Experimental validation of the buildings energy performance (PEC) assessment methods with reference to occupied spaces heating

This paper is part of the series of pre-standardization research aimed to analyze the existing methods of calculating the Buildings Energy Performance (PEC) in view of their correction of completing. The entire research activity aims to experimentally validate the PEC Calculation Algorithm as well as the comparative application, on the support of several case studies focused on representative buildings of the stock of buildings in Romania, of the PEC calculation methodology for buildings equipped with occupied spaces heating systems. The targets of the report are the experimental testing of the calculation models so far known (NP 048-2000, Mc 001-2006, SR EN 13790:2009), on the support provided by the CE INCERC Bucharest experimental building, together with the complex calculation algorithms specific to the dynamic modeling, for the evaluation of the occupied spaces heat demand in the cold season, specific to the traditional buildings and to modern buildings equipped with solar radiation passive systems, of the ventilated solar space type. The schedule of the measurements performed in the 2008-2009 cold season is presented as well as the primary processing of the measured data and the experimental validation of the heat demand monthly calculation methods, on the support of CE INCERC Bucharest. The calculation error per heating season (153 days of measurements) between the measured heat demand and the calculated one was of 0.61%, an exceptional value confirming the phenomenological nature of the INCERC method, NP 048-2006. The mathematical model specific to the hourly thermal balance is recurrent – decisional with alternating paces. The experimental validation of the theoretical model is based on the measurements performed on the CE INCERC Bucharest building, within a time lag of 57 days (06.01-04.03.2009). The measurements performed on the CE INCERC Bucharest building confirm the accuracy of the hourly calculation model by comparison to the values provided by measurements and to those provided by the monthly calculation (NP 048-2006). The deviations of 1.45% and 2.2% respectively validate the hourly calculation model, as they actually have no physical significance. The report presents a phenomenological analysis of the building transfer functions synthesized as tev (τ), functions which attest their phenomenological objectivity in macro and hourly terms. The case studies completing the calculation models experimental validation emphasize unacceptably large differences between the results provided by the use of standardized calculation methods (Mc 001 / 2-2006 and SR EN 13790:2009) and those specific to the methods referred to in this report, experimentally validated

Existing buildings energy footprint (AE) – an instrument for the evaluation of real PEC (building energy performance) in real conditions of climatic and anthropic loads

The energy footprint of a building is an operational characteristic specific to the building structure as well as to the energyrelated operational conditions of the building. This paper presents the experimental programme carried out on the support of the CE INCERC Bucharest experimental building in the 2008-2009 cold season and the results obtained in the form of the building energy footprint. At the same time, the building energy footprint before the energy-related upgrading (2003-2004 cold season) are presented, as well as those subsequent to the energy-related upgrading (thermal protection, equipping with a ventilated solar space and heating system replacement). The character natural laws of the energy footprint are emphasized. This paper presents a theoretical substantiation of the use of the energy footprint method in the case of condominiums in the form of the operational method, which is useful in settling the functional characteristic in any climatic conditions and in any operational conditions

Identification of the Real Thermal Characteristics of Existing Buildings

The identification of the real thermal characteristic of an existing building implies mainly the assessment of the invariants specific to that structure, namely the equivalent thermal conductivity of the materials used for the opaque external envelope of the dwelling space. The paper focuses on the problem of identifying the thermal characteristic of the opaque external envelope of the apartment buildings with central heating system and implicitly with heating units in the dwelling and commune. The method used is of the inverse modelling type, based on the building global balance and on the thermal response of the heating system to random climatic conditions. The problem implies two phases as follows: - the preliminary phase, consisting in the integration of the heat balance differential equation of the dwelling spaces; - the final phase, based on the thermal response characteristic of the heating system in real operation conditions

Seismic Behavior of Self-Balancing Post-Tensioned Reinforced Concrete Spatial Structure

The construction industry is currently trying to develop sustainable reinforced concrete structures. In trying to aid in the effort, the research presented in this paper aims to prove the efficiency of modified special hybrid moment frames composed of discretely jointed precast and post-tensioned concrete members. This aim is due to the fact that current design standards do not cover the spatial design of moment frame structures assembled by post-tensioning with special hybrid joints. This lack of standardization is coupled with the fact that previous experimental programs, available in scientific literature, deal mainly with plane structures and offer little information regarding spatial behavior. A spatial model of a modified hybrid moment frame is experimentally analyzed. The experimental results of a natural scale model test of a corner column-beams sub-structure, cut from an actual multilevel building tested to seismic type loading are presented in order to highlight the behavior of this type of structure. The test is performed under alternative cycles of imposed lateral displacements, up to a storey drift ratio of 0.035. Seismic response of the spatial model is discussed considering the acceptance criteria for reinforced concrete frame structures designed based on experimental tests, as well as some of its major sustainability features. The results obtained show an overall excellent behavior of the system. The joint detailing allows for quick and cheap repairs after an accidental event and a self-balancing behavior of the system that ensures it can be used almost immediately after an accidental event it