Simple modelling for energy consumption estimation in air conditionned buildings

A simplified tool for estimating energy consumption of a whole air conditionned building is presented. It is developped to help design engineers to quickly estimate HVAC solutions till initial design. HVAC systems as fan coils, variable and constant air volume are available. The model is developped to need few inputs in such a way that it could be used very soon in the design process, when materials and building characteristics are not fixed in details. For a better optimisation of the global energy consumption of the building, the interaction between natural and artificial lighting is taken into account, with energy characteristics of the lighting system. Different stages are chained : calculation of energy needs of the building, calculation of the air handling unit energy rates for different components : humidifier, cooling and heating coils, calculation of primary energy rates demanded by chillers or boilers. For each system, a typical operation logic in all intermediary conditions is stated. The consumptions of auxiliary machines and the heat losses of the plant are counted. Finally, energy consumptions are determined and ventilated over different electrical price periods. So operating costs are estimated.