Publications associées à Airflow

Experimental study of the hydrodynamic and thermal performances of ventilated wall structures

The presence of a ventilated air gap behind the external cladding in a building envelope is known to have a tangible contribution to the overall performance of the wall assembly. In the present study, the hydrodynamic and thermal performances of ventilated ...

2023

Optimal sensor placement for personal inhalation exposure detection in static and dynamic office environments

Dusan Licina, Seoyeon Yun

Modern health and productivity concerns related to air pollutant exposure in buildings have sparked the need for occupant-centric monitoring and ventilation control. The existing personal exposure monitoring is often restricted to stationary air quality se ...

PERGAMON-ELSEVIER SCIENCE LTD2023

A new chapter of healthy indoor air: antiviral air treatments

Shannon Christa David

Aerosol transmission remains a major challenge for the control of respiratory viruses. To date, prevention strategies include masks, vaccinations, physical distancing, travel restrictions, and lockdowns. Such measures are effective but come with heavy soci ...

Wiley2023

Measuring the effective thermal resistance of ventilated air-spaces behind common wall assemblies: Theoretical uncertainty analysis and recommendations for the hot box method modifications (ASHRAE 1759-RP)

Dolaana Khovalyg, Mohammad Rahiminejad

A well-designed ventilated wall that incorporates air-space behind cladding can reduce energy use for conditioning buildings by adding a thermally resistive layer. The scarcity of thermal performance data and standardized test methods is a particular barri ...

2022

Continuous raw particle number concentration data in 10 sec resolution, measured in the Swiss aerosol container during MOSAiC 2019/2020

Julia Schmale, Ivo Fabio Beck

This dataset contains raw particle number concentration data measured during the year long MOSAiC expedition from October 2019 to September 2020. The measurement was performed in the Swiss aerosol container on the D-deck of Research Vessel Polarstern using ...

Zenodo2022

Numerical and experimental study of the dynamic thermal resistance of ventilated air-spaces behind passive and active façades

Dolaana Khovalyg, Mohammad Rahiminejad

The variation of the thermo-hydrodynamic behavior of the airflow in the ventilated cavity behind external claddings in a wall structure could potentially affect the overall thermal resistance of the entire structure. Although the impact of an enclosed air- ...

2022

Impact of the Ventilated Cavity on the Thermal Performance of Traditional Wall Structures

Dolaana Khovalyg, Mohammad Rahiminejad

The amount of heat flux passing through the building envelope directly affects the energy use for the thermal conditioning of the building. The ventilated cavity behind the traditional external claddings (e.g., vinyl siding, brick veneer) adjacent to the w ...

AMER SOC HEATING, REFRIGERATING AND AIR-CONDITIONING ENGS2021

Impact of air-flow on thermal performance of air-spaces behind cladding (ASHRAE 1759-TRP)

Dolaana Khovalyg, Mohammad Rahiminejad

The project ASHRAE 1759-RP addresses the impact of the ventilated cavity behind external claddings on the thermal performance of the wall structure by defining “effective thermal resistance” of air gaps based on the linearized network of thermal resistance ...

ASHRAE2020

Review on ventilation rates in the ventilated air-spaces behind common wall assemblies with external cladding

Dolaana Khovalyg, Mohammad Rahiminejad

For many decades, ventilated cavities in wall assemblies of buildings have been essential for creating moisture resilient constructions by allowing airflow within the air gap to promote drying. In addition to that, the airflow in the cavity can enhance the ...

2021

Pcm-based heat exchanger and uses thereof

Véronique Michaud, Sophia Haussener, Matthieu Gani, Lucas Fuentes Valenzuela, Marc Roulin

A PCM-based heat exchanger is disclosed, said phase change material (PCM)-based heat exchanger comprising: a) a case having insulated walls comprising an inlet and an outlet; and b) a plurality of modules comprising a support structure containing a phase c ...

2019

On the Influence of Thermal Mass and Natural Ventilation on Overheating Risk in Offices

Flourentzos Flourentzou, Thomas Bernard Paul Jusselme, Arianna Brambilla, Jérôme Philippe Bonvin

Free cooling strategies are gaining importance in design practice due to the increased risk of overheating in well-insulated buildings with high internal loads such as offices. The state of the art highlights that the most efficient passive solution for in ...

2018

Experimental evaluation of the thermal performances of a thermosyphon cooling system rejecting heat by natural and forced convection

John Richard Thome, Filippo Cataldo

In the present paper, a closed-loop thermosyphon cooling system for power electronics has been developed and tested. The evaporator is a multi-microchannel heat sink designed for high heat fluxes. The power electronics module is emulated by four independen ...

Pergamon-Elsevier Science Ltd2017

Benchmark Models for Air Conditioned Residential Buildings in Hot Humid Climate

Shady Galal Mohamed Attia

This study reports the results of a recent field survey for residential apartment buildings in Egypt. The aim of the survey is to create representative building energy models. Two building performance simulation models are created reflecting the average en ...

2013

A facile approach for controlling the orientation of one-dimensional mesochannels in mesoporous titania films

Paul Joseph Dyson, Zhaofu Fei, Yi Wang

Controlling of the orientation of mesochannels in mesostructured thin films is important for the development of novel molecular devices and, in particular, generating vertically aligned mesochannels with respect to the substrate plane is extremely challeng ...

Amer Chemical Soc2012

Air Side Contamination in Solid Oxide Fuel Cell Stack Testing

Jan Van Herle, Christian Ludwig, Aïcha Hessler-Wyser, Josef Andreas Schuler, Zacharie Wuillemin, Christian Gehrig

Solid Oxide Fuel Cells (SOFCs) are likely candidates for electricity production with high efficiency and promise reasonable fuel tolerance. While fuel impurities are known anode poisons, less attention is brought to air-purity, especially to air-side conta ...

Elsevier2011

Atmospheric Boundary Layer Dynamics of Transitional Flows over Complex Terrain

Daniel Nadeau

Recent advances in boundary-layer meteorology are beginning to allow the study of atmospheric flow phenomena that have previously been poorly understood. In this dissertation, we study the effects of complex terrain and unsteady regimes on the atmospheric ...

EPFL2011

Air Side Contamination in SOFC Stack Testing

Jan Van Herle, Aïcha Hessler-Wyser, Christian Ludwig, Josef Andreas Schuler, Zacharie Wuillemin, Christian Gehrig

Solid Oxide Fuel Cells (SOFCs) are likely candidates for electricity production with high efficiency and promise reasonable fuel tolerance. While fuel impurities are known anode poisons, less attention is brought to air-purity, especially to air-side conta ...

2010

Optimisation of Buildings Daylight Availability

Jérôme Henri Kämpf, Darren Robinson, Marylène Montavon

Many researchers have the goal of improving buildings daylight availability in order to decrease the HVAC energy intake. Indeed by achieving/identifying sustainable urban forms and their design concepts, the benefits of the solar radiation can be of threef ...

EPFL2007

A comparative study of VOCs in Singapore and European office buildings

Claude-Alain Roulet

This study compares the characteristics of volatile organic compounds (VOCs) and the associated factors affecting them within European (EU) and Singapore buildings. Generally, concentrations of target VOCs determined in the two types of buildings were with ...

2006

Tracer Gas Measurement of Airflow Rates in Spaces with Several Air-Handling Units, Recirculation, or Large Time Constants

Claude-Alain Roulet

Methods to measure airflow rates using tracer gas in single air handling units are well known. In some buildings however, in particular in Singapore, rooms are often ventilated with two or more units and present large recirculation rates. Large recirculati ...

2006