Whole-Building Energy Modeling with OpenStudio (text version)
The National Renewable Energy Laboratory (NREL) hosted a webinar focusing on the application suite of OpenStudio, a free open-platform software product developed by the U.S. Department of Energy (DOE) and NREL. The application suite is primarily used by architects, engineers, and others involved in the design, construction, or facility management industries, including building owners and homeowners who are considering retrofits to existing structures or design options for new construction. The presenters were Nicholas Long and David Goldwasser of NREL. They discussed energy modeling, the use of energy simulation, and typical barriers to using energy simulation. They also demonstrated how OpenStudio can support energy modeling as an integrated part of the design process, from pre-design through post-occupancy.
Below is the text version of the webinar titled "Whole-Building Energy Modeling with OpenStudio," originally presented on August 24, 2011. In addition to this text version of the audio, you can view the presentation slides and a recording of the Webinar (WMV 28 MB).
Angie with Verizon LiveMeeting:
Good afternoon, and thank you all for standing by. All participants will be able to listen only until the question-and-answer session of today's conference call. Today's call is being recorded. If anyone has any objections, you may disconnect at this time. And now I'll turn the call over to your first speaker for today, Ms. Michelle Rowland. Ma'am, you may begin.
Thank you, Angie. My name is Michelle Rowland, and I'd like to welcome you to today's webinar, titled, "OpenStudio: Whole-Building Energy Modeling." This webinar's presented by the Building Technologies Program at the U.S. Department of Energy. We're excited to have with us today the developers of OpenStudio, who will provide an overview of the application suite. But before we start, I have some housekeeping items to cover. First, I want to mention that everyone today is on listen-only mode. Our speakers will address questions at the end of the session if time allows. You can submit your questions electronically during the webinar by clicking on the Q&A link on the top bar of your screen. When you do so, type the question in the box and "Ask." Be sure to click "Ask" and not the symbol of the raised hand.
You can also submit your questions by emailing them to the address firstname.lastname@example.org. And now, I will turn the presentation over to Nicholas Long.
Thank you, Michelle, and welcome everybody. Today, I'm gonna be talking about OpenStudio and how we use it for whole-building energy modeling. In general, I'm going to go over a few points here. First, just kinda give a high-level overview of what energy modeling is and why it's important and what it can be used for. And then I'm gonna actually do a live demo—or actually David Goldwasser's gonna do a live demo of OpenStudio, mainly focusing on the Google SketchUp and results of ERPs. And then we're gonna go back and talk a little bit about barriers to simulation and then wrap up with some conclusions and questions.
But first, I'm gonna talk a little bit about energy modeling and the design process. So traditionally, the state of the current and energy modeling is typically the view of this graph, here, where on the bottom axis you have the phases in the design process from pre-design all the way through design development, and on the left axis you have, you know, the percent of the decisions made. So you go all the way to the top, the decision's all the way complete and typically could not be changed without a change order.
So if you look at simulation right now, it typically occurs in the far right-hand side of this graph in the sense that it's used mainly for equipment sizing, HVAC capacity selection, standards compliance, and then LEED certification. What we've been trying to do at NREL and the Department of Energy is trying to move energy modeling to be more holistic in the sense that you can use energy modeling from the pre-design all the way through the design development phase, and this is only possible if energy modeling is available in the program phase of the design process where you're laying out your building and your zoning and everything else.
So what we're doing here is using simulation to help inform the design processes way up in the early stages, and part of this is why we're choosing to use the Google SketchUp framework, which I'll talk about in a little bit in the future here.
So a second point here is that we are trying to help the design teams and the owner focus on the energy use. If the design team and the owner focus on the energy use, they realize that they're gonna have to have a way to somehow evaluate the energy performance of their building along the process and with that, you come with energy simulation.
Several other things where simulation is used is the sizing of renewable systems—determine the contribution of that; evaluating design alternatives and then also, and most importantly, is that if you're doing simulation throughout the whole design process, it's a lot cheaper to do a simulation than it is to construct the wrong building.
So what can simulation do for a typical building? And in the construction world, typically you can use it for load calculations for energy performance, peak demand, cost-benefit calculations, but I think more importantly is to simulate more complex technologies that are typically seen as more risky in building buildings because they're technologies that have not been tested a lot in buildings, and so you can use simulations to actually evaluate the potential impact of doing various of these complex technologies. Some of those listed—and especially using EnergyPlus™, which is our analysis engine—we can do natural ventilation and passive buildings; thermal energy storage; advanced daylighting, you know, checking to see if overheating … is occurring, and then advanced controls. And going down the list further, you see, you know, you can do heating and cooling; equipment design; you can deal with the dynamic response of buildings. You can also deal with regulatory compliances and the green building ratings.
In the retrofit world, typically, you can strain the space a lot more in the sense that you don't have the freedom to move whole parts of the building or design the layout of the building. So typically, the packages for evaluating technology packages is more constrained and this is just some examples here but in the retrofit world, you can probably use the … simulation for lighting technology retrofits, for envelope retrofits, and then for analyzing specific components in the retrofit, you know, perhaps what would happen if you came down a specific HVAC component, such as a boiler or chiller, and determine how that will impact the overall efficiency of the building. Other things here are the operational characteristics, you know, what happens if you lower or raise your thermostat setpoint, what benefit can you see on the energy side in your whole building.
So before I go too far, I wanna hit a couple things about energy modeling. You know, there's definitely questions between what's the difference between the actual operating energy and the simulation energy use and, in general, simulations are great for comparing to other simulations. Simulations to comparing to actual built buildings is very difficult to do and, in general—this is a blanket statement—you have real buildings typically use more energy than a simulation would use; produces less power; has worse controls; had more varied schedules and then had more occupant complaints; and the conclusion of all of this is that you can make a building simulation look very close to the actual operated building if you have all the data input correct. The challenge is is that typically, the data input needed for the whole-building simulation is difficult to gather and is driven by the occupants' behavior, which changes every day. So garbage in is garbage out.
And then the second point that I wanna hit about energy modeling is that there's this concept between the thick wall and the thin wall model. When we dive into the demo, you're gonna see some models being created, and you're gonna notice that none of the walls have a thickness to them. And so on the left image here, what you see is a thin wall model, and this is what energy modeling cares about, typically; and if you look on the right-hand side, you see a representation of a thick wall model in the sense that this is the—the thickness of the wall is represented in the overall architecture. In the world of energy modeling, we deal with the thin wall models, and so the thicknesses are implied when you actually build up the construction but you don't actually see them in the geometric way out of the building.
So I'm gonna go and dive into an actual energy model analysis that we have done in the past to kind of give you a really high-level example of what energy modeling can do. This is a daylighting analysis that we did for a large retail building. The building was 133,000 square feet. Of that, we were trying to figure out what was the optimal skylight and lighting controls needed for the states, and the states area was 100,000 of the 133,000. And so what we did is we took an energy model. We created the layout and we basically created five different … from 1–5% of the skylight to floor area with these skylight properties listed and had lighting controls at 50 foot-candle setpoints. And we investigated this analysis for seven different climate zones.
So here's a representation of the model. This is a large retail building, like I said. The skylights here were—are actually already installed, and what we did is we allowed those areas to change as we went along. So in this graph output—on the bottom, you see the skylight to floor area. On the left-hand side you get the energy use intensity. And what we noticed is that the curves typically will go down to some level and then flatten out, and in some cases they were increasing. And what we decided was that at 3% skylight to floor area, this was the quote/unquote optimal value that you could use, based on the inputs given for the majority of these climate zones. And this was important to the large retail store because they were trying to also minimize costs, and knowing that if they were to go to 4% skylight to floor area that they'd have to install more skylights and perhaps deal with more maintenance costs.
