MEP Engineering and BIM: Connecting Teams and Workflows in Revit and Autodesk Construction Cloud

STEFAN PANDACIUC: Hi, welcome to this class. I'm Panda. I'll be presenting this class today all by myself. It's about MEP engineering and BIM, how you can connect themes and workflows in Revit, also in Autodesk Construction Cloud. First, the safe harbor statement-- it may be that we showcase some future developments or other softwares or developments that we are doing that are really not sure that we're going to end up in the way that we want.

A little bit about the today presenters. I'm Stefan. I'm from Romania. I'm a MEP engineer. Quite some experience in BIM and Revit. And lately, I've been appointed as a design automation lead for places in our excellent centers from Arcadis. Normally, with me today should have been Toon. But unfortunately, he couldn't make it to this presentation, but know that we are recording. He's from Belgium. Also has a background as a MEP engineer, also have been taking the role of BIM coordinator. And lately, he's been acting as a design automation lead for Belgium.

We're both working at Arcadis, quite a big company with more than 36,000 people, taking place in more than 70 countries. And we are running over 40,000 client projects every year. Now about the agenda-- I have divided the agenda in three. First, introduction part, then talking about HVAC loads and last part, the mechanical and plumbing. This is how much we can afford to present in the time given.

For the introduction, you will see what is about, what we intend to present, what are the benefits, and a little bit about how we set up the workflows and how to create an object library. For the HVAC loads, we're going to talk about the ventilation and heating loads calculations, a little bit about the lessons learned. And when it comes to the mechanical and plumbing part, we're going to talk about some data management and transfer and then how to calculate our systems directly in Revit.

So moving on to the introduction part. This is a part that Toon will tackle it. I would really start from the beginning saying that this class is a follow up from the sessions that we held in '21 and '22 at the Autodesk University. If you search for the code on the top, you're going to see how the session evolved.

This first slide really showcase the difference between a traditional workload and an integrated workload in Revit. You can imagine some benefits regarding collaboration, the storing of data in a single source of truth about modeling that you can have-- intelligent modeling in Revit and not only about checking when it comes to updates, the easiness of working in an integrated workflow rather than in a traditional workflow, and then the increased involvement of the teams, given the fact that the results are very visible using an integrated workflow.

About this session's learning objectives-- you're going to see on the top right some bullet points here showcasing what learning objectives the slide has. So, we're talking about benefits, workflows, creation, implementation, and better communication, each having a description on this slide. So look on the top right, which is called up. It means that that's like a showcase the learning objective.

When it comes to the benefits of the integrated workflows, I'll not develop very much on this. But as was shown in the previous classes, it really-- there really are a lot of positive outcomes-- reducing repetitive work, efficiency, quality, option to have generative design, have a lot of clients that are happy with what they get. And of course, in the end, it's all about our employees being healthier and caring about their well-being, given the fact that we can produce the final outputs in a faster and better way.

Now, a generic MEP workflow, if I have to draw in a mind map of just thinking an overview, we do have from the start in the calculation-- in the design, we do have the load requirements that we're going to showcase later how to calculate. Then we have a little bit of data management, making sure that the BIM model is available, and the data inside it is correct and consistent, then the sizing and the selection of the different systems. And here we're talking about pipes, ducts, cable trays, et cetera, and lately, of course, the design updates, which really happen a lot, especially for MEP. We [INAUDIBLE] to work with the clients and architects. They do change things a lot.

Now, how to create an integrated workflow? This is quite important because we've seen at Arcadis that this is really the start point of getting success. And as you see here on the left part, the middle geometry is really success. And the starting point really goes to the stakeholders. And we are using agile teams to perform our development, using a management platform, and then moving on.

Most of the time, we are using the agile teams. So what that means is that every two or three weeks, we do have a review meeting in which we try to optimize everything that we are doing. We try to learn it. We establish new terms, new actions for the next sprints. And all part of this is the stakeholders, which are the reviewers in our case-- most of the time, engineers, BIM managers, leads in the design automation or BIM territory.

You'll hear a lot in this presentation about tools. You can make use of own-developed tools or standard Revit or tools that you can find on App Store or get from different parties. I have listed here just a few. I can say that during this presentation, you're going to hear from all of them. And we're going to see how we made use of these add-ins to make our workflows efficient.

