The garage door is the dominant hole in the thermal envelope. Opening it exchanges a large slab of indoor air with outdoor conditions in seconds—often faster than the rest of the structure responds. Probes near the door record this clearly; probes farther away may barely notice a single short opening.
What probes show
Expect sudden drops in winter or jumps in summer humidity when cold or humid outdoor air rolls in. Short spikes during brief errands are normal. Prolonged door-open work sessions can drive the entire bay toward outdoor dew point—watch for condensation on metal tools afterward.
Separating signal from placement error
If every daily spike aligns with commute times, your door-adjacent probe is doing its job. If the interior probe mirrors the same amplitude, consider relocating it—see probe mounting. Compare patterns with temperature changes overview and the probe demo door toggle.
Mitigation without new hardware
- Weather stripping on the door reduces idle infiltration between openings.
- Interior probe on the opposite wall gives context for how far the wave travels.
- History charts help distinguish one-off events from chronic heat loss—see history dashboard browsing.