Manual S Performance Data Example 3
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.
This example shows a performance data table that does not include entering dry bulb as a parameter in the table, but is instead handled by a direct adjustment factor in the notes section that follows. So we can uncheck the Entering Dry Bulb checkbox under Interpolation Conditions, which means we have 8 fewer inputs to enter in the Interpolation Values section.
The note after the table says to use an adjustment to the capacity for entering dry bulb temperatures other than 80 degrees F. Since this example uses 76 degrees F we need to figure out the how much to adjust the total. It says to deduct 835 Btuh per 1000 CFM of indoor coil air for each degree below 80 degrees F. The airflow in this example is 780 CFM, so we multiply 835 Btuh times 0.780, and then multiply the result by 4 to account for being 4 degrees cooler than 80.
-835 x 0.780 x 4 = -2605.2
Since we are using capacity units of MBtuh, we enter -2.605 in the Direct capacity adjustment input.
The Interpolation Results area shows that the selected equipment's total capacity is 103% as large as the total load, and its sensible capacity is 97% of the sensible load.