Cultivation · Controlled Procedure
VC-SOP-0103 — Greenhouse Climate & Lighting Control
The procedure governing temperature, humidity, CO₂, airflow, and photoperiod across all growth zones of the Sector-7 Arboretum. Stable climate is the foundation of specimen health, predictable toxin yield, and containment integrity.
Setpoints are per growth zone, not facility-wide. Each zone profile is bound to the dominant specimen class and its containment grade. Never apply a single global override; doing so will violate the climate envelope of at least one zone. All deviations are logged per
VC-SOP-0103.1. Purpose
To define the authorized setpoints, control bands, and corrective responses for the greenhouse climate and lighting systems such that every growth zone remains within its specimen-specific environmental envelope, and that any drift is detected and corrected before it stresses living stock or destabilizes a containment sphere.
2. Scope
Applies to all cultivation and containment growth zones (Z-01 through Z-19) served by the central climate plant and the Spectral Canopy lighting rigs. Nutrient delivery is governed by VC-SOP-0118; hydraulic faults by VC-SOP-0402; sensor accuracy by VC-SOP-0501. This SOP does not authorize changes to GCL-4 sphere atmospheres, which remain under VC-SOP-0204.
3. Definitions
| Term | Definition |
|---|---|
| Climate Envelope | The full set of authorized control bands (temperature, RH, CO₂, VPD, light) for a given growth zone. |
| VPD | Vapor Pressure Deficit — the driving force for transpiration, expressed in kPa; the primary humidity control target. |
| Photoperiod | The programmed light/dark cycle (hours) and spectral recipe delivered by the canopy lighting rig. |
| DLI | Daily Light Integral — total photosynthetic photon flux delivered per day, in mol·m⁻²·d⁻¹. |
| Control Band | The acceptable range around a setpoint; excursion beyond it triggers a graded alarm. |
| Free-Cooling | Use of filtered outside air for cooling when external conditions permit, reducing chiller load. |
4. Responsibilities
| Role | Responsibility |
|---|---|
| Climate Systems Engineer (Owner) | Maintains zone climate profiles; approves envelope changes; owns this SOP. |
| Watch Commander | Holds shift authority over setpoint adjustments; approves manual overrides. |
| Cultivar Technician | Verifies plant-side response to climate; reports stress symptoms not flagged by sensors. |
| CHLORA | Executes automated control loops; raises graded alarms; logs all setpoint and actuator events. |
| PhytoSense Mesh | Supplies zone temperature, RH, CO₂, and canopy-level VPD/fluorescence data. |
5. Equipment & Pre-Checks
- Central climate plant (chiller, boiler, dehumidifier, CO₂ injection) status green on CHLORA
- Zone air-handling units and damper actuators confirmed responsive
- Spectral Canopy lighting rigs reporting per-channel driver health
- PhytoSense Mesh nodes for the target zone within calibration window (see VC-SOP-0501)
- Redundant sensor cross-check: primary vs. reference probe within tolerance
6. Authorized Zone Setpoints
The following are the standard climate envelopes. Zone-specific profiles in the CHLORA library override these defaults where a specimen demands it.
| Parameter | Setpoint | Control Band | Warn / Crit Excursion |
|---|---|---|---|
| Day temperature | 24.0 °C | ±1.5 °C | >±2.0 / >±3.5 °C |
| Night temperature | 18.0 °C | ±1.5 °C | >±2.0 / >±3.5 °C |
| Relative humidity | 65 % | ±5 % | >±8 / >±12 % |
| VPD (canopy) | 0.95 kPa | 0.8–1.2 kPa | <0.6 / >1.6 kPa |
| CO₂ (lights-on) | 900 ppm | ±100 ppm | <600 / >1500 ppm |
| DLI | 22 mol·m⁻²·d⁻¹ | ±2 | <16 / >30 |
| Photoperiod | 16 h light / 8 h dark | profile-bound | unscheduled transition |
7. Procedure
7.1 Shift Start & Envelope Verification
- On watch handover, the Cultivar Technician reviews the climate dashboard for all assigned zones; confirm each parameter sits inside its control band.
