Energy Effectiveness or Economic Profitability? A Case Study of Thermal Modernization of a School Building

Abstract

Thermal refurbishment of buildings results in certain energy, financial, and environmental effects. Such investments are financially supported in Poland after meeting the legally defined conditions of thermal protection and energy consumption. This paper presents a complex thermal modernization of a school building, performed by following Polish regulations. A detailed description of the studied object was given, and the calculation procedure was described. Then an optimal variant of an investment and an ex-post analysis were described. Simple payback time (SPBT) of modernization measures was from 15.8 years (insulation of the ceiling under the unheated attic) to 87 years for insulation of the wooden external wall, with 35.6 years for the whole project, which is shorter than the predicted lifespan of the whole building (50–70 years). Annual calculated heating demand decreased from 464.78 to 168.73 GJ, resulting in the primary energy consumption indicator (EP) of 484.44 and 129.46 kWh/m2, respectively. Thermal refurbishment with the replacement of an old boiler into a new wood-pellet one resulted in a significant reduction of SO2 and dust emissions from 451 to 27.5 kg and from 399 to 13 kg, respectively.

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“…The NECP of Poland presents information on protection measures for vulnerable energy consumers (e.g., on energy allowances for vulnerable electricity consumers), and the improvement of energy efficiency in schools is mentioned among energy efficiency measures (Ministry of National Assets, 2019). It should be noted that, despite the fact that 60% of schools have had their energy performance improved, a significant number of educational facilities still require modernization (Michalak, Szczotka, & Szymiczek, 2021).…”

Hourly Simulation of an Earth-to-Air Heat Exchanger in a Low-Energy Residential Building

“…This is especially true in residential buildings, where the amount of available space rarely allows for installation of an air handling unit with necessary equipment. What is more, in such objects the heat transmission loss through external partitions is usually the most significant [7,14,15] and it can be efficiently minimised at relatively low cost by additional insulation. This approach to the required energy standards of a building can be achieved in a simple way without too much interference with the structure of the building and without costly installation work which is burdensome for the residents [16].…”

Old and Modern Wooden Buildings in the Context of Sustainable Development

“…Global business models increasingly embrace social responsibility and sustainability. A sustainable renovation and investment process encompasses the creation of a complete life cycle of a building or structure-from the production, transport, and assembly of materials, to maintenance during operation, and then to the Life Cycle Assessment (LCA) group [18][19][20][21][38][39][40]. An essential aspect of sustainable development is the concept of sustainable energy, defined as an energy efficient way of producing and using energy that has less harmful effects on the environment [23,[41][42][43][44][45][46][47][48].…”

“…Buildings account for more than 30% of total energy consumption. Due to rising energy prices and environmental pollution, energy savings has become one of the most important economic and political objectives since the late 1980s, so numerous efficiency-related regulations and support schemes have been introduced [23,37,40,44,46,[48][49][50][51][52][53][54][55][56].…”

“…At present, they are still in use, although they are mostly only exhibits in open-air museums. Recently, a return to the construction of wooden buildings using the above-mentioned technology has been observed [1,39,40,70,[78][79][80]. Many authors also focus on analysing the condition of historic buildings [81][82][83], in particular, timber structures [84,85], of cultural heritage.…”