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00:00:870Jacopo Vivian: Okay?
00:02:580Jacopo Vivian: So no, we go on with this.
00:11:150Jacopo Vivian: With this presentation, with this lecture on design.
00:18:90Jacopo Vivian: and we talked about other components, the dog. Let him
00:25:460Jacopo Vivian: that you find in every hydronic system, also in your house.
00:31:310Jacopo Vivian: which component is the expansion vessel. Okay, the expansion vessel or expansion tanker has 2 important functions.
00:44:390Jacopo Vivian: First, st is a thermal function, because it provides space where your compressible liquid can
00:53:570Jacopo Vivian: non sorry, non compressible, if it can expand.
00:58:180Jacopo Vivian: or from which it can contract as the liquid undergoes volumetric changes.
01:05:50Jacopo Vivian: Why do we have volumetric changes?
01:08:550Jacopo Vivian: Because, for example, when you switch off the heating system.
01:15:420Jacopo Vivian: your water in the system will go to the ambient temperature around 20 degrees.
01:23:990Jacopo Vivian: When you switch it on.
01:26:70Jacopo Vivian: your generation system will warm up the liquid that will be distributed to the formal unit.
01:34:810Jacopo Vivian: so the water inside the system will go from 20 to 70 degrees.
01:43:520Jacopo Vivian: What is the density and some integration? We have seen that in the previous lecture.
01:51:400Jacopo Vivian: that although it does not change as much as the
01:56:670Jacopo Vivian: viscosity, but still you have some change
02:01:370Jacopo Vivian: in the density, and therefore the volume
02:06:520Jacopo Vivian: occupied by this partner will change.
02:09:940Jacopo Vivian: How much we have seen that if I remember correctly from yesterday, around 3, 4%,
02:18:950Jacopo Vivian: this 3, 4% is very important. Because if you count all the liters that you have in the system.
02:29:180Jacopo Vivian: okay, maybe for one apartment, the 3% is not much.
02:34:400Jacopo Vivian: But still, since the fluid is not compressible to either.
02:40:230Jacopo Vivian: When it expands, it can break some joints, or it can anyway damage the pipe system.
02:50:900Jacopo Vivian: Okay?
02:52:210Jacopo Vivian: So we want to avoid that. This thermal expansion damage the pipes.
03:01:620Jacopo Vivian: And the second function is the hydraulic function.
03:06:480Jacopo Vivian: So then we always, if you, if you think about it, we always spoke about the delta fee.
03:16:500Jacopo Vivian: Even when when I speak about the bumper, I speak about the
03:23:540Jacopo Vivian: the head, which is the Delta V, between inland and outland.
03:28:410Jacopo Vivian: When I speak about the friction
03:31:900Jacopo Vivian: I speak about Delta P, due to continuous and localized pressure losses.
03:39:10Jacopo Vivian: So always delta P. Delta P. Delta P.
03:42:620Jacopo Vivian: But what is the absolute value of the correction?
03:46:610Jacopo Vivian: Is the Delta P. If we have a delta P of one button, or we don't know.
03:56:670Jacopo Vivian: it means that the lower pressure do you use? Zoom?
04:02:670Jacopo Vivian: It could be one, the lowest, and 2 the highest, or it could be
04:09:970Jacopo Vivian: 3, the lowest, and for the highest, or it could be 0 point 0 1 and 1.0 1. Okay, we never said, what is the reference? Actually?
04:21:510Jacopo Vivian: So, the expansion vessel is exactly used for controlling the reference pressure of the system.
04:30:220Jacopo Vivian: because it is a a free charge system at a certain pressure, and all the Delta P
04:41:160Jacopo Vivian: will give you the pressure changer
04:45:20Jacopo Vivian: with regard to the transfer pressure.
04:47:780Jacopo Vivian: Okay, so each. And then it controls the personalization
04:55:20Jacopo Vivian: of them. See if we can.
05:01:590Jacopo Vivian: we have, we can have it.
05:03:800Jacopo Vivian: Normally, we have closed tanks.
