Supply Tubing

The Unico System supply tubes are available in either 2 and 2.5" I.D. (inside diameter). They are often referred to as Sound Attenuator due to the sound deadening properties of the duct. The tubes core is made with nylon, which is then wrapped with insulation and finally wrapped with an outer vapor barrier to stop moisture and also to reduce thermal losses.

Three supply tubes with round outlets in various finishes

Standard 2" Duct

  • Our standard duct can deliver up to 40 CFM
  • Full range of round and slotted outlets which are available in a variety of finishes
  • Outlets can also be painted to match any color
  • Recommended to use 8 outlets per nominal ton to keep noise levels very quiet
Coiled, flexible supply tubing


2.5" Duct

  • 2.5" tubing paired with a new threaded outlet
  • The 2.5" tubing can deliver up to 50 CFM
  • Full range of round outlets available
  • Has the same sound level as a 2" outlet but more airflow
  • If you have normal duct lengths and can maintain the same static pressure, you can reduce the number of outlets and save on installation time
  • Because of greater airflow capabilities, the 2.5" tubing and outlet are ideal for high altitude installations

Technical Specifications

Engineering Specifications: Bulletin 20-54 Supply and Sound Attenuator Duct (PDF)

Installation Manual: Bulletin 30-55 Installation Manual for Supply Tubing (PDF)



California residents please see Proposition 65.