Modern buildings are filled with electronics. Your sheet should account for: The number of people and their activity levels. Lighting: LED vs. traditional lighting loads.
Unlike "black box" software, an Excel sheet allows you to see the math behind the load, making it easier to spot errors. hvac calculation excel sheet 2021
This is the core of the calculation. You need to input the U-values (thermal transmittance) for: Modern buildings are filled with electronics