Why Summer Intake Temperature Matters More Than Hash Rate on Paper
South Korean mining facilities see intake temperatures swing 18°C between January and August. Here is how that affects sustained hash rate on ASIC hardware above 0.05 PH/s.
Every March, operators across Gyeonggi-do start planning summer cooling upgrades. By July, our emergency callouts spike — not because fans fail, but because intake air crossing 34°C pushes junction temperatures past the point where ASIC chips throttle hash rate silently.
The Measurement Gap
Manufacturer spec sheets test at 25°C ambient. A warehouse in Paju with a single wall-mounted exhaust fan routinely sees 31°C at the intake grille by 2 PM in August. We have measured a fleet of Antminer S19 Pros losing 6.8% of rated hash rate at that temperature without a single error log entry.
The throttling is gradual. Pool dashboards show a slow decline over weeks, which operators often attribute to network difficulty adjustments rather than thermals.
What We Recommend
For any deployment above 0.05 PH/s in a non-climate-controlled building:
- Install intake temperature sensors at rack level, not room level. Ceiling air can be 4°C cooler than air entering the miner chassis.
- Set pool alert thresholds at 3% below your winter baseline, not at manufacturer spec.
- Budget for auxiliary intake ducting before adding units. Scaling hash rate without scaling airflow is the most common summer mistake we see.
A Real Example
One client in Suwon ran 0.24 PH/s through two summers without issues, then added 40 units in spring without upgrading exhaust capacity. By August, effective hash rate had dropped to 0.21 PH/s. Reorienting two racks and adding a 120 cm exhaust duct recovered 0.022 PH/s within 48 hours — no new hardware required.
Bottom Line
Before comparing S21 against M60S on efficiency alone, model your worst-case intake temperature. A more efficient chip running hot performs worse than an older generation with proper airflow.