FDD (Fault Detection and Diagnostic) Analytics

BAS (Building Automation System) analytics is commonly referred to as FDD or AFDD (Automatic FDD). Implementing a BAS analytic project typically consists of the following steps:

  1. Identify a project champion
  2. Obtain a consistent source of facility data
  3. Apply metadata to the trend data (sometimes referred to as "mapping" the data)
  4. Train the team on how to leverage the output from the analytic software

Applying metadata correctly to the trend data is so critical to a successful project, that we offer this as a "stand-alone" service.   We create metadata for the trend data in the scalable manner required for new construction, providing feedback while the contractors are still on site.  We recommend using metadata based on the Project Haystack open source initiative and have metadata recommendations for equipment that is not in the Project Haystack directory yet.

 

Below is a list of popular analytics.  In general, an analytic can be developed with any multivariate condition based on the available sensors in an asset class.  When the asset properties are known (cfm, hp etc.) the cost associated with the undesirable equipment operation can be quantified.

Daily Equipment Operation and Schedules

  1. Equipment/Lighting/Buildings operating on a daily schedule
  2. Equipment/Lighting/Buildings operating on the correct schedule
  3. Optimum Stop/Start functionality for equipment being utilized
  4. Identify excessive cycling of equipment on/off

Seasonal Equipment Operation and Schedules

  1. Sequencing of equipment appropriately to match loads
  2. Lead/Lag – equipment is cycled for equal operating hours
  3. Identify excessive cycling between modes (ex: heating/cooling winter/summer)
  4. Seasonally appropriate schedules; set points and equipment enable strategies utilized.

Sensor Calibrations

  1. Data values are reasonable for sensor type
  2. Data values are reasonable for sensor application
  3. Data is not stagnant (data values change by a pre-determined amount)
  4. Environmental sensors such as outside air, humidity and enthalpy are calibrated to local weather stations

Outside Air Fraction

  1. Air handler outside air % matches damper positions
  2. Air side economizer cycle operating properly
  3. Demand Control Ventilation integrated with economizer properly

VFDs (Variable Frequency Drives)

  1. VFDs operating automatically
  2. VFD set points being met (pressure, temperature, etc)
  3. VFD Speeds reasonable and consistent with benchmarks/models

Set points – Space Temperatures appropriate for the following conditions:

  1. Occupied
  2. Un-Occupied
  3. Standby
  4. Vacant

Demand Control Ventilation

  1. CO2 space set points being maintained
  2. CO2 Sensor calibration appears accurate

Sequences of Operation

  1. Equipment sequences of operation are reasonable
  2. Equipment sequences of operation are as specified

Heat Recovery

  1. Proper set points utilized
  2. Sensors calibrated and located properly
  3. Heat recovery equipment effectively integrated with other systems
  4. Heat recovery levels achieved

Reset Strategies are Operating as desired

  1. Hot Water Reset
  2. Chilled Water Reset
  3. Condenser Water Reset
  4. Discharge Air Temperature Reset
  5. Static Pressure Reset
  6. Are hot water or chilled water reset strategies sacrificing pump and air handler VFD speeds?

Economizer 

  1. AHU (Air Handling Unit) - Air Side economizer operating properly (valves, dampers & mechanical cooling working together)
  2. Chiller plant water-side economizer operating properly
  3. Boiler plant feedwater economizer operating efficiently

Valves

  1. Verify chilled water & hot water valves are not leaking
  2. Confirm 1/3, 2/3 steam valve control is working effectively
  3. Unoccupied hot water valve control in cold climates
  4. Verify AHU chilled water & hot water valves are coordinated with each other and the outside air dampers to avoid simultaneous heating and cooling.

Central Plants

  1. Is the plant operated at the desired temperature drop?
  2. Do flows in the primary and secondary loops remain balanced as loads change?
  3. Are boilers and chillers being staged on/off appropriately?
  4. Are flexible fuel plants dispatched economically - reflecting current fuel prices?
  5. Is the proper amount of condensate being returned to steam plant?
  6. Is the Heating and Cooling equipment “enabled” at the desired weather conditions?
  7. Are variable frequency drives for cooling towers, condenser water pumps, chilled water pumps, chillers and air handlers working effectively together?