Now, we are going to go a little bit into the back technical side. And I'm going to talk a little bit about the object libraries because it's really stands at the core of everything that we are doing in terms of design. So to start with, I will go into the object type library. So, I think-- so, there are quite a lot of questions when it comes to what is an object type library. And shortly, I usually answer that.

It's an object library just without any geometry. So everything inside it-- it's data is descriptive data. I say here that it's a family of digital products aiming to standardize the data in our professional service delivery. But if you go into depth, you're going to see that an object type library, if it's-- at the core, it's really a collection of relationships, a collection of attributes, a lot of data inside it. And in the end, it's the single source of truth where all or most of the platforms can interpret and use its data. And here, I'm really referring to Revit, Civil 3D because that's mostly what we are using.

This is our database. And this is our backend intelligence if I can say like this. This is something that we are currently developing at Arcadis. And it's been already in place for a few time now. Now I'll go really toward the MEP part, and I'll talk about the global library that we have been working in, and we have being set up.

In the previous session, I showed you and I talked a little about our MEP object library, what it contains. I was saying that it's really developed to be at an LOD of 300, which is kind of generic-- not too much into detail about as well-- not very light in terms of geometry. We have most common parameters added. And you can think about air flows, velocities, powers, et cetera. It's meant to be used by different regions and of course, having the annotations tied to it.

Now, I will go into detail because last year I showcased and talked about a little bit how I've managed to push and actually manage the parameters for the global libraries. So first, I'll go to say some considerations. This is actually a product that we are developing that is actually one of the projects, so it has a product owner. And part of the team-- we do have two full-time employees only dedicated for the MEP global library, as you can see one for architecture and one for structure. And there is another one for the ontology, so basically, the connection with the object type library.

There must be said that our global library is connected with the object type library. And it's via parameters. It's via the-- so every family has an IRI parameter that is set to the correct object type. I should explain what an IRI parameter is. It's actually a connection [INAUDIBLE] or an address, same as, I don't know. If I have to think about it, it's like a barcode. If you scan it, you can see inside the computer what that object is and how much it cost and what are the details.

As I said, the global library is really meant to be a multi-regional library. So it means that we have to build with imperial and metric system. And also to say that for MEP, there are weekly meetings. And we have-- our stakeholders are from different regions-- in our case, work for seven different regions. And they are specialized on design engineering, BIM, most of the time. And they're even very specialized on special subjects like electrical or some subdisciplines of electricity.

We usually have two meetings-- one in the morning, one in the afternoon because of the different regions. So we have to accommodate different time zones. But that's in our case. And as a last remark, when it comes to a very special subject, we usually contact our specialist and avoid having long meetings with all the stakeholders.

Now about the approach that we've taken. So we see here a graphic showcasing a lot of appliance and really quite complex if you look at the [INAUDIBLE]. But the story is very simple. We had a few libraries that were already developed-- a few countries like Belgium, Netherlands, that were having already a library very well defined in their way. So what we did, we just collected all these objects. Of course, we had to push in all the base parameters that we needed informally with the right naming convention and replace it with the shared parameters that were accepted globally.

Of course, we had to make the mapping with the OTL, implement the costing parameters. And you're going to see a little bit later about the symbols. When you're starting working on a global library, you'll see very from the start that there are some key family factors for each region. And that's for electrical. It's really data symbols, geometry connectors. And for mechanical, is really connectors of course, in different-- a little bit differently put. But those are the most important we have to take care, of and are your keys to success.

First, we had a traditional approach to work by categories. So taking, for example, finishing all the terminals. Completing that will include duct accessories, and then to telephone devices, for example. It did not work because of the different disciplines. And we saw that it disrupted the workflow. We were focusing, at some point, too much on mechanical, and then the electrical team was disconnected.

So we set up a voting process. And through that voting process, we selected the most common families being used. We picked three to five families for each category. And we started off-- actually, first, the first started was with the electrical families because of the [INAUDIBLE], the completion time to be ready for use. During our review meetings, we first were going to the families, selecting the other one. Actually, in the end getting the action items for the next set of families and for the next period.

There is something that you see here-- MagiCAD and MagiCAD standards. It's really [INAUDIBLE] of us that we want to make our library to work with the MagiCAD software. I will tell a little bit later. But the conclusion is that we are working to have the data license for the symbols according to the MagiCAD standards.

