July 2025 brought sustained afternoon intake temperatures above 33°C at three client halls we visited within 40 km of Gumi. We logged parallel nameplate 0.06–0.09 PH/s units under normal operating policies—no intentional throttling.
Method
- Intake thermocouples at louver face
- Rear exhaust probe 30 cm from unit outlet
- Hash logging via pool API at five-minute intervals
- Ambient outdoor temperature from KMA station for correlation
Findings
| Site | Intake peak | Avg hash derate vs spring baseline |
|---|---|---|
| North Gumi warehouse | 34.1°C | −12% |
| West Gumi industrial unit | 32.8°C | −8% |
| Converted storage hall | 35.2°C | −15% |
Derating correlated more strongly with intake than outdoor temperature. One site with shaded intake maintained −6% despite hotter outdoor readings.
Operator takeaway
Spec sheets citing 0.07 PH/s at 25°C ambient understate summer output for unshaded louvers facing afternoon sun. Budget hash forecasts using July intake, not spring commissioning data.
Mitigation we documented
Operators who saw −6% or better had:
- Intake louvers on north-facing walls or shaded baffles
- Minimum 1.5 m separation between exhaust outlet and intake path
- Filters cleaned within the prior 30 days
Related service
Our On-Site Equipment Assessment includes seasonal comparison when prior visit data exists in our archive.