Type1221: 2-Stage Water to Water Heat Pump - Normalized Data File Approach (a TESS model) has two quite interesting inputs: “Scale Factor” and “Number of heat pumps on”. This must be related to the parameter “Number of identical heat pumps”. In testing the proforma, I have noticed that these two inputs have a similar, but not identical, impact on the outputs. I am fairly certain that I should not use both, since the effects are compounding. Is there a mathematical description available? (I couldn’t find it in the documentation) If not, can anyone explain the design intent of these inputs? Ben Heymer, PE Energy Engineer | Energy Center of Wisconsin | Madison.Chicago.Minneapolis 608.210.7168 Mobile: 312.315.4783 | www.ecw.org |