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This paper investigates the possibility of using a dry fluid cooler with advanced control strategies in a vertical closed-loop GSHP system to reduce the borehole size with the intention of increasing the cost-effectiveness of the system without compromising system efficiency. The developed system is expected to be a game changer in the residential sector of the USA involving the use of high-efficiency heat pump systems as a substitute for conventional systems for space cooling and heating in hot/warm climates. The simulation results show that (1) the use of a dry fluid cooler with advanced control strategies in a GSHP system contributes to increasing or maintaining the GSHP system’s efficiency in the long run by balancing the heating and cooling through charging thermal energy to the ground in hot climates; (2) the concept of integrating a dry fluid cooler into a GSHP system with advanced control strategies is proven to be effective for the studied house located in hot climates, such as Miami. In comparison to a conventional GSHP system, the initial system costs can be reduced by up to around 14% by shortening the borehole length without compromising system efficiency because of the use of a dry fluid cooler.

The need to conduct complex operations over time results in U.S. forces remaining in deployed locations for long periods. In such cases, more sustainable facilities are required to better accommodate and protect forward deployed forces. Current efforts to develop safer, more sustainable operating facilities for contingency bases involve construction activities that redesign the types and characteris-tics of the structures constructed, reduce the resources required to build, and reduce resources needed to operate and maintain the com-pleted facilities. The Automated Construction of Expeditionary Structures (ACES) project was undertaken to develop the capability to “print” custom-designed expeditionary structures on demand, in the field, using locally available materials with the minimum number of personnel. This work investigated large-scale automated “additive construction” (i.e., 3D printing with concrete) for construction applications. This document, which documents ACES energy and modeling, is one of four technical reports, each of which details a major area of the ACES research project, its research processes, and associated results, including: System Requirements, Construction, and Performance; Energy and Modeling; Materials and Testing; Architectural and Structural Analysis.

International audience

This paper reports the results of thermal comfort and indoor air quality measurements aboard aircraft from 43 flights on commercial airlines with a duration of more than 1 h. The measurements were performed contin uously during the whole flight (from the departure gate to the arrival gate), and the parameters monitored were temperature, relative humidity and carbon dioxide con centration. The results were then compared with the ASHRAE Standards for the thermal comfort (ASHRAE Standard 55-92) and indoor air quality (ASHRAE Stan dard 62-89). The evaluation of the indoor air quality was based mainly upon comparison of the carbon dioxide concentrations measured with standards and recom mendations for the indoor environment. Overall, the lev els of relative humidity were far lower than the limit set by the ASHRAE Standard 55-92. The levels of carbon dioxide on most flights were higher than that recom mended by the ASHRAE Standard 62-89. The results of this study, mainly the low level of humidity and high con centrations of carbon dioxide, led us to expect that the crew and the passengers would have been dissatisfied with their degree of thermal comfort and the quality of the air in the cabin. This conclusion is based simply on a comparison of our measurements with the values stated in the ASHRAE Standards. However, we must bear in mind that these were developed for an indoor environ ment at atmospheric pressure. More research is needed to study the validity of these standards for sub-atmo spheric conditions.

International audience; The amount of energy used to heat and cool buildings is a significant concern that impacts on issues from national policies to personal desires of cost and comfort. The key to achieving optimum performance is the control of the energy flows in the building and its environment. Such control is secured through monitoring and altering the driving sources to maintain the desired thermal and air quality conditions in a space while external and internal conditions (e.g. seasonal climate, indoor heat gains, pollutants etc.) change over time. Thermal modelling tools are essential for the energy efficient design of buildings and their associated control systems. They are used for a wide range of tasks including policy making, cost analysis and comfort evaluation. This paper reviews the evolution of zonal airflow and thermal models, principally for single room analysis, used to design and control heating and cooling in the built environment. Insight is offered into the problems of modelling building energy flows and the results of various models are compared with experimental measurement. Finally, current state-of-the-art modelling is reviewed with emphasis on the development of models that designers and engineers can use to obtain a more accurate evaluation of building energy flows.