What are the key considerations when using thermal design software like HTRI or Aspen EDR?

Considerations: input data quality (physical properties, fouling factors, and design basis significantly affect results), understanding model assumptions (single-phase correlations, ideal distribution, clean surface heat transfer), validating against field data when available, iterating geometry for optimization. Common pitfalls: unrealistic fouling factors, ignoring shell-side maldistribution, accepting first solution without optimization, not checking velocity limits, and ignoring vibration warnings. Always review detailed output including velocity profiles, pressure drops, and warning messages.