Thermal comfort and energy utilization analysis of a personalised conditioned space

Abstract

In this study, the analysis of thermal comfort and energy utilized by occupants in a personal conditioned space at Lagos State, Nigeria is examined. Since thermal comfort expresses the satisfaction of an occupant in a space, therefore it enhances or inhibits the productivity of occupants in an environment. The heat transfer through the conditioned space with optimal insulation using brick walls and insulation typical of a Nigerian building is formulated using the heat conduction and Navier–Stokes equation. While the comfortability of occupants in the space is determined using the predicted mean vote (PMV) and predicted percentage dissatisfied (PPD) indices. It is observed that occupants in the conditioned space are thermally comfortable when the ventilation rate is set to 8 l s−1 with non-insulated walls. With insulated wall, thermal comfortability of the space is set to 2 l s−1 adopting insulated wall thickness of 0.045 m. Energy cost using on grid power for non-insulated wall cost N4, 016.996 and N1, 015.512 for insulated walls annually. Utilizing off grid power source (diesel powered generator set) annual energy cost is determined as N2, 137.97 using thermal insulation and N8, 527.85 without insulation. It is observed that personalized cooling helps to achieve increased comfort of occupants in a conditioned space, also maximizing energy utilized. Consequently reducing energy wastage.