Supercharge Your Electrical Predesign with Electrical Analytical Tools

ANDREW LEAVITT: Hello and welcome to Supercharge Your Electrical Predesign with Electrical Analytical Tools. We are part of the unofficial MEP track at Autodesk University 2024. If you're attending this course, there's a good chance that you might be interested in some of the other courses in this track. So please take a look at these. Check out the course numbers and titles. See if there's anything that interests you, and encourage you to check out these recordings. I am Andrew Leavitt. I'm a Digital Practice Manager at Victus Engineering.

WILLOW NICHOLS: And I'm Willow Nichols, a founding Partner and Electrical Engineer at Victus. Victus Engineering is an MEP and technology design firm based out of Minnesota. In our six years, we have grown from the founding partners to a team of 32. We focus on teamwork, technical excellence, and continuous improvement, and this presentation is our work to bring some of that technical excellence and continuous improvement to you.

ANDREW LEAVITT: Now, let's look at electrical analysis. These are tools that are available for electrical predesign in all versions of Revit since Revit 2023. To begin, let's start with what these electrical analysis tools are and discuss why we are going to use these tools. We'll need to know what information we need from the architect. And we'll go through the whole workflow from start to finish. And then finally, we'll look at the results and what we do with them. And then the exciting part, we're going to have a live demonstration of this process.

So what are electrical analysis tools? Well, these are tools that are going to allow you to create electrical analytical loads based on architectural information, regardless of the level of information that you have. So this could be very early in design based on a programming study, existing drawings, a scanned PDF, AutoCAD backgrounds, or even a Revit model. And based on this preliminary information, you can lay out areas, and you can assign loads to these areas, and then you can assign the loads to a conceptual distribution system. And using this, you can calculate connected and demand load and current on equipment in that conceptual distribution system.

You can add and modify loads as the building design evolves and as you move from SD to DD and into CD. And that allows us to fully participate in early design phases to have discussions with architects about where the building is going, how this compares to other designs, and maybe discuss some sustainability solutions. These tools are available in all versions of Revit from 2023 onward. They're not an add-on. They don't require an additional download. They're just available in the Analyze tab. So I hope that you'll be able to get back and start using these tools right away.

Why do we want to use these tools? I think some of you might look at what they're capable of and say, I have spreadsheets and calculators, and I can do all of this stuff on my own. And you're probably right. But these tools allow us some advantages. First, we can set up that conceptual distribution system and create a hierarchy so we can supply one piece of equipment from another piece of equipment and see how all of these loads translate from where they are assigned all the way upstream to the power source.

Additionally, it's a fully integrated Revit process, so we're working in Revit from the very beginning. Hopefully, the architect is also working in Revit early, and so we have all of these results available as Revit elements in schedules in Revit so we can toss the external spreadsheets and calculations and just worry about working in Revit.

So in Revit, what we're going to do is we're going to estimate electrical loads based on areas that we lay out, and these areas could be based on an architectural model or lines that are actually representing walls in Revit. Or they could just be areas that you lay out to represent rough areas that the architect is giving you in a programming study. And we can use the results from this to design a more sustainable building so we can estimate our electrical loads early and hopefully try to reduce them.

We can also design a distribution system from a utility to transfer switches, transformers, and buses, and we can rightsize our equipment early. We can note the necessary load and current connected to equipment and we can determine equipment sizes very early in design. So we can figure out how to lay out our tidal electrical room based on the sizes of equipment and necessary clearances.

And we can push the architect to give us enough space because I know that many of us have had discussions about how much space we actually need for our utility rooms. Well, now we can justify our decisions based on real world evidence. And hopefully, we can use this to drive our equipment orders and make them a little bit earlier in the design process, rather than pushing everything to the last minute.

So let's get started. Let's look at your first project with electrical analysis tools. First, what do we need? We need to some basic building information. We need to know the building type, whether it's a library or an airport, so that we can determine some load densities, whether things are going to be high density or low density power or lighting. And we can use previous project experience to drive this information.

We also need some architectural data. So we're going to need something from the architect, whether it's a programming study, telling us the areas of specific programs for the building, whether it's an ancient scan drawing. It could be more than 100 years old. You could have AutoCAD plans, a PDF background, or even a full-fledged Revit model. And regardless of the data that you're working with, you can lay out these areas.

