Seasonal coefficient of performance of air-to-air heat pump and energy performance of a building in Poland

The article discusses the problem of determining for air heat pumps the seasonal efficiency of energy production necessary to determine the energy performance of a building. On the example of selected Polish cities (Suwalki, Bialystok, Warsaw, Wroclaw, Zielona Gora, Resko, Szczecinek, Koszalin) the influence of climatic conditions on the SCOP of an exemplary air-to-air heat pump and on the result of building energy performance calculations was analysed. SCOPs for each location were determined according to the method of EN 14825. The difference between SCOP for average (A) and colder (C) climates according to EN 14825 was 35.6%. It has been shown that the climate of Polish cities may be similar to both the average climate (A) and the colder climate (C), or they significantly differ from both climates. The most significant difference in SCOP between the analysed cities was obtained for Suwalki and Szczecinek. It was 31.9% and 31.4% for the assumed heating season length as for climate (A) and (C) respectively. For the exemplary building in Suwalki, taking SCOP for the average climate (A) and not based on climatic data of Suwalki gives an error of 39.3% in the calculation of primary energy for heating. For the same locations, the differences in SCOP and EP resulting from the assumption of the heating season length as for the average climate (A) or as for the colder climate (C) were respectively from 2.4% to 3.3% and from -3.4% to -2.2%. In diversified Polish climate, assuming the same SCOP values of air heat pumps regardless of location does not allow for their full comparison with devices whose efficiency does not depend on climatic conditions. The authors suggest that when calculating the energy performance of the building, the SCOP should be always determined on the basis of the local climate and the length of the heating season

Computational and the real energy performance of a single-family residential building in Poland – an attempt to compare: a case study

The paper presents energy use for heating and ventilation (one of the energy performance components) determined in three ways. A case of a single family building located near Wroclaw in Poland is analyzed. The first and the second variant are both computational and the third presents actual measured energy consumption. Computational variants are based on the Polish methodology for the EPC (the Energy Performance Certificate). This methodology is based on ‘the Energy Performance of Buildings Directive 2010/31/EU’. Energy use for heating and ventilation is calculated using monthly method presented in EN ISO 13790. In the first computational option standard input data (parameters such as indoor and outdoor air temperature etc. are taken from standards and regulations) are implemented. In the second variant this input data are partially taken from measurements. The results of energy use from both computational variants are compared to the actual measured energy consumption. On the basis of this comparison the influence of three factors: solar radiation heat gains, building air tightness and the SCOP of the heat pump on energy use calculations are analyzed. Conclusions aim to point the differences between them and the actual energy consumption

Computational and the real energy performance of a single-family residential building in Poland – an attempt to compare: a case study

The paper presents energy use for heating and ventilation (one of the energy performance components) determined in three ways. A case of a single family building located near Wroclaw in Poland is analyzed. The first and the second variant are both computational and the third presents actual measured energy consumption. Computational variants are based on the Polish methodology for the EPC (the Energy Performance Certificate). This methodology is based on ‘the Energy Performance of Buildings Directive 2010/31/EU’. Energy use for heating and ventilation is calculated using monthly method presented in EN ISO 13790. In the first computational option standard input data (parameters such as indoor and outdoor air temperature etc. are taken from standards and regulations) are implemented. In the second variant this input data are partially taken from measurements. The results of energy use from both computational variants are compared to the actual measured energy consumption. On the basis of this comparison the influence of three factors: solar radiation heat gains, building air tightness and the SCOP of the heat pump on energy use calculations are analyzed. Conclusions aim to point the differences between them and the actual energy consumption

Airtightness test of single-family building and calculation result of the energy need for heating in Polish conditions

The article presents results of air permeability measurements carried out for envelopes of two entire typical single-family residential buildings and separately for envelopes of garages and residential zones of these buildings. The effect of taking into account separate air permeability measurements of building zones on the calculation results of infiltration heat losses and on the energy need for heating is analysed. The calculation results obtained in this way are then compared to calculation results obtained in the case of air permeability measurements of the entire building envelope

