Test Cell Facility Research Articles

Outdoor test facilities for the experimental performance evaluation of construction materials and systems: The BeTOP case

Proposing new materials and systems to improve the performance and energy efficiency of buildings is often followed by performance evaluation to monitor how they perform and contribute. Experimental performance characterization of new and existing building materials and systems is crucial to understanding their behaviour in relation to indoor environmental and conditional changes, in addition to outdoor environmental changes. Full-scale experimental test cell facilities have been at the forefront of experimental performance evaluation in building-related research, as they can provide a realistic representation of buildings, which includes environmental conditions, building structure, and operational characteristics. In this paper, the new test cell facility of BeTOP, located in the city of Toronto, Ontario, is introduced as a full-scale experimental facility with the capability of multiple practical tests simultaneously. This paper describes the characteristics of this test cell, including structure details, testing capabilities, system details, previous testing campaigns, and future testing potential. The design of such a full-scale testing facility is shown to be crucial in a continental climate, such as Toronto, to observe the long-term performance of new systems under variable boundary conditions with cold winters and hot and humid summer seasons.

The BeTOP facility for performance testing of building systems

Proposing new materials and systems to improve buildings' performance and energy efficiency often requires testing their performance in the field. Experimental performance characterization of new and existing building systems is crucial to understanding their behaviour. Full-scale experimental test cell facilities have been at the forefront of experimental performance evaluation in building-related research, as they provide a realistic representation of buildings, including environmental conditions, assembling challenges, and operational characteristics. In this paper, trends in the design and construction of outdoor testing facilities are first discussed. Then, based on the current literature and the knowledge gained through visits to multiple facilities, the new test cell facility “BeTOP”, located in Toronto (Ontario), is described. BeTOP is a full-scale experimental facility with the capacity to perform multiple experimental tests simultaneously. This paper describes its characteristics, including structure details, testing capabilities, system details, current monitoring campaigns, and future testing potential. The paper concludes by showing that the design of a full-scale testing facility is crucial to observe the long-term performance of new systems under variable boundary conditions in a continental climate with cold winters and hot and humid summers.

Experimental performance evaluation of a climate-responsive ventilated building façade

Enhancing building energy performance has become a focal point in reducing the environmental impacts of buildings to address climate change. Considering the high share of comfort-related energy use in buildings, and the importance of indoor environmental quality (IEQ), a balance between energy conservation and IEQ provision is required. Building façades are the primary boundary controlling mass and energy flow to and from buildings. Dynamic and climate-responsive façades are potential improvements to existing high-performance façades to enhance IEQ in buildings, as they change their functionality with time, in response to changing environmental loads. A multifunctional, integrated, climate-responsive, opaque, and ventilated building façade (MICRO-V) was designed to regulate the flow of heat, air, and moisture into buildings. The MICRO-V façade has a novel design to pre-condition the fresh air and regulate thermal loads in buildings on a daily and seasonal basis. The multiple components of this façade include phase change materials (PCMs), a bi-directional ventilation module and an adjustable insulation system. In this paper, the thermal performance of this façade was evaluated using long-term experimental tests. The real-scale prototype of the façade was constructed and installed in the full-scale BETOP test cell facility in Toronto, Canada. The results of different tests showed how the façade could pre-condition the fresh air acting as a decentralized ventilation module due to a high heat recovery efficiency of 81%. However, it was also shown that the significant impact of solar irradiance, which requires constant adjustment to the operation schedule of the ventilation fans in the façade.

