We were recently asked by a client to review his system and evaluate the energy savings to seal up the supply ductwork. The building is conditioned by three packaged rooftop units that serve the spaces through a mix of cooling-only and-fan powered variable air volume (VAV) boxes. The ductwork design is unique in that the supply ductwork runs down the middle of the return ductwork — it's concentric. There is a building automation system (BAS), and the rooftop units are BACnet integrated, so we have a larger amount of data available for our analysis. The BAS system pushes data out to a building analytics server, where we can crunch the data.
During the heat of summer, the client noticed the building was struggling to cool. The client’s staff had already performed a survey of the air distribution system and discovered the supply air duct had visible gaps in the seams. Trying to diagnose the extent of the problem on the BAS can be tedious and may only provide a snapshot of what is occurring.