Author: Marcelo Ceccon
Project Type: Engineering concept baseline for containerized Bitcoin mining & AI GPU air treatment
Most operators equip every single mining or GPU container with its own cooling units, dust filters, and redundant fans. The result is multiplied CAPEX, frequent maintenance shutdowns, and unnecessarily high OPEX.
ChillForge-250 takes a different approach.
One standard 40 ft ISO container becomes a centralized, zero-downtime air factory with a peak nameplate capacity of 250,000 m³/h (147,000 CFM) of pure, filtered, evaporatively cooled air. At full capacity this supports ~920 kW of heat load; at the recommended 75 % continuous operating point — which guarantees maintenance headroom and true zero-downtime — the system supports ~680 kW.
Every stage is fully redundant and live-swappable. You never shut down the GPU racks for filter changes, media cleaning, or fan service. This centralized approach is the foundation I would propose for any serious multi-MW mining or AI deployment where uptime and cost discipline are non-negotiable.
This document is the detailed starting baseline — the engineering foundation that would be taken into CFD, 3D packing studies, and prototype validation in a real project.
The images were generated with AI; the actual layout and specs would of course be done on CAD for proper fabrication.
- Deliver pure, cool, droplet-free air to containerized Bitcoin miners or AI GPU racks with zero operational downtime.
- Implement true dual redundancy at every stage so the system maintains 100 % of the required continuous capacity even when 50 % of components are isolated.
- Operate normally at 75 % of nameplate capacity (187,500 m³/h) to provide permanent headroom for maintenance and component failures.
- Push hardware performance to the edge while staying strictly inside the ISO envelope.
- Establish a clear CAPEX and OPEX advantage over traditional distributed cooling as the starting point for detailed engineering.
- Peak nameplate airflow: 250,000 m³/h (147,000 CFM)
- Normal operating airflow: 187,500 m³/h (75 % of peak)
- Supported heat load at 100 % airflow (11 °C server ΔT): ~920 kW (3.14 million BTU/h)
- Supported heat load at 75 % airflow (11 °C server ΔT): ~680 kW (2.32 million BTU/h)
- Supply air temperature (worst-case 44 °C DB / 23 °C WB): 26.0 °C
- Total system static pressure budget: 1,050–1,450 Pa (dirty condition)
- Spot power consumption (peak at 100 %): 255 kW
- Average power consumption (at 75 % continuous): ~150 kW
- Water consumption (peak): 1,850–2,600 L/h (evaporation + bleed)
- Redundancy: Any 50 % of fans, filters, or cooling paths can be serviced while delivering 100 % of the continuous 187,500 m³/h (680 kW capacity).
The 40 ft container is divided into four functional zones with full-length aluminium diamond-plate grounded flooring (sloped to central drainage trench), UVC dark-mode lighting when idle, bright LED inspection floods, and comprehensive temperature/pressure sensor array.
ChillForge-250 is a supply-side air treatment system. Server exhaust air management (return ducting, hot-aisle containment, or direct venting) is site- and container-specific and falls outside the scope of this unit.
The air treatment follows a clear thermodynamic path on the psychrometric chart (California desert worst-case design point).
Process points:
- Ambient inlet: 44.0 °C DB / 23.0 °C WB → ~16 % RH, humidity ratio 0.009 kg/kg
- After gross filtration & ionized vanes: negligible change (sensible only)
- After evaporative cooling (85 % effectiveness): 26.0 °C DB / ~76 % RH, humidity ratio 0.016 kg/kg
- After mist eliminators: same state (droplets removed, no temperature change)
- After fine filtration: same state
- Server racks (sensible heating only): +11 °C rise → exhaust 37.0 °C DB, constant humidity ratio 0.016 kg/kg, ~40 % RH
Note: 76 % RH at the supply point is within ASHRAE A2 allowable range (max 80 % RH non-condensing) and well within tolerance for Bitcoin mining ASICs and AI GPUs. In milder ambient conditions supply RH will be proportionally lower.
Generated with psychrolib/python - code here
The curved aluminum ionized guide vanes in the gross intake plenum are a critical performance enabler. They simultaneously straighten vortex flow into the fans, act as a passive electrostatic pre-stage, and — most importantly — will be fully optimized via CFD to minimize turbulence and pressure loss across the entire container length. This CFD-driven vane design is the key reason the system can push face velocities and overall packing density to the practical limit while still delivering reliable redundancy and low power consumption. A professional 3D CFD study and detailed packing analysis would be the immediate next step in any real project.
- All isolation and maintenance procedures are designed around confined-space and lockout-tagout (LOTO) protocols; detailed safety procedures will be developed during detailed design.
- 4 main + 4 booster fans, each sized for 50 % of peak flow.
- Every filtration and cooling stage split into two independent parallel paths with motorized isolation dampers, arranged in V-bank configuration to maximize effective face area within the ISO envelope.
- Normal 75 % operation provides permanent 25 % headroom — any single path or two fans can be isolated without affecting delivered capacity at the continuous rating.
