In the pursuit of sustainable cooling solutions, passive techniques have gained significant attention for their ability to reduce energy consumption in indoor and outdoor applications. Adiabatic cooling efficiently lowers air temperatures through water evaporation. The success of such a technique depends heavily on the ability of the air jet to disperse the droplets in the target volume. To improve droplet dispersion, it is necessary to enhance the entrainment capacity of the carrier air jet. This study investigates for the first-time flow entrainment intensification using lobes as vortex generators into a multi-jet diffuser for adiabatic cooling application. A multi-lobed jet diffuser consists of a tube pierced with a series of lobed orifices each is a daisy shaped orifice on a hemisphere (DOH). Such a geometry is intended to offer promising potential for improving overall performance in cooling applications compared to the convention-al multi-round jet diffuser (ROH). As a first step, before integrating water evaporation, it is essential to understand airflow dynamics under monophasic conditions. Experiments were conducted in a climatic chamber, providing precise control over temperature and airflow conditions to investigate the jet behavior by employing Particle Image Velocimetry and fast visualization techniques. The results indicate that DOH multi-jet flow expands more than traditional ROH multi-jet flow under the tested conditions. Specifically, in the minor plane, the dynamic jet widths Y0.5 and Y0.1 for DOH were 10

The energy performance of any building depends on its orientation, the architectural and constructive design of its envelope and the energy systems installed within it. A highly glazed envelope is sometimes chosen for its aesthetics and transparency, offering maximum natural lighting and solar gain. The potential drawbacks of such an architectural choice, namely the cold-wall effect in winter associated with heat loss, and overheating in summer, call for fine-tuned energy optimization of the coupling of the envelope with the systems, particularly those managing ventilation and solar shading in hot weather. The aim of this study is to numerically test renovation solutions for a commercial building with two heavily glazed facades, facing south-east and north-west. An initial validation stage of the model reproducing the building's current state is based on actual monthly heating consumption. It is then shown that the addition of a double-skin wall protects the building against overheating in summer, and coupled with ventilation in winter, preheats the fresh air, thus minimizing aeraulic losses. The addition of a buffer zone on the north-west side reduces the maximum summer temperature by 4 ℃, at the expense of a 9

The aim of the Serres+ project is to develop energy-efficient greenhouses with low carbon footprint for tomato cultivation. In this context, a greenhouse was modelled using TRNSYS software. Experimental data from the CTIFL (Centre Technique Interprofessionnel des Fruits et Légumes) reference greenhouse validated the model. This work is continued here by dynamic thermal simulations using the model adapted to innovative greenhouse geometries. The results show that the sphericity of the greenhouse plays an important role in the transmission of solar radiation. The use of a double skin of ETFE (ethylene tetrafluoroethylene) instead of glass contributes to a more intense greenhouse effect. Heat in excess, captured by the greenhouse, can potentially be stored for reuse during the heating season. These amounts are calculated using the Type56 cooling module, assuming a set temperature of 32 ℃ in the greenhouse and are equal to 11 kWh/m2/year for the CTIFL greenhouse (sphericity 0.585), and 36 and 79 kWh/m2/year for the two innovative greenhouses (sphericity 0.443 and 0.418). Therefore, a link can be established between the greenhouse effect, the potentially storable energy and the sphericity of the greenhouses.

