Muhyiddine Jradi

Demand response in commercial buildings with an Assessable impact on occupant comfort

Electricity grids are facing challenges due to peak consumption and renewable electricity generation. In this context, demand response offers a solution to many of the challenges, by enabling the integration of consumer side flexibility in grid management. Commercial buildings are good candidates for providing flexible demand due to their volume and the stability of their loads. However, existing technologies and strategies for demand response in commercial buildings fail to enable services with an assessable impact on load changes and occupant comfort. In this paper we propose the ADRALOC system for Automated Demand Response with an Assessable impact on Loads and Occupant Comfort. This enhances the quality of demand response services from a grid management perspective, as these become predictable and trustworthy. At the same time building managers and owners can participate without worrying about the comfort of occupants. We present results from a case study in a real office building where we illustrate the advantages of the system (i.e., load sheds of 3kW within comfort limits). Presenting a better system for demand response in commercial buildings is a step towards enabling a higher penetration of intelligent smart grid solutions in commercial buildings.

Energy performance of an innovative liquid desiccant dehumidification system with a counter-flow heat and mass exchanger using potassium formate

Abstract An innovative micro-scale liquid desiccant dehumidification system is numerically investigated. The liquid desiccant dehumidification unit employs a counter-flow low-cost and efficient heat and mass exchange core, improving

Poster Abstract: Towards a Categorization Framework for Occupancy Sensing Systems

A large share of the energy consumption of buildings is driven by occupancy behavior. Means to minimize this share of consumption depend upon accurate information about occupant behavior. Therefore, it is important to improve sensing systems for gathering such information. However, as research on occupancy sensing systems goes beyond basic methods, there is an increasing need for better comparison of proposed occupancy sensing systems. Developers of occupancy sensing systems are also lacking good frameworks for understanding different options when building occupancy sensing systems. This poster abstract motivates the need for working towards a better categorization framework to address both of these problems. For researchers, the categorization framework is also an aid when scoping out future research in the area of occupancy sensing systems.

Testing and performance analysis of a hollow fiber-based core for evaporative cooling and liquid desiccant dehumidification

ABSTRACT In this study, an innovative heat and mass transfer core is proposed to provide thermal comfort and humidity control using a hollow fiber contactor with multiple bundles of micro-porous hollow fibers. The hollow fiber-based core utilizes 12 bundles aligned vertically, each with 1,000 packed polypropylene hollow fibers. The proposed core was developed and tested under various operating and ambient conditions as a cooling core for a compact evaporative cooling unit and a dehumidification core for a liquid desiccant dehumidification unit. As a cooling core, the fiber-based evaporative cooler provides a maximum cooling capacity of 502 W with a wet bulb effectiveness of 85%. As a dehumidification core and employing potassium formate as a liquid desiccant, the dehumidifier is capable of reducing the air relative humidity by 17% with an overall dehumidification capacity of 733 W and humidity effectiveness of 47%. Being cheap and simple to design with their attractive heat and mass transfer characteristics and the corresponding large surface area-to-volume ratio, hollow fiber membrane contactors provide a promising alternative for cooling and dehumidification applications.

Recent Developments in Solar-Powered Micro CHP Systems

Over the last two decades, the world has exhibited an unprecedented increase in the energy resources demand due to the huge technological and industrial developments accompanied by a tremendous population growth. The fluctuations in the conventional fossil fuel prices and the global warming problem are urging the need for switching towards renewable energy resources. With the buildings and residential sector contributing to a large portion of energy consumption, micro-scale combined heat and power systems (CHP) tend to be an effective solution to satisfy heating and electricity needs for buildings and residential accommodations. Taking advantage of the decentralized production and the capability of being driven by renewable energy resources, micro CHP systems are presented as a feasible substitute to the central production stations especially in rural and developed areas. The current work provides a comprehensive overview for the recent developments in the field of micro CHP systems. Research studies regarding micro CHP systems applications in buildings and residential accommodations are reviewed. Moreover, recent options for micro CHP prime movers are reviewed and compared in terms of the technology development, performance, environmental and economic impacts. Different applications of solar organic Rankine systems in the residential sector are presented including small-scale electricity production and reverse osmosis desalination systems. Discussions are concentrated on micro CHP systems driven by organic Rankine cycle (ORC) which provides more durability and reliability in operation and reduces maintenance levels and safety concerns. In addition, recent studies dealing with solar ORC micro CHP systems are examined. The current work doesn’t only add to the literature on micro CHP systems but also provides recommendations for future design and development of ORC solar-powered micro CHP systems including working fluid selection and solar collector technology used.

Continuous Commissioning of Buildings: A Case Study of a Campus Building in Denmark

The general trend in building commissioning is that the commissioning is often either insufficiently comprehensive in its execution, or it is not conducted at all. As such, it has been observed that buildings often will contain faults that have not been discovered during the commissioning phase. In this paper, we present a framework for continuous verification and commissioning of a building with a set of performance tests that are able to monitor the performance and functionality with a daily granularity. The performance tests are run on a newly constructed campus building in Denmark, over the course of three months, and the results of the performance tests are presented within a dashboard application, which helps verify that the building is performing accordingly to its original design intent.