05:06:860Jacopo Vivian: They contain an a capture volume of compressed air and water.
05:13:860Jacopo Vivian: So wow, we have a compressible with them, meaning that
05:23:190Jacopo Vivian: we can the our fluid, the water of the system can expand.
05:30:410Jacopo Vivian: and then you can contract them.
05:33:220Jacopo Vivian: And this change in volume is accommodated by this air or other gases.
05:44:570Jacopo Vivian: That are either in direct contact with the
05:50:480Jacopo Vivian: with the water, or there is a flexible membrane that separates the air from the water.
06:00:10Jacopo Vivian: Okay, so this is more typical. We haven't and and membrane.
06:09:420Jacopo Vivian: And in this case we call them via partner.
06:14:520Jacopo Vivian: The other possible yeah, solution is an open tanker, which is also not used.
06:26:750Jacopo Vivian: but you can still find some open tanks where the reference, where basically the variation
06:37:670Jacopo Vivian: of the volume takes place as a level.
06:44:40Jacopo Vivian: Change it.
06:45:870Jacopo Vivian: Okay? And the reference pressure is the atmospheric pressure on the open cluster.
06:57:330Jacopo Vivian: So you can see the situation here
07:01:420Jacopo Vivian: where you have in the. When the system is called, you have the air occupying all the
07:09:640Jacopo Vivian: almost all the space in the vessel, and when the
07:16:330Jacopo Vivian: generation is on in the heating system the temperature will increase.
07:23:110Jacopo Vivian: and therefore the specific volume of the water will increase, and therefore
07:29:210Jacopo Vivian: we need to account for a Delta V change in volume.
07:34:480Jacopo Vivian: This Delta V is exactly the difference between this situation and this situation.
07:42:70Jacopo Vivian: You can see that in this case the water occupies
07:46:670Jacopo Vivian: more space in the expansion vessel.
07:52:70Jacopo Vivian: And what is it in this situation? Yes.
07:58:650Jacopo Vivian: you can have both cases. You can have the expansion vessel below, and then about the the pipeline.
08:13:770Jacopo Vivian: Yes, if they don't have it.
08:20:560Jacopo Vivian: you need to place it above.
08:27:520Jacopo Vivian: Okay, so this is the formula to size and expansion by SIM.
08:35:110Jacopo Vivian: Okay, so simply by calculating the
08:42:940Jacopo Vivian: the change in the specific volume.
08:46:460Jacopo Vivian: So Vw. Is the volume of water in the system.
08:51:470Jacopo Vivian: In that actual school we should, and
08:56:540Jacopo Vivian: V. 2 and v. 1, are the changes in the specific volume.
09:03:750Jacopo Vivian: And then Alpha is the linear coefficient of thermal expansion.
09:12:830Jacopo Vivian: which means which is, refer to that. Goodbye.
09:22:200Jacopo Vivian: Okay.
09:23:740Jacopo Vivian: So because also the pipes will be some subjected to this thermal expansion.
09:33:210Jacopo Vivian: So we have the true terms
09:41:690Jacopo Vivian: volume.
09:43:800Jacopo Vivian: That's good.
09:45:680Jacopo Vivian: For example. Yes, be wonderful.
09:49:770Jacopo Vivian: Yes.
09:53:80Jacopo Vivian: And p. 2 is the temperature, the hot temperature. p. 1 is the cold temperature.
09:58:990Jacopo Vivian: Alpha is relative to the buy, some material.
10:08:450Jacopo Vivian: the same for closed diaphrag and tanks.
10:13:810Jacopo Vivian: The 1st the one before, was for open times.
10:18:630Jacopo Vivian: This is for close diagnos tanks, where you also have this term, sir, all foot. But I'm sure.
10:36:780Jacopo Vivian: and this is for close ranks with air water in the face.
10:43:130Jacopo Vivian: So you have different type of classes. But basically this is the most typical solution
10:54:600Jacopo Vivian: example.
