- Green the MLS
- Energy Code
Meeting the NC 2012 Energy Code Requirements:
The NC 2012 Residential Energy Code requires duct testing in new homes. Total duct leakage rate must be 6% or less, and recorded on the energy efficiency certificate. Use only approved, durable materials to seal ducts; UL181 labeled tape or mastic. Mastic works best on metal ducts and seams. UL181 rated tape works well to seal seams on air handler unit boxes.
- HVAC and Duct Sealing Guide for requirements and common problem areas
- Ducts and HVAC section of the photo library
- Duct Sealing and Testing YouTube video
- Free training is available for HVAC Contractors upon request through May 2017
- Download this energy efficient certificate, and be sure duct leakage results are recorded
- Seal supply boots and return boxes to the sub-floor or finished ceiling.
- Wall framing is still allowed to be used for returns, if used seal all seams and joints with mastic.
- The air handler is under the highest pressure and is often the leakiest part of the duct system. Be sure to seal up the air handler with mastic or UL 181 tape.
- Flexible ducts should not be pinched, squeezed, or supported in a way that prevents air flow.
Building America Solution Center Resources:
- Air Seal HVAC Cabinet Seams
- Total Duct Leakage Tests
- Duct Leakage to Outdoors
- Ducts in Dropped Ceilings
- Sealed and Insulated Metal Ducts
- Sealed and Insulated Flex Ducts
Go Beyond Code:
- Place ductwork in the conditioned space, this will reduce energy loss. Duct leakage testing is not required when ducts are in the conditioned space.
- Zero Energy Ready Home Technical Training - Ducts in Conditioned Space, from energy.gov
The NCEEA has created a document to help the HVAC Contractor become qualified to work on ENERGY STAR jobs and become a leading energy efficient contractor. Click here to download the pdf.