Low-Energy Retrofitted Homes from their Occupants’ Perspectives: Indoor Environmental Quality and Satisfaction with Heating and Mechanical Ventilation Systems

This study aims at obtaining feedback from occupants of low-energy retrofitted houses concerning the indoor environmental quality (IEQ) and the building systems in their homes. A questionnaire study was carried out in a social housing complex consisting of 2007 single-family houses, of which 1305 were retrofitted between 2014 and 2019. The different retrofitted houses were equipped with two types of heating systems, as well as balanced mechanical ventilation with two inlet locations.

Exergy evaluation of mechanical ventilation systems

Energy performance of mechanical ventilation systems in modern low energy and passive buildings is a crucial factor influencing overall energy performance of building. Energy balance is commonly used tool in evaluation of mechanical ventilation systems. In the case of low energy and passive buildings that tool might be insufficient and should be replaced by exergy analysis taking into account the first and the second Law of Thermodynamics. The paper presents principles of exergy evaluation of mechanical ventilation systems and case study calculations for an office building.