What's nice about the skylight analysis is that you can then—or the energy modeling is that you can then dive into the very—more details about the actual model, and in this case, you see the baseline model on the left, and the right-hand side is the 3% optimal building. This is for Atlanta, Climate Zone 3A, and what you see here is the breakdowns of the energy uses and since they have lighting controls, you know, so the lighting energy efficiency went from 28 down to 16. You see that the equipment use stayed the same. Fans went up a little bit—went down a little bit, I'm sorry. But what's interesting is looking at the cooling and the heating is that the heating actually went up in the more efficient model, and the reason why is that since we have lighting controls, the lighting systems could be off more, therefore rejecting less heat to the space, therefore needing to be supplemented by more of the actual heating system. And cooling had the opposite effect in the sense that we were rejecting less heat from the light to the space, so therefore, the cooling system didn't have to work as hard.
So I'm gonna go now and talk a little bit about EnergyPlus and OpenStudio. So you can see how we've done the analyses. So EnergyPlus is a program that has been around for about 10 years now. It is a fully integrated building analysis program. It deals more than just energy. It also does water and renewable, and it is definitely one of the most whole building simulation tools out there. And it integrates not just the analysis of envelope building, HVAC, water; but it does a lot of these low-energy technologies that are available currently on the market today. It is available free through the website listed there as energyplus.gov, and there's also interfaces available from the private sector, and then we're showing you one that is available freely from the public sector as well, and it works on all the platforms, and OpenStudio is a wrapper to EnergyPlus, so basically, the way that we talk about OpenStudio is that it's the framework that allows people to access the capabilities, the core capabilities of EnergyPlus for various purposes. OpenStudio, the analysis platform here, is available for free. It's open source and it is cross-platform as well, supporting Mac, Windows, and Linux. The other piece on this is that we do provide basic support for Radiance as well, and Radiance is a reverse … facing program needed for detailed daylighting analysis. So we actually allow people to create their models and Google SketchUp and export the Radiance capabilities to do that analysis and then feed results back into EnergyPlus.
So what does OpenStudio include? The OpenStudio is—and historically, if you go back a couple years, was just a Google SketchUp plugin. So SketchUp is a pretty complex program that's been around for several years—probably about 10 years also, and the statistic that we have from SketchUp is that there's over 2 million users per week, worldwide, of SketchUp and about 55 percent of those are architects. And it's definitely a mature product and has a very well-defined interface for extension. We basically tied in OpenStudio through these extensions that are available.
So in the last several years, we have done more than just the SketchUp plugin and we're integrating all these pieces together so that there's other plugins available. So currently—and today you'll see the results visualization. It's called the ResultsViewer and allows people to dive into the detailed analysis of the simulation. We have simple HVAC outliner which allows users to go and drag and drop results—to drag and drop HVAC components onto a loop, apparently have functionality for air loops … are coming. We have a model editor, which allows you just to access all the input parameters needed for the model in a GUI—as a graphical user interface, as opposed to a text editor.
And then we have a run manager, which, honestly, is one of our major workhorses at the national labs, which allows us to do, you know, complex workflows and batch a large number of simulations—up in the couple hundred thousand simulation range.
The back-end functionality is probably the bread and butter as well for the national labs in the sense that we export most of the functionality that you see on the front end through scripting interfaces, and basically what that means is that an advanced user of OpenStudio doesn't have to go through any graphical user interface to access the methods to create the model. They can write scripts in various languages that allow them to get this functionality. We also, on the back end, have the workflow management capabilities exported, and there's a bunch of pre- and post-processing capabilities available. A lot of this stuff is getting exported to the front end so that the functionality is visible to a common user, but if this functionality is not there to the common user, there's definitely the back-end capability for it. And lastly, the interoperability for the other engines is coming and we are supporting more file formats so that we can actually import from the GBS and RISC.
So with that said, I'm gonna turn it over to David, and he's actually going to walk through a demo here of taking images of buildings and creating the 3-D model needed for energy modeling directly.
OK, so my name is David Goldwasser, and I'm also one of the developers on OpenStudio. And today, as Nick described, I'm gonna do a demo of an existing building, but I wanted to show this slide to talk about the other ways you can get geometry into OpenStudio. You can start with 2-D plans, which is shown on the middle and the bottom, and you can have 3-D models, or as I'm gonna demonstrate today, you can have photographs of existing buildings.
So I'm gonna exit out of the slide show here and I'm gonna launch SketchUp, so it might take a second for that show up on your screen. And I'm gonna try to move things slowly so that if the refresh rate is slow, you'll still be able to follow what's happening. So if you don't yet, you'll see SketchUp on your screen in a second and on the left side of the screen is SketchUp's toolbar. So you have tools to draw and tools to manipulate and select objects. On the top, you see the OpenStudio toolbar. And those toolbars can be moved around, so they might look different on your machine, but these tools are tools that allow the EnergyPlus and OpenStudio functionality.
So this is an empty file and the first thing I'm going to do is bring in a photograph of a building. So this is gonna use a SketchUp native function called Match Photo, so I'm in the Window menu. You can launch Match Photograph. It'll open a dialogue and then you click the Plus and you go to your photograph. So it's gonna load in a photograph and you're gonna see a grid with some green and yellow dotted lines. And what it's asking us to do at this point is to calibrate the photograph; in essence, you know, define the x and the y vanishing point so that we can create a camera view in SketchUp that matches the camera view when that photograph was taken.
So I'm gonna go, and you might not see this movement as quick on the screen, but I'm gonna drag the end points of these dotted lines and I'm gonna move them to horizontal lines on the building. Now one mistake people make with this is that they'll use the ground as one of their horizontal lines, and more often than not, the ground will not be level, so you don't wanna do that. So I'm gonna pick a bottom of a windowsill and then the top of the building. You may notice as I'm doing this that the yellow line is moving. That yellow line represents our horizon, so by the time I finish the calibration, our horizon should look level.
So now I'm gonna set the other vanishing point. And this doesn't have to be perfect. You know if you're off a fraction of a percent or a few percent on your geometry, it's not gonna have a large impact on your energy models, but you can spend as much time as you would like getting this accurate. And you can also import multiple photographs, although for today's demonstration, I'm just gonna use one.
So I'm now gonna move where this blue line—solid blue and red and green is model origin. You could leave that anywhere, but just for simplicity here, I'm gonna move that to the corner of my building, and then I'm gonna right click and choose Done. So one thing you'll notice here is that scale figure—her name is Susan—she's a little big, so we're gonna address that in a minute, here. So I just didn't want you to think that was gonna be a problem.
I'm gonna use SketchUp's drawing tool, the pencil tool, now, to actually just trace over the photograph. So I'm gonna start at the origin and I'm gonna go to the edge of my building. I'm going to go, kind of, to the bottom of my parapet, just judging from what I know about this building—it's a little bit below, you know, the cornice—and I'm gonna close this off to a surface. One of the workhorse tools of SketchUp is this push/pull tool on the left side. It has the upward arrow on a box. That allows me to take a surface and then just extrude it back. Now in this particular case, my building has a little step where I ended that box and so the building steps back but it maintains the same roof height, and that's gonna be important in a minute to understand. Actually, I'm gonna rotate around here so we'll see how the Refresh works. So I don't know the size of that setback but I know it exists, so I'm gonna draw it and I'm gonna extrude it back and then I'm gonna jump back to my previous camera view. So what I can do now is use the push/pull tool to extrude this wall to the appropriate position, and now that I've done that, I need to grab the back space on the very back of the building. I'm gonna select it. Switch back to my camera view. The push/pull tool, remember, is what I have selected and now I can bring the back edge of that building where it should be. So now my geometry looks right, but I need to address the scale of the building.