Now, there is a big challenge that we have. And that's the symbols within the families, and the symbols do differ between regions, especially Germany, Belgium, France. They are quite different. So we start by gathering all the project templates for each region as reference for the symbols. We made centralize Excel. And we've made sure that the symbols and descriptions of the symbols are correct.

So we also make use of the ACC to showcase each region, their families, so that only the regional symbols would pop out to a family and to the respective region. And at this moment, we are developing an automated tool, an add-in, to checkbox-- a check-- the checkbox for a specific region. So you may be working with the same library for projects in Germany but also in Belgium in our case. Together, with this checkbox, which controls the symbols, it's also controlling or copying the description in the language that the family is set. As I've mentioned earlier, the costing parameters are also filled out in this part.

And now we go to the solution. So we've made use of the type catalogs, and this really helped us on storing the imperial and metric values. But we didn't really need to create different libraries, different families. It's just that we've created type catalog. And when you select your family type, there's one available in both measuring system, and will not give you strange results in terms of the dimensions that usually happens. Additionally, we've added to the type catalog additional parameters that Revit does not accept, for example, the family type parameter.

A little bit about the MagiCAD integration-- so I just-- really for colleagues working in Europe, and not only in [INAUDIBLE], but they do know what MagiCAD may be on the softwares that are based on software MagiCAD. But for others, it may not be clear. So just to put it briefly, MagiCAD has a lot of capability in design calculation. And our target is we intend to use it. So that's why we try to make the global library viable for MagiCAD use.

We had a lot of testing. We have issues that we are working on fixing. Of course, we did a lot of testing with and without modified parameters to see if the calculations in MagiCAD do work. We are now at the point where we are looking at using MagiCAD schematics module and detail items that are being made to make sure that the global library works with MagiCAD.

Moving on, I'll take some conclusions on this because it has been a long process. Making up the global library first is that it's really-- the object type libraries are useful tool to standardize data from different platforms and use them in various ways. We have been noticing that it is really a good investment in Unifi. We are very anxious to see if Unifi will move into cloud like the ACC.

And then of course, the teams collaboration-- it's really important that you have passionate people around from different region that will make-- would make the process easier. And you can build on it. Then, really, the last one is because it's a long and tedious task, you must have a roadmap to keep you on track and try to divide a huge task into small ones that keeps the overview process nice. And you can track it and can report on it.

All right, moving on. We are really moving into the design part. So first of all, is the ventilation. And as mentioned, we're going to start with the loads. So what you see here on the bottom is actually a schedule from Revit with a few bullet points. So what really this is our calculation tool for the fresh air requirements. And if I-- I'll reveal one by one what these columns are. It starts with the space type. So really, what space type will-- is it actually calculated for [? the end of ?] the row, and then the details for all the others.

It is clear to see that the space type do influence the three and the fourth column-- so air per person and outer area per person. This is really from the standard. The area of the space is automatically read from our Revit project there. The fourth one, as I said, the outdoor area and the person comes from the standard. The required fresh air, it's actually a formula, as you see here-- area divided by area per person multiplied by outdoor area per person.

And then the sixth one is the specified area per person. This value is the one that you put if you have a preferred value of area per person. Moving on with the next ones, the specified occupant, this value knows your preferred number of people in this space. It's actually like a manual mode if you don't want to use the specified area per person. The specified required fresh air is the value that you use if you use the specified area per person or specified number of people.

Moving on to the ninth one, this is the design fresh air. This value goes from the final fresh air value that will be used, and last part is the remarks that we have open. As we have different centers, we are using Unifi to store our toolkit. So what this means is that the schedule is actually stored in a project in Unifi. And you can use it to-- you can use the harvest functionality to really get the schedule. Then you can use the transfer project standards to really get-- just get the space types based on the standard like I showed you, [? ACC, ?] and so on.

Now how to use the schedule-- so I've been mentioning a few times about the schedule. And I'll show you how easy it is to really give-- to really get the minimum pressure requirements. So first, we see that the schedule makes the work for us in terms of listing out the spaces that we have. The first step really is to open it and then really select what type of office it is. So when we are creating-- the space it is-- so you can see that this is the first setting that you will make normally. You think what designation does have the space that you are calculating the lowest for.

So if you click on those three dots, you're going to be prompted with the space type settings. And this is really small, but this is really the list. This is a snapshot coming from the CIBSE standard with all the spaces listed there and the settings as well. So right now, we just have to select the right space type for the right destination. And then,

the schedule will automatically calculate the minimum pressure requirement. As I said, this is an example based on the CIBSE standard.