Indoor air quality and heating energy consumption are closely linked, especially in densely occupied spaces, as classrooms. In a classroom of Rennes University, a transient thermal simulation highlights the impact of ventilation on heating consumptions for different cases: (1) without controlled mechanical ventilation (CMV), (2) with a single flow CMV (SF CMV) of a regulatory flow of 18 m 3 .h −1 . person −1 during periods of occupancy, and (3) a double flow CMV (DF CMV) whose flow is during periods of occupancy either equal to 18 m 3 .h −1 . person −1 or (4) to 35 m 3 .h −1 .person −1 . The infiltration flowrate was evaluated experimentally using CO 2 concentration measurements in the first case, which corresponds to the actual situation. In the normal use of the classroom with 30 persons inside, CO 2 concentration exceeds 5000 ppm and the heating energy consumption is equal to 52 kWh.m −2 .year −1 . In case (2) and (3), CO 2 concentration has a maximum level of 1350 ppm and the energy consumption is equal to 65 and 53 kWh.m −2 .year −1 , respectively. In case (4), the maximum CO 2 concentration stays in the range 800-900 ppm without excessive heating consumption (58 kWh.m −2 .year −1 ). Finally, by limiting the fresh air flowrate to 18 m 3 .h −1 .person −1 in DF CMV and coupling it to a façade insulation (extra Case 5), the heating consumption is reduced to 32 kWh.m −2 .year −1 . These results are valuable within the context of the upcoming energy renovation strategy of the campus. Practical application In most schools, in France and elsewhere, insufficient ventilation flowrates are often observed compared to regulatory requirements. If compliance with ventilation standards and the subsequent revision of CMV installations are necessary to ensure the health of users, it is important to evaluate the energy cost of these renovations, and to identify the best choice to reduce heating consumptions. Our contribution is to compare different renovation choices in terms of two indicators: energy consumption and indoor air quality evaluated using CO2 concentration.

Escherichia coli ( E. coli), ), Salmonella typhimurium ( S. typhimurium), ), Listeria monocytogenes (L. monocytogenes), and Cladosporium cladosporioides (C. C. cladosporioides), ), as microorganisms, and ethyl acetate (EA), as a volatile organic compound, were chosen as target pollutants to be removed from indoor air. The E. coli degradation was firstly investigated. Second, the simultaneous degradation of all studied microorganisms was assessed. Third, a separate investigation was conducted for EA. These investigations focused on the antibacterial and photocatalytic behaviors of the TiO2, 2 , Ag/TiO2, 2, and Cu/TiO2 2 luminous textiles. Compared to other photocatalysts, the Cu/TiO2, 2 , exhibits the highest bacterial disinfection and EA removal. Fourth, simultaneous degradation of E. coli and EA was assessed with the most efficient photocatalyst. The Cu/TiO2 2 catalyst proved to be efficient by inactivating 4.72log of E. coli, , 5.18log of S. typhimurium, , 4.76log of L. monocytogenes, and 0.61log of C. cladosporioides, , at the same time. The performance of the Cu/TiO2 2 catalyst can be assigned to the intrinsic conduction band and valence band positions of CuO, Cu2O, 2 O, and TiO2. 2 . Using the Cu/TiO2 2 photocatalyst, a bacterial inactivation of 3.63log and an EA degradation efficiency of 91.13% were obtained within 60 min of UV light irradiation. It was unequivocally established that E. coli's 's presence inhibited the removal of EA (reducing from 91.13% to 65.97%), which can be attributed to the humidity effect and the competition reactions of the photocatalyst among E. coli, , EA, and EA by-products. The bactericidal inactivation was equivalent to 3log for E. coli, , but it increased to 4log for the E. coli /EA mixture. The damage caused to bacteria proteins by the by-products of EA was the reason for this outcome. The explanation for E. coli inactivation and EA photodegradation on Cu/TiO2 2 luminous textiles is discussed. The low-cost configuration of a luminous textile photocatalyst used showed a superior performance for the simultaneous elimination of E. coli and EA from indoor air in a modular and low-cost photoreactor.

Earth-based building materials offer promising potential for reducing the environment footprint of construction projects, due to their low energy requirements during production and the prospect of post-lifecycle reusability when not stabilized. In this study, we focus on thermal and hygric performances of compacted earth blocks (CEBs). This research aims to analyze the impact of density and water content on the thermal conductivity of CEBs. Within this framework, cylindrical samples of compacted and unstabilized earth, formulated by Laboratoire CBTP, are manufactured using fines from quarries, targeting three distinct densities ranging from 1.90 to 2.15 g/cm(3). Thermal conductivity measurements are conducted at different moisture levels for each density using the transient hot-wire methodology. At the dry state, thermal conductivity values range from 0.8 to 1.1 W/(m.K). The experimental results show a linear correlation between thermal conductivity and both density and moisture content. A simple model based on the combined effect of the degree of saturation and the dry density of the material is applied to model the moisture-dependent thermal conductivity.