SketchUp has a tape measure tool, which on the left just looks like a tape measure. And I'm gonna measure from the bottom of my building to the top. Now you'll notice it says it's 9 feet and 1/8th of an inch, so I know that's really 26 feet. In SketchUp, often after using a tool, you can type something new and then it'll have a secondary behavior, and in this case, if I type in 26 feet, it will prompt me to rescale the entire model to make that 26 feet. So in essence, you just need to know the dimension of the single object in your model. Ideally, you want a big number—a big dimension like the height of the building as opposed to, like, the size of a brick, but, you know, if you don't know the whole building, a door would work as well.
So if I were going to use this for architectural purposes, one thing you might wanna do at this point is actually project textures onto your model. I'm gonna select all the surfaces and project on the photograph. So if I orbit to a different view away from that camera now, you get orthographically corrected photographs on the side of your model. That won't be really useful here, but it's something I wanted to demonstrate for how it's normally used.
At this point, I need to make an OpenStudio model, so I'm gonna use this geometry to do that, but first I'm gonna decide what kind of building I'm gonna model. So if you click to make a new OpenStudio model—I'm not gonna save my existing one—so this isn't gonna close my SketchUp file, it's just gonna close my energy model that's contained within it. And we have different building types, so I'm gonna pick a full-service restaurant here, which is the first on the list, and click OK. It doesn't look like it did anything here, but those templates contain a lot of default values for construction, schedules and internal loads for that building type for different vintages, and then later in the demo, we'll get into that, but first I need to create some zones.
Now I'm gonna go in to select the geometry I made, and I'm gonna cut the geometry, and this first button with the plus sign on the top is a new zone button. So when you click that, it's gonna prompt you to pick a position for the origin of that, so I'm just gonna click the model origin. And then I'm gonna enter into that zone and I'm gonna use Edit, Paste in Place. So now, when I orbit around, instead of having building photograph textures, I now have these colors, and that's because within an OpenStudio zone, we classify surfaces and then automatically render them based on different attributes. So I can pick one of these surfaces, and this magnifying glass is our object information window is what lets you see attributes about whatever object is selected. So in this case, it's a surface. If I picked a zone, I would get different fields and I would get the name of the zone and the origin and the multiplier.
At any rate, you'll notice the surface I have selected, which is a wall, has construction assigned as an exterior wall. It has boundary conditions. It tells whether or not it's sun or wind exposed, and if you're interested in seeing all the IDF text that goes with it, you can look at the bottom and see the EnergyPlus fields that get created from this.
So another thing we can do here is switch rendering modes. So our rendering modes are rendering by different building attributes. On the first one, I was rendering by class. So walls—it's a class; roof is a class; floor is a class. The blue one here, Render by Boundary Condition, … renders by the boundary conditions. Now, all of my surfaces here are set to Outdoors, with the exception of the ground. So if I orbit underneath—and give it some time—you can see a different color. In a little bit we're gonna do multiple zones and do surface matching, and then you'll see where this becomes more usable of a rendering mode.
So I don't wanna have just one zone. I want to make a multi-zone model, so I'm gonna make some changes here and I'm gonna select my roof and I'm going to use the push/pull tool and I'm gonna lower that down to the first floor. Now what I'm gonna do is if you were in this building, you can measure the height from the windowsill to the floor, and that could tell you approximately where your first floor should stop. So that's about there. I'm gonna make a new zone on top of that and I'm gonna enter into that and I'm gonna paste in place, and in this case, I need to push the surface up so that it matches with the zone below it. And I'm actually going to make this a restaurant, and upstairs is going to be all dining. The downstairs is going to be dining and kitchen. So you need to create thermal zones for the different building uses. You could also do a core and perimeter—more complex model but in this case, I'm just gonna do three zones.
So I'm gonna hide the other zones. There's a button up here that will show or hide the rest of the model, and I'm gonna draw a line dividing the kitchen and the dining area. So now that I've done that, I'm gonna copy this geometry to use in my next zone and then go ahead and get rid of the dining area. So this just represents the kitchen. I can hide this extra line or delete that line. So I look up—I'm missing a piece of my model but I'm gonna go back and re-create a new zone. I'm gonna use Paste in Place again and I'm gonna orbit around and delete this half of the model. So now I have my three zones, and I'm actually just gonna spend a second here to just name them. So I'm gonna call this Dining B, Dining A, and if I move just a little, I can pick the kitchen—we'll just call that Kitchen. This just becomes meaningful when you are looking at the results out of EnergyPlus and you don't wanna have to map what the zone is to what activity's going on in there.
So now that I've done that, I'm gonna switch back to another render mode and orbit around. If I go into this—a particular zone, everything's still blue, so I need to do surface matching, and we have a tool built into SketchUp that allows you to do that, and then I'll explain how it works here, but basically, you just click Match Entire Model, and I'm gonna use SketchUp at the section cut tool, and I know I'm introducing a lot of tools for SketchUp, and if you're not familiar with these, there's a lot of tutorials available, but basically, I define the direction I want the section cut to go and I hold down Shift, move it to the specific position, and then show the section cuts. Now what you'll notice here is there is a green surface in the bottom. That correctly matched, but the top didn't match, and the reason for that is that EnergyPlus requires matched surfaces to have the exact same geometry. The zones below here are two separate surfaces, and I'm gonna—this is a single surface—so I could just manually draw a line connecting this, but you might have hundreds of those in a model, and it would be a lot of work to go into the zones to individually do that.
So new in the surface matching tool is this top section, which says Intersect and Divide Inter-Zone Surfaces. That will go ahead and make all that additional geometry for you, and then you rematch the surfaces and it will correctly match all of the surfaces in the model. So that can be a big time-saver on a large model, and if I go and look at one of these surfaces, now—I'm gonna, in fact, turn off that section cut and delete it. So I'm gonna go to my object information window again. It's done a few things. It's set my boundary conditions to Surface, instead of Outdoors, and in doing that, it also found the name of the surface on the adjacent zone and put that in the boundary object field, and since it's now an interior wall instead of an exterior wall, it's changed the construction to a default construction that we've assigned for interior walls. So that's—and I'll get into, in a few minutes, how to change the construction, but before I do that, there's a little bit more to do with the geometry, which is to draw some fenestration and then some shading surfaces.
So drawing fenestration's pretty easy because we have this photograph. So I can go into a zone here and I'm gonna use the rectangle tool, and with that, I can actually just click on one corner of the window and click on another and I have the window, and if I look in my object information window, it's correctly classified as what it is. So I need more windows, and I don't wanna draw them by hand, so I'm gonna select it and use the move tool, which in SketchUp can also be a copy tool. So you can hit Ctrl+C. And I'm gonna pick up the addition. You'll notice right now that there's a black line connecting them. As I move down, that line turns green. SketchUp has inferencing engines that help to make your building orthogonal and correct and so it gives you indications of when you're picking at a center point or when you're parallel, and so that's a good guide to use.
