Series Fan-Powered Terminal Unit Animations

[@slee3286]

Thank you!! It is so informative.

[@thomastrang4815]

Are the AHU and VAVs working together in conjunction based on the BAS sequencing?

[@ACHVACTAB1]

Typically No . The Fpvav or Vav Etc... are pressure Independent. There are DDC systems that have static reset which looks at all vav damper position(s) and will lower a static set point until at least one box is near 90% open. Caution on this: sometimes it will get static way to low like 0.40" and than many boxes can fall short of air or the system gets stuck and never increases again. Always insert a "Not drop lower than" static set point of about 0.7"w.g. Controllers get to sluggish below that.

[@chevyescobar3057]

I transferred to a building where some rooms have 2. Can these interfere with the rtu's?

[@KruegerHVAC]

That’s a great question! Some spaces are large enough to require two fan powered terminal units in order to deliver the required amount of airflow. In these instances, it’s possible that the fan powered terminal units might each have a thermostat on opposite sides of the room, essentially splitting up the space into two zones. It could also be that the building controls are using one thermostat to control both fan powered terminal units together in tandem.

[@brickboiler]

Are these units typically supplied with a filter for the plenum air inlet?

[@KruegerHVAC]

There is a throwaway filter that comes standard, but it’s meant to be on the unit only during the installation. However, some units offer optional MERV filters for use during normal operation.

[@brickboiler]

@@KruegerHVAC Thanks! So it might be normal to find one pulling in plenum air without a filter.