Loss of Liquid Lithium Coolant in an Accident in a DONES Test Cell Facility

A Demo-Oriented early NEutron Source (DONES) facility for material irradiation with nuclear is currently being designed. DONES aims to produce neutrons with fusion-relevant spectrum and fluence by means of D–Li stripping reactions occurring between a deuteron beam impacting a stable liquid lithium flowing film implementing the target. Given the hazard constituted by the liquid lithium inventory and the potential risk of reactions with water, air, and concrete eventually resulting in fire events, the Target Test Cell (TTC) is filled with helium and the reinforced concrete walls forming the bio-shield are covered with steel liners. A loss of Li in TTC, due to a large break in the Quench Tank, is postulated, and consequences are deterministically studied. With the TTC liner being water-cooled, the impact of the liner temperature rise following a leakage event is evaluated. Two separate MELCOR code models have been defined for the liquid lithium loop and water-cooled loop and are numerically coupled. The amount of leaked inventory dependent on the implemented safety logic and impact on TTC containment is evaluated. The water pressurization pattern within the liner cooling loop is studied to highlight possible risks of lithium–water/concrete reactions.

Studies on how to counteract overheating caused by sun patch exposure in ventilated highly glazed spaces heated by floor heating systems

Enhancing the glazing areas in buildings could save energy by increasing solar gain and thus decreasing the demand for heating and artificial lighting during the cold season. However, relatively large glazed buildings often cause thermal discomfort to occupants due to the midseason heating, especially in the case of inertial heating systems. This study was conducted to examine the impact of direct solar radiation on the dynamic thermal behavior of a floor heating system. A series of experiments were conducted on a monitored full-scale controlled test cell facility simulating a dynamic sun patch on a radiant heating slab. A previously published bi-dimensional dynamic model based on the finite difference method was extended and validated to consider the additional heat flux brought by the sun patch. The findings show that the overheating time induced by the sun patch exposure was approximately 8.5 h after the disappearance of the solar patch. The average heating floor surface temperature attained 33.91 °C, whereas the indoor air temperature reached 26 °C. The conducted numerical parametric study revealed that when the sun patch occurs, ventilation remarkably decreases the indoor air temperature but keeps the average surface temperature almost unchanged and primarily over the standard upper limits. In contrast, water-based cooling technique appeared to be efficient under sun patch exposure since the average surface temperature and indoor air temperature can be decreased and maintained under acceptable limits in the average comfort zone.

Thermal mass and the effects on heating and cooling demands – an experimental study of an exposed concrete floor

The increase of thermal mass in buildings is discussed as a useful measure for reducing the energy demand for heating and cooling while contributing to improve the internal comfort. Several studies confirmed its positive effect, but few conducted a solid comparative measurement campaign and rarely in comparative conditions. The present work reports the results of an extensive comparative campaign in a test cell facility, where the internal conditions are measured in two identical rooms. One of the rooms was equipped with a large concrete mass while the other was constructed with a thin wooden floor. Measurements were conducted for circa a month, divided in four phases. The internal temperature of the two rooms was kept within typical boundaries of actual office rooms by a water-based cooling and heating systems. The energy demand of both heating and cooling was measured. Occupancy was simulated by a mannequin and by the lighting, both active only in office hours. The results demonstrated a positive impact of the thermal mass on the energy use. Since the test rooms are highly insulated, the energy use associated to cooling was dominant. During the experimental campaign, a reduction of up to 44% of the energy demand due to cooling was registered.

Power performance analysis of a transparent DSSC BIPV window based on 2 year measurement data in a full-scale mock-up