So now that I've copied that window, instead of manually making the other copy, I can choose to divide it and make the rest of the windows. So it's just doing a linear array. In fact we're making energy … objects to go with all those as they're created. And another nice thing you can do—I'm gonna draw the large window. You can copy it—I'm using Ctrl+C and then you can Ctrl+V to paste it. So you can wrap that copy around the window. I can wrap it over here, paste it on. The inferencing engine was getting in the way, but if I zoom in now, I can see that I'm gonna place it where it should go, and now if I orbit around, I have windows that look like windows. I'm gonna let that sit for a minute before I change it.
So the next thing I wanted to add, and then I'll be done with geometry, is the shading surface. It's very much like a thermal zone, but we have a button next to the thermal zone that says New Shading Surface, so when I pick that, I'm gonna shade this black awning in the middle. I'm gonna click an origin, just like I would for a thermal zone, I'm gonna enter in the zone, and I'm gonna draw a little triangle here to represent the edge of this awning. The inferencing engine becomes important here. Notice how now that inference is red, which is what I want. That's coming off the building. If I move just a little bit, it turns green, but I wanna make sure it's red, and then I'm gonna close off the end of my awning, and I'm gonna use my favorite tool, the push/pull tool, to extrude this off to make my awning. And again, I'm gonna orbit so we can see what's happening here.
In the actual awning, there's really just the front surface. Those back surfaces, I was just making as a guide, so I'm gonna use the eraser tool and I'm gonna click over here and I'm gonna erase those surfaces so that when I'm done, all that's there is that single edge for the front of the awning. So at this point, I'm not gonna model the rest of the fenestration. We're gonna move on to construction, for what the envelope materials are made of. So I'm—in that green section of tools, on the OpenStudio toolbar, one of them which looks like a hammer and a wrench is a default construction window.
Now this is where the template that we chose becomes important. The top pull-down menu says Default Constructions Sets, and when you click the pull-down, it populates the list with different climate zones, different vintages, and so in this case, I'm gonna—this building was, I'm gonna say, post-1980 and then it's in Boulder, so it's Climate Zone 5B. So I'm gonna scroll down and I'm gonna select that, and if you look on the fields below, they will get populated, at least the exterior walls will get populated with the … constructions for that climate zone. So I can just click apply and this will only affect future surfaces I draw beyond this one, but I wanna go backwards in a step, apply it to geometry that might be drawn, so I'm gonna choose "Apply to Entire Model."
And if I wanna confirm that that happens, I can just pick a surface, pick my object information window, and if you look at the construction, which is the third field down, or fourth if you count the name, it has a 1980 exterior wall, steel frame. Now if you had picked a school instead of a restaurant, that may have been a … model. We also have wood frame—those are picked based on the appropriate construction for that type of building.
So now that constructions are done, another piece that's in the template is zone loads. So next to the default constructions is the Zone Loads button, but before I do that, I'm gonna pick the two zones that are dining zones, and I'm gonna select them. And the reason I'm doing that is, unlike constructions, which are global for the entire building, zone loads are specific to the activity in the space or the space type. So when I go to the top pull-down menu, I get vintages just like I did for constructions, but instead of climate zones, I get space types—in this case, Dining and Kitchen, and there's an attic but I'm not gonna use the attic today. So I'm gonna pick post-1980 Dining, and that will populate the fields that you see below—for square footage values, for people, for lighting, for electric and gas appointment, infiltration, outdoor air—so these are all just square foot values. That's a good starting point for a model.
You can then change those to more specific numbers as you get data further in design. It also sets schedules that are specific to the space types, and then we have thermostats, so I'm gonna make sure I'm picking a dining thermostat and I'm gonna leave the box checked for ideal air loads. Ideal Air Loads is a way to get feedback on the behavior of your building prior to adding a full mechanical system, so if I put a setpoint in, a thermostat, then I have internal loads as well as external loads. The Ideal Air Loads will tell me how much energy's required to maintain that setpoint, given all these conditions' interaction on the building. So it's a good starting point for conceptual design.
Now, unlike the constructions that I applied to the entire model, here I just wanna apply it to my selection, which are the two zones that represent the dining zones. So I'm gonna click OK. This is just warning me that it's gonna delete other similar objects if I've already done them. So this allows you to change your mind and go back and change the space value. So now that that's done, I'm gonna pick the kitchen, which I just selected in SketchUp, and now I'm gonna come back to the dialogue and switch my space type to post-1980 Kitchen. The values will change below. I need to make sure I change to the appropriate thermostat, and that's changing both the schedule of the thermostat as well as the setpoint temperatures, and you can edit those within Model Editor if you wanna create, kinda, some thermostats. And then I'm gonna Apply Again to selection.
So at this point, we're almost ready to run the simulation, but there's one more thing I've not told EnergyPlus yet. And so if I go to this run simulation dialogue, I need to give it a weather file, and you have some options at the top on running design days, but for now, I'm just gonna run a weather file simulation. So I happen to have those stored just in the EnergyPlus install—their weather data, and I'm gonna pick Golden. I've not located my model yet and there's another feature for geolocation. I haven't mentioned this but there's a four-hour video series on YouTube, and also available on our website, and it's made of three-minute videos. It goes through this process I'm doing in a lot more detail, and then our presentation has a link to that. So if I go over something too quickly or skip over something like, for example, geolocation, then you can get more detail on that there.
So at any rate, in this case, this will just locate the model as Golden, and before I actually run the simulation, I am required to save the file, and the reason for that is running the simulation, you're creating output files, and it needs to know where to put them. So I haven't saved this entire presentation. My general advice, though, is to save often and as you make changes, save alternate copies so you can have a history of your model. So I'm gonna click Save here, and it's in the demo files, I'm just gonna call it "test.osm." I'm gonna do an annual simulation. It's already prepopulated without the variables. You can change what variables are there, and you can even change the reporting frequency of those. So some could be reported monthly instead of hourly, for example. At the very bottom, when I click there, there's a Run option. So I'm gonna give it a second so you all can see that and then I'm gonna click Run.
So what's happening is that the window is opened called the Simulation Status, and it converted the .osm file to an .idf file. So that was happening here and then if I scroll down and click this green EnergyPlus, that's the currently running activity. Again—one sec, I was just checking something. So it'll pick the—OK, I'm sorry. Anyway, so the simulation is running now and it's using EnergyPlus as the simulation engine, but we're using our run manager application that Nick mentioned. You can use it as a standalone application, but you can also—other applications can use our API to access that and in this case, it's a simplified version of this CG—this widget that opens up the status and lets me see, for example, the standard output from EnergyPlus. So our simulation ran in just under a minute.
So what I can do now is I have the data and there's a number of ways to look at that. I'm gonna look at time series data and the results here in a bit, but one nice feature is viewing the data in SketchUp. Now I've shown rendering modes before. I've shown Render by Class and we've seen Render by Boundary Condition. We have not seen Render by Construction or Render by Data. Right now, everything's white because there's no data. The data's gonna be the SQL file that EnergyPlus created. So I'm gonna click this button next to Run Manager. It's called—it says—View Results. It's already loaded in the path to the SQL file, but that's right here at the top. I'm gonna click Load, and that's gonna actually load the SQL file into SketchUp, and it exposes the different variables we have. So for the purposes here, I'm gonna leave the variables at surface, over Exterior Solar Incident, and then I'm gonna click Apply or OK. OK will close the window. So we'll notice now that those surfaces have been colored with the exception of the shading surface, and that's because the shading surface doesn't have any data associated with it regarding solar and ….
