Indoor and Energy quality assessment in buildings

Interest on Indoor Environmental Quality (IEQ) increased more and more in the last years. This attention is evidenced by the fact that nowadays maintaining a certain level of comfort in the building, as it is prescribed by the standards, means to deal with a rising energy demand. For this reason increasing attention needs to be spent in the envelope and systems building design, as well in the building robustness at the occupants actions. Further than the design phase it becomes necessary to shift the focus on to the building management and maintenance too. To this aim energy and environmental long term monitoring are introduced in the building life cycle, with the objective to optimize the building-plant system and to look for a good balance between different levels of comfort and energy consumption. Main objective of the research is the critical analysis of the indoor environment quality assessment existing methods, within the evaluation of the energy consumptions required to maintain specific comfort levels, and suggesting new methods of analysis and representation of data from monitorings or simulations. In order to reach high level of IEQ, the study also focuses on the performance evaluation of energy saving by radiant systems, through tests in thermostatic room or in situ. Research is therefore conceived in three deepening phases. The first phase is based on the indoor environment quality assessment through the use of categories. Comfort, and particularly thermal comfort, is regulated by the standards ISO 7730/2005, EN 15251/2007, and ASHRAE 55/2004. Methods for data elaboration and representation suggested by the standards (specifically by EN 15251) are in this work compared and discussed, investigating, also through the use of a case study, the effective utility of these instruments, of their applications and limitations. Maintaining specific comfort categories in a building often comport to spend energy. Energy demand can be varied depending on the envelope characteristics and quality, and from the systems controls and the outdoor climate conditions. With the aim to demonstrate what enounced, the second phase of the study is explained through an office room energy simulation, conducted with the aim to assess the heating and cooling energy demand variation with the thermal and air quality variation, as well as for different climate zones. Buildings energy simulation is however only one of the tools that can be used for this kind of analysis. Direct monitoring of the energy consumptions is in fact another method that is becoming more and more important. Energy monitoring plans, with IEQ monitoring plans, give a detailed overview about levels of comfort and related costs in a building, moreover investigating on the correct or wrong systems operation and controls. The correlation between the two measurements conducted simultaneously allows to give, as output of the analysis, a complete building energy and environment evaluation. In addition to the data processing, the study also addresses the results representation, through the analysis of energy and environmental data from one year of monitoring in an office building. As mentioned above, the connecting element between ICQ in a room and the related energy consumptions, beyond the building thermo physical properties, is the installed plants system. In recent years many studies in literature about comfort in buildings treated the topic of low energy radiant systems to reach the indoor environmental quality objective. Among the many typologies of radiant systems, this work faces with two kinds of them, very different one from each other, and both object of analysis and experimentation: the first is represented by vertical electric radiant plates for heating, and the second is about TABS (Thermal Active Building System) for cooling. In both cases energy and environmental measurements were carried out. In the first case the experiments took place in test rooms, in the second case they were performed in situ (office room). Differences between the two analysis and strategies adopted for the measurements during the operational time of the building using TABS are shown. Results of the work are shown and widely explained in internationals journals and international conference papers.