Shipping-container yards dominate the mid-range mining landscape along the southern coast. They are fast to deploy, modular, and familiar to operators converting industrial land. They are also thermal nightmares when inlet air regularly crosses 35 °C and salt spray corrodes galvanized ductwork within two seasons.
Deployment One: Passive Vents Only
The first Ulsan yard we assessed in 2023 ran three 40-foot containers with factory cut-outs and roof turbines. No powered exhaust. Inlet temperatures during August afternoons hit 38–40 °C. Mid-range units rated above 0.08 TH/s throttled to 72–78% of nominal hash rate.
The operator had assumed container walls would insulate against heat. In practice, steel skin absorbed radiant energy and radiated it inward. Passive turbines could not move enough volume when ambient wind dropped.
Fix: Variable-speed wall-mounted exhaust fans (one per container, 4,500 CFM rated) plus inlet baffles to prevent hot exhaust recirculation. Post-retrofit inlet temps stabilised at 31–33 °C on equivalent days.
Deployment Two: Shared Plenum Mistake
A second yard connected three containers with a shared intake plenum made from corrugated steel duct. Looked efficient on paper — one intake point, three supply runs. Measured performance was poor because the centre container drew the majority of airflow, starving the end units.
Fix: Individual intake louvers per container with backdraft dampers. Removed the shared plenum entirely. Airflow balance improved within one day of installation.
Deployment Three: Corrosion Timeline
Galvanized duct installed in 2022 showed pinhole corrosion by mid-2024. Salt air from the nearby harbour accelerated oxidation at duct joints. Fan bearings seized on two units during a July heat wave.
Fix: Replaced galvanized runs with marine-grade aluminium duct and stainless hardware. Added quarterly inspection to the maintenance retainer. Higher upfront material cost, but fan replacements dropped from four per season to one.
Design Principles We Now Apply
- Powered exhaust is mandatory for coastal container yards above 30 mid-range units.
- Never share intake plenums across more than two containers without flow-balancing dampers.
- Specify marine-grade materials for any duct within 500 metres of salt water.
- Measure delta-T, not just inlet temp. Target 20–24 °C difference between inlet and exhaust during full-load operation.
If your container row is losing hash rate every summer, a site assessment costs less than one month of throttled output. We document current airflow, model the upgrade, and provide a fixed quote before any materials are ordered.