The drying of construction materials is a challenge regarding structure's durability and costly construction delays. Long drying periods induce high-moisture content that leads to fungal growth risks. This study presents the development of an innovative forced convection drying method, inspired by unglazed transpired solar wall system and repurposed here for its drying potential at the wall scale. This method employs a metal perforated panel placed at a short distance from the material to dry. This creates an air cavity between them where forced convection is applied with ambient air penetrating through the perforated panel. The moistened air is evacuated thanks to an air circuit composed of a fan and an extraction duct. Two panel configurations with round and crossshaped perforations are investigated and compared to a natural convection reference. The efficiency of the method is evaluated on Earth-Lime-Hemp composites. With forced convection method, the evaporation front moves moisture towards the near wall forced convection surface and leads to more efficient moisture removal. The results demonstrate a 50 % reduction in drying time using forced convection drying compared to natural convection drying in an open area. Both panel configurations show similar efficiency. The proposed drying method meets the challenges above-mentioned and is applicable for both prefabricated elements and on-site construction. Additionally, it can be effective for the restoration after water damage, enhancing overall construction resilience.

This paper proposes a new correlation to evaluate the heat transfer coefficient between a vertical wall containing a phase change material (PCM) and air in a square enclosure. This correlation was determined in order to simulate the transient process during PCM discharge and its effect on the heat transfer inside the cavity without using complex CFD models. A 2D CFD model based on the resolution of Navier–Stokes and energy equations inside the air and the PCM was previously validated. It was used to generate numerical data in order to build the proposed heat transfer correlation. The new correlation is Nu=0.186·Ra^0.28θ^0.271Ste^0.022 valid for: 10^5≤Ra≤ 4.3 10^7, 0.05 ≤θ≤ 1 and 0.05 ≤ste≤ 0.6 . The accuracy of the proposed correlation versus the correlations established without phase change is analysed through a simplified model considering only the PCM layer and replacing the air cavity by a flux condition with an appropriate heat transfer coefficient. The relative error being lower than 1

Abstract As global temperatures continue to rise, climate change impacts are now being observed in all aspects of life, driving the need to transition to a low-carbon economy. In the building sector and as a construction material, Earth-Hemp composites present a sustainable solution due to their low embodied energy and low environmental impact. However, at the construction site, and as with any other material, the drying process of Earth-Hemp can be very slow, which can lead to costly delays for building work and even serious problems in term of mold growth affecting their durability. The objective of this work is to develop an innovative drying method to reduce drying time of construction materials and speed up the completion of a project. In this paper, a comparative study of natural convection drying with innovative forced convection drying is carried out on sprayed Earth-Hemp-Lime "ELH" prototypes. The results show that the innovative forced convection method is very effective for drying ELH materials at an accelerated rate, where the drying period has been reduced by a factor of 2, compared to the drying time required when using the natural convection method.

This article presents the study of a ventilation solution using cross-flow fans for the crew quarters (CQ) aboard the International Space Station. Currently the CQ uses two axial fans for ventilation, which occasionally generate insufficient flow rate or acoustic issues. A ventilation circuit using two cross-flow fans was designed, its acoustic performance was measured and the flow was investigated via CFD by using the measured cross-flow fan operating curves as boundary conditions. The acoustic performance of the fans was evaluated in isothermal conditions, under the assumption that the heat generated by the occupants and equipment would produce negligible thermal buoyancy effects in microgravity on the station. Future studies will investigate how the internal heat generated in the enclosure affects the thermal comfort conditions of the occupants. After a comparison between the axial and cross-flow fan systems, results indicate that the latter provides better acoustic parameters for the same flow rate with less energy consumption.

