealing with all the stuff. Okay, it will cost more, but it will be less
47:15:20Michele De Carli: plus problematic. Okay? In the contract strategy. Yes, we have a building with a lot of targets.
47:30:110Michele De Carli: a modern based solution.
47:36:690Michele De Carli: That's a good question.
47:40:840Michele De Carli: It depends.
47:43:470Michele De Carli: And there is not only a unique answer. Okay.
47:49:30Michele De Carli: if you have small flats. Okay.
47:52:370Michele De Carli: it might be that you could use a fuller system. So the only one solution could be a possibility. Okay, if you have small flats.
48:02:950Michele De Carli: the larger the flatter the better. To go with the with hydronic solution.
48:12:910Michele De Carli: Hotels. That would be an option. Yes, but in hotels.
48:19:50Michele De Carli: you know, as I told you, we we cannot go below. Yes, in orders, yes, even with the even with even in case of mixed solution, water and air solution
48:31:720Michele De Carli: by adjusting the velocity of the according to the because in the hotel it's quite easy. Okay, to know when people is inside or outside, because they have the key, the electronic key, and when they they, they, they are in the in the, in the room. You know that?
48:47:560Michele De Carli: Okay, so it's a 0 1.
48:49:460Michele De Carli: Okay? And in that case, if you know that people are in the room, you can switch the you can go 100% of ventilation. And if they are out you go. 30% of ventilation.
49:02:540Michele De Carli: Yes.
49:11:610Michele De Carli: education
49:16:00Michele De Carli: way. No. It's you know.
49:21:800Michele De Carli: the interest is is full air system. Okay? Usually they have.
49:27:720Michele De Carli: we have a perforated dot nitro, perforated dots. They are textile dots. Okay? You, you can see them on the
49:37:140Michele De Carli: on the 2 sides. Okay, on the top. You see that there is behind the dots with the horse. There is a textile dot. Okay, we will see them.
49:50:591Michele De Carli: In 2 lectures, 2 or 3 lectures. Okay? So usually they have. They are
49:59:15Michele De Carli: plastic dots. Okay with those in order to distribute the air.
50:04:710Michele De Carli: And and usually you have one
50:09:686Michele De Carli: reversible heat pump on in each. yes.
50:19:490Michele De Carli: okay, and the control
50:26:88Michele De Carli: it's still not the but I mean.
50:30:889Michele De Carli: I'm not under. I'm not. I mean, there are okay so usually the the
50:40:440Michele De Carli: there there are. Let's say,
50:44:40Michele De Carli: specific target machines. Okay, on this.
50:47:813Michele De Carli: I've never worked on that. I know how they work. I know more or less who are the providers, but I've never worked on that.
50:57:500Michele De Carli: But I mean, I I have traveled with trains, and I know I know what you mean. So and okay, I can agree upon it.
51:07:279Michele De Carli: Okay.
51:11:440Michele De Carli: alright. So we move to the next.
51:23:30Michele De Carli: So we stop the recording and we move to the next section