If you’ve been following along (post 0, post 1, post 2), we’ve got a detail that is ready to analyze. Almost. We’ve designated what’s air and what’s earth in the Thermal Bridging Simulation Window. We’ve also made sure our building is located in the right spot on the earth and set the elevation above sea level. There’s now one final step before we can press the Start Simulation button. We need to designate what the fills mean. Like I mentioned in my first post, I haven’t done any energy analysis before. So my template is lacking thermal properties for anything. But this isn’t so hard to resolve.
Anytime you get to a screen in ArchiCAD with that many Missing Alerts, you’re liable to feel a bit panicky. But there’s no need. Select one of the fills and click on the […] button. This will bring up the Thermal Property Assignment window. Next click on the the [catalog…] button. Now you’ll see the Material Catalog window. Built into ArchiCAD are a TON of default materials. Search through the list and find something that is (or is close to) the material you need. If you knew the material’s thermal conductivity, density, and heat capacity, you could of course enter that in manually in the first window, but presumably you don’t. And a shortcut is nice. So for our purposes let’s focus on using standards and approximations. Let’s not sweat the details just yet or worry that there are some questions remaining. For instance, I don’t quite understand the difference between Timber 1, 2, 3, and 4. Or which one I want. I’m just going to pick one. In the next post we’ll detour and learn about what the numbers mean. Or find resources that can teach us. That’ll help make our guesses more educated. It’d be nice if the help/how-to documentation for EcoDesigner STAR was complete and available for us to read, but alas… this is what you have to deal with when using a BETA version of a software.
Note: now that you’ve assigned these fills some thermal properties, they are set up for the rest of the project. Whether you realized it or not, as you were assigning thermal properties to your fills, you were making a global change to the fill attributes within your file. This will make the remaining investigations into the rest of EcoDesigner STAR easier. And once you append these fills to your template, you’ll be ready to use Energy Evaluation that much sooner and faster since all your default fills will already have these parameters set. Templates! They’re the best. 🙂
Other Note: when we get to the final screen of the Thermal Bridging Simulation we can set the grid size of how closely ArchiCAD looks at the geometry of the detail (and whether or not we see the grid). I’m going to set it to max and not worry. The smaller the scale of the grid, the longer the simulation takes. I’m using a simple detail and have the time, so I see no reason not to crank it up to 11.
Having completed this step, we can run the simulation. Refinements can wait until later. I’ll show the results of the simulation in the next post and talk about what the numbers mean. Then I’ll write one more post that focuses on doing things right from the beginning: a lessons learned and tips for setting up your template type post. After that post I’ll take a break from energy modeling, focus on some other aspects of ArchiCAD, research the next bits of EcoDesigner STAR, and then start a new series on more BEM.