This investigation and optimization of the adsorption and photocatalysis coupling process for treating chemical warfare agents (CWAs) were performed with a compact cartridge based on activated carbon felt (AF) and TiO2 photocatalyst deposited on luminous textiles. The target pollutants were simulants of the chemical warfare agent (yperite), methyl salicylate, diethyl sulfur (a simulant of sulfur mustard gas), and cyclohexane, which is the benchmark for type A gas filtration tests. To take better advantage of this new configuration, an optimization of the photocatalytic process was highlighted with an improvement of the regeneration process by implementing the integrated compactness of desorption by the Joule effect (in situ). In the case of methyl salicylate treatment, the recovery of the adsorption capacity of the AF were about 95% and a working time of 85% compared to initial adsorbent performance. For the second cycle regeneration, the recovered adsorption capacity was about 88% compared to initial capacity. We note also that the working time decrease by 15% for each regeneration step. The evaluation of the new coupling configuration aimed at highlighting the influence of a sulfur compound was encouraging, with a regeneration rate of the adsorbent of about 80%. Compared to MS, the regeneration seems to be more difficult. This is due to by-products (SO2, MSH) formation which is highlighted by the degradation pathway proposed. The removal efficiency of the coupling system (UV-LED/AF) under continuous process, was equal to 36%. This leads an increase in filter working time of 50 min over that of a conventional adsorption process. Special attention was paid to validating the coupling system performance in real conditions. The system was placed on a humanlike seated thermal manikin used to simulate an occupant of a chamber of 30 m3 with the realistic condition of applying chemical, biological, radiological, and nuclear (CBRN) agent protection. The time protection was 60 and 30 min for respective concentrations of about 150 and 300 mg.m  3.This global investigation addressed how to overcome the scientific barriers to designing a compact, self-contained filtration cartridge for personal protection in CBRN emergency response and management in accor-dance with the United Nations Sustainable Development Goals (SDGs).

Thermal comfort evaluation for vehicle occupants is very complicated due to the transient nature and non-uniformity of the vehicle interior. The thermal sensation of an automobile occupant is affected by the surrounding environment. Furthermore, the existing standard was developed for steady state and controlled conditions and it utilizes three evaluation indices, some of which are not adapted for this complex environment. In this article, the three standardized indices are compared in terms of thermal comfort, for a passenger vehicle in summer season. The results show that the mean values of the PMV/PPD model calculated at a single point with Comfort Sense equipment are far from the TSV mean values which were collected in questionnaires, while the teq index which was calculated with an advanced thermal manikin are closer to the TSV comfort votes. This may be explained by the fact that the TSV and teq consider the sensation for each body part at the local level. For a correct evaluation of the thermal comfort in non-uniform and transient environments like in vehicles, it is not enough to measure a single point.

New COVID-19 variants, either of higher viral load such as delta or higher contagiousness like omicron, can lead to higher airborne transmission than historical strains. This paper highlights their implications for health policies, based on a clear analytical understanding and modeling of the airborne contamination paths, of the dose following exposure, and the importance of the counting unit for pathogens, itself linked to the dose-response law. Using the counting unit of Wells, i.e. the quantum of contagium, we develop the conservation equation of quanta which allows deriving the value of the quantum concentration at steady state for a well-mixed room. The link with the monitoring concentration of carbon dioxide is made and used for a risk analysis of a variety of situations for which we collected CO2 time-series observations. The main conclusions of these observations are that 1) the present norms of ventilation, are both insufficient and not respected, especially in a variety of public premises, leading to high risk of contamination and that 2) air can often be considered well-mixed. Finally, we insist that public health policy in the field of airborne transmission should be based on a multi parameter analysis such as the time of exposure, the quantum production rate, mask wearing and the infector proportion in the population in order to evaluate the risk, considering the whole complexity of dose evaluation. Recognizing airborne transmission requires thinking in terms of time of exposure rather than in terms of proximal distance.

This paper studies the impact of a personalized ventilation system on the thermal comfort of occupants in the crew quarters aboard the International Space Station. The personalized ventilation system was initially designed as a means to improve air quality in the occupant's breathing zone. Introducing a ventilation jet in close proximity to the human face can adversely affect thermal comfort and thus, three comfort criteria are evaluated. The evaluation is performed in a numerical model of the crew quarters with the personalized ventilation system and a virtual human occupant. Two cases are compared: one with personalized ventilation and one without it in order to assess the impact. Different airflow temperatures are investigated as well. The comfort criteria are evaluated in the representative planes of the crew quarters ventilation system. Results show generally acceptable levels of thermal comfort around the occupant's body, with few outliers signaling potential mild discomforts.