10:59:360Jacopo Vivian: You can calculate it for these conditions.
11:07:880Jacopo Vivian: In the keeping season you might have a design supply temperature of 60 degrees, an ambient temperature
11:17:330Jacopo Vivian: of 10 degrees.
11:19:960Jacopo Vivian: When you feel that the system with the water technical water
11:26:970Jacopo Vivian: you taking from the after that
11:30:540Jacopo Vivian: and the and the cooling in the cooling season.
11:36:770Jacopo Vivian: the ambient temperature. So t, 1 is
11:41:640Jacopo Vivian: the maximum temperature reached by the onion air.
11:46:430Jacopo Vivian: Okay, when the cooling system is awful
11:52:140Jacopo Vivian: and the design supply. Temperature is 7 Celsius degrees
11:57:370Jacopo Vivian: typical supply temperature of a cooling system
12:02:190Jacopo Vivian: for Alpha. You can have different values for different materials.
12:12:450Jacopo Vivian: of course, is, if the nominal temperatures are different. You can use different values.
12:27:980Jacopo Vivian: Okay, so
12:41:740Jacopo Vivian: what should be the pressure, the reference pressure of the system.
12:47:480Jacopo Vivian: We have already seen that we, the main constraint that we have
12:52:910Jacopo Vivian: is to have a minimum pressure bit before the panto.
13:00:530Jacopo Vivian: Okay, one moment.
13:04:170Jacopo Vivian: And normally we have the lowest pressure
13:11:551Jacopo Vivian: Holds a positive pressure at the highest point of the system. So in the highest point of the system.
13:20:310Jacopo Vivian: in terms of paper, you want to have the
13:25:490Jacopo Vivian: a positive gauge pressure. So you want to be above the atmospheric pressure. How much
13:32:770Jacopo Vivian: at least 17 Kilo Pascal.
13:39:800Jacopo Vivian: the highest pressure corresponds to the maximum pressure.
13:44:490Jacopo Vivian: And now we'll go at the location of the safety relief cloud.
13:49:150Jacopo Vivian: So the minimum pressure depends on this criteria right?
13:57:40Jacopo Vivian: And the highest pressure is also important, because at high pressure
14:04:510Jacopo Vivian: the valve with open, because we don't want to be the system to be risky for operators. So there is a safety valve that we open, and then the water out
14:20:460Jacopo Vivian: in order not to increase the pressure to 10 bucks better.
14:26:580Jacopo Vivian: Why is that?
14:28:250Jacopo Vivian: Then close? Okay.
14:30:390Jacopo Vivian: So the stage they really need valve has a nominal fracture.
14:37:140Jacopo Vivian: and that which it will open.
14:41:70Jacopo Vivian: So of course, we don't want the system to be sized for a pressure that is close to the
14:50:560Jacopo Vivian: maximum
14:52:690Jacopo Vivian: pressure of the relief valve. Otherwise the valve will open every time, and you will need to fill the system again and again.
15:02:910Jacopo Vivian: Okay, so we have this practical limits for the
15:08:756Jacopo Vivian: pressures for the absolute pressures in the system. So we are not talking about Delta P anymore. We're talking about the
15:16:950Jacopo Vivian: the maximum and the minimum.
15:20:110Jacopo Vivian: Okay.
15:21:490Jacopo Vivian: you remember the phone, we have the maximum up there. We found. Then we have all the pressure losses
15:27:680Jacopo Vivian: to have the minimum before the 5. Those 2 points are the ones that I'm talking about.
15:40:150Jacopo Vivian: Be interested.
15:41:430Jacopo Vivian: Oh.
15:55:260Jacopo Vivian: that's no issue.
15:58:470Jacopo Vivian: I think it is. It is released in a position where it does not reach the operator.
16:07:570Jacopo Vivian: I'm not
16:14:320Jacopo Vivian: working in place right now.
16:16:90Jacopo Vivian: That's 1 piece.
16:21:420Jacopo Vivian: all right.
