Comparison of foil and aluminum duct
Foil Flex Hose
"Spiral type multi-ply foil flexible duct"
In compressed state, only 3 1/4" inside dimension
Pros:
- Easy to work with and install
- Very flexible
- Much less efficient (a lot of interior friction)
- Not allowable by most dryer manufacturers
- Has been known to not contain a lint fire
Provides a delta of .35 inches of water column pressure
Flexible Aluminium
"Semi-rigid flexible aluminum duct"
In compressed state, a full 4" inside dimension
Pros:
- Maintains a full 4" diameter in compressed or bent configuration
- Smooth or smoother interior
- Very efficient and safe
- Specified by most manufacturers
- Insisted upon by numerous building codes
- Harder to work with and install
- Does not have the ability to twist
Provides a delta of .10 inches of water column pressure
Popular Efficiency Value Chart for
Dryer Exhaust Terminations and Fittings