Odzysk ciepła odpadowego za pomocą elektrycznej pompy ciepła z wywiewanego powietrza wentylacyjnego do systemu ciepłej wody użytkowej w wielorodzinnych budynkach mieszkalnych

The article discusses the possibility of recovering waste heat from the exhaust air from the ventilation system of multi-family residential buildings. A system of waste heat recovery from the extracted air with an electric heat pump was proposed for the preparation of domestic hot water (DHW). The proposed system has been analysed in TRNSYS 17 software for exemplary multi-family residential building. The influence of exhaust air humidity and heat pump outlet temperature on the energy effect was analysed. For the analysed case and the Polish conditions of electricity production, a possible reduction of the final energy amount for DHW preparation (EKW) by 35.1% and primary energy consumption (EPW) by 9.1% was determined in comparison with the use of a gas condensing boiler only. The factors influencing the energy effect of the system for the recovery of waste heat from the exhaust air were indicated. The authors specified directions of further research aimed at determining how to recover available waste heat from the exhaust air with lower energy expenditure and for which installations in the building they should be used.W artykule podjęto temat możliwości odzyskania ciepła odpadowego z powietrza wywiewanego z systemu wentylacyjnego budynków wielorodzinnych mieszkalnych. Zaproponowano system odzysku ciepła odpadowego z powietrza wywiewanego elektryczną pompą ciepła dla potrzeb przygotowania ciepłej wody. Zaproponowany system przeanalizowano w oprogramowaniu TRNSYS 17 dla przykładowego budynku wielorodzinnego. Przedstawiono wpływ wilgotności względnej powietrza wywiewanego i temperatury zasilania pompy ciepłej na efekt energetyczny. Dla analizowanego przypadku i polskich warunków produkcji energii elektrycznej, wyznaczono możliwe zmniejszenie zapotrzebowania energii końcowej na przygotowanie ciepłej wody użytkowej (EKW) o 35,1% i energii pierwotnej (EPW) o 9,1% w porównaniu z zastosowaniem tylko gazowego kotła kondensacyjnego. Wskazano czynniki wpływające na efekt energetyczny systemu do odzysku ciepła odpadowego z powietrza wywiewanego. Autorzy podali kierunki dalszych badań zmierzających do określenia jak odzyskać dostępne ciepło odpadowe z wywiewu przy mniejszym nakładzie energetycznym i do jakich instalacji w budynku je wykorzystać

Chorzy trudni typowiTętniak rozwarstwiający aorty wstępującej u 80-letniej kobiety

We present a case of 80-year-old woman with a history of paroxysmal atrial fibrillation admitted to the cardiology department due to syncope and chest pain with suspicion of pulmonary embolism. In course of further diagnostics the initial diagnosis was excluded and anticoagulant treatment was stopped. The real cause of the above signs and symptoms was aortic dissection. It was diagnosed by echocardiography and confirmed by CT scan. Patient was immediately transferred to the cardiosurgery department and successfully operated. The patient was discharged after 33 days in good condition

Ocena angiograficzna i obciążeniowa echokardiograficzna po chirurgicznym leczeniu zespołu Bland−White−Garlanda oraz wady zastawki mitralnej

We report case of 58-year-old male patient with severe mitral insufficiency in whom in preoperative angiography anomalous left anterior descending coronary artery arising from pulmonary artery was revealed. Patient successfully underwent mitral valve replacement, ligation and bypass of left anterior descending artery. Eighteen months after surgery control exercise echocardiography and angiography were performed to evaluate coronary flow, valve prosthesis and left ventricle function.We report case of 58-year-old male patient with severe mitral insufficiency in whom in preoperative angiography anomalous left anterior descending coronary artery arising from pulmonary artery was revealed. Patient successfully underwent mitral valve replacement, ligation and bypass of left anterior descending artery. Eighteen months after surgery control exercise echocardiography and angiography were performed to evaluate coronary flow, valve prosthesis and left ventricle function