16:23:310Jacopo Vivian: I'm not sure if this connected to a to a yes, but
16:32:380Jacopo Vivian: want to give you an answer I'm not sure about.
16:38:940Jacopo Vivian: Maybe some of you have experience.
16:47:900Jacopo Vivian: Yeah, we have? Yeah, to answer
16:55:100Jacopo Vivian: to answer the question before we can have the
16:59:400Jacopo Vivian: pressure. Sorry the vessel above or below
17:04:829Jacopo Vivian: the pipeline in case of closed question.
17:09:680Jacopo Vivian: Okay?
17:10:829Jacopo Vivian: And you have it a bugger in case of the open duster.
17:17:339Jacopo Vivian: In this case, if you have the in the closed expansion vessel, you have that
17:26:270Jacopo Vivian: that the reference pressure at this point
17:31:180Jacopo Vivian: is the pressure of the vessel plus visa water column, which is not much okay, but
17:43:910Jacopo Vivian: for big for big systems it could be should be counted.
17:50:820Jacopo Vivian: And in case of the vessel below the Pipeliner, you subtract the water column right
18:01:200Jacopo Vivian: to calculate the pressure here.
18:21:370Jacopo Vivian: Okay, we were talking about the expansion of the water. So we have this component
18:32:560Jacopo Vivian: to allow the thermal expansion of the fluid.
18:36:410Jacopo Vivian: But we should also consider the thermal expansion of the pipes themselves.
18:44:770Jacopo Vivian: Yeah, which is also account. We also counted it before to sizing of the expansion
18:55:800Jacopo Vivian: which is related to the thermal expansion of the pipes.
19:00:700Jacopo Vivian: but particularly for big systems with the
19:06:340Jacopo Vivian: very long systems we need to. We need the parts to be able to expand without without breaking.
19:17:700Jacopo Vivian: So these are typical values of linear expansion, coefficient of different market areas.
19:32:930Jacopo Vivian: So imagine that you have 50 meters for 5.
19:43:610Jacopo Vivian: Okay?
19:44:910Jacopo Vivian: And you have a
19:48:500Jacopo Vivian: That's the key of, let's use the value before 60 minus 10 is 15.
19:57:550Jacopo Vivian: So 50 times 50 and you apply this on file.
20:08:460Jacopo Vivian: If- if this is a
20:18:220Jacopo Vivian: polyetically 5, we multiply by 0 over 10,
20:26:870Jacopo Vivian: and that we get this for each 50 meters of 5,
20:32:270Jacopo Vivian: a thermal expansion, a linear thermal expansion of the 350 which is 35 cm.
20:48:900Jacopo Vivian: Okay, 35 cm for each 50 meter.
20:54:880Jacopo Vivian: So this is what I'm talking about. We need to account for this
20:59:920Jacopo Vivian: volume changes due to thermal expansion of the pipe.
21:04:40Jacopo Vivian: Of course I calculated with 0 point 14,
21:07:770Jacopo Vivian: but if you change material, you should calculate accordingly. Okay.
21:15:450Jacopo Vivian: as Delta T. What did I choose?
21:18:980Jacopo Vivian: I always choose the situation that you have to decide
21:23:940Jacopo Vivian: in the worst scenario, which is the maximum temperature during location minus, sir, if is a keeping system.
21:36:680Jacopo Vivian: the cold water that is in the system when it is just filled with technical water
21:44:600Jacopo Vivian: at ambient temperature, I assume 10 degrees.
21:48:420Jacopo Vivian: Okay.
21:49:770Jacopo Vivian: so this is the delta. Here. L is the length of the pipe, and alpha is the linear expansion, too.
22:00:400Jacopo Vivian: The maximum limit. Yeah.
22:06:220Jacopo Vivian: yeah, we have reduced.
22:10:740Jacopo Vivian: Yes, you know that the the lower display temperature, the higher the efficiency of the generation.
22:20:80Jacopo Vivian: But it's always. And then. So when you side system, the 1st concern is that, oh, cool.
