Modeling the Convection Coefficient with EnergyPlus and its Effects on a Energy Simulation of a Typical Uruguayan Household

Abstract

The design of energy efficient buildings has become the main focus of many studies given that the energy consumed by the residential sector represents an important part of the total world energy consumption. One of the most popularized tools for these practises are the Building Energy Simulation (BES) software. This study focuses on the use of EnergyPlus, one of the most utilized software in this front. These type of programmes allow for a quick realization of many complex calculations, albeit the veracity of the results depends on the correct application of the different models available for the user. EnergyPlus provides a series of algorithms for modeling different phenomena and it is up to the user to choose the most appropriate model for the application intended. This study centers around the evaluation of the influence over the estimated demand of the different models available in EnergyPlus for calculating the convection coefficients, both for the interior and exterior ones. A brief description of the provided models is presented, followed by the results of the sensitivity study that was conducted, evaluating the different impact they have over the design parameters of a typical Uruguayan household. Focusing on the ideal loads as the main comparison factor, the difference presented among the different algorithms is significant, ranging up to a 70% difference from one model to another. In addition to this the higher difference presented between the actual convection coefficients was up to 60%. Results like these, highlight the importance of the proper modelling of these parameters when it comes to studying and designing buildings.