Now, let's say you want to use your own area for the persons or the number of occupants. You just simply input your data in the schedule. In the image, you can see you can place values for both specified area per person or specified [? air ?] occupant. But only one of them will be used for [? air ?] per calculations. And it's the one highlighted with green. When you place 0, it will switch automatically and take into account the Specified Area Per Person column for computation.

In the end, the design fresh air column determines the fresh air requirement to be used. So this is the end. Of course, you can place remarks, but that's not really designed. It's just for you to know what you're doing.

Now, you have the schedule. Of course, you can export it to Excel. We do have colleagues that are requesting this to export to Excel. But we also do have colleagues that are requesting to publish it to ACC together with our project. And I've seen that happening more and more. So I do see a lot of colleagues going to ACC, opening up the model, and navigating to the views, and checking out the schedule.

Of course, there is one extra that they're getting. And this is the potential calculation report-- so a sheet, something that looks kind of like this. This is an example, but you can already see the spaces. You can already see the calculations and the results at a glance. And you don't have to have Excel. You don't have to have Revit open. It's all into ACC, and it's viewable. We do have quite a lot of colleagues that are going on site. And while waiting, or while on the [INAUDIBLE], they're doing these checks. They only need to have a proper connection to open up a Autodesk Construction Cloud project. And they can do it.

All right, now that we are at the point where we have the calculated ventilation rates, I will continue with how do we manage this data. So now we've made the analytics. We need to make sure that the data is really in our spaces and afterwards, in our [INAUDIBLE]. So last year, I showed this slide showcasing that we are using Dynamo but together with some other apps from App Store or different sources to really manage data.

I was saying that, for example, we use [INAUDIBLE] link to-- [INAUDIBLE] and one filter from [INAUDIBLE] to manage our data and to transfer data from one place to the other, export it, import it, and also to-- we are using Dynamo script that we've made quite easy to transfer the actual values from the spaces to the actual equipment.

And here I have to develop a little bit regarding this Dynamo screen because I've been asked a lot last year how does this work and to share it. So in the next slides, I will show the actual how the Dynamo script is really built. So this is actually what you see in the Dynamo player. We're also using Orkestra to run it. But since not everyone has Orkestra, I wanted to showcase from Dynamo player.

First step is really to-- it works on selection, so preselection. You have to select the elements or the equipment that you want to push the data from the spaces to those equipments. Then, you have the translation points. And why do we have that is, as I explained last year-- but I'll refresh it-- it is possible that sometimes we do have equipment that are placed somewhere in the corridor or somewhere really in the thick ceiling, and they're not intersecting the space that they can be easily recognized by Revit or by API.

So the trick is that we are getting those elements. We get their position. Sometimes, their position is aligned, for example, for pipes, it could be that sometimes they align. But for some, it's just a point. So for example, an air terminal is really a point as a position. When we get the location via Dynamo, we get either [? a ?] [? line ?] either one point.

And this is a little bit of management here. We just use replace by condition. And if it's null, we are going to use the point. If it's not null, we are going to use the start-- the start point of the line. And then use the translation to really tweak the software, the actual point where that equipment is actually in the space. I've used it a lot with [INAUDIBLE] because the equipment was in the [? fake ?] ceiling.

And moving on, here, there's another part of management data. You first have to place in the space parameter name, so the one that is being read, and then the element parameter name, the one that the data is being pushed to. So given on the point that we've got earlier, we are identifying the spaces and reading the value of the space to that parameter.

And moving on, we are pushing it to the actual parameter of the equipment. There could be errors. So it could be that some elements are not found in the space, could be that the element does not intersect with the space with the settings that we gave. So that's shown here. And also, we can see here the actual elements and the actual values that are pushed.

There is a continuation to this script. I didn't want to make it complex. I just wanted to show how you can trick the system by copying automatically the values from spaces to the actual equipment if the equipment is not contained within the space. But if you have multiple elements or equipments in the same space, like air terminals, this must be further developed by you. And you just need to group by-- group the elements by space. And then divide the value of the source parameter by the count of the elements. And that's the value that you write to the element.

