Paper Conference

Proceedings of BSA Conference 2015: Second Conference of IBPSA-Italy


Study of the energy performance of a retrofitting office

Paolo Valdiserri

Abstract: Building retrofitting is the most feasible and costeffective method to improve building energy efficiency. To this aim, the building envelope should be equipped with new windows having low thermal transmission coefficients and/or with insulation material in the external partitions. This approach leads to considerable energy saving, but at the same time if the users do not properly ventilate the occupied spaces, it results in a worsening of indoor air quality. The paper presents a comparative analysis of two different strategies to enhance the energy performance of an existing building. The first is to reduce the heat transfer by transmission (i.e. use of low-emissivity glass) and the second to decrease the heat transfer by ventilation (i.e. installation of a heat recovery). The study has been applied to an office block, located in the city of Bologna, Italy. Potential energy savings were calculated by dynamic simulation using Trnsys software. To this purpose, a reference office was selected and then the following cases were studied. The first one took into account the replacement of all the windows, the second one consisted in installing a total energy ventilation recovery system and the last one contemplated both the solutions. Finally, an evaluation of the simple payback time and the net present value was performed.
Pages: 281 - 288