22:31:360Jacopo Vivian: you don't want discomfort, otherwise they call you that's the whole.
22:37:150Jacopo Vivian: And then the second concern is efficiency.
22:40:540Jacopo Vivian: So you have a maybe you size the system for 7 days.
22:47:180Jacopo Vivian: And then, after one meeting season, okay, it's fine. I can try to decrease.
22:54:220Jacopo Vivian: 2, 65, single purpose.
22:57:990Jacopo Vivian: Right? So maybe normal operation. We have lower temperatures than in the design.
23:06:585Jacopo Vivian: Yeah, 1, 1, 2.
23:11:90Jacopo Vivian: Yes. So we are talking about design. So these values are always for design in this case. Yeah.
23:18:980Jacopo Vivian: you might want to be on the safe side.
23:22:80Jacopo Vivian: because we are talking about design.
23:24:600Jacopo Vivian: And it's really demand for another end.
23:27:790Jacopo Vivian: Yes, yes.
23:37:770Jacopo Vivian: in the for audience systems you don't have this problem, because typically you don't have a
23:47:730Jacopo Vivian: very long time to leverage Iranian system, and the Iranian system has a
23:54:470Jacopo Vivian: light temperature which is quite close to the ambient temperature.
23:59:700Jacopo Vivian: So I'm talking about here. I'm talking about basic users with loan types bringing up heat to
24:10:200Jacopo Vivian: on call instead of the occurrence.
24:18:980Jacopo Vivian: Okay, okay. So so this chart there, as you can see, it's a million.
24:30:370Jacopo Vivian: No. So it's just the same
24:33:600Jacopo Vivian: thing of this equation. It gives you the Delta L depending on the Delta P,
24:44:220Jacopo Vivian: or different lengths of the pipes, and also if you have.
24:53:440Jacopo Vivian: if you are in the design phase of that system, sir, you want to consider the
25:01:690Jacopo Vivian: the pipe elasticity which is the capacity of these pipes to accommodate the change in
25:14:530Jacopo Vivian: in in volume, because they are not expired.
25:19:340Jacopo Vivian: This support, natural elasticity of the system is due to the banks.
25:32:300Jacopo Vivian: Then, when you have a a very long file, sir, strength, fiber there, there is almost no elasticity.
25:44:990Jacopo Vivian: Okay, but if you have some bent curves.
25:51:650Jacopo Vivian: then this curves are able to accommodate some small changes
25:58:80Jacopo Vivian: in that due to the term expansion.
26:02:410Jacopo Vivian: So basically this, the elasticity depends on the number and type of bands in the network.
26:12:500Jacopo Vivian: And since the more systems have the generation unit close to the terminal unit, the small systems have
26:27:530Jacopo Vivian: a good natural elasticity, because
26:30:830Jacopo Vivian: the system itself is- is always full of bands to reach all the terminal units. Okay?
26:38:580Jacopo Vivian: So the problem of thermal expansion of the pipes is not very important for most systems that have
26:48:780Jacopo Vivian: natural elasticity due to this limited length and quite significant number of benefits.
27:00:330Jacopo Vivian: The problem is more on big systems where you have longer
27:09:240Jacopo Vivian: long term long pipes, and we need to compensate for this thermal expansion and shortening of the pipes.
27:18:340Jacopo Vivian: So the pipe and the Ccp.
27:21:783Jacopo Vivian: Is the inclusion for a small diameters and large banking ranges.
27:32:150Jacopo Vivian: so you might have a bandwidth of 90 degrees like in this case, but having 90 degrees with the
27:44:260Jacopo Vivian: D and 20 is better than having an integration with you and whatnot.
27:53:380Jacopo Vivian: Okay in terms of elasticity, meaning that the is able to accommodate for
28:04:660Jacopo Vivian: changes in the in the volume better than a big pipe with bigger telemeter
28:15:437Jacopo Vivian: so in systems with large extension.
28:20:230Jacopo Vivian: the elasticity of the network, the natural elasticity of the network due to this pension is not able to accommodate these changes in volume due to the thermal expansion.
