Numerical simulation for energy consumption and thermal comfort in a naturally ventilated indoor environment under different orientations of inlet diffuser

This study numerically analyses a well-validated comprehensive work on IEQ in a naturally ventilated, occupied 3-dimensional office building with installed furniture and internal heat-generating surfaces. This study analyzes the effect of the inlet diffuser orientation (IDO) on the indoor thermal comfort (ITC) of occupants and the energy demand of the building for heating indoor air. The Optimization of ITC has also been calculated for the acceptable indoor occupant comfort and energy consumption. The study is valuable to analyze the relationship between IDO of 0 degrees, 15 degrees 30 degrees, 45 degrees, 6045 degrees and 7545 degrees, on ITC and the energy consumption of the indoor environment. Different methods have been chosen to study the ITC of the occupants such as air temperature, air movement in the occupied zone, vertical temperature gradient, and PMV and PPD index according to ISO7730. The results show that under a uniform indoor air distribution, the variation in IDO considerably affects the ITC and energy consumption. Optimized ITC can reduce indoor energy consumption by 35.14%. The IDO slightly affects the PMV and PPD index. Occupant's legs are more sensitive to the naturally ventilated indoor environment due to the adverse effect of buoyancy force which may create the problem of the cold draft. For optimization of the ITC, the air temperature in the occupied zone plays a key role.