What is the difference between Block-Load and Room-by-Room?

Essentially "block load" calculates heating and cooling loads for the entire conditioned space whereas room-by-room provides heating and cooling load calculation for individual rooms.

Both options should result in the exact same heat loss and heat gain totals. However, if you are considering a zoned system, or are looking to design or verify ductwork, room-by-room calculations are necessary to calculate the CFM required in each room.

Due to the way CoolCalc determines default internal loads, the load calculation type cannot be changed after dimensional data has been created.