Costs of ventilation systems for the retrofit of residential buildings

The cost of energy retrofit is the main barrier to an increase of the retrofit rate in Europe. Among the retrofit measures, ventilation is often neglected to allow a more significant part of the budget to façade insulation, window exchange or for the heating system. The importance of a good ventilation system in order to guarantee a correct indoor air quality as well as to avoid high heat losses has been underlined by a large number of scientific articles. Therefore, an analysis of the costs of different ventilation systems within the context of energy retrofit is necessary. The total costs are divided in invest effort, maintenance and energy costs (heat demand due to the ventilation and electricity demand of the fans). Different case studies are analysed and, in order to increase the reliability of the comparison between different concepts, virtual costs are calculated for the retrofit of a unique building for all compared ventilation systems.