1@ 110,000 cfm FANWALL®
1@16,500 cfm FANWALL®

The General Services Building has two main air distribution systems – an Induction system serving the building perimeter and a VAV/Reheat system serving the interior zones. The supply fans for both systems were replaced with fan arrays.

The VAV reheat system had two centrifugal supply fans operating in parallel. These two fans were replaced with an 18 fan array, with a total supply air capacity of 110,000 cfm. Three variable frequency drives (VFD) control this system, with six fans per VFD.

The Induction system had one centrifugal fan which was replaced with a 4 fan array, a total supply air capacity of 16,500 cfm. There are two variable frequency drives (VFD) for this system, with each VFD capable of controlling the entire fan array up to full capacity. Under normal circumstances each VFD will control two fans, but in the event of a VFD failure there is to be a manual switchover to the operating VFD to control all four fans.