Case Study: CFD-Driven Ventilation Design for a Battery Rack System

Project Summary

Deratec was engaged to optimise the ventilation system of a battery rack enclosure experiencing high thermal loads during fast charging cycles. Using Computational Fluid Dynamics (CFD), we tested and compared ventilation layouts to ensure the system remained within safe temperature limits — all without costly physical prototyping.

Objectives

The battery enclosure measured 1500 mm (L) × 600 mm (W) × 2300 mm (H) and could reach up to 5000 W of heat during peak 4C charging. The design challenge was to prevent overheating while ensuring even airflow inside a compact, fully enclosed rack.

Free-standing battery rack version showcasing an organized array of power modules and electronic components, designed for efficient energy storage and management.

Our CFD Approach

We modelled two forced ventilation layouts using real fan data (Rittal SK series):

• Case 1: Rear-lower inlet filters with two wall-mounted exhaust fans

Configuration of Case 1: Diagram illustrating two inlet air filters located on the lower back side of the cabinet, with two exhaust fans mounted at the top of the side wall, and maintaining a 600 mm gap between the backs of the racks.

• Case 2: Front-bottom inlets with one roof-mounted exhaust fan

CFD was used to simulate airflow, temperature distribution, and pressure fields under the worst-case 4C thermal load.

Cooling system schematic: Two inlet air filters located at the bottom, with a single fan positioned on the roof; racks are aligned facing each other, maintaining a 900 mm gap for efficient airflow.

Results

✅ Best Configuration: Case 1 – Wall-Mounted Exhaust Fans

This setup consistently maintained internal temperatures below 45°C, even under 4C operation. It created a stable negative pressure, drawing cool air from the rear and exhausting hot air effectively from the top sides.

CFD temperature contours illustrate effective cooling across the rack at three floor-to-floor levels (1000 mm, 1500 mm, and 2000 mm), achieved through strategic placement of wall-mounted exhaust fans.

🔺 Alternative: Roof-Mounted Fan (Case 2)

Although simpler, the roof-exhaust layout led to heat stagnation near the top, with max temperatures reaching ~50°C.

CFD temperature contours for a roof-mounted fan design demonstrate varying cooling efficiency under high loads at different floor-to-floor levels (FFL): 1000 mm, 1500 mm, and 2000 mm, highlighting less uniform cooling distribution.

Conclusion

This case study highlights how CFD simulation helped our client choose the right fan configuration before installation — saving time, cost, and energy. A well-designed ventilation system not only ensures battery safety but also extends equipment life.

If you're designing enclosures for batteries, electronics, or critical equipment — we’re here to help.

👉 Contact Deratec for CFD-driven thermal solutions.