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Wagner J.,University of Kassel | Schafer M.,Imtech Deutschland GmbH and Co. KG | Phan L.,Florida International University | Schluter A.,Institute Decentralised Energy Technologies gGmbH | And 3 more authors.
ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE) | Year: 2014

Many industries have significant requirements regarding temperature control, air humidity and air pollution which must be strictly adhered to avoid bacterial formation and contamination. High refrigeration specifications are only required in certain areas. However, these specifications are often applied across the whole production hall which results in unnecessarily high energy demand and usage. A more energy efficient approach is the localized cooling of the product, which conditions the direct environment of the product only. This leads to the consideration of separating or localizing the products specifically requiring refrigeration in the production hall. In this paper, localized product cooling systems are analyzed in order to identify the savings potential associated with a localized refrigeration system. The study shows the energy savings potential for a manufacturing company located in three different locations: in Germany, Canada and the USA. Copyright © 2014 by ASME.

Schafer M.,University of Kassel | Detzer R.,Imtech Deutschland GmbH and Co. KG | Hesselbach J.,University of Kassel | Bohm S.,University of Kassel | And 2 more authors.
HVAC and R Research | Year: 2013

Industrial production processes often emit air pollutants that have adverse health effects and affect product quality. Essentially, several mechanisms, such as mixed and stratified ventilation systems, have been established in companies to remove generated thermal and mass loads from manufacturing areas. The widely used mixed ventilation generates a homogenous temperature and pollutant level in the entire production hall. However, fresh air supply is only needed in the area that is used by employees and needed for processes. As most factories do not adjust the ventilation system to current production conditions, the production hall is over-supplied with clean and conditioned air during idle times. This study describes experimental measurements and simulation analysis to compare mixed and stratified ventilation systems. The measurements include carbon dioxide and temperature profiles with various intake airflows, intake air temperature, thermal load, and machine layouts. Results show advantages in airflow, air quality, cooling capacity, and energy demand when using automatically demand-driven stratified ventilation. The experimental results validate the thermal simulation results. Controlling the layer height, ambient temperature of the room, and concentration of contaminants are vital parameters. © 2013 ASHRAE.

Wagner J.,University of Kassel | Schafer M.,Imtech Deutschland GmbH and Co. KG | Schluter A.,IDE Technologies | Harsch L.,AuE Kassel GmbH | And 3 more authors.
HVAC and R Research | Year: 2014

Food and pharmaceutical refrigeration areas place significant demands on air temperature and air humidity control. This leads to high energy requirements on the HVAC system. In the majority of cases, the entire production hall is "over conditioned" with fresh air. However, very often the products are located in a small part of the overall production area (hall). From an energy efficiency and sustainability point of view, it makes sense to only air condition that area in which the products require refrigerated temperature control. One approach to reduce the refrigeration energy demand is to house the product in localized product cooling systems.In this study, localized product cooling systems are analyzed in order to identify the saving potentials associated with a localized HVAC refrigeration system. Experimental systems were built and evaluated. The simulation analysis highlighted that smaller localized refrigeration housing can reduce total energy demand by up to 65%. Copyright © 2014 ASHRAE.

Belleil E.,EI. CESI | Phan L.,Florida International University | Lin C.-X.,Florida International University | Schafer M.,University of Kassel | And 2 more authors.
ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE) | Year: 2014

The solar powered house at the Engineering Center of Florida International University is out of the U.S. Solar Decathlon 2005 competition. A computational simulation using EnergyPlus is conducted to study different ventilation strategies in this solar house model, with consideration of the hot and humid climate in Miami, Florida. Several modes of ventilation including mechanical cooling systems, natural ventilation utilization, and hybrid systems were considered to seek the best possible option for ventilation in such extreme climate. While the need for a mechanical ventilation system is always present, a resort to natural ventilation could significantly reduce energy consumption. As for natural ventilation utilization, a few methods including earth tubes (ET), thermal chimneys (TC), cooling towers (CT), and openings have been simulated and compared with the mechanical cooling system of the original house. However, as the simulation results suggested, relying on only natural ventilation could cause a dramatic impact to the human thermal comfort. Therefore, a coupling strategy between mechanical systems and natural ventilation was extensively investigated in hope for a better solution in terms of both energy consumption and thermal comfort. In fact, the hybrid system has proved to tremendously reduce energy consumption while complying with the minimum requirements for thermal comfort recommended by ASHRAE standards. Copyright © 2014 by ASME.

Vorbeck L.,Fraunhofer Institute for Solar Energy Systems | Gschwander S.,Fraunhofer Institute for Solar Energy Systems | Thiel P.,Imtech Deutschland GmbH and Co. KG | Ludemann B.,Imtech Deutschland GmbH and Co. KG | Schossig P.,Fraunhofer Institute for Solar Energy Systems
Applied Energy | Year: 2013

Thermal storage can make an important contribution towards tackling the rise in energy consumption by balancing energy supply with demand. In buildings Phase Change Materials (PCMs) are increasingly being used to reduce the heating and cooling peak demand. Phase Change Slurries (PCSs) are heat transfer fluids, which consist of a latent heat component, a dispersed PCM, and a sensible heat component, a carrier fluid that provides fluidity. This combination of sensible and latent heat storage offers high heat storage capacity, while circumventing the low thermal conductivity problems associated with PCMs. The fluidity of PCSs enables pumping through pipes and the spatial separation of the heat transfer unit and storage tank. Thus PCS is an alternative to conventional single phase fluids. A new PCS was tested in a 5m3 storage tank pilot application. Material properties, such as melting range, viscosity, density, enthalpy and particle diameter have been determined by laboratory measurements. Experimental investigations were conducted in a pilot application, in order to allow an energetic comparison of the two heat storage fluids, water as reference medium and PCS. Depending on the operation temperature range the tested PCS can store more than twice as much heat compared to water as conventional heat transfer fluid. Due to the higher viscosity the required pumping energy for PCS is around five times higher as compared with water. © 2012 Elsevier Ltd.

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