We modelled airflow and temperature distribution in a pharmaceutical cold store, using CFD to evaluate evaporator layout, discharge velocities and return‑air paths around racking. Scenarios covered door‑open events, infiltration flows, product loads and defrost cycles to represent realistic operating envelopes. The study focused on maintaining tight temperature uniformity and avoiding recirculation or stagnation that can compromise product integrity. Mesh and solver choices were tuned to capture jet entrainment and mixing while maintaining turnaround time; verification checks supported stable comparisons between layout options. We reported KPIs that the client use to make decisions such as maximum temperature deviation, time to recovery after disturbance, and airflow uniformity indices, alongside intuitive maps and velocity profiles that explain the physics. Findings highlighted adjustments to diffuser angles, fan set‑points and return placements that improve uniformity without excessive energy penalty. The outcome is an evidence‑based set of changes and a reproducible model that Piggott&Whitfield can use to guide implementation and future operational tuning.