IES Consulting used the IESVE Apache HVAC tool to model multiple HVAC system types ranging from single zone to Under Floor Air configurations for this multi-storey development.
The tower section of the building accounts for the vast majority of the total building floor area and is primarily conditioned by custom built VAV UFAD (underfloor air distribution) dual path multi-zone systems.
Each tower floor is served by two separate UFAD systems split into east west zoning arrangement. This unique system was explicitly modeled using the IESVE.
All HVAC cooling coils are served by chilled water at 40oF supply, with a design return temperature of 56oF. Chilled water is generated by four centrifugal water cooled chillers with multi stage compressors (3 x 1100ton & 1 x 400ton). Cooling tower fans & condenser pumps are of a VSD type. Chilled water is circulated via a number of secondary side VSD pumps. All heating is provided via direct electric heating coils.
The building consists of the following energy conservation measures (ECM’s):
• High performance building envelop (better glazing than baseline minimum)
• High efficiency parking garage lighting design + Occupancy sensors (0.144W/ft2)
• High efficiency lighting design in developer areas
• High efficiency exterior lighting design including LED fittings
• UFAD dual path multi-zone HVAC system (reduced fan power, increased supply air effectiveness & reduce terminal reheat energy)
• DCV (Demand control ventilation) for all tower floors
• VAV box ECM fans (0.22W/cfm fan power density) in all series fan power boxes
• Multi stage compressors in centrifugal water cooled chillers
• VSD Cooling tower fans
• VSD Condenser pumps
• VSD chilled water pumps
• Low temperature VAV system (resulting in reduced primary fan energy)
• 15% VAV terminal unit minimum turndown (reduced reheat), VAV sFPB’s
• Low flow SHW water future’s (43% saving in hot water demand as per WEc3)
• High efficiency SHW heating source (97% eff)