Transcript
00:08:10Michele De Carli: Oh, so we have seen the thermal comfort. Okay. So thermal comfort, I told you, is one is a part of the of the
00:19:30Michele De Carli: indoor environmental quality. And when we talk about Hvac system, we have to consider not only the thermal comfort, but also the air quality, indoor indoor air quality.
00:38:680Michele De Carli: and in order to provide good indirect quality we need to.
00:43:900Michele De Carli: they delayed the meetings. Okay, we need the.
00:47:310Michele De Carli: So this part is called indoor ventilation. So how much we have to ventilate in order to provide a proper or adequate air quality in the room.
01:05:369Michele De Carli: Okay, let me 1st of all. Again, I mentioned briefly, yesterday and the day before the environmental quality is related to the mix of these 4, let's say.
01:23:170Michele De Carli: topics. Okay, so we have thermal comfort, indoor quality, noise, control and visual comfort.
01:29:870Michele De Carli: Okay? And and related to this
01:36:140Michele De Carli: for parameters, we have, let's say, 3 concepts. Okay, comfort comfortable place or well, being in general healthy or healthiness. Okay.
01:50:960Michele De Carli: you need to have a health environment where they want to live
01:54:790Michele De Carli: and also in in in some applications. Okay, people, productivity. Okay? So if we increase the the comfort well being and have a certain environment, we can increase the productivity of people. Okay? So these are, let's say, 3 aspects that can be taken into account. And that, let's say, these are the 3
02:21:160Michele De Carli: issues that are should, let's say.
02:28:130Michele De Carli: should be the drivers, let's say, of having a an adequate indoor planet.
02:36:940Michele De Carli: No? This is the 1st performance. Bid in directive in 2,000.
02:45:590Michele De Carli: Yeah, 5.
02:47:560Michele De Carli: Please don't be short.
02:49:710Michele De Carli: 2,002.
02:51:870Michele De Carli: And in the 1st article you can see that the the proposal of, or the the main focus of the Epbd, so the Energy Performance Building Directive was to have efficient buildings. Okay.
03:09:220Michele De Carli: but we should consider auto, climatic and local conditions and also indoor climate requirements and cost effectiveness. Okay, so we need to take into account the cost of benefit analysis for retrofitting for a retrofitting solution. Okay.
03:31:887Michele De Carli: so the indoor environment is important also for the
03:38:830Michele De Carli: European policy. Okay? And especially because we have to consider that we are.
03:47:530Michele De Carli: I mean, 100 years ago we were mostly living outside. Okay. But today, we spend just 10% of our time outside and 90% of our time in our life is spent in a closed environment.
04:02:260Michele De Carli: Okay, we spend 55% of time at home. Of course, this is on average. Okay, maybe you are young and you spend more time outside than at home. Okay, but let's say that in the in the whole lifespan. Okay. So when you become older with me, you spend more time in the house than in other places. But let's say, on average, we spend 55% of our time in the home. 24% of time in the work.
04:30:765Michele De Carli: Space 6% of our time. We are in the in the vehicle. Okay, train bus car. 5% public premises for shopping. Okay? So supermarket shopping areas and cinemas, okay or other. And just 10% out.
04:55:610Michele De Carli: Okay, now.
05:02:130Michele De Carli: what do you think that we have as intake. So we have 1 kg of fruit in one day. We have 2 kg of 2 liters of
05:14:860Michele De Carli: liquids. Water okay, partly could be some other liquid and we are
05:23:280Michele De Carli: breathing 50, 15 kg of air. Okay, so we are much more interested in looking at the water or the drinking fluids, or where we, where the food comes from, what we are not interested in the air that we're breathing. Actually.
05:42:710Michele De Carli: So if we spread, then this. So if we consider the food, the drinking, and where the kilograms of air we take from, you can see that most of the air most of this air is in at home or at work. Okay? And so these are the most effective, affecting spaces for our, let's say, restoration.