So what can I do with those colors and what are the colors? We got some windows. There's a color scale and then you also have the option to drag over specific surfaces. At the top, there's a little arrow with a cube next to it. If you click that, that's called the data tool, and this works in different rendering modes, and you basically hover over a surface and it gives you data about that surface. In this case, it gives you the exterior solar incident in watts per square meters.
Now this is time series data. So how do we address that? SketchUp has a shadow toolbar, or shadow dialogue, and it lets you turn shadows on and off, but in addition to that, it also allows you to change the time of day and the time of year. In the SketchUp …, we use that time of day and time of year to access the appropriate SQL data for that time set. So I'm not gonna try to slide through this 'cause I know our refresh rate won't work, but I'm just gonna jump to another time and another day and you'll see that those values change. If I go early in the morning, you'll see some different colors. So this is something that's a little easier to explore on your own, but it's a nice way to view the data.
Another way to view the data, as I mentioned, is in the ResultsViewer. So I'm gonna jump out of SketchUp now into ResultsViewer. So it'll take a second for me to switch the shared application. So this is ResultsViewer. It's out of the file a little bit so to load a SQL file, you just go to File, Open, and in this case, I'm gonna load a previously run version of this, just to make it easier.
On the left side of the screen, you see all of the different variables that you requested for the different surfaces and zones, or in some cases, some building meters. On the right side, you see the annual building utility performance summaries. It's an HTML file, and that gives you annual data on your building, as opposed to time series data, and there's a lot of tables available. One of them that I'm gonna actually use later is called this End Use Table. Now in our model, we didn't have a full … system. We used idle air loads so we just have a number for heating and cooling. We have interior lighting and we have equipment, and we don't have any other loads associated with the building. So we're gonna come back to that later on when we look at some retrofit options.
But on the left side, we have actual … data and to start with, I'm going to pick one of these walls and look at the data. I'm gonna pick this dining wall here and I'm gonna right click and I can choose two kinds of plots—a flood plot or a line plot. So I'm gonna do a line plot to start with. That's what people are probably used to seeing. It gives you a plot of the entire year all at once. On the left is watts per meter squared and on the bottom is the time of day, or time of year, rather. So if you can see the bottom of the screen, I'm not sure if all of you have this scale … or not. The bottom has some sliders and one of the sliders lets you zoom in and look at a much tighter time frame where you can see the individual fluctuations from one day to the next. So once you zoom in, you can have span … you can then use the top slider to re-center what you're looking at. So that's one way to view the time series data.
Another approach is actually to look at something called a flood plot. So the flood plot displays the exact same data but in a different way. It displays temperatures and color. So on the very right side, that color scale—I'm sorry, we're not looking at temperatures, we're looking at incident angles. So it displays the incident, or the incident value as a color, and then it displays time of day on the left and then the days of the year on the bottom, and so what you can tell here is that this is an east-facing wall because it's getting all of its solar incident energy in the morning and then not in the afternoon.
If you look at another—I can take that same wall and scroll down here for a second and look at the outside surface temperature, it's gonna look similar to this. The reason it looks different is that as soon as the sun moves around the building, that building doesn't instantly cool down. So you can look at the rate at which surfaces cool after they're not exposed to the sun and then get some knowledge on the mass of those resources, and we just have a nice diagnostic tool to learn how the constructions in your building or other attributes are behaving.
So one other thing I wanted to jump to on this is actually looking at the loads since we put in the add load system. So I'm gonna look at Sensible Cooling. We have three zones. We have dining A and B and C – or I'm sorry – Dining A and B and then Kitchen, and I'm gonna right click on Dining A. Actually, I'm gonna show something else, I think, here but I'm gonna click Dining A and B and Kitchen and I'm gonna do a right click and do a line plot. This is just to demonstrate that you can actually plot multiple variables at the same time, and had you run multiple simulations, you can actually plot variables from multiple SQL files. In other words, you can take your kitchen and load Kitchen Sensible Cooling from Option A against Option B, but in this case, I'm looking at just loading from some different zones.
So what's evident here is your dining zones are generally cooling just in the summer, while your kitchen is cooling all year, which, you know, makes sense for internal loading that occur in those spaces. So just to demonstrate the flood plots again, I'm gonna go back in the dining and I'm gonna do a flood plot, and so instead of just telling you that there's cooling in the summer, this tells me specifically what time of day. So I notice that there's a cluster around lunchtime, and a few hours later, even though the sun's hotter, the cooling load actually goes down, and then picks up again at dinner. So it's a combination of the weather file and the sun exposure as well as the internal loads that are determining when there's cooling. So if, for example, you saw a hot spot at, you know, midnight, you might wonder, "Did I do something wrong in my model and my schedule's wrong and there's some big piece of machinery that's running when it shouldn't be?" So it's a way you can look for either mistakes or anomalies in your model.
If I do the kitchen—and again, I go right click and choose flood plot. You see completely in a flood plot. And immediately looking at this, it should be evident that what's impacting this phase mostly is the activity inside as opposed to the temperature and the weather, because you're not seeing changes throughout the time of day if it's based on—or it doesn't match with the sun movement and temperatures. It's tied to the stripes, horizontal stripes that are the activities of the building at different times of day. The step that is occurring on the left and the right is the daylight-saving time change.
So I'm gonna spend a few more minutes and I'm going back to talk about doing retrofits. So I wanna actually make a whole 'nother simulation, but I wanna talk about some approaches you might take. So I'm gonna switch applications back to SketchUp—might take a second. I'm gonna turn off my shadows and go back to a normal view. So what kind of things would I change? One option would be to change construction. So I'm gonna open up my default construction—and get a drink of water.
So it's unlikely that I will change all of my constructions. I could go pick 2009 low EnergyCase, Climate Zone 5 constructions, but it's an existing building, so unless you plan on rebuilding it, that's probably not gonna happen. So what's more likely is you'll take a specific aspect, for example, windows, and you can just pick that particular construction, and then you can scroll down and replace your windows and set the windows to Climate Zone 5 or a newer vintage. So you could do that for any aspect of the building that you wanted to.
So if you didn't want to change constructions, something else you could change your load. And again, you can create your own values, so we populated some things so you have a starting point to work from. And so you could take a particular zone—for example, I could select the kitchen and I could choose 2009 kitchen. And in this case, maybe I wanna replace everything. I'll replace the kitchen equipment, the lighting, and everything, or you can just pick a specific value. So you change those values, you save your model as a new name, keeping your baseline model untouched, and then you rerun the simulation. So what I'm gonna show next is kinda the data you'd see after you ran those perturbations on your model.
So we've created a Google Documents spreadsheet, and you can get to that from openstudio.nrel.gov or from our retrofit store, which has the PDF component but also the video series. So I'm not gonna actually open Google Documents for this. I'm just gonna show you the PDF created by that and so I'm gonna show you the PDF created by that. And so I'm gonna switch screens again to do that.
