The Verizon MSC Phase II project was an active switch site that was retrofitted to accommodate additional DC power. The facility was remodeled and the entire mechanical system was updated while accommodating the needs of a business which remained in operation throughout construction. The heart of the mechanical cooling system was comprised of three 160-ton air cooled chillers with multiple stages of economizer functionality to leverage Colorado’s climate and maximize energy conservation. The prime building heat load was serviced by a bank of water source computer room air handlers. This system was started and proven prior to decommissioning the existing mechanical equipment that was serving the building's cooling needs.