Water-Cooled Chiller Curve Coefficients Spreadsheet (Metric)

Spreadsheet to calculate curve coefficients for water-cooled ApacheHVAC input from manufacturer data (metric units).

This spreadsheet performs the calculations to calculate the curve coefficient inputs in ApacheHVAC from chiller manufacturer performance specifications in metric units. Users will need part load chiller data at multiple constant entering condenser water temperatures (ECT) and leaving chilled water temperatures (CHWS).

On the “Data Entry” tab of the spreadsheet, enter the leaving chilled water and entering condenser water temperatures provided by the manufacturer in columns C and D, following the format of the values already populated in the spreadsheet. Edit the values in column B for the Part Load Ratio table to match the data provided by the manufacturer. As you edit these yellow cells, it is important that the data on row 15 match the data on row 40. The data on row 26 should match the data on row 45 and the data on row 34 should match the data on row 55. Color coding in column E reflects this coordination.

Complete columns E and F in the Full Load Ratio table. Operating capacity (CapOp) data should be provided from the manufacturer along with the electrical input in kilowatts. Power input can be divided by the operating capacity to generate the kW/ton value required in column F.

Once all inputs are entered in the spreadsheet, the calculated coefficients for ApacheHVAC can be found on the “Curve Coefficients & Validation” tab. Three sets of coefficients are shown, corresponding to the three chiller curves in each chiller model.