Artur Rogoža

Criterion to evaluate the "twofold benefit" of the renovation of buildings and their elements

Abstract At present a benefit of energy saving projects for buildings renovation is considered as only the saving of energy. It is obvious, however, that most energy saving measures allow one not only to save energy, but also to improve the building’s condition and in turn to increase the value of a building. In practice, considering only the reduction of energy cost, the implementation of such measures is usually hard to prove through cost effectiveness. The authors of this paper suggest one of possible methods of how the assessment of the cost effectiveness of energy saving measures could include a twofold benefit of building’s renovation—the energy saving and the rehabilitation of the buildings elements physical condition. The presented method could form a “new attitude” towards the assessment of the energy saving projects for buildings renovation.

A sustainable analysis of a detached house heating system throughout its life cycle. A case study

Approximately 40% of final energy is consumed in buildings both in Lithuania and the European Union. In cold climate countries major part of the consumed energy is heat. Therefore, in order to build energy efficient buildings it is very important at the design stage to make a right decision regarding the choice of the heating system. The aim of the study is to compare three different heating systems from the point of view of a sustainable development concept. This paper summarizes results of the life cycle analysis, which has been made on the heating systems of an existing residential building. The purpose of this study is to define the primary energy consumption, CO 2 emissions and investments necessary for the three different heating systems during their life span and to evaluate them applying a multicriteria approach. The systems under consideration are the heating systems comprising a standard cast‐iron gas boiler and steel radiators or a condensing gas boiler combined with floor heating or a condensing gas boiler combined with steel radiators. A life cycle assessment has been made for the life span of 80 years. As a final decision making criteria the 3E criteria is proposed.

Quantitative estimation of improvements in the efficiency of district heating substation control system

Evaluation of energy performance of buildings is becoming increasingly applicable and constantly requires more and more precise forecasting of energy savings, which could be further interpreted in the economic evaluations of building renovation. Despite the development of a wide range of energy auditing methodologies and software tools, one important component has still not garnered enough attention and has no quantitative evaluation method. This component is energy savings attributed to improved performance of the heating control system. Currently, these savings are evaluated on the basis of arbitrary indices that have been extrapolated from real modernization projects. This approach is simplification and usually has no actual energy savings estimations. This article presents a method for the evaluation of energy savings attributed to improved performance of the district heating substation control system. The idea is based on employing the specific heat losses (H) of a building. Theoretically, the evaluated H values represent ideal work performance of the heating control system and the actual collected data represent the current state of efficiency of the control system. The estimation of possible energy saving potential between ideal and actual H values results in quantitative energy savings due to the improved performance of the heating control system. This article presents in detail the method application sequence. It provides additional explanation on actual data processing mechanisms by applying regression analysis in order to determine base temperature and accumulated duration curves. Practical application : None of the energy audit methodologies or software tools answer the question on the amount of energy that can be saved due to improved performance of the heating control system. The method presented in this article is simple, saves on time and enables energy auditors to have a quantifiably based groundwork for estimation of possible energy savings attributed to improved performance of the heating control system.

ESTIMATION OF EXISTING DISTRICT HEATING DISTRIBUTION NETWORK FROM THE STANDPOINT OF LIFE CYCLE ANALYSIS

Abstract Life cycle analysis is a widespread method in most countries. Its principle is to evaluate direct and indirect influences of searching object on environment during its all life cycle. Life cycle model calculations of two existing district heating distribution networks were investigated in this case. Two variants of district heating network maintenance works were computed and compared: renovations using pipes assembled in channels and pre-insulated pipes technologies. Primary energy, heat losses, expenses for maintenance works and heat losses were calculated. The most suitable periodicities of maintenance works and character of the networks depreciation using those periodicities were determined.