Modelagem Digital do Processo de Cálculo de Carga Térmica de Ambientes com Ar-Condicionado

Abstract

Cooling load calculation is a fundamental step in the design of air conditioning systems, as it determines the required capacity to provide adequate thermal comfort according to the occupancy and characteristics of indoor environments. In Brazil, this process is regulated by ABNT NBR 16401, which establishes the criteria for determining sensible and latent cooling loads resulting from building characteristics, occupancy, lighting, equipment, and ventilation. This study presents the digital modeling of the cooling load calculation process for conditioned environments through the development of a Microsoft Excel-based tool with a Visual Basic for Applications (VBA) interface, following the procedures established by ABNT NBR 16401. The tool automatically integrates the different cooling load components, including heat transfer through building elements, internal loads generated by occupants, lighting and equipment, as well as the sensible and latent loads associated with ventilation. To evaluate its application, three case studies were conducted in administrative environments, allowing the assessment of the implementation consistency and the tool performance under different input conditions. The results enabled the determination of the total cooling load and the recommended air conditioning system capacity, expressed in kilowatts (kW), refrigeration tons (RT), and BTU/h. The main contribution of this work is an accessible, standardized, and low-cost tool to support the early stages of cooling load calculation by reducing execution time, standardizing the calculation procedure, and minimizing errors associated with manual calculations.