Among transparent solar cells or modules, the DSSC (Dye-sensitized solar cell) has a relatively low production cost compared to silicon-based solar cells and provides a range of colors for building design. On the other hand, its commercialization has been limited by the low power generation efficiency and durability. Few studies have examined the power generation performance of a full scale DSSC module applied to actual buildings. In this study, a long-term performance test was conducted on vertical and inclined DSSC BIPV (Building Integrated Photovoltaic) windows applied to a full-scale mock-up facility to verify the power performance and power characteristics of transparent DSSC BIPV glazing under actual conditions over a 2 year period.The DSSC module was fabricated by the serial connection of nine 2.26Wp transparent DSSC sub-modules. The multi-layered DSSC BIPV glazing, which was composed of a “DSSC module (9mm)” + “air space (12 mm)” + “clear glass (5mm)” was joined to the curtain wall frame of the test cell facility.The unit size of the DSSC BIPV glazing was 0.975 m (W) × 0.965 m (H) and its maximum capacity was 20.34Wp. The size of the test cell facility was 3 m (W) × 3 m (H) × 9 m (D). The building is a container type insulated with 100 mm urethane foam. Four and two DSSC BIPV windows were installed on the vertical south wall and on the 30° sloped roof, respectively. Through the monitoring system, the power performance data of each DSSC BIPV windows and meteorological data were analyzed over a two year period (from 1st Jan. 2015 to 31st Dec. 2016).The 2 year data showed that the average daily power yield for each month of the vertical DSSC BIPV window ranged from 1.75 to 3.93 kWh/kWp·day (average 2.53 kWh/kWp·day), whereas that of the 30° sloped DSSC BIPV window ranged from 2.16 to 5.34 kWh/kWp·day (average 3.60 kWh/kWp·day).The operating power efficiency of the vertical DSSC BIPV window ranged from 2.65 to 4.14% with an average of 3.40%, whereas that of the sloped DSSC BIPV window was in the range of 2.64–3.63% with a mean of 3.01%. The power generation efficiency of the vertical plane BIPV window was higher than the sloped BIPV window. In contrast to the average daily power yield, the power efficiency of the vertical window was higher than that of the sloped window, which may be due to the higher efficiency of the DSSCs under overcast conditions. This is consistent with the power performance of the DSSC BIPV windows according to the sky conditions, which showed an increase in power efficiency with increasing cloud cover or decreasing solar intensity.

Activity inventories and decay heat generation of the Test Cell facility of IFMIF-DONES

This paper presents the analyses performed within the ENS (Early Neutron Source) project of EUROfusion/PPPT for providing up-to-date estimates of the activity inventories and the decay heat generation in the DONES TC facility. To this end, a series of coupled McDeLicious transport and FISPACT inventory calculations were performed using the 2016 DONES TC model and nuclear cross-section data from the FENDL-3.1 data library. Activity inventories and decay heat data were assessed for the HFTM assembly, consisting pre-dominantly of the low activation steel Eurofer, the TC cell liner, made of SS-316, the TC walls built of heavy concrete and the water pipes assumed for cooling the walls. The paper discusses the results obtained for the activity and the decay heat as a function of the decay time after radiation and also addresses the issue of the radiation dose loads which are to be expected due to the activated components/systems including the cooling water system.

Empirical and comparative validation of an original model to simulate the thermal behaviour of outdoor test cells

Calorimetric methods for the performance assessment (e.g. for the determination of the solar factor) of transparent building components have been largely applied in indoor laboratories under steady-state conditions and in outdoor test cells under dynamic boundary conditions provided by real weather. In the latter case the accuracy of the measurements depends significantly on the temporary storage of energy in the test cell envelope. An analysis by Pagliano et al. (2017) developed a dedicated lumped thermal model in Matlab environment in order to improve the design of calorimeters for the measurement of the solar factor by minimizing the energy storage effects in the envelope of the calorimeter and estimating precisely their entity. The developed model was based on literature studies on buildings’ dynamic energy simulations and adopted some common hypotheses used by existing building energy simulation software tools. However, when modelling light-mass and highly insulated buildings, such as test cell facilities, small variations in the power inputs can generate significant variations of the internal temperatures, challenging for the model to follow accurately. In order to verify the accuracy of the developed model in predicting the thermal behaviour of an outdoor test cell, an extensive validation work has been carried out. In particular, this paper summarises (i) an experimental validation carried out using a data set from the BESTLab facility, located at the research centre Électricité de France R&D Les Renardières (FR) and (ii) an intermodel comparison between the code developed in the Matlab environment and TRNSYS, a well-established building energy simulation tool.Concerning the validation at the BESTLab, the results show that the model is able to predict the temperature evolution of the internal air and of the internal surfaces of the envelope with good accuracy, with residuals lying within a range of ± 1°C; reasons for discrepancies between measurements and predictions are discussed in the paper. As regards the intermodel comparison, the correspondence between the two software tools is generally good, with residuals lying most of the time within a range of ± 0.5 °C. The residuals are lower for the intermodel comparison, partly because input values are in this case not affected by uncertainty. Although TRNSYS and the developed Matlab code adopt some similar assumptions and simplifications, they also present some modelling differences that are highlighted in the paper.

