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Comfort stability is a range held over time
A thermostat reading says little about comfort. Share of occupied hours inside a temperature and humidity band says a lot.
Example note This shows the format. The figures are illustrative and do not come from a real job.
The problem
A space can sit at its setpoint and still feel wrong. The air swings a few degrees each cycle, or the temperature holds while humidity climbs. A single reading at the thermostat misses both.
What we measure
A logger goes in the occupied zone, away from supply air, for 72 hours. It records temperature and relative humidity once a minute. From that log we report three numbers:
- Time in band. Share of occupied hours inside the agreed range for both temperature and humidity.
- Swing. The typical rise and fall within one equipment cycle.
- Cycles per hour. How often the equipment starts.
Example readings
| Measure | Before | After |
|---|---|---|
| Time in band, 72 to 76 °F and 40 to 55 % RH | 61 % | 93 % |
| Typical swing per cycle | 3.4 °F | 1.1 °F |
| Cycles per hour at peak | 7 | 3 |
What usually explains it
- Equipment larger than the load, so it satisfies the thermostat before it removes moisture.
- A thermostat placed where it reads supply air or afternoon sun.
- Return air starved by an undersized grille or a closed door.
What changes on the job
The fix is chosen from the log, and the same 72 hour log is repeated afterward. If time in band did not move, the job is not closed.