Unavailable can describe three different boundaries
| Pattern | Likely boundary | Meaning |
|---|---|---|
| One category is unavailable | Known keys for that aggregate were not readable | Other categories may still provide live monitoring |
| Selected category falls back | Requested input is absent but another live input exists | Use is possible only when the fallback is clearly labeled |
| Every category and Hottest are unavailable | The hardware snapshot or discovery path produced no usable temperature | Do not make temperature-based control decisions |
| Value appears but never refreshes | Freshness or transport may be broken | Treat stale data as unavailable for control |
Run the safe monitoring checklist
- Confirm Smart Breeze version 1.0.0 Build 37, the exact model identifier, and macOS version/build.
- Choose Any Sensor and note whether a fallback label appears.
- Start an ordinary known workload and verify whether any category updates.
- Restart once, reopen the canonical copy in /Applications, and repeat the read-only observation.
- Check Known issues, then copy Smart Breeze diagnostics if the state persists.
Do not move between duplicate app copies, run from the DMG, or change fan-helper state while diagnosing a read-only sensor problem. Those variables add noise without creating temperature-key compatibility.
Build 21 result and Build 37 status on the tested M5 MacBook Air
WarningAll temperature categories remain unavailable
On one tested fanless M5 MacBook Air, Build 21 downloads and installs, but its snapshot stops after the Mac does not expose the FNum fan-count key. Model, CPU, GPU, Memory, Battery, and Hottest remain unavailable instead of continuing to independent temperature-key discovery.
Build 37 now treats missing FNum as an explicit unknown fan topology, keeps fan control ineligible, and continues read-only temperature discovery into the new Thermal Sensors explorer. This path has been verified on that M5 Air.
The lack of a fan is expected for this Mac. Build 21's monitoring failure was not. Build 37's temperature discovery has been verified on the M5 Air.
Why the privileged helper is not a sensor fix
Smart Breeze reads monitoring data without administrator access. The privileged helper exists for authenticated, bounded fan-control writes and verified System handoff on qualified fan hardware. Installing it does not change which read-only keys the app discovers.
- It cannot create a temperature key that Build 37 does not discover.
- It cannot turn aggregate private keys into Apple-supported sensor metadata.
- It cannot add fans to a fanless Mac.
- It cannot bypass fan-control hardware discovery.
Temperature-driven control must fail closed
Smart Boost depends on a current temperature input. Smart Breeze's helper safety model requests verified System control when temperature data remains missing for about ten seconds during manual ownership. A stale or absent source must never be replaced with an invented low value that keeps a fan target active indefinitely.
Unknown topology follows the same principle. Missing fan count, bounds, or ownership readback means no fan write. Monitoring compatibility and control qualification are separate gates, and either can stop an action safely.
Send a report that can improve compatibility
Copy diagnostics from Smart Breeze and include the exact steps, whether any category ever appeared, whether the issue followed sleep or was present at first launch, and whether the Mac is fanless. The diagnostic report contains hardware and app state, not personal files, and is never sent automatically.
MethodKeep sensitive identifiers out
The model identifier is useful; a serial number, hardware UUID, Apple ID, administrator password, and personal files are not. Send only what the compatibility investigation needs.
Sources
- Smart Breeze Build 37 known issues (Smart Breeze)
- Smart Breeze compatibility and hardware discovery (Smart Breeze)
- Smart Breeze monitoring and control troubleshooting (Smart Breeze)
- Smart Breeze safety model (Smart Breeze)
- Keep your Mac laptop within acceptable operating temperatures (Apple Support)
More from the guides
Mac thermal fundamentalsHow to check Mac temperature and keep the reading honestCheck Mac temperature with the right sensor context, validate that readings refresh, and pair them with Activity Monitor and macOS thermal state.
Mac thermal fundamentalsDoes your Mac have a fan? Check the exact modelLearn why MacBook Air and MacBook Pro cooling differs, how to find your model identifier, and why fan detection must fail closed.
TroubleshootingUse Apple Diagnostics for fan and thermal symptomsRun Apple Diagnostics on an Apple-silicon Mac, understand what a reference code means, and pair it with workload and fan evidence without overclaiming.Related docs: Read the dated M5 Air issue, Interpret unavailable categories
Fanless Macs get full temperature monitoring and the sensor explorer. No fan helper, no fan controls. Download Smart Breeze