06:12:550Michele De Carli: And what is important to remember is that without food you can live for 3 weeks
06:20:630Michele De Carli: yet. You can leave few days for without drinking, but you can justify a few minutes without breathing. So I mean, the the the importance of air is more relevant than drinking and food
06:43:20Michele De Carli: game.
06:46:810Michele De Carli: Another perspective, I told you, is that
06:50:970Michele De Carli: productivity? Okay, you are hopefully going to work in a service company. Okay?
06:59:40Michele De Carli: So you are studying and you will work in office. Okay? And if you work in a service company. Okay?
07:10:391Michele De Carli: The company budget. Okay, the the company budget is yearly okay, is can be shared in these 2 different voices. Okay, so
07:25:140Michele De Carli: most of the cost to you is Uk, because the personal cost sees the what is much more relevant than your company.
07:35:670Michele De Carli: Then you can see that you have energy. Is just 1%. Okay.
07:43:662Michele De Carli: maintenance is 8%. And the financing 8%. Okay, so energy is just
07:53:340Michele De Carli: important for 1% of the budget of the company. Okay?
07:57:920Michele De Carli: But maybe a little bit more. Because today the the Internet has increased. So maybe electricity for Internet and servers. It's a little bit
08:05:530Michele De Carli: great, anyway.
08:09:300Michele De Carli: What is it more important to save energy, or to or to improve the
08:17:490Michele De Carli: comfort? And so having do? Is it better to spend more, or to invest more in in a healthy environment, or to save money, to have poor heating and cooling system in a poor, let's say comfortable space. If you here, just to give you a
08:38:500Michele De Carli: an example. Okay? You can increase the cost of 20% of energy. Okay, which means 0 point 2% of overall cost. But if you increase the productivity of 5% will decrease the overall cost of by 4%. Okay.
08:56:720Michele De Carli: of course there is a balance. You need to try the balance. You cannot cannot use too much energy. Okay?
09:02:830Michele De Carli: But I mean the intention of this is to say that people they are, they might don't care about the Hva system that they use. So they want to use cheap solutions. Okay? And maybe to avoid urbanization. But if you provide a very good heating and cooling system, so you can invest there, and if you provide a better space in your space that will be beneficial for the productivity of people.
09:30:360Michele De Carli: Okay, so this is the sense of this introduction. Okay, now.
09:39:380Michele De Carli: what about indoor quality and and in in comfort. So have a comfort for indoor. So we are going to go more detail. So let's talk about
09:54:480Michele De Carli: okay, so we needed to provide a healthy space.
10:01:150Michele De Carli: Okay? Which means that we don't.
10:03:730Michele De Carli: We want to avoid any topology
10:08:150Michele De Carli: problems. Okay? Sorry photos. But we want also to have a comfortable space. Okay? So we want, let's say, to avoid problems related to building okay building materials to provide a healthy space.
10:29:970Michele De Carli: And the
10:34:90Michele De Carli: in some cases. Okay, we might have even the so called sick building syndrome. Okay, so sick building syndrome is a building where people are really affected. Okay, in the health by the building. Okay? What are the usual problems that you might have in a building?
10:58:880Michele De Carli: Intigo caffeine battery problems. Usually there are some buildings where you have the where people
11:20:100Michele De Carli: come after the weekend. They spend their their time on Monday, and then on Tuesday they are here. Okay? Of course not all meetings, but there might be sick building sick meetings. Okay, so what I want to say is that you need
11:40:470Michele De Carli: to have a proper indoor quality. Proper indoor quality can be met only by ventilation. Okay, so ventilation is important because we need to
11:53:00Michele De Carli: in order to remove all the all the politics that we have immediately.
12:00:860Michele De Carli: and one of the major pollutants
12:05:40Michele De Carli: are ourselves. And so persons is actually one of the main sources of pollution in a building, especially in buildings where, like office buildings, we are the main the main pollution source. Okay in a building. And we have to remove the the pollutants.