So what is the workflow? Well, we're going to start by creating area-based loads. So we're going to lay out areas based on architectural data. And then we're going to assign loads to these areas. And an area can have multiple loads assigned to it, for instance, lighting and power, and you can assign a load to multiple areas. So this area could be high density power. This area could be low density power. And this area could be high density power again. And you can join and separate areas as needed. So it's a little bit more flexible than working with rooms and spaces. You can add multiple spaces or multiple areas to one load and have it calculate as one cohesive load.

Finally, once we have this information, based on the loads and the load densities, we're going to be able to calculate the overall load and current for these areas. We're also able to create equipment loads so we can create virtual equipment and size this equipment based on voltage and apparent load. And then we can assign these equipment loads to load sets, so we can say of these 10 motors, four are expected to be on standby, and six are expected to be in continuous operation. And we can calculate the appropriate loading current based on those motor loads.

Finally, what we do with these loads is we create a conceptual distribution system and assign loads to electrical analytical elements in the conceptual distribution system. So what does that look like? The conceptual distribution system consists of four components, the power source, the bus, the transformer, and the transfer switch. And we create this conceptual distribution system in a system browser. And these buttons are the buttons that you're going to see in the systems browser in red.

So here's the system browser. Here are the buttons that we use to create these electrical analytical components. Once we create these components, we can assign a hierarchy. So we can connect transfer switches to power sources. We can connect transformers to power sources or transfer switches. We can connect buses directly to power sources, to transfer switches, or to transformers so we can create a virtual distribution system that is similar to the real world distribution system that we expect to create.

Once we have that hierarchy, we can assign loads to individual components in the hierarchy, so we can assign loads to panel boards. We can assign motors to buses. We can assign panel boards to transformers and then loads to our panel boards. And then we can see, going upstream, what the connected load and demand load are based on our connected loads, so we can review each piece of equipment and size it appropriately.

So here we have our connected load, our demand load, our connected current, and our demand current, starting from the bottom and going upward to each piece of equipment. So on this bus we have 2,000 VA and up. On this utility, we have 2.44 kVA.

So what do we do with these results once we have them? Well, we can determine the required equipment sizes, and quantities. So that will give us an idea of what is required for this project. We can start to lay out our riser or one line diagram and put that on a detail sheet. And getting ahead of that work is always pretty advantageous. We can also lay out our electrical route, which again, usually gets pretty tight. And it's good to lay it out early while we still have a little bit of time to work with, instead of pushing up against deadlines.

Finally, we can order equipment. So hopefully, we can get ahead of those long lead times. Some of these lead times have been exceeding a year, even, for ordering equipment. So I know that a lot of you have run into problems with ordering equipment. And now, we can hopefully order our equipment a little bit earlier in the design process and get equipment on site when it's time for construction.

We can also create schedules, so we can communicate the results clearly. We can present these schedules to the owner or the architect or contractor so that we can say this is the equipment and these are the expected loads that we're going to have in this building. We can also discuss any outsized loads based on previous project experience. And we can say, this area seems a little bit out of line. Maybe we need to adjust this a little bit and start planning for sustainability, start designing a building that has lower equipment loads, lower electrical loads, and we can use less energy.

Then we can use the information that we get from this process to monitor project progress as we move from SD to DD to CD. Is the project in line with our expectations? If not, maybe we need to adjust some project parameters, or maybe we need to adjust our expectations. We can use the results from this analysis on future projects so that we can define our required loads a little bit more accurately and make more accurate predictions for the future. So now, it's time for the exciting part. Let's have a live demonstration of these tools in a real project led by an electrical engineer.

WILLOW NICHOLS: Yeah, so let's get started. In this case, we never know exactly what kind of information we're going to get from an architect or our design partners early in a project. We're lucky. In this case, we'll use in this example, we'll have a Revit model, but we could just as easily do this if we had just a sketch, a PDF, even just a programming plan. We don't have areas laid out specifically. We have them identified in a table or something like that. So we can be really flexible in what we use as an input to inform our design here.

So in this case, we do have a preliminary floor plan. And the first thing we want to do is lay it out into some different areas based on what we expect the loads to be. So for a full-scale project, we might have quite a few different areas. We might break them down much smaller. For this demonstration, we're going to simplify a little bit and identify areas where we expect a high density of loads and areas where we expect a low density of loads.

So let's start just by creating some areas, thinking about that high density and low density. Circulation spaces like hallways, stairways, vestibules, storage areas, those are going to be low lighting density and low receptacle density areas. So we'll identify those, draw them out here onto our floor plan.

ANDREW LEAVITT: So we're going to use our typical Revit drawing tools. Hopefully you're familiar with these. You can draw lines or pick lines.