Now one thing I'll mention about the Google Documents is that to work—so we have the Google Document publicly accessible where anyone could see it, but to actually change the values to your own, you need to save it as a copy to your own Google Documents account. If you don't have a Google Documents account, you can actually save this as an Excel file, and then you can print as a PDF to export, which is what I've done here. So basically, the stack of results you were … is end-use tables. You can select that data from the end-use table and copy it into the tan or brown area here to create your baseline model, and then we add a second colored area where you can put your proposed records changes, and I'm gonna scroll that up so that displays at the top. So that's in green. Now an important thing to know is that the values you see in this green table are not directly creating the chart on the right. And the reason for that is that ideal loads, themselves, are not the best way to evaluate the building, and there's real mechanical systems or air conditioning and your heating has a coefficient of performance or an efficiency for the heating. So if you look below the green table, we have values, and so I put in 0.8 and 3 for heating and cooling, and then you can adjust those as you see fit for whatever system is in your building.
So those values, in turn, generate the tables at the bottom. You get EUI values in EI, SI, and … units. And then that data from the EUI table calculates the charts that you see on the left—or on the right. So the four values, there, the green, the red, the yellow, and the blue, are well …. Red is heating, blue is cooling, yellow is lighting, and then green is equipment, and I'll zoom in here so we can see this a little better.
So on the baseline, we have those values, and if we scroll down, we'll see that we are saving 13% …. And—oh, if I zoom in, it's tough to see this all at once, but so we have a chart in the middle that does a breakdown of where that savings comes from—and in this case, the savings comes from cooling, reduction in cooling loads, as well as reduction in interior equipment loads, interior loads. Now if you look, there's a tiny sliver, which you probably can't see. We have a 0.2 percent increase in heating loads because there are certain times in the year when we benefited from that heat in the kitchen, and so that we didn't have to run our heater, but that's pretty minimal in this case. And if you wanna see the actual numbers, can you scroll down. Any losses will show up in red, so there's that 0.2 percent near the middle of the screen.
So in our Google Documents spreadsheet, we actually have a lot of examples that are tied to this tutorial, so this first one that saved 13% was an upgrade of the kitchen's equipment. If I go down a page, I instead upgraded the windows. Now we'll notice that my little gauge only shows a 0.4% savings for that, so given the two, you know, you have to evaluate the cost, but it's more likely that the equipment upgrade in this case will be better than the changes to the envelope. And I'm actually gonna jump to the last page here.
In doing this exercise, I wanted to see how much I could improve the envelope by getting the best constructions possible. So I actually replaced the walls, the windows, the roof, with a perfect construction that didn't have any heat transfer, and so what that told me is that no matter what I do to my envelope, I'm only gonna save 3% at max energy. So that's a nice study you can do to learn what, you know, what can I gain—how much can I get for doing the best possible lights that use no energy or the best possible windows. But there's a few other ones that are kind of interesting here.
If I go up a page, I looked at operational changes, too. I said, "What," now this particular example takes the same geometry and it's in an office building in Florida, in Tampa, because I wanted to look at how the building behaved in different climates, where there's a stronger cooling load instead of heating. But anyway, the point to this is to show that just changing the thermostats 1 degree Celsius throughout the year saved 10% energy. So it's an interesting thing to look at. You don't have to spend any money, necessarily, to save energy. Instead you can evaluate "How much do I care about the temperatures? Am I willing to go half a degree or 1 degree, you know, depending upon what savings I'm gonna get out of it?"
So that's all I really wanted to show for now. I'm gonna hand the screen back to Nick, and he can talk about some of the challenges and obstacles to getting data for energy models and making energy models. So I'll switch it back to the presentation for you, Nick, and then hand it over to you.
OK, thank you, David, and you know, it's good to see that the results that we can get from just doing the Google SketchUp side of OpenStudio, but what you noticed when Dave was going through this is that there's a lot of challenges on getting the right data. I mean, you saw walls and roofs and replacing walls and roofs for certain values or getting the right equipment loads, etc., for the kitchens. And, you know, we realize that this is a large barrier for energy modeling, so—well, first, I wanna talk about, you know, the general barriers that are out there; some are real, some are perceived, and there's a question that came in about, you know, how long does it take to actually build a model, for instance, the supermarket building that we showed earlier. And you know, that's such a great question, and depending on the expertise of the person who is developing the model, that could take anywhere from one day to a couple weeks, and also depending on how detailed you wanna make that model and how exact you wanna get your data, you know, that can now range another couple weeks, or it could even range months. I would say that the month's dream is quite not true. I mean, it is if you were trying to get an exact replica of the operating conditions. Typically, a model like that could take a couple days to build for someone who is very experienced in energy modeling.
So time investment is a real barrier. Experience required—there's definitely lack of data, and then the belief of inaccurate results. So how to overcome some of this? I just wanna list some of these resources that are available. There are plenty of training courses that are happening across the U.S. There's a group called IBPSA, the I-B-P-S-A, International Building Performance Simulation Agency, or Administration, can't remember. They provide conference proceedings, and they have great reports about various types of modeling, not just energy modeling, but daylighting, etc.
There is the energy modeling conferences that are occurring more frequently now. There's listservs out there; just email exchanges that happen and large listservs and a couple out there. Documentation—EnergyPlus is very, very well-documented with thousands of pages of documentation, so if you have a question on the engineering approach of how something is happening inside of EnergyPlus, it is documented. You can go into it. You can see how it is calculated to help, you know, curb any perceptions about how it's being done.
This other piece that's out there—these design guides. So ASHRAE, along with AIA, Department of Energy, IES, and USGBC have been working on these Advanced Energy Design Guide series and they're available for free on ASHRAE's website, and the technical support documents which is basically the analysis that happens on the back end of these are available on various national labs websites. And you can go and see how these analyses were created and run via energy models and basically they get wrapped up into these design guides.
So I guess the last part of the example file has been starting points. It's definitely included in the software and then we have the reference buildings that are available from the Department of Energy. So I kinda just wanted to hit high level, you know, what kind of inputs are needed for whole-building simulation. Here is a quick view of some of them. If you look at this, there's definitely more that are available, but what you'll see is you have to do everything from the geometry or the design through loads, through HVAC, through utility rates, water uses, control sequences. There's a lot of data that are needed, and so what we've been doing at NREL with support from the Department of Energy is work on the, what's called the Building Component Library, and what this is is a site that allows currently only administrators to publish content, but we're working on the ability for any general users to make content to this, and the content that will be on this is anything that has to do with energy modeling, and if you look at some of the examples on the screen I have there, you see the Sony television that is there. This is a metered television that we, in turn, made it a EnergyPlus model with an operating schedule for a retail store so that you can download this and plug it into your EnergyPlus via OpenStudio, and this component is wrapped up in such a way that you get the capabilities to see the attributes of the component and the tags of the component.
So the components in the Building Component Library are nothing more than just a wrapper of data and you get walls, windows, MELs, miscellaneous electrical—that is fans, utility rates, etc.—and then each of those components have attributes which define the component, and once we open this up to the general public to submit components, you know, basically anyone can contribute their own components with their own attributes and how they wanna define it. We have a specific, you know, specific set of attributes that we use for components, but perhaps someone wants to add another attribute to make it more specific or more searchable. And then we also provide meta data, such as the provenance; that is, who submitted it, the files in the sense of, you know, what files are associated with this and the videos and images.
And to further clarify this is that you have the component, which is it describes it, it's the component and the attributes and then you have a file that's attached to it, which is actually the energy model. So what you do is you go, you search this. For instance, you type in "ASHRAE" and it goes through all the attributes that have ever been in there and it says, "Oh great, here you go. Here's 26,000 results for you." We then take the attributes on the left-hand side and you're able to basically … it down or further search into it. And so for instance, here, we said, "Use a U factor between 4 and 5, with a … gain coefficient of 0.4 to 0.7," then what you see happen right away is that you go from, you know, 26,000 down to 19.
