Methodology
The calculators provide SI-unit preliminary estimates using simplified engineering formulas and published methodology references.
Standards And Assumptions
English pages default to international assumptions such as ASHRAE, EN 442, and ISO-style methodology where implemented. Chinese pages default to China-standard assumptions such as GB 50736-2012, GB/T 13754-2017, and CJJ/T 34-2010.
Limitations
Results are intended for early-stage screening, comparison, and educational use. Final HVAC designs should account for local climate data, building envelope details, equipment manufacturer data, commissioning requirements, and applicable codes.
Units
All calculators use SI metric units. Inputs and results are labeled on each calculator page.