WILLOW NICHOLS: And one of the things I like about this is that at this point in time, it's still very simple. We're working in 2D. You can be as precise or as imprecise as you like, as long as you're following the layouts here, the information that we have. You can use these drawing tools like you would for any kind of other linework in a project. So we've got a--

ANDREW LEAVITT: We have a few areas that we made in advance and then the area that we drew right here. These area boundaries are closed. As you can see, the lines are pink. If they were open, there would be orange ends on the lines. It would be difficult to see once we have the wall. There's the orange end on the line.

WILLOW NICHOLS: So just like any other areas that we define in Revit, we want to make sure they're totally bounded. So at this point, we've got our areas created, separated into the circulation spaces, and then in this case, essentially everything else. So we have an event space, a catering kitchen, an area that's called a cultural exchange. We'll be conservative and assume that's a high density area.

So once we have those areas defined, now we want to create the area load types to assign to each of these. Now, these load types might be lighting loads. They could be receptacle loads. They could be anything that's based on the size of the space. In this case, we're going to focus on general lighting. We'll have a high density general lighting load and a low density general lighting load. We'll also create analytical load types for receptacle loads.

ANDREW LEAVITT: You can access this menu. We want to go to the Manage tab, MEP Settings, and click on our Electrical Analytical Load Type Settings.

WILLOW NICHOLS: So you can see, we have a few load types created here, high density lighting, low density lighting, emergency lighting. If you're working with ASHRAE, you might base these on lighting power densities in ASHRAE.

ANDREW LEAVITT: And we can always make a new one--

WILLOW NICHOLS: Absolutely

ANDREW LEAVITT: --or edit the ones that you have.

WILLOW NICHOLS: So in this case, you can see-- let's select emergency lighting. We've created a category, a power density of a tenth of a watt per square foot, given the load classification lighting, so we get the correct demand factor. And now we can apply this to one or more of the areas in our analytical model. Similarly, when we look at general power-- this would be something like receptacle power-- we've defined it as the receptacle load classification. We've given a rather high power density, 20 watts per square foot. And we can apply that to the areas where we expect a higher convenience power density. So now, we can go ahead and apply some of those loads to these areas.

ANDREW LEAVITT: We want to go to the Analyze tab. And our electrical analysis tools are in the Electrical Analysis Panel right here.

WILLOW NICHOLS: So we said high density loads for general power would be for areas like the cultural exchange or the event space or the catering kitchen.

ANDREW LEAVITT: We can name the load using the Properties window. We can add and remove load areas. And now, we have a load. There we go.

WILLOW NICHOLS: We can do the same thing with the low density areas.

ANDREW LEAVITT: Do we want to fix anything?

WILLOW NICHOLS: We may. That's a great point. So we're looking at receptacle loads here, and we know that those are going to be on a 208 volt distribution system. So there'll be a-- let's set that voltage here.

And so we've applied some convenience power loads. Now, we can do the same with our lighting power loads. You might expect there to be more lighting within the event center, for example.

Then last for lighting, we'll apply the emergency lighting area based load to all of the areas we've defined. Now, if this were a project where you wanted to get more specific about which areas receive emergency lighting, you could do that. In this case, we're going to make the assumption that this owner would like some egress lighting throughout the space. Excellent.

We've created our area based loads. And we've added them to our analytical electrical model here. And so the next thing that we want to do is add some equipment loads to this. Not everything is going to be area based. Occasionally, you have loads that are associated with a particular piece of equipment.

So if we go to the system browser, we can pull this up and see our electrical analytical system. And you can see the area based loads that we've already created. Right now, they're not associated with anything. They're unconnected. They're not categorized. They're not separated. But they exist within the model. So now that we've added those area based loads, let's move on to the equipment loads.

So this is where we might have something not associated with an area. So let's just start with mechanical equipment. We might have an air handling unit, for example. This air handling unit, let's say it's a 25 kVA unit. We expect it to be fed at 480 volt. And let's give it a motor load classification.

There we can see that equipment load has popped up into our system browser. And then let's add another sort of unique load. We know this building's going to have an elevator. It probably has a sump pump at the bottom. Let's add a sump pump. And we'll assume that's a 2 KW motor.

Now, in this case, this owner is very concerned about water in the elevator pit. They may have redundant sump pumps. So we can create a second sump pump. But this does create the challenge for us in our system here of only one of those sump pumps is going to run at a time.

ANDREW LEAVITT: Did you say 2,000 or 2,500?

WILLOW NICHOLS: 2,000.

