Appendix G Baseline Systems 1 (PTAC) and 2 (PTHP) have cooling
efficiencies (and for PTHP, heating efficiencies) that vary with cooling
capacity per Table 6.8.1D. Since each thermal block is modeled with its
own system, you can end up modeling as many as 100 or more systems per
project. For LEED projects (or other App. G models), I have been
calculating and manually entering values for cooling EIR for every
single system, based on capacities reported in the SV-A reports. I
factor in the unique fan power (per G3.1.2.9) for each system and remove
its contribution from the efficiency, since fan power is included in EER
and needs to be separated per G3.1.2.1. Once you enter efficiency for
each system, just about any change you make in the model changes the
supply flow rate and/or system capacities, which means you need to redo
all the efficiency calculations.
Does this method seem correct?
Has anyone figured out a way to automate this process? (And by
"automate", I don't mean give it to the intern.)
Thanks,
Bill