And so now, you basically have constrained yourself to knowing that you're going to get windows, then you can say "Download," and when you hit Download, you get more information about the component before you download it and you get the actual U factors, the overall effective U factor, and then you hit Download and you get the description file, and you get the file needed for the energy model exactly as the EnergyPlus requires it or OpenStudio requires it.
So just zooming in, looking at the attributes themselves. So with all this said, you know, this is kind of where we're trying to go to help manage the components of buildings, because if you notice the OpenStudio setup for templates, I know the next question everyone always has is, "Well, how do you create a new template? How do I put in a very specific window, etc.?" And so what this is about is allowing people to go and get custom components somehow, some way, and eventually allow people to contribute components back.
So with that said, and we're actually going to hit conclusions and then address some questions. Basically, we started with—we talked about energy modeling and why it's useful for evaluating designs in both new and retrofit projects, and you saw David go through the OpenStudio demo showing how you can create a model from an existing photograph. He just showed one photograph. You can actually take multiple photographs and walk around the building. There's a tutorial on our openstudio.nrel.gov site that walks you through the full process via different forms of input data, be that photographs or GS file import, so that you can actually go and see how to get, you know, existing models created from existing data.
And then we kinda just delved, really briefly, into the Building Component Library and how we're gonna manage data in the future, because having data on a personal computer is great but eventually we have to share it so that other people can use the same data and actually drop in similar data sources. So with that said, I'll be happy to—actually, I think we're going to hand it off to the moderator, and she's going to address questions.
Thank you. That was Nicholas Long and David Goldwasser from the National Renewable Energy Laboratory. Our previous moderator had to step off, so what I'll be doing here is just going through some of the questions that we had received through the Q&A. The Q&A function in LiveMeeting, if you look at the top of your window, you should see a Q&A option in your menu, and if you click on that, you'll be able to submit questions that we'll be able to review. We have a few minutes left here to go over some of the questions that have been submitted so far, but if you have additional questions, feel free to send them to us and we'll look through, and depending on the volume, we'll see how many questions we can get through. But if we could take a look at the last slide here—if you have additional questions, you'll be able to submit those through either taking a look at the website that was mentioned before, openstudio.nrel.gov, or the email address email@example.com. So let's take a moment here and we'll pull up the questions that have been seen so far, and I'll take a look at what our presenters may be able to answer.
So one of the questions that was asked was that it seems that the version of OpenStudio that was used in the demonstration is different from the one that I may have downloaded. So I guess Nick or David, would you like to address what the best way is to get the most current version?
Right. So if you historically have used OpenStudio, you're probably going to the eere.energy.gov site to download it. We are rapidly developing OpenStudio in the sense that every two weeks we're doing a new release, and so we've moved over the majority of our package management to openstudio.nrel.gov. If you go to openstudio.nrel.gov and hit Downloads, you can actually get the version that was displayed here today. So the current version as of what the new OpenStudio is, is on 0.4. So that was the version we were showing today. We basically do a development release every two weeks, and so if you are on that website, you can hit Developers and then Download Latest Iteration, and you can see where we went in the last two weeks, that is. So we do suggest, though, that you keep on the download version of that as opposed to doing the iteration build unless you're willing to deal with software that is more buggy in the sense that we have not gone through our code-hardening cycle.
So yeah, another question that we received is whether the combination of OpenStudio and EnergyPlus is either meant to replace previous applications such as Go To or the application that was derived from Go To, eQUEST®.
Right—so just to kinda clarify some of the semantics here. So Go To is the simulation engine. That would be analogous to EnergyPlus in the sense of how it fits into the analysis—it's just the engine. EnergyPlus is an engine, though, too, the engine. eQUEST was a graphical user interface built on top of a derivative Go To, and OpenStudio is a analysis engine that is built on top of EnergyPlus. I would say that currently that there's—that is not the plan. We're not trying to replace eQUEST, mainly because the functionality of eQUEST is not where we're going with OpenStudio. We are trying to, in the world of OpenStudio, provide energy modeling at early design phases through doing quick geometry development as you saw there, and then next up is to do, you know, more detailed HVAC.
I guess that answers that question. So there's two of them. So the other question was is it supposed to replace Go To and like I said, so OpenStudio uses EnergyPlus and we're not planning on making OpenStudio use Go To as the engine.
Another question we have is whether the recording of this meeting and this PowerPoint is going to be emailed? The recording of the meeting and the PowerPoint will be provided online. Typically, there's at least a week of turnaround time before these items go online. But the Department of Energy webinar website will provide access to the slides that you saw today, along with an audio recording of the information that we heard today. So let's see here if there are any other questions. Do you wanna ask that … ?
OK. Another question that was asked was one of the viewers has tried using OS on Windows 7 64-bit; however, OS loses some of the elements; it loses envelope recognition, etc. OS only appears to work on 32-bit. So the question is, will you offer a version that works on 64-bit?
So I run OpenStudio on Windows7 64-bit, and I have not seen this problem. Excuse me. So first of all, I would just double-check to make sure that you're on 0.4 release, and if that's the case, shoot an email to firstname.lastname@example.org and we can help address it. If you're a Linux user, we do do the 64-bit builds, but for some—but we have not done that for Windows 7 yet, mainly because dependencies and having to compile those for 64-bit as well. So please try it on a 0.4. If that doesn't work, shoot email@example.com a question and we'll try to figure it out.
Yeah. One more point I will add to that is part of an optional installed with 0.4 that is open SSL, and if you have a 64-bit machine, you actually don't have to install open SSL unless you're sending to supercomputers, but if you do install it, you need to install the 32-bit version, even if you're on a 64-bit machine. So that could be one issue, but if not, then yeah, email us.
OK. A couple more questions have come in here. Another question that has come in. Is OpenStudio working to be made compatible with VPI's new HPBXML or a similar protocol?
So HPBXML was a format that if you ever go to the example file generator page for EnergyPlus, when you actually submit the simulation, you get back the results of the simulation along with the info file, along with this XML file that is being referred to. Currently, what we're doing with the HPBML file is letting it sit where it is and providing the functionality that the pre-processor, which is what took the XML file and created the EnergyPlus input file, and we're making that functionality available inside of OpenStudio. So this is a great question, and if that person would be willing to contact us so we could actually help, you know, explain this more about the plans on the HPBML.
So again, is that a person you'd—you'd refer that person to the address there: firstname.lastname@example.org?
Yes, that's correct.
OK. Another question that we received—what kind of companies have been using this modeling? And I'm gonna guess that might be interpreted as AE firms vs. energy consulting companies or, and more generally, what kind of companies have been using this modeling and what would motivate one company to use this over other options, such as eQUEST, Passive House, or just the simple use of CBEX ballpark figures?
So OpenStudio has a very broad user base. So we use it internally at NREL for a lot of research. Universities use it; architecture firms, engineering firms. So one of the tricks was designing it to work well across of all those, and clearly it was our goal to push energy modeling into early design. We need to get it in the hands of more of the design teams. So that's getting it into the engineers and the architects earlier in design. You know, one reason to use it over eQUEST or possibly other solutions—it depends on what—there's not a best solution always, but it's what's best for your need and then which simulation engine you wanna use. And as far as the CBEX ballpark figures, you know those could be good starting points, and if you're—depending on the goals in your project, it might get you where you need to go, but you can't customize it as much to your specific projects. So I think one of the reasons to use those ballpark figures before was that it took so long to create a model, and there was such a learning curve, but if we can remove those obstacles, I think there won't be a reason to fall back on ballpark figures. You should create a simulation in almost all projects.
