A Discussion Regarding the Measurement of Ventilation Rates Using Tracer Gas and Decay Technique

• Type: Article in International Scientific Journal
• Date: 2020

Authors

Ricardo M. S. F. Almeida (Author) Other; Eva Barreira (Author) FEUP; Pedro Moreira (Author) Other

Journal

Title: Infrastructures

Vol. 5 No. 10

Pages: 1-13

Publisher: MDPI

Indexing

ISI Web of Knowledge - 1 Citation

Scopus - 2 Citations

Other information

Authenticus ID: P-00S-V06

DOI: 10.3390/infrastructures5100085

Abstract (EN): <jats:p>The measurement of ventilation rates is crucial in understanding buildings¿ performances, but can be a rather complex task due to the time-dependency of wind and buoyancy forces, which are responsible for the pressure differences that induce air movement across the envelope. Thus, assessing air change rate through one-time measurements during brief periods of time may not be a reliable indicator. In this paper, the variability in the measurement of ventilation rates using the decay technique was evaluated. To that end, two compartments of a typical single-family detached dwelling were selected as a case study and 132 tests were performed, considering two different boundary conditions (door closed and door open). This work allowed the large variability of the results to be highlighted, as the coefficient of variation ranged from 20% to 64%. Wind speed had a key effect on the results, especially because during the measurements indoor¿outdoor temperature differences were not so significant. The possibility of using occupant-generated carbon dioxide as tracer gas was also analyzed, but problems of cross-contamination were identified.</jats:p>

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 13