This method requires the assessment of three duct characteristics as mentioned below:
- Percentage of ductwork done in the conditioned space
- Duct leakage evaluation
- Duct insulation evaluation
These three characteristics help determine the distribution efficiency by using the Building Performance Institutes ‘Distribution Efficiency Look-Up Table’ found in the below Section, or calculated via a program-approved energy modeling software. Distribution system efficiency will be assessed in the two conditions defined below.
- Definition of Baseline Condition: The existing baseline condition is leaky ductwork within the unconditioned space in the home.
- Definition of Efficient Condition: The efficient condition is sealed ductwork throughout the unconditioned space in the home.