I guess I would add to that the—if your goal is to create lead documentation to get your energy points, then, you know, eQUEST … I guess that's an eQUEST in this case. That is probably suitable as the point is you're not—most cases, you're not trying to influence design process. Normally, you're just trying to get, you know, the model done in a way that you can get your certification. But if your point is that you wanna try to have a model live with the design, that is where we're trying to go with this, for sure.
Another question that's come in. A viewer asks, can I select all the model elements by boundary condition or by material types if to view key load to data, or is the ResultsViewer application in OpenStudio a better option?
So I would say that if—I'm interpreting the key loads of data is trying to say you wanna sum up all the data with all walls that meet this specific condition. I would say that that is not doable inside of OpenStudio, and in the ResultsViewer, you would have to create a custom query to do that, which we have not exposed the capability of the custom queries, either, to make that happen. So you're probably back down to if you wanna do a very custom reporting mechanism, I would install something like SQLiteManager inside of Firefox or something like that, write the query, and create your own view for the data. That's probably the best approach, assuming it is as difficult as I was interpreting this question.
And now if you're just looking at, for example, loads for a collection of zones, then you can make a zone list in EnergyPlus and then have a meter tied to that, but for surfaces or something else, you wouldn't be able to do that, sure.
OK, so again, that Q&A function is at the top of your screen in LiveMeeting, and click on the Q&A bars and submit a question electronically. I'll give folks one more minute here to submit additional questions, as I think we have gone through the bulk of the questions that have been submitted so far. Is there anything else that—
I've seen one somewhere asking what version of SketchUp and what version of OpenStudio I was using for the demo.
OK, I think that was addressed during the presentation but we can … absolutely.
So we support SketchUp 7 and SketchUp 8 pro or free versions in Mac and Windows. There's no Linux version, so that's the one part of OpenStudio that's not on the Linux. So I was using SketchUp 8 and I was using the 0.4 version of OpenStudio. One thing I should point out, too. If you do have the EERE website version, which is 1.06, you can install that side-by-side with our new beta and then you have a switch that can go back and forth between the two. So if you wanna use the beta but you don't wanna make that leap and give up 1.06, you can install them side-by-side and switch back and forth.
One more question that's come in—if one is new to energy modeling, would you consider this program too advanced for a new person to start with? Should they start with another program?
No, I would say there's a couple barriers to that. One is we heavily rely on SketchUp to help create the geometry and if one is not comfortable with SketchUp, there's a learning curve there to start with. Most people, especially coming from the CAD world, the AutoDesk world, that is, you know, are used to drawing lines. In SketchUp, you draw surfaces and things kind of—things are different. There's no trim tool, there's no extend tool, for instance. So—and there's definitely a learning curve there. If you're comfortable with SketchUp, I would say that OpenStudio and using EnergyPlus is a reasonable place to start, and it's not too advanced, especially if you're just trying to do very standard systems in the sense that you want to …. If you're trying to do simple geometry with simple loads and wanted to do some … with ideal loads that David was showing, not a problem. If you're trying to dive into some standard HVAC, then EnergyPlus has templates that allow you to do HVAC pretty quickly for standard HVAC systems, and as soon as you wanna get to something more advanced, then you have to dive into another level of EnergyPlus that is challenging but is definitely for an advanced user.
So I think it's a reasonable place to start if you're comfortable with SketchUp. If not, you should probably start with an engine that's a little easier, such as eQUEST, except for—and the newest release that's coming out in September, we're adding a lot of capabilities inside of SketchUp that allow you to create what are called thermal primitives that allow one user to quickly match up, or sorry, to sketch out what you think would be the floor print and then extrude that up, you know, certain a number of floors. That way you can quickly create the models to get the analysis or at least your thermal primitive started.
The second thing is is that we have the Example File Generator or ModelMaker that do exist that could help you print a thermal primitive model that you can then import into OpenStudio. OpenStudio opens up EnergyPlus input files or imports them so you're actually able to use any input file from EnergyPlus currently to actually see what's there.
OK, it looks like a follow-up question to one of the OpenStudio questions. If I wanted to share site-specific or energy modeling information with OpenStudio, how would I go about doing that? How exactly is open source information being collected and used, and how is that information being tested for accuracy?
First part, share site-specific or energy modeling information with OpenStudio. To me, I read that as—if you're—I'm thinking you wanna add site-specific context to your model that OpenStudio can see and become part of your simulation. If that's the case, SketchUp has connections to Google Earth and to Google 3-D Warehouse, so we import existing buildings, and so if you geolocate your building, you can add that to the shading surfaces for the surrounding context in a—our retrofit tutorial has some videos on that. I'll let Nick address the second part of that.
Open source information being collected. So there's a couple parts here. I'll address it as OpenStudio and then as the Building Component Library. Open source information—so we as OpenStudio team members have adopted the open source license to disseminate all this. Currently, we—if anyone wants to submit code back to OpenStudio, it goes through a process that we internally review it and then accept it. We have some other national labs that are helping start contribute code back into OpenStudio, and so at that point, they basically commit it on a branch, and then we review it, and if it's acceptable, we then add it to the source—or sorry, to the trunk, which is basically the core part of it.
On the Building Component Library side, if this is referring to the idea of anyone generating and submitting components, currently that is only available as a user who has elevated privileges, and so we are only giving permissions to those whom we trust currently. When it becomes bigger, then we are going to actually add, basically sandboxes of content that has been verified and validated or accurate, however you wanna term that, into a separate sandbox, and then the rest of the world can have their own sandbox as well.
And another question. Do you have any models already built for passive house or house standards and a follow-on, do you have components already established for, as an example, triple-pane windows?
So we do not have any models for the passive house standards. That has not ever been one of our targets. I would be interested in discussing more exactly what you mean by that. And the second part is, you know, having components already available for triple-pane windows. We have not uploaded those to the Building Component Library. Just double-checking—no, we have not. So in that case, we have some triple-pane window constructions available; we just haven't shared them widely. We typically do more simple window construction; depending on how detailed you want your window constructions to be, you may have to use a program such as Windows 5 or Windows 6 to actually create the full characteristics of the window and then import that into EnergyPlus.
I think that covers the questions that have been submitted so far. In case there are follow-ups, we'll give it just one more minute here, in case someone wants to follow up on one of the questions that was asked. And as reminder to folks, questions can be submitted after this presentation to email@example.com. If those of you who have the questions that you did not have a chance to ask today or if you'd like to discuss one of the topics further with the staff at the National Renewable Energy Laboratory, that website there, openstudio.nrel.gov, and the email address, firstname.lastname@example.org, can be used to submit those questions.
So it looks like we've reached the end of our list today. So thank you again to Nicholas Long and David Goldwasser for presenting from the National Renewable Energy Laboratory. There are a number of resources available at openstudio.nrel.gov, including tutorials that go into much more detail than what we have done today. And there's a forum available at that website as well, for continuing discussion on this topic. So thank you again for everyone who has taken the time to attend today. I hope this has been informative and look forward to seeing these materials added to the Department of Energy's websites in the near future. Thank you.
Angie with Verizon LiveMeeting:
This will conclude today's conference call. You may now disconnect.
[End of Audio]
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