References of "Shirani, Arsalan 1170008419"
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See detailEnergy performance comparison of ventilation-based heating versus water-based heating systems in an efficient residential building
Shirani, Arsalan UL; Merzkirch, Alexander; Leyer, Stephan UL et al

in Fluid Dynamics & Material Processing (in press)

The application of air-based heating systems as a possible approach to reduce the construction costs in highly efficient residential buildings is becoming popular. Air-based heating systems have been well ... [more ▼]

The application of air-based heating systems as a possible approach to reduce the construction costs in highly efficient residential buildings is becoming popular. Air-based heating systems have been well-known for their usage in passive houses during the past three decades. Available studies on such systems tend mostly to focus only on comparing exhaust air heat pump technology with conventional systems in efficient buildings. Moreover, most of the existing studies ignore the usual presence of the electrical heaters as backup. Besides, a comprehensive study and comparison between different air-based heating system concepts is still missing. In this study, four different air-based heating system concepts separated by the type of heat source of heat pump for heating and domestic hot water are defined. These systems are compared to four conventional heating system, including floor heating and direct electrical system employing dynamic annual simulations. According to simulation results, the systems with floor heating have shown the best system efficiencies and the lowest energy demand in comparison to the other systems. The main reason for this was the lower supply temperatures of the floor heating systems. Between the air heating systems, the system equipped with an outdoor air heat pump showed a better energy performance than an exhaust air system. The main reason for this could be attributed to the power limitation of exhaust air heat pump systems. [less ▲]

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See detailCOMBINED HEATING AND VENTILATION SYSTEMS FOR LOW-ENERGY RESIDENTIAL BUILDINGS; OPTIMIZATION OF ENERGY EFFICIENCY AND USER COMFORT
Shirani, Arsalan UL

Doctoral thesis (2022)

Combined heating and ventilation systems are applied here in highly energy-efficient residential buildings to save construction cost. Combining a Heat Pump with a Heat Recovery Ventilation system to heat ... [more ▼]

Combined heating and ventilation systems are applied here in highly energy-efficient residential buildings to save construction cost. Combining a Heat Pump with a Heat Recovery Ventilation system to heat and cool the building offers faster response times, a smaller footprint and an increased cooling capacity, compared to floor heating systems. As a result, such systems are expected to have a larger market share in the future. The available research on Ventilation Based Heating systems focuses mostly on comparing Exhaust Air Heat Pumps with conventional systems in energy-efficient buildings. The majority of published research neglects the usual existence of electrical backup heaters as well as the need to develop and use an adapted and optimized control strategy for such systems. This work compares the energy efficiency of the common-standard ventilation-based heating concepts including Exhaust Air Heat Pumps with the conventional floor heating systems using single room control strategy to achieve similar user comfort. The comparison is carried out in a simulation environment in order to optimize the systems under exactly reproducible boundary conditions. Additionally, two field tests were performed to achieve a better understanding and validation of the simulation models. The measured data was used to model the dynamic behavior of the Exhaust Air Heat Pump and the air distribution system. These field tests revealed that the overall run time and heating output of the heat pump were much lower than expected. This was the motivation to investigate and optimize the heat pump and electric heater control strategy. It could be demonstrated that the applied control strategy has a significant impact on the overall performance of the system. The suggested control strategy was tested and validated in a third field measurement. Based on the gained knowledge using the system simulation tool and the conducted field tests, an improved second concept for Ventilation Based Heating systems was defined with three optimization steps. It could be demonstrated that using the suggested methodologies in the hard- and software of such a system, can significantly improve its overall efficiency. However, Ventilation Based Heating systems cannot compete with floor heating systems in terms of total system energy efficiency, due to the necessity of electrical backup heaters and due to the higher supply temperatures. [less ▲]

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See detailExperimental and analytical evaluation of exhaust air heat pumps in ventilation-based heating systems
Shirani, Arsalan UL; Merzkirch, Alexander UL; Roesler, Jennifer et al

in Journal of Building Engineering (2021)

Due to the significant energy loss in the building sector, energy efficiency of the buildings and their heating systems is gaining interest especially in the last decades. Application of exhaust air heat ... [more ▼]

Due to the significant energy loss in the building sector, energy efficiency of the buildings and their heating systems is gaining interest especially in the last decades. Application of exhaust air heat pumps as an energy efficient heating technology to cover the heating and venting demand of the building is becoming conventional. The exhaust air heat pumps are attracting considerable interest due to their normally reasonable price and small footprint. This heat pump type is often installed as part of an air based heating system together with electrical heaters. These electrical heaters are installed to cover the residual heating demand and/or to insure thermal comfort. The technology of exhaust air heat pumps has been investigated in several studies. Available studies on exhaust air heat pumps have tended mostly to focus on comparison between different technologies utilized in efficient buildings. Almost all of the existing studies have ignored the actual application of this technology in air based heating systems together with electrical heaters. In this sense, there is still a need for discussion on the influence of different buildings’ standards and control strategies on the heating system performance. The present paper aims to call into question the energy efficiency of exhaust air heat pumps under different boundary conditions. In this study, the results of a long time field monitoring are utilized in order to model the dynamic behavior of an exhaust air heat pump in MATLAB/Simulink. The impact of different boundary conditions on the heat pump’s efficiency is studied and additionally compared to previous studies. The developed model is used for annual simulations of air based hybrid heating systems in three different building standards. Finally, the influence of control strategy on the system performance is investigated. It is shown that under certain boundary conditions and control strategy, the studied system could provide an efficient heating system with acceptable user comfort. Nevertheless, applying conventional heating control methods or installing the system in buildings with high heating energy demand could lead to high electrical energy consumption and/or undesirable thermal comfort. [less ▲]

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See detailField monitoring data on a residential exhaust air heat pump system (air-to-air heat pump)
Shirani, Arsalan UL; Merzkirch, Alexander; Roesler, Jennifer et al

in Data in Brief (2021)

This data article presents the raw data used in the article “Experimental and analytical evaluation of exhaust air heat pumps in ventilation-based heating systems” (in review). The data set contains ... [more ▼]

This data article presents the raw data used in the article “Experimental and analytical evaluation of exhaust air heat pumps in ventilation-based heating systems” (in review). The data set contains measurement results of a field monitoring on a residential exhaust air heat pump system (air-to-air heat pump) in Germany. This data could be used to investigate the dynamic behaviour and performance of the exhaust air heat pump systems. The data set contains air temperature and humidity of all four sides of the heat pump unit. Moreover, the electrical consumption of the unit and the dynamic pressure difference on the exhaust side (as indication of the air volume rate) could be also found in the data set. [less ▲]

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