Field measurement of natural ventilation rate in an idealised full-scale building located in a staggered urban array: comparison between tracer gas and pressure-based methods

Gough, H. L., Luo, Z. ORCID: https://orcid.org/0000-0002-2082-3958, Halios, C. H. ORCID: https://orcid.org/0000-0001-8301-8449, King, M.-F., Noakes, C. J., Grimmond, C. S. B. ORCID: https://orcid.org/0000-0002-3166-9415, Barlow, J. F., Hoxey, R. and Quinn, A. D. (2018) Field measurement of natural ventilation rate in an idealised full-scale building located in a staggered urban array: comparison between tracer gas and pressure-based methods. Building and Environment, 137. pp. 246-256. ISSN 0360-1323 doi: 10.1016/j.buildenv.2018.03.055

Abstract/Summary

Currently, no clear standards exist for determining urban building natural ventilation rates, especially under varying realistic meteorological conditions. In this study, ventilation rates are determined using tracer gas decay and pressure-based measurements for a full-scale (6 m tall) cube. The cube was either isolated (2 months of observations) or sheltered within a staggered array (7 months), for both single-sided and cross ventilation (openings 0.4 x 1 m). Wind speeds at cube height ranged between 0.04 m s-1 and 13.1 m s-1. Errors for both ventilation methods are carefully assessed. There is no discernible linear relation between normalised ventilation rates from the two methods, except for cross ventilation in the array case. The ratio of tracer gas and pressure derived ventilation rates is assessed with wind direction. For single-sided (leeward opening) cases it approached 1. For cross ventilation the ratio was closer to 1 but with more scatter. One explanation is that agreement is better when internal mixing is less jet-dominated, i.e. for oblique directions in the isolated case and for all directions for unsteady array flows. Sheltering may reduce the flushing rate of the tracer gas from the cube relative to internal mixing rate. This new dataset provides an extensive range of conditions for numerical model evaluation and for understanding uncertainty of ventilation rates. Knowledge of the latter is critical in building

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/76381
Identification Number/DOI	10.1016/j.buildenv.2018.03.055
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology Science > School of the Built Environment > Urban Living group Science > School of the Built Environment > Energy and Environmental Engineering group
Uncontrolled Keywords	Natural ventilation, ventilation rate, tracer gas, full-scale, pressure, wind direction
Publisher	Elsevier
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