Packaged Rooftop Unit Economizer Functional Test

Inspection template for verifying air-side economizer operation on packaged rooftop units, including damper stroke, position feedback, outdoor air sensor calibration, and high-limit lockout performance in line with ASHRAE 90.1 expectations.

Test Setup and Equipment Identification

• RTU identification matches test record
  Verify unit tag, location, model, and serial number match the inspection record and control sequence documentation.
• Test conditions documented
  Record outdoor air temperature, return air temperature, occupancy status, and whether the unit is in occupied mode.
• Controls sequence and setpoints available
  Confirm the current economizer sequence of operation, mixed air setpoint, minimum outdoor air position, and high-limit lockout settings are available for review.
• Unit accessible for safe testing
  Verify rooftop access, fall protection, and safe access to dampers, sensors, and control panels before testing begins.

Damper Stroke and Mechanical Operation

• Outdoor air damper strokes smoothly through full range
  Command the damper from minimum to full open and verify full travel without binding, chatter, or abnormal noise.
• Return air damper responds oppositely to outdoor air damper command
  Verify return air damper movement is coordinated with outdoor air damper operation and does not stick or lag.
• Minimum outdoor air position achieved
  Measure or confirm the minimum outdoor air position against the design or sequence requirement.
• Damper linkage and actuator condition acceptable
  Inspect linkage, actuator mounting, fasteners, and blade condition for looseness, damage, or misalignment.
• Damper position feedback matches commanded position
  Verify feedback signal or indication corresponds to the actual damper position within acceptable tolerance.

Sensor Calibration and Control Response

• Outdoor air temperature sensor calibrated
  Compare sensor reading to a calibrated reference and confirm acceptable accuracy.
• Mixed air temperature sensor calibrated
  Compare mixed air sensor reading to a calibrated reference and confirm acceptable accuracy.
• Controller responds to economizer enable/disable command
  Verify the controller changes damper position and mode status appropriately when economizer operation is enabled and disabled.
• Sensor wiring, mounting, and shielding acceptable
  Inspect sensor placement, wiring terminations, and protection from direct solar gain or physical damage.

High-Limit Lockout and Free Cooling Logic

• High-limit lockout setting matches design intent
  Verify the configured high-limit strategy and setpoint align with the project requirements and applicable economizer sequence.
• High-limit lockout prevents economizer operation when required
  Simulate or verify outdoor conditions above the lockout threshold and confirm outdoor air damper does not provide free cooling.
• Mechanical cooling stages engage when economizer is locked out
  Confirm compressor or mechanical cooling stages operate as intended when economizer free cooling is unavailable.
• Mixed air temperature remains within safe operating range
  Observe mixed air temperature during lockout and verify it remains within the acceptable range for the unit and controls sequence.

Exceptions, Corrective Actions, and Approval

• Deficiencies documented with corrective actions
  Record each deficiency, responsible party, target completion date, and required corrective action.
• Inspection result reviewed with responsible party
  Confirm findings were communicated to the owner, facility representative, or commissioning authority.
• Inspector signature
  Inspector attests that the functional test was performed and results were recorded accurately.