Load Calculation Type

The Manual J procedure implements 2 variations on calculating heating and cooling loads: "Block load" and "Room by room". Block load calculates heating and cooling loads for the entire conditioned space whereas room-by-room provides a more accurate heating and cooling load calculation for individual rooms. For most purposes block load calculations are sufficient but if you require detailed CFM airflow data per room or are considering a zoned system, room-by-room load calculations are recommended.

Load Calculation type - CoolCalc Documentation
Note: Due to the way CoolCalc determines default internal loads, the load calculation type cannot be changed after dimensional data has been created.