Skip to content
University of Maryland LibrariesDigital Repository at the University of Maryland
    • Login
    View Item 
    •   DRUM
    • Theses and Dissertations from UMD
    • UMD Theses and Dissertations
    • View Item
    •   DRUM
    • Theses and Dissertations from UMD
    • UMD Theses and Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    EXPERIMENTAL EVALUATION OF A MULTIFUNTIONAL VARIABLE REFRIGERANT FLOW SYSTEM IN AN EDUCATIONAL OFFICE BUILDING

    Thumbnail
    View/Open
    Kwon_umd_0117N_14303.pdf (3.298Mb)
    No. of downloads: 1081

    Date
    2013
    Author
    Kwon, Laeun
    Advisor
    Hwang, Yunho
    Metadata
    Show full item record
    Abstract
    The top three end uses - space heating, space cooling, and water heating - accounted for close to 41 percent of site energy consumption in U.S. building primary energy consumption. Therefore, energy efficient heating, ventilating and air-conditioning (HVAC) systems in buildings is essential for energy savings in the building sectors. A multifunctional variable refrigerant flow (MFVRF) system is finding its way into residential and commercial buildings since it can simultaneously provide space cooling, space heating and hot water. The MFVRF system was installed in an educational office building and fully instrumented to measure the performance of the system under a wide range of outdoor weather conditions. The effects of a part-load ratio (PLR) on the daily performance factor (DPF) and total energy consumption were experimentally investigated in the field performance tests. Although the higher PLR represents a more effective cooling and/or heating the system, the DPF is not always increased with PLR because the system is optimized at a certain range of PLR. Furthermore, the effects of the hot water demand and the heat recovery operation modes on the performance of the system were investigated in a field test for the heating and shoulder seasons. Integrating the water heating functions into the heat recovery type variable refrigerant flow (HR-VRF) system, not only supplies hot water year-round, it also improves the system performance. As the hot water demand for the MFVRF system increased, the PLR was improved, which resulted in an increase system heating performance. In the heat recovery operation mode, the heat absorbed from the indoor units operating in the cooling mode was transferred to other indoor units operating in the heating mode. The DPF was 2.14 and 3.54 when the ratio of daily total cooling energy to daily total heating energy was 13.0% and 28.4%, respectively, at the similar outdoor weather conditions. This enhancement was attributed to the waste heat recovered during the heat recovery operation mode and the decrease in pressure ratio, which is a result of the improvement of the compressor efficiency. Energy saving potential of the MFVRF system in a building with high internal heat gains, resulted in a high cooling load for the cooling season and a low heating load for the heating season, was verified through the field performance test. The performance of the MFVRF system for the heating and shoulder seasons was improved by transferring the recovered energy to the indoor space and supplying the hot water.
    URI
    http://hdl.handle.net/1903/14305
    Collections
    • Mechanical Engineering Theses and Dissertations
    • UMD Theses and Dissertations

    DRUM is brought to you by the University of Maryland Libraries
    University of Maryland, College Park, MD 20742-7011 (301)314-1328.
    Please send us your comments.
    Web Accessibility
     

     

    Browse

    All of DRUMCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

    My Account

    LoginRegister
    Pages
    About DRUMAbout Download Statistics

    DRUM is brought to you by the University of Maryland Libraries
    University of Maryland, College Park, MD 20742-7011 (301)314-1328.
    Please send us your comments.
    Web Accessibility