scholarly journals System efficiency of PVT-collector driven heat pumps

2019 ◽  
Vol 116 ◽  
pp. 00026
Author(s):  
Franz Hengel ◽  
Christian Heschl ◽  
Franz Inschlag ◽  
Peter Klanatsky

Standard heat pump (HP) systems with horizontal ground heat exchangers (HGHE) are commonly designed based on arbitrary knowledge gained over time and the use of the rule of thumb. Where an undersizing of the HGHE occurs, the HP efficiencies are lowered. Undersizing could result as a consequence of underestimating the soils thermal conductivity. Therefore, this paper considers the combined photovoltaic and solar thermal (PVT) collectors as an extension to standard HP heating systems with a HGHE in single-family houses with the possibility of improving the COP of the HP at a later stage and effortlessly. With the implemented hydronic scheme, the PVT-collector is also used to regenerate the soil around the ground to increase the temperature level of the heat source resulting in improved performance. However, the efficiency potential of the PV-Cells due to active cooling of the modules is analyzed. The results show an increase of the seasonal performance factor (SPF) of 4.1 % and higher electric energy output of 4.4% due to active cooling of the PV-Cells while energy consumption of the regeneration pump is covered.

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4625
Author(s):  
Alisa Freyre ◽  
Stefano Cozza ◽  
Matthias Rüetschi ◽  
Meinrad Bürer ◽  
Marlyne Sahakian ◽  
...  

In this paper, we perform a literature review on the current state of knowledge about homeowners in the context of the adoption of renewable heating systems. Despite a considerable number of studies about homeowners, homeowner–installer interactions, and ways to improve the effectiveness of renewable heating programs, based on homeowner knowledge, have not yet been studied in much detail. To address these knowledge gaps, we conduct a qualitative study on single-family house owners who installed heat pumps and took part in a renewable heating program in Geneva, Switzerland. We cover homeowner practices in choosing installers and heating system types, homeowners’ feedback about heat pump installation and use, as well as their experience in participation in the renewable heating program. Based on the literature review and the findings from the interviews, we provide the following recommendations on how to increase the effectiveness of renewable heating programs: (a) support for homeowners should not be limited to financial incentives; (b) partnership programs with installers could help to increase the quality of installation services and enable homeowners to choose qualified installers; and (c) assisting homeowners in pre-qualification and ex-post analysis, in learning how to operate their renewable heating systems and in solving problems during the post-installation period, can contribute to improved technology reputation, which can, in turn, increase technology uptake by other homeowners.


2018 ◽  
Vol 44 ◽  
pp. 00157
Author(s):  
Piotr Rynkowski

The paper presents the ground temperature analysis, heat flows and energy transferred from the soil massif by the vertical ground heat exchangers (VGHE). Three cases – with one, two and three vertical heat exchangers were compared. Their influences on the soil massif temperature in the heat exchangers area were shown. The mass flow and the temperature at the inlet and outlet side of the heat pump were measured in each circuit. Additional, the electricity consumption by the heat pump and energy supply to buffer vessel were measured. Finally, the Coefficient of Performance (COP) as a function of length of VGHE is shown for selected interval time.


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