How it controls

This chapter explains the control loop from a user's point of view: what the two setpoints mean, how a device decides to engage and release, and what happens on every cycle. For the architecture and the maths behind it, see the developer guide.

Two setpoints, not one

A normal thermostat has a single target and flips a heater on and off around it. Climate Orchestrator uses a band with two edges:

• a heat setpoint — the bottom of the band; drop below it and heating engages.
• a cool setpoint — the top of the band; rise above it and cooling engages.

Between the two is a neutral zone where nothing runs. That gap keeps the radiators and the AC from fighting (one heating while the other cools the same air), so you can leave both heating and cooling armed all year and the system does whichever the room needs, or nothing. Each preset (Home / Away / Sleep) is a pair of these setpoints, editable live.

If you've configured only one kind of device the thermostat adapts: TRVs with no AC become a plain heat / off thermostat with a single setpoint, and an AC with no TRVs becomes cool / off — no inert second handle. (Turning on AC heating assist makes an AC count as heat-capable, so an AC-only setup then presents the full heat/cool band — a reversible heat pump.)

Two temperatures, asymmetric trigger

For each device, Climate Orchestrator looks at two temperatures: the device's own room and the whole-home average.

• To start: either temperature crossing an edge is enough. A cold bedroom turns on its own radiator; a house that's warm on average can switch on the AC in a room that's only borderline.
• To stop: both have to be back at target before the device backs off.

By default the home average is computed over the area sensors of rooms that have managed devices. If you'd rather it reflect the entire home (or a specific sensor you trust), pick your own whole-home average temperature / humidity sensors in the integration options — they replace the computed average wherever it's used. If an override sensor goes unavailable or stale, the computed average quietly stands in, and the Home average source diagnostic shows where the values are coming from (external, computed, fallback, or mixed when temperature and humidity differ).

Don't want the home average influencing rooms at all? Turn off the Home average trigger switch and every room runs purely on its own sensor (see the reference).

This "eager on, reluctant off" asymmetry prevents short-cycling on small sensor fluctuations.

Where it aims

When heating, Climate Orchestrator drives to just past the heat setpoint — the heat setpoint plus the Switching tolerance (0.3 °C by default) — and stops. Cooling mirrors it: down to just past the cool setpoint. Rooms settle at the efficient end of the band: the cool end in winter, the warm end in summer. The small overshoot past the edge also gives the anti-short-cycling its margin.

One band still doesn't suit every room equally — a per-area band offset number can run a single room warmer or cooler than the rest; see Per-area band offsets.

Feels-like, not just the number (Comfort index)

With Comfort index targeting on (default), the room and home temperatures are converted to a humidity-adjusted "feels-like" (apparent) temperature before they meet the band, so a muggy room is treated as warmer than the bare number. Cooling then engages a little earlier in humid weather and a little later in dry weather. Comfort humidity influence scales how strongly humidity counts (0 = ignore it, 1 = full feels-like, >1 = amplify). A separate dew-point guard can put the AC in dry mode when humidity is high.

No humidity sensors? Nothing breaks — the switch expresses intent, not a requirement. Every consumer falls back to the plain dry-bulb temperature when humidity is missing, and it degrades per room: a room with a humidity sensor is judged on its feels-like value, a room without one on dry-bulb. Without any humidity at all you simply get an ordinary dry-bulb thermostat: the Home feels-like temperature sensor reads unknown and the dew-point guard never engages. The moment a humidity sensor appears in an area, the comfort index starts applying there — no toggling needed.

Manual override takeover

Someone turns a radiator dial or points the AC remote — and most orchestrators silently fight them back within a minute. Climate Orchestrator notices instead: a device that was at its commanded state and then moved away (in mode, or in target setpoint by at least one device step) without a command from us was adjusted by a human (or an external automation), and the orchestrator stands back from that device for the Manual override duration (default 60 min, 0 disables the takeover).

While a device is overridden it receives no commands at all, its MPC learning pauses (so the model isn't poisoned by samples it can't explain), and the HVAC action reason sensor reports Paused — manual override for it (the device's action sensor carries the remaining minutes). The override ends when the timer runs out, when the device drops offline, when frost protection needs it (safety always punches through), or the moment you touch the whole-home thermostat — changing the preset, mode, or setpoints means "I'm in charge again" and reasserts control over every device at once. Each start and end is also announced as a bus event.

Safety guards

Layered over the decision, highest priority first: frost protection (force heat if a room is freezing — overrides everything, even an open window) → window open (a window/door open in a room stops that room's heating/cooling, after an optional grace delay — though a portable AC can ignore its own room's vent window via AC ignores open windows, while still stopping for a window open in another room) → device capability (a radiator can't cool; an AC only heats if allowed) → outdoor gating (don't heat when it's mild out or cool when it's cool out).

Each cycle, step by step

Climate Orchestrator re-evaluates whenever a relevant sensor changes (plus a periodic safety check). A device under a manual takeover is left alone entirely (unless frost protection punches through); for every other managed device:

1. Read the room — the device's area temperature/humidity and the home average, as feels-like values when Comfort index targeting is on. An area sensor that has stopped reporting (older than the Sensor staleness timeout) is treated as missing and the home average is used instead.
2. Place it against the band, after any adaptive-comfort shift: below the heat setpoint → wants heat; above the cool setpoint → wants cooling; between → content.
3. Decide, with memory — apply the eager-on / reluctant-off rule, remembering what the device was already doing, and settle on heat, cool, or idle.
4. Run the safety guards — any can override the decision (order above).
5. Send the smallest possible command — anything that wouldn't change the device is skipped, to keep the radios quiet and the logs clean.

Examples

All scenarios assume the Home preset (heat 20.5 °C / cool 24.5 °C) and default settings.

A humid living room calls in the AC. The living room reads 23.8 °C — under the cool edge — but it's muggy, and the comfort index treats it as ~24.8 °C. That's over the edge, so the AC engages, commanded a setpoint below the cool target so the room (not the AC's own sensor) is what reaches it.

One hot room pulls in a comfortable one. The bedroom sits at 24.1 °C — fine on its own — but a hot kitchen has pushed the home average over the cool edge. The OR-trigger engages the bedroom's AC too; each room then releases individually as it cools past the target. Flip the Home average trigger switch off and the bedroom would stay out of it.

A window opens mid-heat-up. The study is heating toward 20.8 °C when a window opens. With a Window open delay of 5 minutes, a quick airing changes nothing; if the window stays open past the delay, that room's TRV stands down (the rest keep heating) and resumes when it closes. If the room ever fell below the frost-protection temperature (7 °C default), heating would override the open window.

Muggy but not hot: dry mode. The bedroom reads 24.0 °C at 90 % humidity — under the cool edge, so no cooling demand — but the dew point is over the 16 °C threshold. The dew-point guard runs the AC's dry mode until the air dries out, without overcooling.

Mild evening, nothing to do. Outdoor reads 14 °C with outdoor-temperature gating on: cooling is gated off entirely (outdoor below 16 °C — a stray hot reading can't start the AC), heating stays allowed, and with every room inside the band every device idles. The cycle still runs each minute, re-asserting offsets and feeding the MPC history.

Next: Comfort features