Outdoor Conditions
- Summer Outdoor Conditions: Use the ASHRAE 0.4% Chicago Midway dry- bulb condition (91.9F DB/74.7F WB).
- Winter Outdoor Conditions: -10 degrees Fahrenheit dry-bulb (Exceeds ASHRAE 99.6% DB)
Indoor Conditions (Summer)
- For load calculations and sizing of the Central Plant (chillers, pumps, etc), 78 degrees Fahrenheit dry-bulb and relative humidity between 30% and 60% (occupied areas).
- Air-handlers and terminal equipment shall be sized for 75 degrees Fahrenheit dry-bulb and relative humidity between 30% and 60%. Humidity control shall be incidental to mechanical cooling (No active humidity control).
- Normally unoccupied spaces (Mechanical, Electrical, Janitor’s Closet, Storage, Elevator Machine Rooms, etc.) shall be designed for 85 degrees Fahrenheit or 10 degree Fahrenheit rise.
- Aquatic Centers shall be designed for 80 degrees Fahrenheit dry-bulb (2F above water temperature) @ 50 to 60% RH.
- Kitchens and Gymnasiums shall be designed for 80 degrees Fahrenheit dry-bulb (for new schools only; obtain permission from CPS before air conditioning existing spaces)
- For Control Set Points and Operation, 78 degrees Fahrenheit dry-bulb and 50% relative humidity (maximum level 60% relative humidity). Humidity control shall be incidental to mechanical cooling (No active humidity control).
- 100% Outdoor AHU/MAU/DOAS: Use the ASHRAE Chicago Midway 0.4% dehumidification condition (84F DB/77F WB)
Indoor Conditions (Winter)
- Occupied Spaces: 70 degrees Fahrenheit dry-bulb and 25% relative humidity (or level set by ASHRAE 55) in all normally occupied and transient spaces
- Unoccupied Spaces: 60 degrees Fahrenheit dry-bulb and 25% relative humidity in normally unoccupied spaces (Mechanical, Electrical, Janitor’s Closet, Storage, Elevator Machine Rooms, etc.)
- Humidity Control shall be incidental to mechanical heating (No active humidity control)
Schedules
- Modifications: Where specific project requires modifications, coordinate with CPS during the schematic design phase
- Occupancy
- 10% - 6AM to 7AM Monday through Friday
- 100% - 7AM to 3PM Monday through Friday
- 20% - 3PM to 5PM Monday through Friday
- 0% - All other days and times
- Lighting:
- 10% - Midnight to 6AM Monday through Friday
- 50% - 6AM to 7AM Monday through Friday
- 100% - 7AM to 5PM Monday through Friday
- 10% - 5PM to midnight Monday through Friday
- 10% - All other days
- For the purpose of calculations, lighting values shall be zero in normally unoccupied spaces (Mechanical, Electrical, Janitor’s Closet, Storage, Elevator Machine Rooms, etc.).
- Equipment:
- 100% - 7AM to 3PM Monday through Friday
- 10% - 3PM to 5 PM Monday through Friday
- 0% - All other days and times
- Heating Available: October through May (Simultaneous heating/cooling/reheating not allowed.) *May have to change to comply with ASHRAE 55 discuss
- Cooling Available: April through October (Simultaneous heating/cooling/reheating not allowed.)