If you can’t find a pre-made sheet that fits your workflow, creating one is possible but time-consuming. Use these core formulas:

The represented a pragmatic, accessible bridge between manual hand calculations and expensive professional software. While not a substitute for validated tools in commercial practice, it served – and continues to serve – as a valuable educational resource and preliminary design aid. Users must remain aware of its limitations regarding dynamic simulation, code compliance, and error resilience. For professional HVAC design, upgrading to ACCA-approved or ASHRAE-aligned software remains the industry standard.

Step 2: Input Outdoor and Indoor Design TemperaturesTypically, indoor design temperatures are set to 70°F for heating and 75°F for cooling, though these can be adjusted based on client preference.