If you require the exact McQuay interface for consistency with your team's workflow, you can run the Windows version using virtualization: Parallels Desktop:
You will find dozens of highly rated, touch-friendly HVAC duct sizing apps (like the Carmel Software Duct Sizer) that you can install and run directly on your Mac desktop. Summary: Which Option Should You Choose?
How to Use a Duct Sizer for Properly Sizing Flexible Ducts – KSA - Airlution
Virtualization creates a virtual Windows computer inside your Mac.
Most versions support both I-P (Imperial) and S.I. (Metric) units, making it suitable for global projects. 3. Top Alternatives for Mac Users