28:34:510Jacopo Vivian: So what do we do?
28:36:400Jacopo Vivian: We can introduce some expansion joints that can be natural expansion joints like this one. So we just introduce some bands that will have, of course.
28:52:290Jacopo Vivian: also a disadvantage in terms of delta fee because we are creating someone localized production losses.
29:02:360Jacopo Vivian: But the benefit is much higher because
29:06:200Jacopo Vivian: we don't need the additional components to have to accommodate for the elegation and shortening of the long.
29:18:610Jacopo Vivian: So here you see that we have some characteristic of the natural expansion joint A and B in terms of meter.
29:28:80Jacopo Vivian: and of course there are some chart that give you the
29:36:890Jacopo Vivian: the thermal expansion that is compensated by this natural drawing, so each line is a diameter.
29:47:300Jacopo Vivian: This is the a length.
29:50:910Jacopo Vivian: So in case that we have 2 meters here here, and here
30:02:170Jacopo Vivian: we choose a diameter, and we find that that
30:06:420Jacopo Vivian: the expansion that we can compensate due to the elasticity of these.
30:11:450Jacopo Vivian: Not that I explained from joint.
30:17:710Jacopo Vivian: this is an example, so we have a 100 meter, long steel pipe, and
30:28:300Jacopo Vivian: we need to determine the size of a Z shape. Natural expansion joint for a 4 inch pipe
30:38:130Jacopo Vivian: the Delta team.
30:40:120Jacopo Vivian: Is it 10 to 90 degrees.
30:44:540Jacopo Vivian: Okay? So that there's the L,
30:46:790Jacopo Vivian: it's calculated that, as we said before, and so
30:52:200Jacopo Vivian: Alpha is the linear thermal expansion coefficient of the steel, 0 point
31:00:190Jacopo Vivian: 0 1 1 and 4 per meter. Kelvin.
31:06:890Jacopo Vivian: 100 is the length of this pipe, and the that the the temperature difference is 90 minus 10.
31:16:370Jacopo Vivian: So we get the 91.2
31:21:140Jacopo Vivian: Okay, in this case we go to the exit system, the Delta M,
31:33:210Jacopo Vivian: we choose. We select the diameter for inches.
31:39:160Jacopo Vivian: and we get the length of C 5 meters.
31:43:950Jacopo Vivian: So if you have 5 meters here here.
31:49:580Jacopo Vivian: of course, 5 meters is a lot. So you need to have more than one
31:58:290Jacopo Vivian: with these numbers. Yes, it's just a calculation manual, of course, financially. Will always.
32:13:110Jacopo Vivian: Yes, yes.
32:17:670Jacopo Vivian: okay. So otherwise. So that that was
32:27:230Jacopo Vivian: exploiting the natural elasticity of the of the pipes when there are some buttons.
32:37:190Jacopo Vivian: otherwise there are some components that can be introduced in the section of the pipe.
32:48:560Jacopo Vivian: They can be, and they can accommodate the this elongation and shortening right?
33:00:870Jacopo Vivian: So you can see how they are made.
33:04:200Jacopo Vivian: They, in case of metal balloons. So they are made of metal. They they have good tightness.
33:18:330Jacopo Vivian: but they don't have
33:23:240Jacopo Vivian: A wide range of movement. Okay.
33:27:270Jacopo Vivian: they are suitable for sanitary and heating installation.
33:32:470Jacopo Vivian: and here you can accommodate both axial and the angular also.
33:43:390Jacopo Vivian: so you you can also have a a change in the direction of the file.
33:54:670Jacopo Vivian: Otherwise you can have a rubber expansion joint that can be state launched into the pipe, and then
34:09:489Jacopo Vivian: they have a they can absorb vibration but they are unsuitable to high temperatures
34:21:730Jacopo Vivian: because they are made of rubber.
34:24:120Jacopo Vivian: Okay?
34:25:219Jacopo Vivian: So they haven't practical application limits.
