What Are Standard Access Panel Dimensions for HVAC?

https://www.scribd.com/document/1000494018/Effortless-Plumbing-Access-With-Drywall-Panels-157715

Standard access panel dimensions for HVAC systems usually range from 12x12 inches to 36x36 inches. For residential applications, you'll commonly see sizes like 12x12 and 16x16