Rhvac is an ACCA-approved computer program for Manual J, Manual D, and Manual S calculations. The software’s calculations are performed per ACCA Manual J 8th Edition Version 2, ACCA Manual D, and ACCA Manual S. As a technical software partner with ACCA, Elite Software ensures that Rhvac’s calculations are accurate and up-to-date, providing users with confidence in their HVAC design and sizing decisions.