12:29:835Michele De Carli: So
12:31:730Michele De Carli: after this, let's say introduction, we say we want to ventilate. So we want to really
12:41:660Michele De Carli: make or have insulation. Sorry? Have ventilation in buildings. Okay?
12:47:870Michele De Carli: What is ventilation is the
12:52:710Michele De Carli: The regulation is the process. Okay, where we are going to supply outdoor air to remove the pollutants in the building. Okay?
13:02:430Michele De Carli: And so you can see that there are several possibilities. Okay? You might have
13:14:180Michele De Carli: user ventilation. Okay? Or ventilation. But in induced by the the user, you have infiltration. Okay? And you have some. Let's say, ventilation system. Okay? Is it sufficient? No, not really. Okay. So it is. it is, very well established that
13:40:310Michele De Carli: or it has been established several by several studies that living, or the the
13:48:910Michele De Carli: the autonomy to people to open and close the windows is not sufficient to have enough ventilation, so the air quality should not be just
13:57:870Michele De Carli: met by so called airing. Okay, so airing is the opening and close of windows of openings. Okay? And that is not sufficient because people they are not
14:12:190Michele De Carli: always aware that they have to open the window, even if you you don't really remember to open the window each hour or half an hour. Okay, for few minutes to replace the the the air inside of the of the building. Yes.
14:33:830Michele De Carli: What do you mean?
14:34:930Michele De Carli: Yeah, that is a problem. Yes, that is, this is a problem in many, in many places around the world. And actually, they are thinking about having filtration in in buildings. Okay, in order to, let's say, limit the pollution inside the building. Yes.
14:56:980Michele De Carli: this one. Actually, we live in a in A, in a poor outdoor quality placed.
15:03:690Michele De Carli: But anyway, it's better to
15:06:920Michele De Carli: use the ventilation rather than not ventilating either. You have to use a filter. Okay, but massive filter for the indoor air.
15:21:580Michele De Carli: Okay, so
15:25:360Michele De Carli: I want to close the the introduction. So why do we have to ventilate? We have to ventilate because we want to limit the pollutants usually. You what you could do you can
15:41:186Michele De Carli: especially for hazard or dangerous pollutants you can have, let's say, an estimation of how much you have to ventilate. Okay, by considering the concentration of a certain pollutant in the space. Okay.
15:57:910Michele De Carli: let's say that this is not really common for residential building office building. But let's say, for instance, in an industrial space where you have some dangerous
16:09:360Michele De Carli: pollutant. Okay, or production in this case you should consider the or you should try to limit the the concentration, and you have to do some risk analysis in order to see if the exposure time due to a certain content
16:33:390Michele De Carli: to assess that concentration is is can be problematic.
16:42:640Michele De Carli: Okay, so this is not what you usually do. But it might be that in the future you might find an application, especially not application where you have to check the risk. So the exposure risk usually in this analysis is related to the concentration that you might have, which is actually data
17:05:829Michele De Carli: generation rate divided by the pro rate that you have for ventilation times the the time that you that a person spent there, and and in that case you can. You can check the exposure to some chemicals.
17:26:240Michele De Carli: Now coming back to the usual buildings which are the usual, you can see here a list of potential that we might have in them here. Okay, so we can have a mission for building materials and furniture. Okay, like.
17:50:460Michele De Carli: And so on. Okay, or finishing material and paintings. so these are the main the main solutions. Usually. Okay. This.
18:09:180Michele De Carli: Then then
18:13:240Michele De Carli: the emissions of materials, furniture, finished materials, and so on. They are not comfortable in time. So you have at the beginning there is a greater emission, and then the emission okay will lower over the time. Okay, but it is important, especially especially in the 1st period of time. To really limit the amount of
18:42:00Michele De Carli: consultation on these pollutants. Yes, please.
18:47:260Michele De Carli: Furniture or something that or not.