- Cross-check primary sensor against the reference probe in at least one zone per shift. Disagreement > band width → flag for calibration per VC-SOP-0501.
- Confirm the active lighting profile matches the scheduled photoperiod for the day-of-cycle. Note any specimen in a flowering trigger window.
- Log shift-start state to the metrics board; sign the read-back.
7.2 Setpoint Adjustment
- Setpoint changes require Watch Commander authorization and a stated agronomic justification (e.g., flowering induction, heat-stress mitigation).
- Apply changes in steps no larger than 1.0 °C, 5 % RH, or 150 ppm CO₂ per 30-minute interval to avoid shocking stock.
- Observe the zone for a minimum of two control cycles after each step; confirm CHLORA settles within band without actuator hunting.
- Record the new envelope, justification, and approver in the change log.
7.3 Photoperiod & Spectral Management
- Photoperiod transitions ramp over 15 minutes (dawn/dusk simulation); never hard-switch the canopy array.
- Spectral recipe (blue/red/far-red ratio) is bound to the growth phase profile; deviations require Climate Systems Engineer sign-off.
- Verify DLI accumulation tracks the daily target by mid-photoperiod; adjust intensity, not duration, to correct.
- For any unscheduled dark-period interruption, treat as a quality event and notify Cultivation.
7.4 Quality Checkpoints
- All zones within control band at shift start, mid-shift, and handover
- No actuator hunting (> 4 reversals in 10 min indicates loop instability)
- DLI within ±2 of target at end of photoperiod
- VPD held in the 0.8–1.2 kPa transpiration corridor during lights-on
- CO₂ injection auto-disabled during dark period (no waste, no acidification)
8. Alarm Responses
| Alarm | Indication | Immediate Action |
|---|---|---|
| Temp Drift | Zone temp beyond ±2.0 °C | Confirm sensor validity; check AHU/chiller; if real, step setpoint recovery and notify Watch Commander. |
| VPD Excursion | VPD outside 0.6–1.6 kPa | Adjust humidity, not temperature, first; inspect dehumidifier condensate line. |
| CO₂ High | >1500 ppm in occupied zone | Halt injection; increase ventilation; personnel evacuate the zone until <1000 ppm. |
| Lighting Failure | Canopy channel/driver fault | Switch zone to backup rig; if DLI shortfall projected, extend photoperiod within profile limit; log for monitoring. |
| Plant Stress Flag | Fluorescence/turgor anomaly from PhytoSense | Inspect specimen physically; correlate with climate log; escalate to Cultivar Lead if non-climatic. |
9. Records
- Shift-start and handover climate read-back (retained 3 years)
- Setpoint change log with justification and approver
- Alarm and corrective-action records (cross-filed to Monitoring)
- DLI and photoperiod compliance trend (CHLORA, retained 3 years)
10. References
VC-SOP-0103— Procedure Deviation & Logged Exception Control- VC-SOP-0118 — Hydro-Loop Nutrient Dosing & pH Balance
- VC-SOP-0124 — Spectral Canopy Array Calibration & Imaging
- VC-SOP-0501 — PhytoSense Mesh Calibration
- VC-SOP-0402 — Hydro-Loop Overpressure Response
- Operational Metrics · Monitoring Systems
11. Revision History
| Rev | Date | Author | Summary |
|---|---|---|---|
| A–B | 2087–2088 | Climate Systems Engineer | Initial issue; per-zone envelope concept introduced. |
| C | 2090-04-18 | Climate Systems Engineer | VPD adopted as primary humidity target; step-change limits added. |
| D | 2091-02-20 | Climate Systems Engineer | DLI compliance checkpoint and dawn/dusk ramp formalized. CBO approval. |