While the specifications for both types of duct sealing have recently been updated to be more aligned, there are two primary differences between the two types.
1) Leakage testing: PTCS Duct Sealing requires a pre-leakage test be conducted prior to sealing and a post-leakage test conducted after sealing. Prescriptive Duct Sealing does not require any pre- or post-leakage testing.
2) Certification training:
PTCS Duct Sealing Certification requires training with a PTCS-certified trainer or an approved alternative. Certification is obtained by reviewing an online training. More information about how to become certified can be found on the Training Page.