The current paper proposes a detailed study of the ventilation system of the crew quarters (CQ) aboard the International Space Station (ISS) in order to identify the ventilation system's capacity to reduce CO2 accumulation around an occupant. These results would enable the improvement of the ventilation system, thereby decreasing the health risks of the occupants. The ventilation flow fields are studied through numerical results which are validated with experimental Particle Image Velocimetry (PIV) measurements in a reduced-scale mock-up. The equivalence between the reduced scale experimental and the full-scale numerical results is obtained through a Reynolds-number based similitude criteria. This enabled the authors to validate the isothermal airflow in the full-scale numerical model with the experimental results of the water flow in the reduced-scale mock-up. Normalized numerical and experimental velocity profiles have been superposed and were found to be in good agreement. Both numerical and experimental models highlight a stagnation region in the centre of the CQ volume leading to a ventilation deficit of the astronaut's breathing zone. The results indicate that this stagnant region is a reason for the excess CO2 accumulation in the CQ, despite the high ventilation rate (>45 hourly air exchanges). To the author's best knowledge this is the first numerical study of the CQ ventilation system validated with reduced-scale experimental modelling. The paper's findings have implications in building air quality studies, suggesting that targeted ventilation is preferable to raw increased in flow rates.

The present paper studies the possibility of personalized ventilation (PV) systems to improve air quality in the breathing zone of astronauts resting in the crew quarters aboard the International Space Station. In the absence of gravity CO2 accumulates in pockets near the astronaut's head, potentially leading to symptoms of CO2 intoxication. The addition of a PV system aimed at an astronaut's breathing zone during sleep could provide a supply of fresh air directly to the face and reduce the risks of intoxication. Experimental measurements of the PV diffuser velocity fields were performed in an experimental setup and the results were used to validate the numerical solution for the PV case connected to the already existing general ventilation system of the crew quarters. CFD models were used in order to reproduce the conditions of microgravity. Two PV configurations were studied, the first with the PV diffuser position in front of the human occupant and the second was positioned laterally, both being aimed at the breathing zone. The results were compared to a case without PV. Results indicate that the lateral PV solution is more viable than the frontal solution providing a reduction in overall CO2 levels in the breathing zone. The lateral PV also leads to an 8% reduction in the volume of CO2 inhaled over the course of each breath having the potential to improve air quality over longer periods of time.

The present study deals with experimental measurements of CO2 generation rates, due to the human occupation of a full-scale experimental mock-up simulating the astronaut crew quarters aboard the International Space Station. The estimation of CO2 generation rates follows different methods as described in the literature. A single test subject in four different testing cases is considered, one at rest representing the baseline case and the other three cases at varying levels of physical activity or at rest but with a fixed breathing frequency requested from the human subject. The study results indicate that imposing a fixed breathing rate even while at rest increases the generation rate unpredictably. Following literature metabolic rate estimations, the latter two cases are equivalent to the subject being engaged in light or medium physical activities. The results are used to form recommendations for studies measuring human CO2 generation rates.

There are numerous turbulence models that have been developed in the past years, many of them being used in predicting flows, turbulence, mass and/or heat transfer. The particular case of an impinging jet implies all of the above. The performance of eight highly used Reynolds averaged Navier-Stokes turbulence models is examined in simulating a very sheared lobed impinging jet. The study is based on the investigation of an orthogonally lobed jet, impinging on a flat surface that flows out from a nozzle having a cruciform cross-section at a Reynolds number of 5620. Two experimental methods were implied for the comparison with numerical results. For the measurement of the wall shear rate an electrodiffusion method was employed. The velocity flow fields were measured using particle image velocimetry technique. The relative strengths and drawbacks of the SST k-ω, k-ω, TransSST, k-e realisable, RNG k-e, k-e, k-kl-ω and RSM turbulence models are compared.