Improved methods for the calorimetric determination of the solar factor in outdoor test cell facilities

Calorimetric methods for the performance assessment of building components have been largely applied in indoor laboratories and under steady-state conditions. Although effects of one or more outdoor weather parameters are sometimes mimicked by means of dynamic schedules, they never fully reproduce the complex interactions of the stochastic processes typical of real climate.The present work introduces improved measurement procedures to determine the solar factor under dynamic conditions, applicable to outdoor test cell experiments and which take into account the variation of internal energy in the control volume. An in-depth uncertainty analysis has been conducted in order to highlight the most relevant uncertainty sources and to suggest improvements to the measurement techniques.Based on an iterative application of the uncertainty analysis, we developed and optimised two new strategies to extract and measure the solar load entering through a test sample and a new design concept of test cell facility, which allows the configuration to be adapted according to various test objectives. In order to accurately analyse the storage and delay effects of the thermal capacities within the control volume of the calorimeter, lumped-parameter models of three alternative designs (the two proposed strategies and a reference, traditional one) have been developed and coded in Matlab.The simulation results suggest that, compared to a traditional solution, the two proposed solutions offer a higher measurement accuracy and measurement precision in the determination of the solar factor. In addition, the results indicate that rapidly variable solar irradiance levels are detrimental to the accuracy level of the solar factor measurement; therefore tests should be carried out under stable clear sky conditions.

Responsive glazing systems: Characterisation methods and winter performance

Responsive envelope components are promising technologies for improving the energy and indoor comfort performance of buildings. As far as the transparent envelope is concerned, several experimental and numerical researches have been carried out in recent years, focusing on the integration of Phase Change Materials (PCM) in glazing systems. To overcome some limitations highlighted during previous experimental campaigns, a new concept was prototyped, and the energy and comfort performance of a full-scale prototype was experimentally assessed in an outdoor test cell facility. In this paper, the focus is placed on the evaluation of the cold-season behaviour. The proposed glazing system comprises a triple-glazed unit with a PCM-filled cavity and a thermotropic glass placed on the outer side. The thermotropic glass acted as a switchable shading system capable of regulating the phase transition of the PCM by modulating the amount of solar radiation impinging on the PCM layer. The thermophysical and optical behaviour of the technology was monitored with the PCM alternately placed in the inner or the outer cavity of the triple-glazed unit and compared against a reference triple-glazing unit. In parallel to the measurements on the glazing with PCM and thermotropic glass, a triple-glazed unit equipped with a thermotropic glass was also monitored, giving a total of three different glazing systems under analysis. Representative days were selected in order to analyse the performance of the proposed technologies under significant and comparable boundary conditions. The equivalent thermal conductance of each technology was evaluated. The energy performance was assessed by means of both a long-term analysis and daily analyses on cloudy and sunny days. In addition, the visible transmittance of the three technologies was estimated through hourly measurements of vertical illuminance performed during a cloudy and a sunny day. Moreover, implications on thermal comfort conditions were evaluated ex-post by means of numerical simulations based on experimental data. The results showed that, during cloudy winter days, the position of the PCM did not influence the overall performance of the prototype since it never changed phase. On the other hand, during sunny winter days, the glazing with the PCM in the outer position underwent phase transition and presented a slightly better performance.

Experimental Analysis of an External Dynamic Solar Shading Integrating PCMs: First Results

This paper presents the first results of an experimental analysis on dynamic translucent solar shadings with PCM, aimed at demonstrating its potential on reducing internal solar heat gains. The study is focused on the assessment of the thermal performance of the prototype panel during the solid phase of the PCM through an experimental campaign in a test cell facility. The total daily solar heat gains were reduced by more than 50% compared to the non-shaded reference triple glazing unit and the internal surface temperature of the glazing decreased of more than 6°C during the maximum external incident solar radiation.

