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A Study on the Effectiveness of Alternative Commercial Ventilation Inlets That Improve Energy Efficiency of Building Ventilation Systems

Authors: Brian Considine, Aonghus McNabola, John Gallagher, Prashant Kumar

Abstract:

Passive air pollution control devices known as aspiration efficiency reducers (AER) have been developed using aspiration efficiency (AE) concepts. Their purpose is to reduce the concentration of particulate matter (PM) drawn into a building air handling unit (AHU) through alterations in the inlet design improving energy consumption. In this paper an examination is conducted into the effect of installing a deflector system around an AER-AHU inlet for both a forward and rear-facing orientations relative to the wind. The results of the study found that these deflectors are an effective passive control method for reducing AE at various ambient wind speeds over a range of microparticles of varying diameter. The deflector system was found to induce a large wake zone at low ambient wind speeds for a rear-facing AER-AHU, resulting in significantly lower AE in comparison to without. As the wind speed increased, both contained a wake zone but have much lower concentration gradients with the deflectors. For the forward-facing models, the deflector system at low ambient wind speed was preferred at higher Stokes numbers but there was negligible difference as the Stokes number decreased. Similarly, there was no significant difference at higher wind speeds across the Stokes number range tested. The results demonstrate that a deflector system is a viable passive control method for the reduction of ventilation energy consumption.

Keywords: Aspiration efficiency, energy, particulate matter, ventilation.

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References:


[1] Kim, K.-H., Kabir, E., and Kabir, S., 2015, “A Review on the Human Health Impact of Airborne Particulate Matter,” Environ. Int., 74, pp. 136–143.
[2] Qian, J., Tavakoli, B., Goldasteh, I., Ahmadi, G., and Ferro, A. R., 2014, “Building Removal of Particulate Pollutant Plume during Outdoor Resuspension Event,” Build. Environ., 75, pp. 161–169.
[3] McCreddin, A., Gill, L., Broderick, B., and McNabola, A., 2013, “Personal Exposure to Air Pollution in Office Workers in Ireland: Measurement, Analysis and Implications,” Toxics, 1, pp. 60–76.
[4] Feng, Z., Long, Z., and Chen, Q., 2014, “Assessment of Various CFD Models for Predicting Airflow and Pressure Drop through Pleated Filter System,” Build. Environ., 75, pp. 132–141.
[5] ISO 16890-1, 2016, “Air Filters for General Ventilation - Part 1: Technical Specifications, Requirements and Classification System Based upon Particulate Matter Efficiency (EPM) (ISO 16890-1:2016).”
[6] Yang, Z., Ghahramani, A., and Becerik-Gerber, B., 2016, “Building Occupancy Diversity and HVAC (Heating, Ventilation, and Air Conditioning) System Energy Efficiency,” Energy, 109, pp. 641–649.
[7] Belyaev, S. P., and Levin, L. M., 1972, “Investigation of Aerosol Aspiration by Photographing Particle Tracks under Flash Illumination,” J. Aerosol Sci., 3(2), pp. 127–140.
[8] Hangal, S., and Willeke, K., 1990, “Aspiration Efficiency: Unified Model for All Forward Sampling Angles,” Environ. Sci. Technol., 24(5), pp. 688–691.
[9] Tao, Y., Yang, W., Inthavong, K., and Tu, J., 2020, “Indoor Particle Inhalability of a Stationary and Moving Manikin,” Build. Environ., 169, p. 106545.
[10] McNabola, A., O’Luanaigh, N., Gallagher, J., and Gill, L., 2013, “The Development and Assessment of an Aspiration Efficiency Reducing System of Air Pollution Control for Particulate Matter in Building Ventilation Systems,” Energy Build., 61, pp. 177–184.
[11] Morgan, D. T., Daly, T., Gallagher, J., and McNabola, A., 2017, “Reducing Energy Consumption and Increasing Filter Life in HVAC Systems Using an Aspiration Efficiency Reducer: Long-Term Performance Assessment at Full-Scale,” J. Build. Eng., 12, pp. 267–274.
[12] Tominaga, Y., Mochida, A., Yoshie, R., Kataoka, H., Nozu, T., Yoshikawa, M., and Shirasawa, T., 2008, “AIJ Guidelines for Practical Applications of CFD to Pedestrian Wind Environment around Buildings,” J. Wind Eng. Ind. Aerodyn., 96(10), pp. 1749–1761.
[13] Menter, F. R., 1994, “Two-Equation Eddy-Viscosity Turbulence Models for Engineering Applications,” AIAA J., 32(8), pp. 1598–1605.
[14] Zhong, H.-Y., Jing, Y., Liu, Y., Zhao, F.-Y., Liu, D., and Li, Y., 2019, “CFD Simulation of ‘Pumping’ Flow Mechanism of an Urban Building Affected by an Upstream Building in High Reynolds Flows,” Energy Build., 202, p. 109330.
[15] Ramponi, R., and Blocken, B., 2012, “CFD Simulation of Cross-Ventilation for a Generic Isolated Building: Impact of Computational Parameters,” Build. Environ., 53, pp. 34–48.
[16] Fluent Inc., 2018, ANSYS Fluent Theory Guide, ANSYS, ANSYS, Inc., 275 Technology Drive Canonsburg, PA 15317.
[17] Haider, A., and Levenspiel, O., 1989, “Drag Coefficient and Terminal Velocity of Spherical and Nonspherical Particles,” Powder Technol., 58(1), pp. 63–70.
[18] Liu, J., and Niu, J., 2016, “CFD Simulation of the Wind Environment around an Isolated High-Rise Building: An Evaluation of SRANS, LES and DES Models,” Build. Environ., 96, pp. 91–106.
[19] Fluent Inc., 2018, ANSYS Fluent User Guide, ANSYS, ANSYS, Inc., 275 Technology Drive Canonsburg, PA 15317.
[20] Roache, P. J., 1994, “Perspective: A Method for Uniform Reporting of Grid Refinement Studies,” J. Fluids Eng., 116(3), pp. 405–413.
[21] Kenny, L. C., Aitken, R. J., Baldwin, P. E. J., Beaumont, G. C., and Maynard, A. D., 1999, “The Sampling Efficiency of Personal Inhalable Aerosol Samplers in Low Air Movement Environments,” J. Aerosol Sci., 30(5), pp. 627–638.
[22] Cui, P.-Y., Li, Z., and Tao, W.-Q., 2017, “Numerical Investigations on Re-Independence for the Turbulent Flow and Pollutant Dispersion under the Urban Boundary Layer with Some Experimental Validations,” Int. J. Heat Mass Transf., 106, pp. 422–436.
[23] Considine, B., McNabola, A., Kumar, P., and Gallagher, J., “Numerical Analysis of the Particle Aspiration Efficiency for a Building Ventilation System under Various Physical and Environmental Operating Conditions,” J. Environ. Manage., submitted for publication.