Investigation of Indoor Air Temperature and Velocity Distribution in an Office at Different Inlet Conditions Using CFD

This paper presents, the distribution of indoor air temperature and velocity in an office environment under different inlet conditions using Computational Fluid Dynamics (CFD). The office, with dimensions of 8 × 5 × 3 m, was cooled by a wall-mounted split air conditioner. The analyses were performed using the k-ɛ turbulence model, with the split air conditioner's inlet temperature set to 18, 20, and 22°C and its velocity set to 0.5, 1, and 2 m/s. The analysis included the heat emitted by five people, five computers, and lamps in the office. The results indicate that increasing inlet velocity leads to a more uniform temperature distribution and lower average indoor temperatures. At an inlet velocity of 0.5 m/s, insufficient air mixing resulted in localized temperature variations, while at 2 m/s, local air velocities in certain regions exceeded 0.25 m/s. According to ASHRAE Standard 55, this value represents the upper limit for acceptable air velocity in occupied zones and may lead to draft risk. At an inlet velocity of 1 m/s, a more balanced distribution of temperature and air velocity was achieved, with indoor temperatures generally within the recommended range of 22–26°C and air velocity remaining mostly below the threshold value. The findings demonstrate that inlet air conditions significantly influence indoor air distribution characteristics. Among the evaluated cases, an inlet velocity of 1 m/s provided the most favorable balance between temperature distribution and air velocity within the investigated conditions.