Good. Now, we are the stage where we have the actual powers into our equipment. So let's say that we do have the [? air ?] values into our air terminals. We already give the selection. We are at the point where we make the calculations. And the calculations are really based on the connection type-- the type of duct in terms of connection. So it could be that duct could be a connection to the air terminal that has different calculations rules if it's a main one that really goes through the corridors and so on. So distributes, and it could be that we have the shaft ducts. Those will have different rules.

And as you can see here, I do have a view in Revit for each and every one of them and one with all the calculation types. And the next step is really just based on the category to really put in the actual design rules. So for connection to our branches, for residential, we use 1.5 meters. But it's up to the project. For a [INAUDIBLE] main duct, it's a little bit higher. And for shafts, it's higher. Shafts are technical.

And using this, you just have to select all the pipes. And using the duct size from native Revit, you calculate it automatically, so it's really based on speed here. And that's how you do. What is the next step then? You have calculated. You went through all the ducts in a fast way. The next step is really to check it. So this is also something that our engineers do love.

So it's by using the color schemes. And as you can see here, very easily applying a color scheme, we can see the actual speeds. This is another view that normally it's placed on ACC. And the engineers do see it, and they really check it at a glance without having-- without having Revit open, without knowing how to use it. They just see this. This is OK for them. The check has been done, and they're happy, and they move on.

Of course, there is a little bit of a downside about the pressure drop calculations. We did them a little bit different, but there are some [INAUDIBLE] here because the truth being told, it's not really that easy. So for straight ducts, the pressure drop calculations are working perfectly. But we don't have only straight ducts.

We are-- using the out of the box calculation only works for 80% of the situation. But with some manual intervention, meaning that you need correct the-- to the correct ASHRAE fitting types. Or pushing in the correct pressure loss coefficient, you can work it out.

Usually-- most of the time, it's a mix of the two, and you can get it out. It's not so easy. That's why we are using MagiCAD because that is being done automatically by MagiCAD, so we prefer to have a third party here.

Now, we are at the stage where we've calculated the loads. We've selected our equipments with the [INAUDIBLE] system. But it happens really that our design changes. So what does that mean? It means that usually, the client either wants a space smaller or bigger or has a different space type where, for example, it was an office. There is now [INAUDIBLE]. The actual workflow just reiterates. So it just matters from where you're picking up from. It is just the space has moved a little bit, or the ceiling height has moved a little bit. Then you just need to reassign-- recheck the design.

But if the building has completely changed, then you are in a mode where you have to do the load calculations again. If that's the case, you saw how it is. It is just need to recheck the space types and the settings, and you have the load calculations, and the [INAUDIBLE] [? build. ?] I will keep on going with the heating, cooling, but it's because here we have a lot of stuff to do, starting with the loads.

So in our case, we are using Revit by default to calculate the loads. There is a catch. For heating calculations, we do have our own add-in. And for cooling calculation, we are using Energy+. I'll go a little bit to showcase the add-in that we have developed in house. Also, my colleague, Toon, explained a little bit about it last year. So this is how it looks like.

It's using the Revit analytical model. It's also based on the European standard. It's doing static heat loss. And at this moment, since last year, it's currently 90% in use. There are [? supposed to be ?] some drawbacks that keeps us from moving it up fully. But it's a tool that we've been seeing that is being used more and more. And it really facilitates the calculation of the [INAUDIBLE] [? flows. ?]

I will showcase a little bit our process. So the process of calculating the heat loss using our own developed Revit add-in goes like this. So we have to create a model from the start. We must have a geometry. It's actually, quite simplified geometry with walls, floors, windows, doors. Then we set up the spaces and adjust some spaces if needed. Then, as you've seen also for the ventilation, we do assign types to the spaces.

There is a catch that we have to set up the right U-values. I'll tell a little bit later about these [INAUDIBLE] errors because we found some limitations regarding the underground elements. And then start the Revit energy model. And here, you have to make the settings for the energy model bridge, and of course, afterwards, for the energy model.

I'm not going into detail about the Revit energy model, but I'll tell a little bit how to use our add-in. So we must just make sure that all the parameters, the entire calculation is being done. There is a shared parameter file that is tied to the add-in, of course, using calculations. And then there are some settings regarding [INAUDIBLE] spaces, also about surfaces.

For example, it happens a lot that a corridor is split into spaces, or a shaft is split into spaces. And there is a divide between them. If that's the case, we just set that divide to air. And then that means that there is no wall between spaces.

