The Experts below are selected from a list of 132 Experts worldwide ranked by ideXlab platform

Soteris A. Kalogirou - One of the best experts on this subject based on the ideXlab platform.

  • Chapter 6 – Solar Space Heating and Cooling
    Solar Energy Engineering, 2020
    Co-Authors: Soteris A. Kalogirou
    Abstract:

    Chapter 6 deals with solar space heating and cooling systems. Initially, methods to estimate the thermal load of buildings are given, including the heat balance method, the transfer function method, heat extraction rate and room temperature, the simple degree-day method, and the building heat transfer. Then some general features of passive space design are presented followed by the active systems design. Passive systems include building construction-thermal mass effects, incidental thermal mass effects, intentional thermal mass effects, characteristics and performance of thermal storage walls, building shape and orientation, insulation, windows, sunspaces, overhangs, and natural ventilation. Active systems include both Water-based and air-based space heating and cooling systems and comprise space heating and Service Hot Water, considerations concerning the location of auxiliary and heat pump systems. The solar cooling systems described in this chapter include both adsorption and absorption systems. The latter comprise the lithium bromide–Water and ammonia–Water systems. Finally, the characteristics for solar cooling with absorption refrigeration systems are given.

  • Chapter 6 - Solar Space Heating and Cooling
    Solar Energy Engineering (Second Edition), 2014
    Co-Authors: Soteris A. Kalogirou
    Abstract:

    Abstract Chapter 6 deals with solar space heating and cooling systems. Initially, methods to estimate the thermal load of buildings are given, including the heat balance method, the transfer function method, heat extraction rate and room temperature, the simple degree-day method, and the building heat transfer. Then some general features of passive space design are presented followed by the active systems design. Passive systems include building construction-thermal mass effects, incidental thermal mass effects, intentional thermal mass effects, characteristics and performance of thermal storage walls, building shape and orientation, insulation, windows, sunspaces, overhangs, and natural ventilation. Active systems include both Water-based and air-based space heating and cooling systems and comprise space heating and Service Hot Water, considerations concerning the location of auxiliary and heat pump systems. The solar cooling systems described in this chapter include both adsorption and absorption systems. The latter comprise the lithium bromide–Water and ammonia–Water systems. Finally, the characteristics for solar cooling with absorption refrigeration systems are given.

  • solar space heating and cooling systems
    Comprehensive Renewable Energy, 2012
    Co-Authors: Soteris A. Kalogirou, Georgios A Florides
    Abstract:

    This chapter examines solar space heating and cooling systems. Initially, the basic system configurations are presented which include active solar systems in which direct circulation systems, indirect Water-heating systems, and air Water-heating systems are presented; space heating and Service Hot Water systems which include air and Water systems, issues concerning the location of auxiliary and heat pump systems; and solar cooling, which includes adsorption units, absorption units, lithium--Water absorption systems, ammonia--Water absorption systems, and solar cooling with absorption refrigeration. Subsequently, heat storage systems are examined which include air and liquid systems thermal storage. Finally, details of various aspects of system design are presented which include module and array design, heat exchangers, and differential temperature controllers.

  • solar space heating and cooling
    Solar Energy Engineering#R##N#Processes and Systems, 2009
    Co-Authors: Soteris A. Kalogirou
    Abstract:

    Chapter 6 deals with solar space heating and cooling systems. Initially, methods to estimate the thermal load of buildings are given, including the heat balance method, the transfer function method, heat extraction rate and room temperature, the simple degree-day method, and the building heat transfer. Then some general features of passive space design are presented followed by the active systems design. Passive systems include building construction-thermal mass effects, incidental thermal mass effects, intentional thermal mass effects, characteristics and performance of thermal storage walls, building shape and orientation, insulation, windows, sunspaces, overhangs, and natural ventilation. Active systems include both Water-based and air-based space heating and cooling systems and comprise space heating and Service Hot Water, considerations concerning the location of auxiliary and heat pump systems. The solar cooling systems described in this chapter include both adsorption and absorption systems. The latter comprise the lithium bromide–Water and ammonia–Water systems. Finally, the characteristics for solar cooling with absorption refrigeration systems are given.

  • Solar thermal collectors and applications
    Progress in Energy and Combustion Science, 2004
    Co-Authors: Soteris A. Kalogirou
    Abstract:

    In this paper a survey of the various types of solar thermal collectors and applications is presented. Initially, an analysis of the environmental problems related to the use of conventional sources of energy is presented and the benefits offered by renewable energy systems are outlined. A historical introduction into the uses of solar energy is attempted followed by a description of the various types of collectors including flat-plate, compound parabolic, evacuated tube, parabolic trough, Fresnel lens, parabolic dish and heliostat field collectors. This is followed by an optical, thermal and thermodynamic analysis of the collectors and a description of the methods used to evaluate their performance. Typical applications of the various types of collectors are presented in order to show to the reader the extent of their applicability. These include solar Water heating, which comprise thermosyphon, integrated collector storage, direct and indirect systems and air systems, space heating and cooling, which comprise, space heating and Service Hot Water, air and Water systems and heat pumps, refrigeration, industrial process heat, which comprise air and Water systems and steam generation systems, desalination, thermal power systems, which comprise the parabolic trough, power tower and dish systems, solar furnaces, and chemistry applications. As can be seen solar energy systems can be used for a wide range of applications and provide significant benefits, therefore, they should be used whenever possible. © 2004 Elsevier Ltd. All rights reserved.

Shiming Deng - One of the best experts on this subject based on the ideXlab platform.

