Amar Abdul-Zahra

University of Technology- Iraq

In the recent decades, the researchers have been focused on the use of photovoltaic thermal (PVT) systems that provide the best performance and cooling for the photovoltaic panels. In this study, a PVT system consisting of a monocrystalline PV panel and a spiral heat exchanger was connected to an underground heat exchanger that is buried at a depth...

Most of the energy consumption in a hot and dry area is used for the air‐conditioning systems. This study aims to investigate the possibility of reducing the electricity consumption in air conditioners using ground cold energy to cool the hot fluid in the pipes. Several experiments were carried out to investigate the performance of the proposed sys...

In a hot and dry climate like the weather of Iraq, near-to-net zero energy buildings (NNZEBs) can become one of the effective solutions to reduce energy demands in the residential buildings sector. Therefore, the current work aims to cornerstone of the developed solution combined the different scenarios for residential building with a total living...

Heat recovery (HR) is often mentioned as a device that operates between two heat sources in different temperatures. In this device, the heat is transferred from one side to another in order to have a heat balance. Therefore, the device is working on reheating/precooling supplying air to the space by waste heat. The main aims of this work are to de...

Evaporative cooling is a good alternative of refrigeration cooling systems. This system is environmentally friendly and consumes low electrical energy. However, this system has some disadvantages which is greatly affect on the performance of the system. One of these problems is the affected by external conditions (humidity) makes space uncomfortabl...

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Thermal discomfort is one of the main triggers for occupants’ interactions with components of the built environment such as adjustments of thermostats and/or opening windows and strongly related to the energy use in buildings. Understanding causes for thermal (dis-)comfort is crucial for design and operation of any type of building. The assessment...

Mit Fokus auf Wohngebäude wurde das Heizsystem SOLINK‐ im Wesentlichen bestehend aus einer Wärmepumpe und einem PVT‐Kollektor‐entwickelt und mithilfe von Systemsimulationen optimiert. Mit einer PVT‐Fläche von 28 m² kann für ein neu gebautes Einfamilienhaus in Deutschland eine Gesamtjahresarbeitszahl von 4,3 erreicht werden. Im Systemvergleich bei g...

Reduction in consumption of non-renewable energy resources at the local level (e.g. district or neighbourhood) is one of the effective manners to support sustainable development. To achieve this goal, engagement of citizens and other actors in the early stage of research is important. In this regard, the "Urban Transition Lab 131" (R131), which act...

Flat plate solar thermal collectors and photovoltaic solar collectors in combination with an electrical resistance heater have been compared as an additional solar heat source of a gas burner-based heating system for a residential building in Germany. The dependency on solar collector field area and retrofitting level of the building has been analy...

Recently, hybrid photovoltaic solar thermal collectors (PVT) became a topic of many research projects because of the possibility to gain heat and electricity simultaneously. PVT represents the alternative to PV panels and solar thermal collectors in one device. The main goal of this study is to evaluate different possibilities to integrate PVT coll...

1 Abstract The growing share of volatile and decentralized electrical energy generation in Germany leads to enormous challenges for the balance of energy generation and demand. Therefore, different strategies are proposed. Beside the direct electrical storage of electricity, it can also be saved as thermal energy by using electrical heating systems...

Der wachsende Anteil erneuerbarer Energien an der Stromversorgung in Deutschland stellt enorme Anforderungen an den Ausgleich von Stromerzeugung und /-verbrauch. Um das Stromnetz weitestgehend zu entlasten, ist eine Speicherung von lokal erzeugtem Photovoltaikstrom (PV-Strom) direkt vor Ort ideal. Eine Möglichkeit zur Stromspeicherung stellen therm...

The rapid growth of installed renewable energy systems in Germany causes higher amplitudes and frequencies of the fluctuations in the electric grid. This goes along with increasing electricity tariffs and a decrease of feed-in tariffs. One strategy to compensate for that is to increase own energy consumption of electricity from photovoltaic (PV) mo...