- When one evaporative path is isolated, all airflow passes through the remaining path at higher face velocity. Evaporative effectiveness drops from ~85 % to ~70 %, raising supply air by approximately 3 °C. This is within acceptable limits for the short duration of a typical maintenance window.
- Isolation and re-commissioning takes <60 seconds per path.
The main suction and booster fans are high-efficiency backward-curved centrifugal units. Top-tier options that perfectly match the duty (62,500 m³/h per fan at 650–850 Pa) include the Nicotra Gebhardt RDH series (European premium), FläktGroup plug or centrifugal range, and New York Blower (USA) Class II/III airfoil series. These manufacturers were selected for their proven reliability in mining and data-center applications, excellent static efficiency (>80 %), low noise, and availability of cassette-mount configurations with quick-access doors.
Preliminary estimates based on typical fan manufacturer data place the unattenuated noise level at approximately 95–105 dBA at 1 m from the container during full-speed operation. In practice, the steel container shell provides some passive attenuation, and fans running at 75 % speed benefit from the cubic relationship between speed and noise power. Intake and discharge acoustic silencers or baffles will be sized and specified during detailed design to meet site-specific noise ordinances and occupational exposure limits.
CAPEX
- Traditional distributed approach (individual DX/cooling units + filters per GPU container, sized for equivalent 920 kW peak capacity): $650,000–$850,000.
- Single ChillForge-250 container (920 kW peak / 680 kW continuous): $420,000–$580,000 turnkey.
→ ~35–40 % CAPEX reduction through centralization and elimination of duplicated equipment.
OPEX (California industrial rates, ~$0.10/kWh)
- ChillForge at 75 % continuous: ~150 kW average vs. 300–400 kW for equivalent distributed DX systems at the same cooling duty.
- Annual electricity savings: ~$130,000–$220,000.
- Water cost (1,800 m³/year average at $4/m³ delivered): ~$7,200.
- Maintenance labor reduced by ~70 % (one central unit vs. multiple scattered systems).
- Net annual OPEX savings: $150,000–$260,000.
- Ambient design: California desert worst-case (44 °C DB / 23 °C WB).
- Airflow rule: 160 CFM/kW (industry standard for GPU racks).
- Server ΔT: 11 °C (ASHRAE data-center standard).
- Normal operation at 75 % of nameplate for built-in maintenance headroom.
- All modifications strictly inside ISO envelope.
- Water and drainage available on site.
- GPU inlet humidity within ASHRAE A2 allowable (max 80 % RH non-condensing).
- Makeup water treatment (softening, biocide dosing, bleed-off control) per ASHRAE 188 and applicable health codes.
- Site provides 480V 3-phase power; main disconnect and utility connection are site-scope.
| Item | Qty | Notes | Rough Cost Estimate (USD) |
|---|---|---|---|
| 40 ft high-cube ISO container | 1 | Cargo-worthy base | $18,000 |
| Structural reinforcements & bulkheads | Lot | Corten + aluminum | $32,000 |
| 1.5 m × 1.5 m × 20 cm gross filter cassettes | 14–18 | Multi-layer mining-grade | $32,000 |
| Curved ionized aluminum guide vanes | Lot | CFD-optimized | $11,000 |
| Main suction fan cassettes (30–35 kW) | 4 | Nicotra / FläktGroup / NY Blower + VFD | $56,000 |
| 300 mm evaporative honeycomb media | 22–26 m² | V-bank config, two parallel paths | $14,000 |
| Chevron mist eliminators | 16–18 m² | Two parallel paths | $11,000 |
| MERV 15–16 deep-pleat fine cartridges | 22–26 m² | V-bank config, two parallel paths | $26,000 |
| Booster fan cassettes (30–35 kW) | 4 | Same specification | $56,000 |
| Motorized isolation dampers + seals | 14+ | Guillotine/roll-up | $22,000 |
| Recirculation pumps, sumps, controls | 2 sets | Fully redundant | $12,000 |
| Aluminium diamond-plate flooring + drain | 1 | Full length, grounded | $15,000 |
| Water treatment skid + chemical dosing | 1 | Softener, biocide, bleed-off control | $10,000–$15,000 |
| Acoustic attenuation (silencers/baffles) | Lot | Intake + discharge, TBD in detail | $8,000–$12,000 |
| Internal electrical distribution | Lot | MCC, VFD wiring, cabling, grounding | $25,000–$35,000 |
| Sensor array, HMI, PLC, UVC + LED | Lot | Automated failover, VFD speed control, remote monitoring via Modbus/BACnet | $18,000 |
Costs are ROM (rough order of magnitude) turnkey first-unit pricing. Subsequent units drop 25–30 %. Real project would include CFD validation and seismic bracing adders.
- Full 3D CAD packing study + CFD optimization of guide vanes and flow paths
- Detailed fan-curve matching and system pressure-drop validation
- Prototype build and live testing (one unit)
- Scale to multi-MW farms
This is the high-performance baseline I would start with on Day 1 of any serious containerized cooling project.
Feedback and collaboration welcome.
— Marcelo Ceccon