Influence of Thermal Retrofitting on Annual Energy Demand for Heating in Multi-Family Buildings

Abstract

The paper presented the analysis of heat consumption for heating in multi-family residential buildings before and after thermal retrofitting. The analysis involved four groups of buildings, i.e., 43 buildings in total, located in various localities, belonging to one weather station. The predicted level of energy savings resulting from thermal retrofitting was achieved from the energy audits. The actual heat consumption, following the calculation into so-called external standard conditions, was obtained based on the readouts from heat-meters. For each building, the values of heat consumption over the periods of 6–10 years were read. The performance measurements involved the periods before, during, and after thermal retrofitting. The following statistical tests were used for data analysis: Wilcoxon–Mann–Whitney, Shapiro–Wilk, Bartlett, ANOVA, Kruskal–Wallis, Dunn and Holm post-hoc. The performed analyses showed that the mean value of energy savings predicted by audits reached 38.5% when the real mean value of savings, achieved from heat-meters, equaled 30.3%. The annual energy demand factors for heating were calculated for final energy and non-renewable primary energy factors. It was established that most of the analyzed objects fulfilled the primary energy factor requirements found in the Polish technical and construction regulations, which were valid at the time of investment.

Energy Benefits of Heat Pipe Technology for Achieving 100% Renewable Heating and Cooling for Fifth-Generation, Low-Temperature District Heating Systems

“…They have also recognized that the same may be true for new buildings because of the poor output of radiators when working at very low temperatures. They explained the reason but could not provide sustainable solutions, except noting that radiators were already oversized in many cases in existing buildings.Życzyńska, A. et al have investigated the impact of thermal retrofitting in Polish buildings on their annual energy budget [34]. They concluded that the thermal retrofitting in multi-family apartments that they have investigated reduced their heating demand up to 43%.…”

Statistical Analysis of the Variability of Energy Efficiency Indicators for a Multi-Family Residential Building

“…The analysis of the methodology to prepare the building energy certificates and related standards indicate that many parameters affect the value of the building indicator for nonrenewable annual primary energy consumption for heating (PE H ). The value of the PE H index depends on the value of the building indicators of usable, final energy and primary energy factor [3,[19][20][21]. The building usable energy demand, expressed through the usable energy demand, is influenced by: climatic conditions related to the location of the building, its orientation relative to world directions, internal heat gains and building envelope parameters, such as thermal insulation of building partitions, protection properties against wind, building glazing, shading of transparent partitions and their ability to transmit solar radiation [18,[22][23][24].…”

Improving the Energy Performance of Public Buildings Equipped with Individual Gas Boilers Due to Thermal Retrofitting

“…This applies to buildings regardless of their location, i.e., in urban and rural areas. First of all, local government units indicated educational facilities for thermal retrofitting investments, and then others, such as offices, related to medical services or cultural activities of the city or commune [7,8]. Co-financing programs were particularly useful in units that did not have a sufficient budget to carry out a thermal retrofitting investment from their own funds [9,10].…”

“…The second one, which takes into account the total efficiency of the heating system, is called the final energy consumption for heating (FE H ). The third is called the non-renewable primary energy index for heating (PE H ), the value of which additionally depends on the type of fuel or energy used to cover the heating needs of the building [8,17].…”