Manual S Performance Data Example 4
Here's an example of entering values from a typical manufacturer's air conditioner or heat pump cooling performance data table into the Manual S Performance Data page. The cells with shaded colors in the performance data table correspond to the colored input cells in the screenshot that follows.
In this example none of the values in the Design column of the Interpolation Conditions area of this page exactly match any of the parameters of the manufacturer's table. For example, the outdoor dry bulb is 99 degrees, but the table has 95 and 105 degree sections. So we need to keep each of the Interpolation Conditions checkboxes checked, and fill in all 32 inputs in the Interpolation Values table (you only ever need to fill in 2 of the 4 columns under Sensible Capacity).
Since the "T.C." and "S.C." rows (total capacity and sensible capacity) in the manufacturer's table shows values in units of 1000 Btuh, set Capacity Units to MBtuh (it's also sometimes called MBH or KBtuh). That way we can enter the numbers exactly as they appear in the table.
For the inputs under Sensible Capacity this time we can enter values only in the MBtuh column instead of the T/C column, since the "S.C." rows of the manufacturer's table show actual sensible capacities and not just ratios.
With this table we needed to make a little bit of a compromise when it comes to the entering wet bulb and entering dry bulb values. Notice that the "ID DB (°F)" and "ID WB (°F)" columns include individual pairings of dry bulb and wet bulb values. So in the light green cells, for example, we had to choose between being accurate with the dry bulb or the wet bulb, since at 75 degrees dry bulb the highest wet bulb provided is 62 degrees. So we decided to use dry bulb and chose the 75 and 62 column, and entered a value of 17.9 under Sensible Capacity at 75 degrees dry bulb even though that value on our page is supposed to be at 67 degrees wet bulb.
The Interpolation Results boxes show that the selected unit's total capacity is 108% of the total load, and its sensible capacity is 104% of the sensible load.