Performance Analysis of Multi-Purpose Fluidic Windows Based on Structured Glass-Glass Laminates in a Triple Glazing

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/(m 2 a).

Nanofluid Based on Glucose‐Derived Carbon Dots Functionalized with [Bmim]Cl for the Next Generation of Smart Windows

“…[29] The channels can be incorporated into the building infrastructure (e.g., walls, ceilings, and floors), thereby transforming them into thermally active components. [30] The windows are basically low cost, switchable, ultrathin SP devices (SPDs) suitable for large-area integration with smart façades. The circulating fluid incorporates magnetic nanoparticles enabling active shading and solar-thermal energy harvesting.…”

Design Guidelines for Thermal Comfort and Energy Consumption of Triple Glazed Fluidic Windows on Building Level

“…[ 17,32 ] It had been detailed described in the previous report. [ 13 ] In this study, the heat capacity of the glass was neglected. This assumption was acceptable, since the time constant of the glass façade was very small compared to it of the wall and ceiling.…”

“…[ 11,12 ] Compared to conventional all‐air‐based systems, the fluidic window device operates at a lower temperature difference between the circulating fluid and the target space for air‐conditioning, thus, higher energy efficiency can be achieved when using with a heat pump. [ 13 ] Moreover, if combined with a ventilation system, the ventilation system only needs to meet the air‐exchange rate requirements and a lower air flow rate is required. Consequently, the draught rate can be reduced, and a higher thermal comfort is expected.…”

“…We previously considered the functionality of such devices as a decentral heat pump, whereby auxiliary photovoltaic energy harvesting was used for driving a heat pump operating between two capillary devices facing indoors and outdoors, respectively. [ 13 ] It was demonstrated that such a system's efficiency strongly depends on the window‐to‐floor ratio of a given model room, reaching competitive performance at a value of about 0.4. However, when implemented in a more straightforward way as a triple glazing on building level with only a single capillary pane (Figure 1, denoted use‐case (B) in Ref.…”

“…However, when implemented in a more straightforward way as a triple glazing on building level with only a single capillary pane (Figure 1, denoted use‐case (B) in Ref. [ 13 ]), it remained unclear how the building's glazing area affects the device energy performance. On one hand, larger glazing area requires lower temperature difference and improves the system efficiency.…”