When installing, replacing, or correcting existing flexible duct problems….
Keep the friction loss characteristics of flexible ducting in mind and design with it in mind. Don’t use old ‘rule-of-thumb’ guidelines.
- Keep all flexible ducts as short and straight as possible.
- Limit the number of connections between the duct branch and the diffusers.
- Limit the connections between duct branch and VAV terminal units.
- Install without any kinks
- Support all elbow supports when making turns into buckets or plenums.
- Install with no more the 15% compression from full stretched length.
- Seal all connections with duct mastic and duct ties… (not use duct tape).