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

Piotr Michalak,Jakub Szymiczek,Krzysztof Szczotka

doi:10.3390/en14071973

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.

Highlights

Buildings in Poland are responsible for over 30% of the total energy consumption.Because of the rising energy prices and environmental pollution since the end of 1980s, energy conservation emerged as one of the most important economic and policy issues.Numerous efficiency-related law regulations and support schemes have been introduced for these purposes [1,2,3,4,5]
This paper aims to fill this gap coherently presenting in detail the abovementioned issues, by providing a complete description of the completed thermal modernization investment, starting from pre-investment conditions, through energy audit and investment design to the finished project
Supported investment is chosen from a set of measures indicated in the energy audit following their simple payback time (SPBT)

Summary

Introduction

Buildings in Poland are responsible for over 30% of the total energy consumption.Because of the rising energy prices and environmental pollution since the end of 1980s, energy conservation emerged as one of the most important economic and policy issues.Numerous efficiency-related law regulations and support schemes have been introduced for these purposes [1,2,3,4,5]. Application of the given measure results in energy savings These parameters are calculated by following the procedure given in Reference [54]. It is divided into different kinds of modernization measures: Reduction of heat transfer through walls, ceilings, and flat roofs; Replacement of windows or doors and the improvement of the ventilation system (natural and mechanical exhaust ventilation); Reduction of energy demand by a mechanical supply and exhaust ventilation system. An on-site inspection showed that the brick and wooden external walls, the wood ceiling under the unheated attic, and concrete floors on the ground and in the baseme were not insulated. Old external doors and PVC windows didnot meet the standards (Table 2)

Objectives

Methods

Findings

Conclusion