Flex Duct Between Floors

Occasionally we need to access the ducts between the floors to improve the airflow.

Flex duct between floors.

Flexible duct performance in. Here are several ways to access ducts. The most common size duct used is 14 in. A duct system located in an attic must be insulated and must have a vapor barrier.

The supports need to be at the manufacturer s recommended spacing but no longer than 4 maximum. Attic installations attic installations lend themselves readily to all of the duct system types. Between floors of multistory structures crawl space installations conditioned space installations embedded in concrete slab. Flex ducts have a fairly non smooth surface inside which can impede airflow over long distance runs.

Another biggie that i see all the time is sagging ducts. Since all flexible ducts are not alike use the flexible duct manufacturer s air friction loss data to size the ducts whenever possible. But without proper support ducts can develops sags or kinks that reduce airflow 4a 4b. No air should be able to penetrate the ductwork and the joints are a natural weak point.

Sometimes the best route for a flexible duct run is up and over an obstruction. Add a false return grille cut an access hole in the ceiling of the first floor in a central area to gain access to the ducts. Without it there would be tons more labor and material to make that final connection. Keep flex ducts as short as possible between the hard duct and the hvac grille.

Hart cooley offers flexible duct products for both residential and commercial applications that provide the most economical solution to your air handling needs. To prevent problems use saddles or straps to support at regular intervals 4c 4d follow the manufacturer s instructions but in case they get lost here is a list of best practices for. Also make sure to use hvac tape and seal all of the joints between duct segments. The insulation you use to wrap your ducts should leave no gaps and be at least two inches thick to work effectively at reducing or eliminating condensation on ductwork.

This size fits just between most floor joists. If no data is available use the generic flexible duct friction loss chart in acca manual d. The official recommendation from the adc is that flex ducts should sag no more than 1 2 per foot of length between supports. Adc flex duct disspelling myths for light commercial systems 1 mb pdf product information.