Neutronic analysis for the IFMIF EVEDA reference test cell and test facility

The IFMIF test cell (TC) design has been further developed and optimized in the EVEDA phase, and finally the reference TC design has been proposed. In order to carry out the detailed neutronic analysis for the reference TC design, a very detailed geometrical model for Monte Carlo neutronic calculations has been prepared directly from engineering CAD data by utilizing the McCad conversion software developed at KIT. The geometrical model includes the detailed descriptions of the lithium target system proposed by Japan, all test modules based on the EVEDA phase design, and the 3-dimesional arrangement of the biological shielding. The Monte Carlo code McDeLicious, which is an enhancement to MCNP5, has been utilized in order to adequately simulate the neutron and photon productions from the 6,7Li(d,xn) reactions in the lithium target. The present analysis is focusing on the nuclear heating distribution inside the biological shielding, the nuclear property of the TC liner, and the biological dose distribution around TC during operation. Some countermeasures for reducing the He production in the liner are discussed.

Energy Performance Assessment of and Advanced Integrated Façade through Experimental Data Analysis

This paper deals with the experimental assessment of the energy performance of two Advanced Integrated Façade modules (AIF) characterized by two very similar configurations. The two AIF modules were installed on the south-exposed façade of an outdoor test cell facility (a real-scale mockup of an office building) and continuous measurements were carried out for more than one year. Data collected during the experimental campaign were analyzed to evaluate the energy performance and thermo-physical behaviour of the AIF modules. The performances of the two systems were assessed by comparison and by means of conventional and advanced synthetic metrics.The results of the activity point out the different performances of the two configurations, which only differs on the inner-side glazing (a stratified single clear glass pane vs a stratified low-e double glazed unit). It was demonstrated that just a single additional glass layer can contribute to substantially improve the energy performance of a quite complex façade technology. On average, the façade configuration with the stratified low-e double glazed unit shows the abatement of heat loss and of solar gain of about 30% during the whole year. Moreover, the reliability of some conventional and less conventional metrics in assessing the performance of dynamic façade technologies was also investigated. The results confirm that conventional metrics are not fully reliable when they are used to assess advanced building envelope components with high level of dynamic.

Status of the McCad geometry conversion tool and related visualization capabilities for 3D fusion neutronics calculations

The McCad geometry conversion tool has been developed at KIT to enable the automatic conversion of CAD models into the semi-algebraic geometry representation as utilized in Monte Carlo particle transport simulations. McCad is entirely based on open source software, it is running under the Linux operating system and utilizes the Open Cascade CAD kernel with the Qt4 libraries for the graphical user interface (GUI). The converted geometry models can be output in the syntax of the Monte Carlo codes MCNP and TRIPOLI. Related visualization capabilities are based on the coupling of McCad with the ParaView software and allow to overlay mesh tally distributions to the CAD geometry. This enables perspective 3D representations or animations on the CAD geometry. The paper presents the current status of the McCad approach and its implementation, and discusses its capabilities, limitations as well as future development needs. The use of McCad for fusion neutronics applications is illustrated on the examples of the MCNP model generation for ITER Test Blanket Modules (TBM) and the test cell facility of the IFMIF neutron source including Monte Carlo shielding calculations using the converted models.

Ventilated active façades with PCM

This article describes an evaluation of the thermal performance of a new type of ventilated active façade that includes a phase change material (PCM) in its outer layer. The research was carried out experimentally by means of a real-scale PASLINK test cell facility, located in the city of Vitoria-Gasteiz in Spain. The results of an experiment performed in March 2010 are presented and evaluated. The behavior of the façade was compared with different traditional constructive systems, using the results of computational simulations performed with the Design Builder software. The experimental results showed that the melting–solidification processes that take place in the PCM led to an increase in the heat absorption during the phase-change temperature intervals, which reduced overheating of the façade. The air circulating through the ventilated chamber was overheated up to 12°C during the daytime. Because of the PCM solidification, 2.5h after the solar radiation faded out, the air circulating through the chamber was still warmed by 2°C. The energy efficiency of the façade during the testing period is attributable to the 10–12% incident radiation gains. This efficiency was found to be a function of the circulating air flow rate. The simulations results showed that the thermal inertia of the ventilated façade with a PCM is higher than that of the four traditional solutions evaluated in the study. Further research is required to study the influence of the air flow rate through the ventilated chamber.

