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00:04:450Michele De Carli: Okay. So we were looking. We were talking yesterday about the temperatures that in my head.
00:16:320Michele De Carli: we're feeding the emission systems. So I told you that basically, we can range, let's say, from 25 degrees to 90 degrees so the 90 degrees were mainly used in all the buildings like before the seventies. Then let's say,
00:41:720Michele De Carli: the the temperature has been reduced. And we can have also lower temperatures. Okay, so we can work with 55 degrees or 60 degrees with
00:56:601Michele De Carli: with the radiators in the buildings, which are insulated. Okay? Even not well insulated. These systems or the phone can work at, let's say, 45 degrees. And the radiance systems can work at this temperature or even at lower temperature.
01:18:787Michele De Carli: An interesting parameter is not useful, I mean for the design point of view. Okay, but it's interesting because you get the feeling of what you can have in terms of, let's say.
01:33:770Michele De Carli: potential efficiency. If especially if
01:37:580Michele De Carli: you couple that with the heat pumps. Okay, is this parameter here is called effectiveness, coefficient? Okay?
01:50:105Michele De Carli: It is once again, it is not. I mean.
01:56:760Michele De Carli: it is not the design parameter. Right? It's just let's say, a qualitative parameter. But it's it's interesting. Okay, so what is this? Basically, it's the temperature difference between supply return minus the overall temperature difference that you have in the room, which is the supply temperature in the initial room in the initial system minus the room temperature.
02:20:00Michele De Carli: Okay? So
02:23:289Michele De Carli: here, you have some references just to see what is Abcd to H, so A and B are radiators, high temperatures, radiators. Okay? Which means them in the past we used 80 degrees more or less temperature in the seventies, then in the nineties
02:47:326Michele De Carli: about an average of 70 degrees was used in the radiators.
02:55:520Michele De Carli: for so we can see low temperatures, radiators with 55
03:02:400Michele De Carli: degrees supply temperature focal unit. So this system can work with the 45 degrees, the supply temperature so deep. So you can see that from A to C, okay, there is not a big change. Okay, you have almost a flat parameter. Then you if you look at phone calls. We can have a slight increase. Of course, once you
03:32:850Michele De Carli: work with lower temperatures, like in the chilled beams, we see what kind of system are. But basically, I'm big. Okay.
03:45:520Michele De Carli: so where you can even lower the temperature. But you can see that when you work with 35 degrees or less, you can have an increase of this efficiency system. You can see that a radiance system in the nineties was
04:07:815Michele De Carli: size to go to have 35 million less. Okay?
04:14:568Michele De Carli: Today, you can have radiant system working, as I told you, let's say, 26 degrees, or even at lower. Okay, in design condition.
04:26:250Michele De Carli: Which means that basically, you are very close to room temperature. Okay? Of course, you have that. The feeling of
04:35:500Michele De Carli: let's say how much efficiently you can transfer the heat into the room as a temperature difference between the water
04:44:940Michele De Carli: side and the difference between the average water temperature in the heat exchanger. And okay? So you can see that with the radiance system, okay, also with active beams or chip beams, as they as you want to call them, you can have a high efficiency systems. Okay? Because you are below, let's say, 14 degrees temperature supply
05:15:520Michele De Carli: for cooling. What can we say for cooling? In cooling, we have a
05:24:260Michele De Carli: a more narrow type of range. Okay?
05:29:103Michele De Carli: Then the one that we use in heating. Basically, when we work. Let's say up to 0 degrees. We usually talk about cooling. Okay, when we are, or let's say, up to 5, 0, down to 5 degrees. We talk about cooling. If we go below 0 degrees. Then we talk about the refrigeration. Okay.
05:55:670Michele De Carli: so cooling is, let's say, from 0 5 degrees today.
06:01:22Michele De Carli: Which are the usual temperatures. Usually the temperature that we use in A/CI told you, is they are.
06:19:270Michele De Carli: The 10 actually are 7 degrees supply and 12 degrees.
06:25:970Michele De Carli: Okay? And you use this temperature for the units, but also for so you can use this for concourse.
06:42:720Michele De Carli: That also helps for the
06:49:640Michele De Carli: air handling units. Okay? So if you want to define the air in the unit.
06:57:980Michele De Carli: you should go with this temperature here. Okay, you might have even slightly higher temperatures. So you can get up to. Let's say.
07:08:130Michele De Carli: 9 13 degrees. C, okay, 14 degrees. C is still okay. Okay, it's a limit. But still, okay for dehumidifying
07:19:650Michele De Carli: here. Okay? As a matter of fact, you might have this recording networks where you might have the network, which is between 7 and 12. And in the heat exchanger, okay? 7, 12. This is the district network. And then in the heat exchanger for your music inside of the building, you might have, let's say, 38. Okay, so we would one degree, currently.
