Thanks. To be clear, you are saying it does not matter if IndxInd or IndxCom is used to create a custom model? That seems counter-intuitive to me.
Here's a quick explanation of why it does not make sense.
First off, here's my understanding of how to "create a custom model."
The eiolca.net recommended procedure is to change direct supply chain economic values within that sector. As I understand it, the direct supply chain values should be modified according to the actual budget to produce the custom product. (Sharrard identifies this as a "bottom up" approach and likens it to Joshi"s Model II method. According to Bilec et al (2006), Joshi Model II is basically a tiered hybrid model.)
Thus, to calculate the environmental impact of a custom building, I would go to "Create custom model" section of the eiolca tool; select the "hybrid product" option; select Commercial Building sector; and enter the budget for my building design and construction, leaving values for unknown sectors unchanged; then calculate. Alternatively, if I only wanted to the know the env. impact of, say, the building's structure and did not know the budget for the structure, I would simply enter 0 for all non-structure-related eiolca sectors (such as 335110 Electric Lamp Bulb and Part manufacturing), then calculate.
It seems counter-intuitive that I'd substitute values from my actual project budget for the IndxInd values, because the IndxInd values include coal, which could clearly never be a part of my project budget. It seems like I'm mixing values that are fundamentally different. IndxCom values seem like the appropriate data for "creating a custom model," because they reflect actual flows of commodities into the industry. But you are saying that it does not matter?
Please let me know if I'm not explaining myself clearly.
Thanks!
Mike
Reference:
Bilec, Melissa, Robert Ries, H. Scott Mathews, Aurora Sharrard. 2006. "Example of a Hybrid Life-Cycle Assessment of Construction Processes"
|