Why 0.05 EH/s Is the Basement Threshold
How we use the 0.05 EH/s band as a practical floor when advising hydro-cooled cabinets in heat-sensitive Korean buildings.
Operators often ask why our practice focuses on rigs at or above 0.05 EH/s rather than smaller home units. The number is not marketing — it reflects thermodynamics in typical Seoul basement footprints.
Heat Rejection in Small Rooms
A 0.03 EH/s air-cooled stack can still push 8–12 kW of sensible heat into a room without ducting. In a 25 m² basement with one small window, that heat accumulates faster than passive transfer removes it. Hydro cooling moves the rejection point to a heat exchanger tied to building water or an external dump, but the loop still has to carry the same thermal load.
Below roughly 0.05 EH/s, some operators successfully run compact air rigs with aggressive fan curves and seasonal throttling. Above that band, fan noise and exhaust temperature at the property line become harder to justify in mixed-use leases. Landlords we work with increasingly reference outlet water temperature caps instead of decibel limits alone.
Cabinet Economics
Integrated hydro cabinets rated from 0.05 EH/s upward usually ship with manifolds, pumps, and monitoring suited to continuous operation. Smaller immersion or DIY loops can work, but spare parts and Korean service coverage thin out below vendor-supported sizes. When we commission, we need OEM curves for pump head and exchanger capacity — documentation that mid-tier hydro cabinets provide more consistently.
When We Still Decline Hydro
If your target is under 0.05 EH/s and the room has adequate ventilation, we may recommend a thermal audit only, with a conditional note that hydro adds complexity without solving a heat problem you do not have. The audit fee is lower than commissioning because the measurement window is shorter.
Planning Your Number
Bring your nameplate hash rate, not pool-reported averages, to the briefing call. We model from manufacturer thermal specs first, then validate on burn-in. If you are shopping and comparing 0.06 versus 0.10 EH/s cabinets, read our Site Thermal Audit scope before purchase — the water tie-in requirements diverge quickly between those sizes.