07:49:348Michele De Carli: one can be difference between the district network and your network inside of the building. Okay, but let's say that in general, you cannot go above these temperatures, because otherwise in the film coil in the air you're not able to air.
08:09:680Michele De Carli: So for this reason, usually you. There was no sense to work with different temperatures, but do
08:20:260Michele De Carli: work in with 7 12 for supply energy.
08:24:850Michele De Carli: Of course you know that you could work at higher temperature.
08:31:200Michele De Carli: But
08:32:419Michele De Carli: so you could increase for work. Let's say, at 70 degrees. C, okay. And maybe you can have an Internet 2021. Of course, if you go at higher temperature, then also the Delta P usually is limited. Okay. So if you go at 7, 26, 5 degrees.
08:56:580Michele De Carli: see temperature difference between supply and return. So the water, if you go at higher temperature. Okay, usually the the Delta T that you have is not that big? Okay? So usually, you have 3 4 degrees temperature difference. Okay, on the mission units.
09:21:70Michele De Carli: Of course.
09:23:852Michele De Carli: You can work with these temperatures here.
09:27:750Michele De Carli: But in any case,
09:30:970Michele De Carli: with these temperatures you are not able to dehumidify the air. So if you want to dehumidify the air, or if you have an air in the unit. You should work with this temperature. What does it mean?
09:45:160Michele De Carli: It means that basically, you could work with so-called high temperature systems. Okay for cooling. Okay? Because usually the reference temperature is 7, 12.
09:59:230Michele De Carli: Okay, did we see?
10:06:490Michele De Carli: You can work, let's say in actor 70 degrees 20 degrees. Okay.
10:13:260Michele De Carli: But if you want to have an efficient system to produce these 2 levels of temperatures, you need 2 chillers. Okay? So if you want children
10:27:180Michele De Carli: done, the evaporation temperature will be driven by this low temperature bank.
10:38:150Michele De Carli: Sometimes people would say, Well, what happens if I have an evaporator which has a greater temperature or if if I could in principle work with an evaporator and is able to provide temperatures. Okay, from 7 to 17 degrees, what should we do?
10:59:20Michele De Carli: I mean the
11:00:870Michele De Carli: ER of the cycle. Okay, ER is energy efficiency ratio, which is the power. Doing that we can have divided by the electricity. Okay.
11:13:500Michele De Carli: cop is the efficiency of the heat pump in it. So this cop is
11:23:280Michele De Carli: the amount of heating divided by the electricity. Okay, in a cooling, cooling load divided by electricity.
11:38:460Michele De Carli: Okay, the evaporation temperature
11:45:150Michele De Carli: is related to this to to the 7 degrees centigrade. So the evaporation temperature will be driven by the minimum temperature. Okay? So
11:58:70Michele De Carli: you can produce 2 temperatures different, 2 different temperatures. But if you have just one evaporator, the evaporator, the efficiency of the of the of the cooling machine will be given by the it has to evaporate at least 5 degrees. Okay.
12:14:940Michele De Carli: okay, maximum, so that there is no efficiency in producing cold water with one source. So with one sugar at 2 different temperatures. Okay, no, doesn't matter how you do that. If you want to do it in an efficient way. You need 2 machines, 2 different machines, one working at 7 degrees.
12:39:250Michele De Carli: and the other work working at a higher temperature. So in that case you will have one machine, one chiller, which will work at 5 degrees at evaporating temperature, and the other chiller will work at 15 degrees as as your evaporating temperature. So in that case you can have a greater year with the chiller, which is cooling at 15 degrees as evaporator evaporating temperature. Okay?
13:07:920Michele De Carli: And so and
13:15:90Michele De Carli: what I want to say is that, as we will see, we can use high temperature emission systems for cooling. But if you want to produce this water at an efficient level. You need to have a dedicated, a tailored or a separate chiller to produce the cooling at this temperature. Okay.
13:42:363Michele De Carli: we will talk about that
13:45:500Michele De Carli: when we do when we talk about the solution. Okay.
13:53:720Michele De Carli: okay, so
13:57:520Michele De Carli: what about the if we if we use the same concept of effectiveness of heat transfer. Okay in the cooling. So if we use the same concept that we used here for heating. Okay, so the same parameter. But okay.
14:19:300Michele De Carli: but calculated in cooling. Okay,
14:23:940Michele De Carli: what could we expect? We can see that basically, okay, which are the terminal units which are the emission systems that we might have in cooling.