ANDREW LEAVITT: That's right.

WILLOW NICHOLS: So in this case, we want to use something called a load set. And what a load set does is it lets us take a set of equipment loads and select how many of those are on standby at any one time. In this case, we've got a couple of sump pumps. We're going to create a load set called sump pumps, and then we'll identify that one of those two units is on standby at any point in time. That's going to feed into our calculations to make sure that we don't count that sump pump twice, knowing that both sump pumps will never run at the same time.

Now that we've created our equipment loads, it's time to actually connect these to a power distribution system. First thing that we're going to need is a source. And for most buildings, that source is going to be a utility. And most of the time, our utility connection is through a transformer.

And when that transformer secondary comes into the building, it usually lands into a bus, a main distribution panel of some kind. So we'll call that MDP. This MDP is our 480 volt main distribution panel, and it's what we're going to connect everything else to. Now, if you're designing a building in a jurisdiction that requires load disaggregation per ASHRAE 90.1, then we do need to separate our lighting and our receptacle and our mechanical loads into different categories.

So here we're going to create a bus for-- let's start with the mechanical. We have a mixture of mechanical equipment load voltages, so we've got 480 volt handled here. We're also going to need a transformer for the 208 volt mechanical loads. And finally, we'll need a bus for the 208 volt mechanical loads. And in this case, a bus is a stand in for a panel board.

Now, we can connect those mechanical equipment pieces to those branches of the distribution. So we'll select which piece of equipment supplies that unit. In this case, the AHU will be connected to the mechanical bus or a 480 volt mechanical panel. And our sump pumps are connected to a mechanical bus to our 208 volt mechanical panel.

So we'll need a couple more buses here. We'll need another 480 volt bus for our lighting loads. Then we'll need a step down transformer and a panel for our receptacle loads.

We move those loads over to that branch of the distribution system. And now, we've got a complete system here all connected to our normal power source. However, in this case, we have an owner that wants to have a generator for this building. They want to have another power source. Maybe they want to connect to that elevator to it. Maybe they want to connect the mechanical system to it. Either way, we want to create another source for this facility. And now, obviously, we need a transfer switch in order to connect loads to multiple sources.

And this transfer switch, we want to connect-- we want to select both of its sources. So in this case, one is the utility. And the other will be the generator. And there you can see that ATS showing up in the system browser under both of those sources. So let's say in this case, the owner is very concerned about losing their HVAC. They want to connect that mechanical bus and that AHU to the generator.

Here we just make sure that is connected to the ATS. And now we see the mechanical bus under each of those sources. So we can take a look at both what our anticipated load on this generator is going to be and what the anticipated load on the normal power source will be. This can be really helpful because as you can see, it's really easy to move loads back and forth between these different sources. So early on in design, this is a great way for me to be able to explain to an owner how much of their building function they can move to a generator without having to move up a size.

So at this point in time, you can customize this. You can add to it as much as you like. You can move these loads around. But the important thing is that we took what was really just a sketch or a programming plan, and we've created all of the electrical calculations necessary to do some real analysis on this.

So we've created this-- we see all this in the system browser. But now, we want to share this information with the client or with other folks on the design team. So we can create schedules that capture this analytical electrical information and present it in a way that suits the audience. So this is a great thing to do, where we might want to pull select information out to put into schedules that might appear in an SD narrative. They might appear in a set of documents that are used for pricing. They might appear in something that goes to the owner to help them understand the electrical implications of the things they've requested.

And of course, just like any other schedule, once you've got a schedule set up that you really like, you might use this on multiple projects. So I think that covers our demonstration portion at this point in time.

ANDREW LEAVITT: It does. Thank you very much.

WILLOW NICHOLS: Yeah.

ANDREW LEAVITT: Well, thank you very much. I hope that gives you all an idea of what these tools are, how you would use them, why you would use them, the use case for them. And I hope that you're ready to use them on a project. Again, they're available in every version of Revit from 2023 onward, so you should have access to them through the Analyze tab. Follow the handout and follow the instructions that you saw on the live demonstration, and you should be able to put together a complete project. So if you have any questions, please feel free to reach out. I will try to answer them. And having said that, that, I believe, is the end of the presentation. Thank you very much.

So once again, we are part of the unofficial MEP track at Autodesk University 2024. We recommend that you check out some of these other courses. Again, if you're watching this one, it's highly likely that you'll find something of interest in at least one of these other courses. So take a look in the course catalog and see if there's something that strikes your fancy. And thank you very much for watching.