宇宙航空研究開発機構における航空エンジン運転試験設備 -地上エンジン運転試験設備および高空性能試験設備

宇宙航空研究開発機構における航空エンジン運転試験設備 -地上エンジン運転試験設備および高空性能試験設備

Investigation of the performance of a ventilated wall

The need for environmental friendly and energy efficient building design has stimulated the design of new facade technologies, including various configurations of double skin facades. This paper investigates the thermal performance of a ventilated wall, both for heating and cooling. A thermal analysis was carried out, paying special attention to the characterization of the heat convection resulting from the buoyancy-induced flow in the open air channel which proved to be a critical aspect of the ventilated wall's behaviour. An integrated thermal and air flow model for the entire system was developed. A model of the ventilated wall construction was developed with the ESP-r simulation program and checked against experimental data from a real-scale test cell facility. The thermal benefits of adding a radiant barrier layer were also investigated. The results showed that this layer was beneficial in terms of the energy performance of the construction. Also, the comparison between the experimental and simulation model results showed satisfactory levels of convergence with the exception of the night hours during the summer period. A sensitivity analysis was also undertaken in order to investigate the main factors and the extent of their effect on the temperature variation inside the ventilated facades.

Lightweight Dividing Walls: Adaptation to Temperate Climates

This paper intends to prove that it is possible to use lightweight membranes on interior partition walls and on external facades, even in housing buildings at temperate climate regions, if their properties are well explored. The few material used, even less than conventional lightweight solutions the most common is plasterboard with light steel frame structure allow a lower specific embodied energy and other more favourable environmental impact indicators. Compared to conventional heavyweight solutions, such as hollow brick walls, lightweight membranes allow easier deconstruction/reuse. In the outer skin, architectural membranes can be used as passive or active systems, for heating (promoting greenhouse effect) and cooling (shading or even evaporative cooling). Lightweight materials are more viable to be used on invariably hot or cold climates, than on temperate climates, as in this context they present problems related with its low thermal storage capacity. However, the research of new architectural membrane materials, with passive and active behavior for thermal regulation, allows extending its possibilities to interior dividing partitions in order to fulfill contemporary demands of comfort. Active and/or passive systems can be used to regulate thermal gains – for example by radiant panels and/or evaporative cooling, but also to achieve thermal inertia. In pavements, thermal storage lightweight elements, using natural Phase Change Materials, were already studied and reported on previous studies from the first author. Examples of how these systems can also be applied to lightweight membrane dividing walls are presented in this paper, and some experimental research is now under course on test cell facilities existing in University of Minho, Guimaraes.

Evaluation of round-robin testing using the PASLINK test facilities

The IQ-TEST Thematic Network has carried out round-robin tests at ten of the PASLINK outdoor test cell facilities. A round-robin test generally produces a clear picture of the overall quality of certain test procedures carried out by the participating organisations. For practical considerations, each organisation constructed its own components according to strict instructions regarding the selection of materials, manufacture and instrumentation. Two components of different levels of complexity were designed: (1) an opaque, homogeneous wall with a removable central section, and (2) a window, which is used to replace the central section of the first component. Using recommended dynamic test procedures and appropriate identification methods, each participant determined the thermal performance of the components. Good agreement between sites was achieved for the U-value of the opaque wall. A range of U-values was obtained for the window; however, the variation can be largely accounted for by variations in the boundary conditions between sites, e.g. wind speed and ambient temperature. For future components the test sequence and analysis methods should account for such non-linear behaviour, in order to estimate thermal and solar performance characteristics for appropriate standardised boundary conditions.