  • A method for evaluating the heat and mass transfer characteristics in a reversibly used Water cooling tower (RUWCT) for heat recovery
    International Journal of Refrigeration-revue Internationale Du Froid, 2002
    Co-Authors: Shiming Deng
    Abstract:

    Abstract In sub-tropical regions, a standard Water cooling tower may be reversibly used, as part of a desuperheater heat recovery system for Service Hot Water heating, to extract free heat from ambient air in colder seasons when building cooling load is reduced. Chilled Water is pumped into a reversibly used Water cooling tower (RUWCT) where it is heated by warmer ambient moist air. This paper presents a method by which the heat and mass transfer characteristics in a counter-flow RUWCT can be evaluated. The method is developed by introducing to the Merkel's equation for standard Water cooling towers the revisions that account for the differences in heat and mass transfer characteristics between a Water cooling tower and a RUWCT. Field experimental results from a RUWCT installed in a sub-tropical region in China indicated that the method developed could be used to evaluate the thermal performance of a RUWCT with an acceptable accuracy.

  • a simulation study on a Water chiller complete with a desuperheater and a reversibly used Water cooling tower ruwct for Service Hot Water generation
    Building and Environment, 2002
    Co-Authors: Shiming Deng
    Abstract:

    Abstract In sub-tropical regions, a standard Water cooling tower may be reversibly used, as part of a desuperheater heat recovery system for Service Hot Water heating, to extract free heat from ambient air in colder seasons when building cooling load is reduced. Part of chilled Water is pumped into a RUWCT where it is heated by warmer ambient moist air. This paper presents a simulation study where a steady-state mathematical model for such a desuperheater heat recovery system complete with a RUWCT has been developed. Simulation results based on the specifications of an actual chiller plant have demonstrated that the model developed is stable and behaves as expected. With the model developed, the operating characteristics of the refrigeration system with a desuperheater and a RUWCT were studied. The required flow rate of chilled Water to be pumped into the RUWCT was calculated in order to satisfy a certain heat load. The maximum heating capacity of the system under different operating conditions were also evaluated. The simulation results also indicated that the use of a RUWCT would achieve a higher energy efficiency than the use of electrical heating as backup heat provisions when building space cooling load is reduced.

  • A numerical analysis of heat and mass transfer inside a reversibly used Water cooling tower
    Building and Environment, 2002
    Co-Authors: Shiming Deng
    Abstract:

    Abstract In subtropical regions, a desuperheater heat recovery system for Service Hot-Water heating can be applied. However, in colder seasons when building cooling load is reduced, a standard Water-cooling tower may be reversibly used to extract free heat from ambient air to make up the reduction of heat source for Water heating. Previous related work included developing an analytical method for evaluating the heat and mass transfer characteristics in a reversibly used Water-cooling tower (RUWCT), which cannot be used to determine the air and Water states at any intermediate horizontal sections along the tower height within an RUWCT. This paper presents a detailed numerical analysis by which the air and Water states at any horizontal plane along the tower height within an RUWCT can be determined. The numerical analysis has been partially validated using the experimental data from an installed RUWCT in a Hotel building in southern China. The numerical analysis reported in this paper, together with the Analytical Method previously developed, provides a complete method for the analysis of heat and mass transfer characteristics within and at the boundaries of an RUWCT.

  • air cooled heat pump with desuperheater retrofit for year round Service Hot Water supply
    Building Services Engineering Research and Technology, 1998
    Co-Authors: Shiming Deng, Ziyan Song
    Abstract:

    In a case study project an air-cooled heat pump unit was retrofitted with a desuperheater to provide Service Hot Water in addition to chilled Water for comfort space cooling in a 24-room holiday villa located in a subtropical region. The retrofit project is described, and system operating performance and energy efficiency are reported. A standard cooling tower was used to extract free heat from ambient air in transitional seasons, thus eliminating the need for electric back-up heating for Service Hot Water.

Georgios A Florides - One of the best experts on this subject based on the ideXlab platform.

  • solar space heating and cooling systems
    Comprehensive Renewable Energy, 2012
    Co-Authors: Soteris A. Kalogirou, Georgios A Florides
    Abstract:

    This chapter examines solar space heating and cooling systems. Initially, the basic system configurations are presented which include active solar systems in which direct circulation systems, indirect Water-heating systems, and air Water-heating systems are presented; space heating and Service Hot Water systems which include air and Water systems, issues concerning the location of auxiliary and heat pump systems; and solar cooling, which includes adsorption units, absorption units, lithium--Water absorption systems, ammonia--Water absorption systems, and solar cooling with absorption refrigeration. Subsequently, heat storage systems are examined which include air and liquid systems thermal storage. Finally, details of various aspects of system design are presented which include module and array design, heat exchangers, and differential temperature controllers.

Noam Lior - One of the best experts on this subject based on the ideXlab platform.

  • A comparative economic analysis of straight-through and recirculation solar Hot Water systems
    Energy, 2003
    Co-Authors: Gary Geoghegan, Noam Lior
    Abstract:

    A thermal and life cycle analysis was conducted to compare two types of solar Service Hot Water systems: 1.(1) the straight-through system with the Water driven by the pressure of the mains through a heat exchanger in which it is heated by the warmer Water in the solar-thermal storage tank, whenever demand for Service Hot Water is created, and2.(2) the recirculation system in which a temperature-difference-controlled recirculation loop is used between the solar-thermal storage tank and the auxiliary (or backup) Service Hot Water tank. The latter configuration which needs to have these additional components (controller, pump, and piping) and may thus also be less reliable, is more frequently used when the solar system is to supply both space heat and Service Hot Water, because it is generally though to provide a larger fraction of the Hot Water from the solar source.

William D. Chvala - One of the best experts on this subject based on the ideXlab platform.