March 6, 2023 - March 8, 2023 Duct and Envelope Tightness (DET) Verifier – Online Training Zoom (Video Conference) This three-day online course is designed to introduce the skills necessary to become a Duct and Envelope Tightness (DET) Verifier, certified to perform the diagnostic testing required for new homes … Continue reading "Duct and Envelope Tightness (DET) Verifier – Online Training"