The climate ladder, failsafe and reality gates

How the hub turns targets into appliance demand: the rung order, min-off, hysteresis, ladder waits, reality gates (ineffective, relay mismatch), the failsafe, priority tent and the shared exhaust.

For each tent the hub compares the corrected readings with the targets and climbs a fixed ladder, one rung at a time:

1. Dehumidifier (RH above band)
2. Humidifier (RH below band)
3. Heater (temperature below band)
4. Cooling (temperature above band; the AC relay is hardware on hold, so this rung shows no actuator)
5. Heat mat (root-zone band, driven by probe votes)

Fans are separate: intake per tent and the shared exhaust chase VPD and temperature under the control strategy, with the priority tent winning the shared exhaust.

• Hysteresis: a rung engages only past the band edge plus a margin, so appliances do not chatter.
• Minimum off-time: after switching off, an appliance is not asked again until its min-off elapses. The tile glows blue meanwhile.
• Ladder wait: the hub waits at a rung for its wait time before escalating. Learning Phase B can propose these waits from observed response.
• Reality gates: the hub checks the appliance did something. A dehumidifier that runs without moving RH trips dehumidifier ineffective (critical). A plug whose relay state disagrees with its demand trips relay mismatch (critical). Heater and humidifier ineffectiveness are judged against the firmware band.

The hub firmware has two safety layers above the ladder. Both outrank manual takeover.

• Emergency failsafe: the 4×8 tent temperature rises above 35 °C. The hub switches the heater, heat mat, humidifier, dehumidifier and 2×4 mister demands off, asks for the AC if it is in service, runs the outside exhaust and both intakes at 100 % with the room exhaust off (a once-through purge to outside), and turns the 2×4 lamp off. It clears below 34 °C and restores the previous fan and lamp state. The Emergency failsafe alert is critical by default, cannot be disabled, and quiet hours and away mode never silence it.
• Sensor fault safe mode: no valid 4×8 tent temperature for 3 minutes. The hub switches the room appliance demands off (heater, heat mat, humidifier, dehumidifier, AC) and runs the fans at a gentle safe ventilation (outside exhaust 40 %, the others 25 %); the 2×4 mister and lamp keep running on their own sensor and clock. It raises Climate sensor fault (critical) and clears when a valid reading returns.

Readings pass through per-zone offsets and clamps (Settings › Sensors). A clamped-out reading is rejected, not smoothed, and raises climate reading rejected (critical, because the ladder would otherwise heat a warm tent on a railed sensor). A stuck sensor (no change for too long) is also critical. The two tent DHTs are compared; disagreement pairs the zones in one alert.

The intake budget per tent and the clone intake scale set how much the intakes may run relative to the exhaust, giving negative, neutral or positive pressure. The brain reports the target and net flow.

Targets and modes on the Climate desk. Hysteresis, min-off, waits and the de-strat pulse under Settings › Climate (advanced rows). Trust thresholds under Settings › Sensors. The rung order and the failsafe are firmware.

Guide contents  ·  How it works  ·  Troubleshooting  ·  Digital Stealth Care

DSC-Brain user guide · The climate ladder, failsafe and reality gates · this page is edited on the site; the Notion original was retired after the mirror