Complex analysis of energy efficiency of public buildings: case study of VGTU

Abstract

The energy audit is a versatile assessment of the present condition of the building, evaluation of the gained results in terms of the energy efficiency and proposition of economically and ecologically efficient, socially acceptable organizational and technical measures pursuing to reduce energy consumption. Beggs [8] found analogy between building and a complaining patient, and energy auditing is the research work very similar to the research work of the medical doctor. Therefore, the right way to make energy audit is firstly to examine the building, state problems and then to suggest measures to eliminate these problems. There exists a problem that at the process of energy audit such parameters as internal temperature, air change rate and thermal characteristics of envelopes usually are presumed theoretically based on the auditor’s experience or standards. Therefore, incorrect assessment of one parameter impacts other parameters and the overall result. That in consequence may skew the savings expected after the refurbishment. The scientific task of the research presented in this paper was solution of this problem – creating more precise energy auditing methodology. Researchers of Vilnius Gediminas Technical University (VGTU) have been participating in the EEI project “USE Efficiency” since 2009 [9, 10] and in frames of that project they have significantly contributed to the promotion of the energy audit. The project is oriented towards students, efficient energy use and implementation of energy efficiency measures in university buildings. Young researchers were encouraged to perform audits of analyzed buildings as more precise and original as possible and thus they were gaining experience in the performance of the audits. Therefore the high attention was paid to the estimation of the real parameters of the building as well as proper selection of measured parameters, points of measurements, methods to be used, duration and time of measurements. These tasks enabled students to go more deeply into the energy audit as well as analyze energy characteristics of the university buildings, identify existing problems and their scale. For this purpose, the equipment of the newly established VGTU Center of Civil Engineering Sciences was used. The kit consists of the measurement devices used to define real energy consumption, characteristics of the building, user behavior and indoor climate conditions.