Thermodynamic investigation of building integrated energy efficiency for building retrofit

Abstract

• The building integrated energy efficiency is proposed in the paper. • The counterbalance of load is proposed in the paper. • The building envelope exergy cost of unit construction area is set up. • The exergy of building envelope and cooling heating load is analyzed. • The scheme-selection optimization model is presented in the paper. A thermodynamic calculation model, building envelope exergy cost of unit construction area, which combines the economic and energy efficiency of building envelope and cooling and heating resource, is proposed in the paper to evaluate the building integrated energy efficiency. The model is found on “counterbalance of load” and the building life cycle is also considered. The model is applied to analyze typical building envelopes of the case to decide which one is the best. An office building with 3 building envelope energy efficiency retrofit schemes is applied as the case. The building envelope exergy cost of unit construction area, energy consumption, exergy consumption and CO 2 emission of the 4 cases are all analyzed to determine the performance of the retrofit schemes. The results show that the building envelope with good insulation can help to reduce energy demand for cooling and heating. The building envelope energy efficiency retrofit schemes would reduce the building's energy consumption and CO 2 emission but it would increase its exergy consumption during its life-cycle. Taking energy efficiency, exergy efficiency, building envelope exergy cost of unit construction area and CO 2 emission into consideration, an optimization algorithm for the building envelope energy efficiency retrofit is brought forward.