14:36:810Michele De Carli: Of course, radiators are not able to provide. Okay, so radiators are not suitable for cooling. Okay.
14:46:190Michele De Carli: if they would cool, you should not use the air conditioning in your house because you could cool just with the radiator that you use for heating. So okay, because
14:59:10Michele De Carli: they they they they are not able to call the the room
15:03:986Michele De Carli: if you use bank OS
15:08:30Michele De Carli: this system here you work at 7 12 as well as you work with on the on the air handling unit. Okay? So, and these are the values.
15:23:267Michele De Carli: If you use larger phone calls, okay, then you can see that you could increase a little bit. The temperature and the the effectiveness coefficient
15:36:400Michele De Carli: for a radiant ceiling. Okay, you can have a an interesting result. Okay, with the radiant floor. You can see that. In this case you're not able to, or you have some. Some. Let's say you can see that there is not a big
15:56:140Michele De Carli: difference between the radiant floor and the usual sequence.
16:02:671Michele De Carli: And then we have this technology here. Okay, tops, thermal activity systems. Okay, they're
16:11:200Michele De Carli: known since long time. Okay.
16:14:290Michele De Carli: actually, it's my 1st love. Okay? From the research point of view, of course. Okay,
16:21:460Michele De Carli: So so they are old. They have been introduced in the end of the nineties, but they are not very much, and you can see that in this case
16:34:380Michele De Carli: this is the only system you can use for cooling, which work at
16:41:261Michele De Carli: more or less 90 degrees 20 degrees as supply temperature. Okay, so there is no other system working at high temperature as the system. Of course, it has some limitations and greasy. We will talk about that. Okay, but it is a very interesting solution, and as a matter of fact.
17:04:680Michele De Carli: is the only solution that reaches a high value with, together with, I would like to mention, anyway, the radiant ceiling. Okay? So radiance, ceiling and taps are the 2 best solution for the okay. Again, this is a parameter, which is not okay.
17:25:69Michele De Carli: is not the Bible. Okay? So it's not.
17:28:870Michele De Carli: But it is okay, somehow interesting, because you have the feeling, the perception on the the the how good that the heat transfer between the water and the is okay. But it is not. I mean.
17:46:180Michele De Carli: it is not very wide widely used in the technology.
17:51:930Michele De Carli: Okay, so after this introduction. Okay, we are going more in detail on the hydraulic emission systems. And these are the
18:05:520Michele De Carli: initial systems that we are going to see in this order. Okay? So we will look 1st at the radiators which are the most diffused and common and present
18:21:90Michele De Carli: systems in
18:23:740Michele De Carli: in Europe. Okay? And then we will talk about the in coils and baseball heating conductor heating system. Okay? And up to here
18:41:10Michele De Carli: they are only providing heating. Okay, so just warm water inside. So no cooling is considered. And then we have. We are going to see the trunk oils, the active beams or cheap beams. Unit heaters. Okay? And these are convective systems.
19:08:300Michele De Carli: Okay? Which are
19:14:360Michele De Carli: suitable for heating and cooling. Okay?
19:17:830Michele De Carli: And then we are going to see the radiance. Okay, which can be also used for heating and cooling. But of course, in this case, for radiance, they.
19:29:780Michele De Carli: the the physics behind a of these systems is a little bit more complicated. Okay? So we will spend
19:41:290Michele De Carli: at least 2 letters. Okay, to talk about the regency. Very, they.
19:48:910Michele De Carli: Okay, they are.
19:51:710Michele De Carli: They are a very interesting solution. Okay?
19:56:870Michele De Carli: Because why? Because we have seen that basically with radiance system, you have high efficiency in the heat transfer.
20:05:500Michele De Carli: Okay?
20:06:590Michele De Carli: And they and for heating, they are today. Okay, the most diffuse system for new buildings. Okay, in new buildings radio systems are the most frequent or most used technology.
20:24:303Michele De Carli: I would like to mention that there are some countries like in Korea, where the radiance system is as the radiator here. So in 99% of 99.9% of buildings, even existing buildings. You have radiance system, even buildings of the fifties and the sixties. Okay? So
20:45:530Michele De Carli: it depends on the culture. Okay? But let's say that in Europe radio system have gained a lot of market, especially in the last years in the Central Europe, they became a very widely used technology at the beginning of, let's say, late end of nineties. Beginning.
21:10:300Michele De Carli: So since 20 years, this residential buildings, radio system in Central and North Europe are the systems which are used in new buildings.
21:21:140Michele De Carli: Okay? So I stopped the recording now and let's enter into the the hydronic system.