19:08:250Michele De Carli: Well, the stove like it depends. Which store I hope you don't not open stove are forbidden. But let's say yes. Open stove is a problem. If you use an open an open stove. That is a problem. Okay? So but when you do cooking
19:30:360Michele De Carli: you, you actually, you are pollute. You have co 2 emission, you vapor emission. And if you are, if you have too much Co 2 emission, then it can be Co production, where you may also die. Okay, so so they they I mean the commercial stores like wooden stoves, and so on. Usually they are
19:54:870Michele De Carli: pulling. Or, yeah, you have the ventilator. You have the fund, and the fun is pushing away. Okay, outside with the chilly, the the combustion pro products. Okay? So it's not a problem. Open source is probably many times most of the problems that you might have for people who die or or can have problems is ready to open. Stocks.
20:18:860Michele De Carli: Don't use open source. Okay? No furniture is. And when you buy new furniture.
20:26:640Michele De Carli: yeah, pollutants, even though you you, they say that it is green and they limit the pollution, and so on. Voc, they are always present, and and what you should do, you should ventilate as much as possible. If you paint also, when you use paintings, even though they are low emission, emitive or emission paintings. They they will anyway, produce. Doc. Okay.
20:54:370Michele De Carli: so this is the volatile organic compound. Okay.
20:58:848Michele De Carli: and you have also combustion products. Okay, for instance, in kitchens. Okay? And yes. And of course, you have vapor. Okay, humidity. And microorganism. Okay? Which can attack the the the indoor air quality.
21:18:710Michele De Carli: So I think this will be the last slide. Okay for today. So
21:27:290Michele De Carli: how can you define a a good air quality. Okay? So the good air quality, okay, is,
21:37:630Michele De Carli: is defined by means of by means of the
21:47:110Michele De Carli: no. Sorry. There is only one play, one source or one definition, or there is only one standard defining the quality of the quality of the air is 62, which is the standard in life standard. Okay for regulation. Okay? And in this case, the definition of a proper or good air quality or
22:14:690Michele De Carli: sufficient air quality is an environment where they
22:22:510Michele De Carli: and the dangerous compounds chemicals are below the legal value. Okay? So they are. So it's a
22:33:880Michele De Carli: for the most relevant and most dangerous chemical compounds. You have a limit of the of the concentration, so these compounds have to be below the minimum, the maximum level allowable for them.
22:54:490Michele De Carli: And in any case. You have maximum 20% of people dissatisfied for okay.
23:05:361Michele De Carli: so that is important, because we see how to correlate this person to people dissatisfied with the current. So the amount of air that you need to provide flow rates are usually provided in this way. Okay, so they are liters per second. Okay, so usually.
23:28:850Michele De Carli: the recommendation is leaders per second per person or
23:35:720Michele De Carli: meters per second per your area, right so
23:41:810Michele De Carli: broad area is one of the parameters that we use in Billings.
23:47:750Michele De Carli: I want to remind remind you that 3 meters per second times 3.6
23:58:380Michele De Carli: is cubic meters bound. Okay, remember, this is.
24:02:480Michele De Carli: I mean this calculation. You have to remember it. Okay? So yeah, if you multiply by 3,600 and divided by 1,000, then you
24:14:440Michele De Carli: switch from meters per second to cubic meter per hour. Roughly, you can also multiply the liters per second flow rate by 4, and you get the cubic meter per hour. As for okay.
24:27:840Michele De Carli: why cubic meters? Power? Because usually the ventilation systems are provided for ventilation flow rates of meter, cubic power.
24:39:120Michele De Carli: There is also another parameter. But we are going to see that next week, which is, the air changes power, air change rate. Okay? Which is taking into account the volume of the room. And how many times, how often you replace the volume of one room? Okay of the volume of your building?
25:00:963Michele De Carli: And and in that case you can also, in a very rough or simple way, estimation of the
25:09:410Michele De Carli: yeah.
25:10:250Michele De Carli: Wait next week, Monday and Tuesday. There is no lecture. We meet again on Wednesday. Okay. So Wednesday, if I'm not here, there will be professional. Okay? But we will do. Lecture on Wednesday. Okay.
25:24:260Michele De Carli: no. Lecture. Monday and Tuesday 10.