christian hepf

Mr. christian hepf

orcid

Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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14 December 2022 in Buildings
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Journal Article
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CHchristian hepf
christian hepf
KBKonstantin Bausch
Konstantin Bausch
LLLukas Lauss
Lukas Lauss
Sebastian KothSebastian Koth
Sebastian Koth
Thomas AuerThomas Auer
Thomas Auer
Due to climate change, emission balancing is a relevant tool to quantify the environmental impact of a building system. The electrification of energy production at a national level, as well as energy supply at a building level, shifts the focus to the emission factor (EF) of the electricity grid. Currently, static EFs are used for calculating the emission balance. However, the electricity grid already shows fluctuations in power generation and EF due to renewable energies. The paper reviews recent literature outlining the research gap and presents the development of a simulation setup and concept, in which the emission balance of the building operation changes, using dynamic EFs that map fluctuations at an hourly resolution. In the first step, we simulate the thermal building and radiance performance. The data are than used in a second step to conduct a system simulation, which analyzes the effects of the dynamic EFs. The results show that the dynamic balance approach for different building system variants deviates considerably from the static approach. By comparing different concepts for the loading strategy, the predictive strategy outperforms a common control strategy, when considering the energy prices and/or the emissions. This is especially true for systems with inert storage units, where charging times significantly influence the balance, as well as for systems with PV integration. This paper outlines the potential of the EFs-optimized control increases when evaluating a potential scenario for the year 2040, factoring in increased seasonal and daily fluctuations in electricity generation.

10 April 2023 in Buildings
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Journal Article
Open access
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CHchristian hepf
christian hepf
LOLennard Overhoff
Lennard Overhoff
Sebastian KothSebastian Koth
Sebastian Koth
MGMartin Gabriel
Martin Gabriel
DBDavid Briels
David Briels
Thomas AuerThomas Auer
Thomas Auer
The sun’s total radiation alone exceeds the world population’s entire energy consumption by 7.500 times and ignites secondary renewable energy sources. The end energy consumption buildings use for heating amounts to 28% of Germany’s total energy consumption. With the ongoing trend of digitalization and the transition of the German energy supply away from fossil fuels and the consequent political dependency, electric heat pumps and photovoltaic (PV) systems have become increasingly important to the discussion. This has led to an increasing demand for smart control strategies, especially for inert systems such as thermally activated building systems (TABS). This paper presents and analyses a weather predictive control (WPC) strategy using a validated thermodynamic simulation model. The literature review of this paper outlines that the current common control strategies are data intense and complex in their implementation into the built environment. The simple approach of the WPC uses future ambient temperature and solar radiation to optimize the control of the heating, cooling, ventilation, and sun protection system. The thermal comfort and energy demand evaluate the concept. We show that with a WPC for TABS, thermal comfort can improve without increasing the energy demand for the office building in the moderate climate of Munich. Furthermore, this paper concludes that the WPC works more effectively with more thermal mass. This simplified building control strategy promotes the European roadmap goal of climate neutrality in 2050, as it bridges the phenomenon of the performance gap.

29 August 2024 in Energy and Buildings
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Journal Article
Open access
SKSebastian Clark Koth
Sebastian Clark Koth
Bilge KobasBilge Kobas
Bilge Kobas
ARAmelie K. Reitmayer
Amelie K. Reitmayer
CHchristian hepf
christian hepf
TAThomas Auer
Thomas Auer

20 January 2024 in Buildings
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Journal Article
Open access
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CHchristian hepf
christian hepf
BGBen Gottkehaskamp
Ben Gottkehaskamp
Clayton MillerClayton Miller
Clayton Miller
Thomas AuerThomas Auer
Thomas Auer
Building operational energy alone accounts for 28% of global carbon emissions. A sustainable building operation promises enormous savings, especially under the increasing concern of climate change and the rising trends of the digitalization and electrification of buildings. Intelligent control strategies play a crucial role in building systems and electrical energy grids to reach the EU goal of carbon neutrality in 2050 and to manage the rising availability of regenerative energy. This study aims to prove that one can create energy and emission savings with simple weather and emission predictive control (WEPC). Furthermore, this should prove that the simplicity of this approach is key for the applicability of this concept in the built world. A thermodynamic simulation (TRNSYS) evaluates the performance of different variants. The parametrical study varies building construction, location, weather, and emission data and gives an outlook for 2050. The study showcases five different climate locations and reveals heating and cooling energy savings of up to 50 kWh/(m2a) and emission savings between 5 and 25% for various building types without harming thermal comfort. This endorses the initial statement to simplify building energy concepts. Furthermore, it proposes preventing energy designers from overoptimizing buildings with technology as the solution to a climate-responsible energy concept.


8 April 2025 in Energy and Buildings
Verified
Journal Article
Open access
JQJose Quesada-Allerhand
Jose Quesada-Allerhand
OKOngun Berk Kazanci
Ongun Berk Kazanci
CHchristian hepf
christian hepf
Thomas AuerThomas Auer
Thomas Auer
ISIan F.C. Smith
Ian F.C. Smith