34:32:170Jacopo Vivian: Then you can have a telescopic expansion joints.
34:37:750Jacopo Vivian: They are made of 2 coaxial tubes, and they are free to slide.
34:47:60Jacopo Vivian: Okay, like the elements of a stethoscope.
34:51:920Jacopo Vivian: so that they accommodate for this change in volume due to the thermal expansion.
35:00:950Jacopo Vivian: and of course, in order for the liquid enough to leak out of the system.
35:08:280Jacopo Vivian: we needed to have some hydraulic steel between the 2 pipes that slide on each other.
35:14:720Jacopo Vivian: Right?
35:16:780Jacopo Vivian: So that's why we have in this case a constraint on the pressure.
35:22:980Jacopo Vivian: Because this, CEO, we'll be tight until a certain pressure and then water will go out.
35:33:220Jacopo Vivian: The problem of this kind of compensator step is that that they can speak.
35:40:580Jacopo Vivian: So if they are not exact sliding exactly in the coaxial direction, the one inside can be
35:52:580Jacopo Vivian: stick on the one outside.
35:58:50Jacopo Vivian: Okay, and in this case they are not serving the purpose of accommodating the change.
36:06:470Jacopo Vivian: And of course they are axial. Only in this case.
36:14:460Jacopo Vivian: Okay, I need to just finish the last very last topical
36:24:637Jacopo Vivian: so you give me a couple of minutes more. I just finish so that we can start with a new topic
36:33:770Jacopo Vivian: tomorrow.
36:37:440Jacopo Vivian: We talked about the thermal expansion. And now we talk about thermal installation.
36:44:120Jacopo Vivian: Why this demo installation important? Because we carry technical water
36:52:840Jacopo Vivian: for heating and pouring. So if we waste the heat, counter the enthalpy of the water before reaching the terminal unit, we are not serving the purpose of having an efficient h. 1 system.
37:09:90Jacopo Vivian: So when we talk about the
37:13:530Jacopo Vivian: thermal insulation, we always think about the energy conservation. We don't want to lose energy. We want to be on the
37:23:740Jacopo Vivian: we want to be efficient. So if you have 80 degrees on the supply of the outlet of the generation, you want to have 80 degrees at the end of the last terminal union.
37:37:560Jacopo Vivian: Okay, this is the concept of efficiency.
37:42:730Jacopo Vivian: But what I want so and of course, in the summer is the other way around.
37:49:190Jacopo Vivian: So in the Standard.
37:51:550Jacopo Vivian: if you have 7 degrees outside of the chiller on the outlet side, you want to have 7 degrees
38:00:60Jacopo Vivian: on the inlever of the control, or whatever you have to distribute
38:07:230Jacopo Vivian: to to make pooling in the building.
38:10:560Jacopo Vivian: So that's why we insulate. But there is also there are also other reasons.
38:16:690Jacopo Vivian: 1st of all, you have any degrees you don't want to capture.
38:23:250Jacopo Vivian: That's diaper and also.
38:31:540Jacopo Vivian: if we insulate them from the outside air, we prevent freezing if the is outside.
38:39:80Jacopo Vivian: because there is water, if the system is off and outside, you have minus 5.
38:46:400Jacopo Vivian: What happens, sir?
38:49:300Jacopo Vivian: We have Isa forming into the system.
38:53:940Jacopo Vivian: and water is one of the
38:57:490Jacopo Vivian: is maybe the only, or there are 2 substances in nature that then when they freeze, they expire.
39:05:950Jacopo Vivian: so if they expand that they they increase the volume
39:12:520Jacopo Vivian: light when they when they were, they are warmed up cool.
39:18:30Jacopo Vivian: So again, there is a risk of damage of the pipes.
39:22:870Jacopo Vivian: so they can also serve the perfect, the purpose of noise, control, and fire safety depending on the material.
39:33:820Jacopo Vivian: But, most importantly for you, that will become an
39:41:00Jacopo Vivian: is the conversation control? Because if you are a sizing a system and
39:51:400Jacopo Vivian: for heating and cooling, or for cooling, only.
