August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica NANO-HVAC GA no : Novel Nano-enabled Energy Efficient and Safe HVAC ducts and systems contributing to an healthier indoor environment Final Dissemination Conference Lavrio, 28 th August 2015 CFD-RANS modeling of turbulent flow, hygrothermal parameters and pollutant dispersion in real working environments CFD=Computational Fluid Dynamics RANS=Reynolds-Averaged Navier Stokes George C. Efthimiou

August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica OFFICAIR Project On the reduction of health effects from combined exposure to indoor air pollutants in modern office buildings (Nov Oct 2013) Funded by : EU 7th Framework Programme (FP7) under the topic: ENV : Indoor air pollution and health risks of modern office buildings

August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica  Standardized buildings spaces, exhibiting an almost identical character, regardless of their location in the world.  Almost unaffected by the local climatic conditions.  Flexible open plan arrangement.  High density of occupation.  Mechanical ventilation.  Electronic equipment.  Artificial lighting.  High levels of energy requirements. Modern Offices Trends

August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica OFFICAIR: Ventilation (provided by TNO, CSTB) There are differences between countries

August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica OFFICAIR: Floor, walls and ceiling (provided by TNO, CSTB) n=161 Figures in %; % higher than 100 because of possible multiple choice main type of floor coveringmain type of wall coveringmain type of ceiling surface

August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica Room conditions differentiation studies The test case: Room and ventilation positions  Office located in Athens (Greece).  Dimensions: 22.26m x 7.80m x 2.54m.  9 windows and 4 doors.  Total glazing area: m 2.  Mechanical ventilation: 7 air inlets (In) and 6 air exhaust outlets (E).

August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica CFD Code Basic Information FLUENT Version 14.0 Developer –ANSYS User –University of West Macedonia, Kozani, Greece

August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica System  The current simulation has been performed on:  PC Windows 7 64bit (4 Host)  1 CPU (4 cores)  TOTAL RAM: 4 GB

August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica Quantities predicted  Velocities U, V, W  Turbulent kinetic energy  Turbulent kinetic energy dissipation  Temperature  Relative Humidity  Formaldehyde

August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica The Computational Domain & Grid Total size of Computation domain (in m) Length (y)22.26 m Width (x) (Office / Outdoor) 8.8 m (7.8 / 1.0) Height (z)2.54 m OFFICE MESH 2 cell zones: Office and Outdoor OUTDOOR MESH Outdoor mesh usage: heat exchange with the outdoor environment (explained below) TOTAL MESH tetrahedral/mixed cells Volume = 441 m 3 Zone 2: Outdoor Zone 1: Office m 2.54 m 8.8 m

August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica Flow Inlet Boundaries  7 inlets at the top (z = 2.54m)  Flow rates from the experiments. NoNo Flow rate per vent (kg/s) T ( o C) RH (%) k (m 2 /s 2 ) ε (m 2 /s 3 )

August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica Formaldehyde Boundary Conditions -Zero inlet concentration, -Building material emission fluxes selected from BUMA database, -Office equipment emissions assumed to be emitted at the floor level.

August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica FORMALDEHYDE CONCENTRATION LEVELS OVER TIME (JRC INDOORTRON 30 m 3 CHAMBER MEASUREMENTS) μg/m 3

August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica Formaldehyde Emissions A/AMATERIALBUILDING TYPE AREA (m 2 )BUMA EMISSION RANGE (μg/m 2 h) ≥ 3 days SELECTED VALUE 1Water based paint Vertical walls – MDFOffice equipment (desks, shelves) Ceiling tileCeiling

August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica The flow results: Mass fluxes

August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica The flow results: Velocities at XY Plane (z=1.5m)

August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica The flow results: Velocities at YZ Plane (x=3.9m)

August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica Temperature

Temperature deviation from the volume average value

August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica The flow results: The humidity

August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica Predicted Percentage Dissatisfied: PPD The PPD is an index that establishes a quantitative prediction of the percentage of thermally dissatisfied people who feel too cool or too warm. Based on ISO 7730:2005, where: PMV = predicts the mean value of the thermal votes of a large group of people exposed to the same environment. PMV is based on the following parameters:  Metabolic rate,  Effective mechanical power,  Clothing surface area factor,  Clothing surface temperature,  Clothing insulation,  Water vapour partial pressure,  Air temperature,  Relative air velocity,  Mean radiant temperature,  Convective heat transfer coefficient. ISO 7730:2005, International Standard, Ergonomics of the thermal environment — Analytical determination and interpretation of thermal comfort using calculation of the PMV and PPD indices and local thermal comfort criteria

August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica Predicted Percentage Dissatisfied: PPD

August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica Exposure factors at the working positions at the height of z = 1.1 m

August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica Conclusions  The detailed flow field and formaldehyde concentration patterns in a large mechanically ventilated modern office room have been analyzed using CFD methodology.  The results on the selected test case have shown significant differentiation:  On the predicted percentage dissatisfied index (up to 34%).  On the VOCs or/and particles exposure factor (at z=1.1m) up to  The results on the selected test case have shown slightly differentiation:  On the temperature (at z=1.1m) up to 0.8%.  The comfort and exposure differentiation within large modern offices is better not to be ignored.  Further validation studies are needed to draw more concrete conclusions.

August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica Thank you