The ventilation values are taken from the Revit spaces, the one that we've just calculated. And with that, we just have to add if there is any transfer air. Sometimes, we need to work with under pressure or over pressure system. So that needs to be added. And in the end, the results are there.

This is really just a really quick storytelling about how to work it. Of course, behind it, there was quite a lot of work developing this add-in, and a lot of calls with Autodesk because we found a lot of limitations. I can showcase some of the issues that we found.

First-- the first issue that we've discovered is that there is a centerline alignment for roof, floors, and walls. So that's really-- you don't really get the entire wall thickness. It's just there is a plane through the middle of the wall. And sometimes, these connections are not very well made because one wall can be thicker. One can be smaller. And then the centerline does not intersect very well. And we've seen that there were some issues.

Also, another interesting finding was that when we were having spaces which were most of one space or totally contained into another space, the calculation would not work well, and we couldn't understand why that space is not recognized. So apparently, the software does not understand that a space can be totally contained by another space.

And here, just a quick solution-- we've thrown in like a fake wall just to divide the containing space in two so that it has a connection to the other spaces. A big drawback is that we cannot use Energy+ for heat calculation. And that's because it does not follow the European standard we require.

Now onto a little bit of a modeling tip. With spaces that touch the roof, make sure that we extend them above the roof. It will solve a lot of issues not recognizing the top layers. Now about the underground elements issue that we found, it's mostly because, as you can see here, in the construction types and the analysis properties, there is nothing related to the underground elements.

There is something related to [INAUDIBLE] but in conceptual types. And that's not easy to use and also not safe, I would say, like this. That's why regarding U-values we are working with special types of elements for the underground surfaces. And we manually map the U-values.

Moving to the cooling load calculations-- as I said, by default we go to the Energy+. With the analysis that Revit performs, you may know or not, but Revit sends a gbXML or XML file to the system, HVAC system loads sizing. And that's using the Energy+. And using the Energy+ with the results, all the results are pushed back to the space.

Yeah, and this is what we see in OpenStudio when the gbXML is sent to. So this is all by default by Revit, using the same analytical model. Now, there are some stories that need to be told regarding external software. So what I've showcased until now does not apply for it. So I think there are a lot of regions that are using external software to do calculations. What we are trying is that we use the geometry that we have in Revit. And then the results that external software completes or reports, we push them back to Revit.

And since last year, I've seen that there were quite a lot of questions or issues regarding gbXML export. So that's why I really want to showcase some tips. So as I said regarding the centerline of the walls, I just find out that modeling walls that have only one thickness is really the best idea. And you can really play with the thermal factors and make it work. Then as I said previously, spaces that are touching the roof, extend them above the roof. Avoid creating Plenums.

And the next step is really interesting. Sometimes, we don't really realize where [INAUDIBLE] come from. And usually, it's because the space was not deleted properly. So delete the spaces from schedules, not only from the plan because it will not be deleted entirely. And before exporting gbXML, make sure that you make an analytical model in Revit and check it. In the Analytical Spaces View, uncheck the analytical spaces from visibility graphics and check the analytical surfaces instead. It will generate a better view, and you can check it easily.

And when you're making the energy settings, make sure that you use the mode of used rooms or spaces if you have created already, and the export complexity, simple, and then the export category, spaces. This is the slide that I'll showcases that we are using external software. So we are using, for example, IES for UK or Australia. We are using DesignBuilder. Sometimes we are using Solar Computer. This is a little bit special because it's in connection with MagiCAD. But as you can see, we are using quite some external software.

But the common workflow is that we do have the building in Revit. We export from Revit, either by gbXML or IFC. We use external tools for calculations, and then we import back. And you may say that you do a lot of work just for some calculations. But the actual Revit building model can be used for a lot of things, as you can see. The pressure requirements, the lighting calculations can be done in Revit. I give the example of ElumTools because that's what we've been using lately.

You can use the managing room space data. You can do quite a lot of things if you have a building model. So it's a lot of gains for all these things now. Once again, we do have in a way or another all the loads into our model. It's now up to us to really manage the power to our equipments and slide equipments, depending on the solution that we selected.

But we are moving to the calculations of the hydraulic system. So a system for the ducts, this is quite simple, at least for us. So we are using parameters to differentiate from noise-sensitive or to non-noise-sensitive areas or to different [? spatial ?] requirements. And based on that, we do have maximum speeds or maximum pressure depths that we use.