39:56:20Jacopo Vivian: you don't want to have a conversation on the surface pipe.
40:01:610Jacopo Vivian: because this compensate. 1st of all, you don't want to have a lake
40:07:10Jacopo Vivian: of water below the bottom, sir.
40:10:100Jacopo Vivian: Okay, now move them.
40:12:940Jacopo Vivian: and then also you can have a corrosion. You can have a damage to the pipes themselves.
40:22:40Jacopo Vivian: So this is why I want to. I want you to focus on them
40:30:690Jacopo Vivian: affected that we don't want to reach the viewpoint temperature of the air on the surface of the pipe.
40:39:160Jacopo Vivian: So if we have 7 sensitive degrees inside the client. But
40:46:440Jacopo Vivian: we have something like between 7 and 20 on the surface. Okay.
40:55:880Jacopo Vivian: that's why we we need to insulate, because we don't want the surface
41:01:400Jacopo Vivian: of the piper to be in contact with the moist air, with the humid air.
41:07:100Jacopo Vivian: because otherwise the humidity that is in the air in the humid air.
41:15:10Jacopo Vivian: when it touches the code surface, would compensate with
41:20:110Jacopo Vivian: cause this damage. So you need to verify that the surface temperature okay, here
41:31:170Jacopo Vivian: is higher than the dew Point temperature.
41:34:980Jacopo Vivian: So here I just calculated the this is just the formula to calculate the surface temperature. Dse, right.
41:44:750Jacopo Vivian: I express the SE. As a function of the
41:49:10Jacopo Vivian: thermal resistance of the insulation that depends on the thickness of the insulation as
41:56:730Jacopo Vivian: and of its thermal conductivity. Lambda.
42:00:660Jacopo Vivian: So if I apply this formula to this case, we can have
42:07:350Jacopo Vivian: a supply temperature of 60 degrees.
42:11:480Jacopo Vivian: a mountain temperature of 30 Celsius degrees.
42:16:340Jacopo Vivian: Okay?
42:17:790Jacopo Vivian: And then we have a certain humidity content depending on where we are. If the air is at the
42:26:250Jacopo Vivian: 75% of relative humidity, the viewpoint temperature will be 25.1,
42:35:710Jacopo Vivian: meaning that already at 25.1, we will have comments on the
42:45:560Jacopo Vivian: If we have a surface of 25.1 for that condition of the air. We have
42:56:100Jacopo Vivian: conversation of the humanity.
42:59:960Jacopo Vivian: In this case we need the 25 off well material with this conductivity
43:10:740Jacopo Vivian: to insulate this pipe to prevent condensation.
43:14:920Jacopo Vivian: But if the air is more humid.
43:19:650Jacopo Vivian: then the dew point temperature drops, sorry increases.
43:25:240Jacopo Vivian: and therefore we need more insulation to prevent compensation until you reach
43:35:430Jacopo Vivian: super high values that are not that visible. Okay? I think you said that 100%, then the
43:46:650Jacopo Vivian: con, the viewpoint temperature is 30 degrees.
43:51:920Jacopo Vivian: So
43:55:230Jacopo Vivian: all of this, to say, don't only think of thermal insulation for efficiency purpose to limit the heat losses on the heat game, but also think about condensation control, especially when not not especially when you have the system for both the heating and cooling.
44:18:150Jacopo Vivian: So don't only think about. Okay, I need to place the term installation to prevent the
44:23:600Jacopo Vivian: it losses, because during the cooling season the thickness
44:28:930Jacopo Vivian: required to prevent procession might be higher than the thickness is designed for thermosulating the pipes.
44:37:50Jacopo Vivian: Okay, and thank you for your patience.
44:45:230Jacopo Vivian: But this is because we wanted that you are ready for the seminar. So I need to be very
44:53:350Jacopo Vivian: faster this lecture and the next one, otherwise they are not ready for the same on Tuesday.
45:01:620Jacopo Vivian: Thank you.