The Experts below are selected from a list of 51 Experts worldwide ranked by ideXlab platform

Younghak Song - One of the best experts on this subject based on the ideXlab platform.

  • study on variation of Internal Heat Gain in office buildings by chronology
    Energies, 2018
    Co-Authors: Kyungsoon Park, Younghak Song
    Abstract:

    The additional process of load calculation during the retrofit of Heating, ventilation, and air conditioning (HVAC) equipment has been generally omitted in Korea, in recent years. Instead, a simple replacement of HVAC equipment, based on existing HVAC capacities, has been used, which is limited when taking the variation of Internal Heat Gain into consideration, due to changes in the consumption power due to light and office automation (OA) equipment in recent years. Thus, this study aimed to identify a change in Internal Heat Gains over 30 years, from 1985 to 2015, study investigated actual measurement-based academic papers and catalogs about OA equipment, lighting, and the number of occupants per unit area. The Heat load produced from OA equipment has increased by approximately 49.6% in 2015 compared to that of 1980, and the Heat load from lighting equipment has decreased by 47% compared to that of fluorescent-based lighting, and the Heat load from human bodies was approximately 10 W/m2 on average, which showed a minimal change over the past 30 years. The Internal Heat Gain calculated for 30,000 m2 of total floor area has increased constantly for the last 30 years. Note that the Internal Heat Gains were designed excessively, as the values used in literature was approximately 17% to 50% smaller than the value used normally in the case of pre-2000 designs, and the values used after 2000 were approximately 35% to 50% smaller than the design standard value.

Kyungsoon Park - One of the best experts on this subject based on the ideXlab platform.

  • study on variation of Internal Heat Gain in office buildings by chronology
    Energies, 2018
    Co-Authors: Kyungsoon Park, Younghak Song
    Abstract:

    The additional process of load calculation during the retrofit of Heating, ventilation, and air conditioning (HVAC) equipment has been generally omitted in Korea, in recent years. Instead, a simple replacement of HVAC equipment, based on existing HVAC capacities, has been used, which is limited when taking the variation of Internal Heat Gain into consideration, due to changes in the consumption power due to light and office automation (OA) equipment in recent years. Thus, this study aimed to identify a change in Internal Heat Gains over 30 years, from 1985 to 2015, study investigated actual measurement-based academic papers and catalogs about OA equipment, lighting, and the number of occupants per unit area. The Heat load produced from OA equipment has increased by approximately 49.6% in 2015 compared to that of 1980, and the Heat load from lighting equipment has decreased by 47% compared to that of fluorescent-based lighting, and the Heat load from human bodies was approximately 10 W/m2 on average, which showed a minimal change over the past 30 years. The Internal Heat Gain calculated for 30,000 m2 of total floor area has increased constantly for the last 30 years. Note that the Internal Heat Gains were designed excessively, as the values used in literature was approximately 17% to 50% smaller than the value used normally in the case of pre-2000 designs, and the values used after 2000 were approximately 35% to 50% smaller than the design standard value.

Lotha Wondraczek - One of the best experts on this subject based on the ideXlab platform.

  • Performance Analysis of Multi-Purpose Fluidic Windows Based on Structured Glass-Glass Laminates in a Triple Glazing
    Frontiers Media S.A., 2019
    Co-Authors: Mathias Fraaß, Matthias Kloas, Lotha Wondraczek
    Abstract:

    For decades, various technologies have been developed aiming to enhance the energy efficiency of buildings. As a recent example, fluidic windows have been reported which literally enable to wrap buildings into a liquid layer and to transform the building envelope into a thermally active system for energy harvesting, distribution and storage. Elaborating on this concept, we now consider the performance of insulation glass units (IGU) which implement glass-glass capillary panels for liquid circulation. Such devices contain a scalable Heat pump that can reversely be operated in active cooling or Heating modes. By bridging the insulation panel inside the window, also passive cooling functionality is achieved. Long-term computational performance analysis shows that adequate thermal comfort can be ensured with different window-to-floor size ratios, and for different Internal Heat Gain, for example, caused by differences in room occupation. For a size ratio of 0.4, we demonstrate a competitive seasonal performance factor, i.e., ~6.5 for Heating and ~10.9 for cooling. On-device photovoltaic power can cover more than four fifths or the annual electricity consumption of all auxiliary components. For the size ratio of 0.4 in a highly-occupied office room, the device specific primary energy consumption ensuring year-over thermal comfort is as low as ~2.9 kWh/(m2a)

Malcolm Mcculloch - One of the best experts on this subject based on the ideXlab platform.

  • a high resolution model of residential Internal Heat Gain the subtle interdependencies among residential end uses
    IEEE Innovative Smart Grid Technologies-Asia, 2015
    Co-Authors: Merkebu Degefa, Matti Lehtone, K J Nixo, Malcolm Mcculloch
    Abstract:

    In principle, all electricity used in a house eventually ends up as Heat. Based on the quantity and the usefulness of supplied Heat energy, an appliance can be qualified as source of Internal Heat Gain. Although the Internal Heat Gain sources are well understood, there is little research into quantifying the gross household Internal Heat Gain with respect to high resolution time series data at per-minute intervals. Moreover, the impact of demand response (DR) programs in building Heat energy demand dynamics has not been investigated fully. Through the combined utilization of engineering and statistical methods based on high-resolution appliance level household load models, we were able to reveal the underlying dependencies between Internal Heat Gain sources. The results show Internal Heat Gain amounts between 5% and 7% from the daily Heating energy demand in typical single-family detached households on a cold winter day. In addition, the practice of DR programs on the non-Heating loads affect the household environment by flattening the indoor temperature to a steady value and by reducing the frequency of bang-bang switching of direct electric Heaters.

Yang Xinya - One of the best experts on this subject based on the ideXlab platform.

  • The impact of building operations on urban Heat/cool islands under urban densification: a comparison between naturally-ventilated and air-conditioned buildings
    'Elsevier BV', 2019
    Co-Authors: Dua Shuangping, Luo Zhiwe, Li Yuguo, Yang Xinya
    Abstract:

    Many cities are suffering the effects of urban Heat islands (UHI) or urban cool islands (UCI) due to rapid urban expansion and numerous infrastructure developments. This paper presents a lumped urban-building thermal coupling model which captures the fundamental physical mechanism for thermal interactions between buildings and their urban environment. The benefits of the model are its simplicity and high computational efficiency for practical use in investigating the diurnal urban air temperature change and its asymmetry in a city with both naturally-ventilated (NV) and air-conditioned (AC) buildings. Our model predicts a lower urban Heat island and higher urban cool island intensity in a city with naturally-ventilated buildings than for a city with air-conditioned buildings. During the urban densification (from a low-rise, low-density city to a high-rise, high-density one), the increases in the time constant and Internal Heat Gain give rise to asymmetric warming phenomena, which become more obvious in a city with air-conditioned buildings rather than naturally-ventilated ones. Unlike previous studies, we found that a low-rise, low-density city experiences a stronger urban cool island effect than a high-rise, high-density city due to less Heat being emitted into the urban atmosphere. The urban cool/Heat island effect will firstly increase/decrease, and then rapidly decrease/increase and ultimately disappear/dominate with increasing time constant in the process of urbanization/urban densification