And just by selecting on the pipe category, I would say, or the classification category or calculation type, we just use the default piping system from Revit. But you have to make sure that you know what you're doing. You must make sure that your system is well set and there are no errors to it.

Moving on, if there are any changes to the design, you just have to pick it up from where it's needed. Either it's the energy model that you have to redo, or you have to change the solution or the actual layout. It's really easy compared to a traditional workflow, this workflow.

Then we move to the water supply. So this is a little bit special. Because as a load, you don't really need to calculate loads. This is really coming straight from the plans. You just have to count in your fixture, count in how many people you have, and so on. So this is the actual load that we have for the water supply, so the actual quantity that you need to-- you need to connect.

Now we need to talk about the actual library that we've been discussing in the start. So you need to make sure that the objects that you are using are well set. And they do incorporate all the fixtures, and they're well-- the connectors are well configured. Otherwise, none of the calculations will work. All right, and that's what I'm showcasing here, that all the primary fixtures must have the correct flow assigned to the connectors.

In the case-- I'll showcase an example for Belgium. So we do have-- from the standard, we have specific design flows for the different primary fixtures. All these are set into the families that we have in Revit. And we use them for calculations. Revit automatically adds up the flows. And using the calculations from Revit that he does, we calculate the peak flows with the formula, of course. And then using this information, we size the pipes correctly.

This is the actual formula to be used, as you can see. It differs a little bit from building to building. And this must be set in your Revit project. But it's as-- it's just one time. It could be that you have different building types within the same-- within the same model, but it's really easy to modify your schedule based on what you have. And what's also easy is that you can differentiate. You can have multiple schedules for different buildings if you give them different names.

Now moving on, this is the actual implementation. So you can see here how the schedule header looks like with all the parameters. You can see how we placed in the formula. So basically, we do have a live Excel connected automatically to our model. And this is really what we use to calculate. So if in our case, one part of the system does cross the line of 1.5 meters per second in peak velocity, we just increase the pipe size. That's how easy it is.

And I do have here a small video showcasing that. So you see that I have the schedule on the right, the 3D view on the left. And using this, I just see that the peak speed is above 1.5. I can change the diameter from the schedule or [? redo ?] from the Revit environment. I can easily highlight [INAUDIBLE] where the pipe or where the sections.

What's really nice is that you can play with the grouping of this schedule to really batch, do calculations. You can really see here the parameters that we've been using also. There are calculated parameters having a formula. But this is how easy it is to really have an Excel spreadsheet straight into Revit connected to the actual elements that you do have in your design.

A few notes-- the schedule is filtered on system abbreviation. So we do filter out everything that's not water supply. Make sure that you set it correctly. You can select the sections of the system of interest one by one. Or you can do that multiple [? interests ?] if you group it differently by checking in 3D [INAUDIBLE] a section is [INAUDIBLE]. That matters, and you can change the parameter so that the peak velocity is in acceptable limits.

It can be that multiple plumbing fixtures or supply fixtures do operate at the same time. Then we don't look at the peak speed. We just look at the total speed, and then make the calculations. It's good practice to document these assumptions for later reference. And one last tip-- this task can be made easier with tags placed in 3D showcasing the section number and the fixture units in each section.

Now we're going to move to the last part of this class, and that's about sewage. And I'll give also the example of Belgium, for example. And in the standard, we are given the picture and the design flow for that fixture with some restrictions. For example, if we said that if the length of the connection is greater than 4 meter, or it has less than-- if the connection is longer or has more than three 45 bands, this means that we have to use the second column here. So that's really the design choice when designing the connection pipes.

In Revit we have different pipe types. And those are connection pipes. Those are-- we have collector, stacks and ventilation pipes. And based-- all the connection pipes are size based on what we've seen earlier, on the number of 45 degree bands. The other ones are really sized on the flow that is running through the pipe. And what you're seeing here on the bottom is actually the color coding. We have filters assigned for each pipe, filters that are reading a parameter that's set in the pipes to differentiate the different calculation for the different types of pipe.

And here is how the Excel looks like. So you can see that the values do change if I change the K factor and the [INAUDIBLE]. And in the first columns, you can notice the difference. The pipe materials, we can either have PVC, PE, et cetera. And on the right side, you can see the peak flow and the sum of flows for the different types.