I am a teaching assistant for a graduate level tech course that uses Ecotect 2010 and we are having serious problems with groups that are getting hardly any benefit from increasing wall and roof insulation on their models. Going from an R20 to an R70 walls and roof only yields a 2 kbtu/sqft improvement. We have tried with windows and without and have 14 teams of 4 plus an Ecotect instructor plus 5 TAs that cannot figure out what is going on. Can some please advise us as to why we are getting bogus numbers with thermal calculations. This is the 4th year we have taught this class using Ecotect and the instructors are very familiar with the software, yet we do not understand why we are seeing such little change in KBTU/sqft despite implementing all of the best thermal and daylighting strategies.
Use SI units for thermal and material properties for layers within various assemblies. Using Imperial units creates an unstable environment in which conductivity fluctuates every time when material properly dialog is being refreshed.
I am experiencing the same problem, although I am using SI units. Major changes in envelope and fenestration reduce hardly some C degrees in temperatures or a few Watts in heat gains. I just wanted to know whether you worked it out by changing units. Did it work for you?