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Steen Englund, JessikaORCID iD iconorcid.org/0000-0002-5822-4838
Publications (2 of 2) Show all publications
Steen Englund, J., Akander, J., Björling, M. & Moshfegh, B. (2017). Assessment of Airflows in a School Building with Mechanical Ventilation Using Passive Tracer Gas Method (1ed.). In: Sayigh, Ali (Ed.), Mediterranean Green Buildings & Renewable Energy: Selected Papers from the World Renewable Energy Network’s Med Green Forum: (pp. 619-631). Springer
Open this publication in new window or tab >>Assessment of Airflows in a School Building with Mechanical Ventilation Using Passive Tracer Gas Method
2017 (English)In: Mediterranean Green Buildings & Renewable Energy: Selected Papers from the World Renewable Energy Network’s Med Green Forum / [ed] Sayigh, Ali, Springer, 2017, 1, p. 619-631Chapter in book (Refereed)
Abstract [en]

The focus of this study is to assess the airflows in a school building built in 1963 in Gävle, Sweden, which is subject to energy conservation measures (ECMs) in a forthcoming renovation. Today, the school building is mainly ventilated by several mechanical ventilation systems, which are controlled by a constant air volume (CAV) strategy. Schedules and presence sensors impose a high operation mode during the day and a low operation mode at night, on weekends and on holidays. The homogeneous tracer gas emission method with passive sampling is used to measure the average local mean age of air (τ) during different operation modes. Temperature, relative humidity and CO2 concentration are simultaneously measured. The calculated relative uncertainty for the average local mean age of air in every measured point is approx. ±20 %. The results during low operation mode show an average value of τ of approx. 8.51 h [corresponding to 0.12 air changes per hour (ACH)], where τ in various zones ranges between 2.55 and 16.37 h (indicating 0.06–0.39 ACH), which is related to the unintentional airflow in the school. The results during mixed operation mode show an average value of τ of approx. 4.60 h (0.22 ACH), where τ in various zones ranges between 2.00 and 8.98 h (0.11–0.50 ACH), which is related to both unintentional and intentional airflows in the school. Corridors, basement and attic rooms and entrances have lower τ compared to classrooms, offices and other rooms. High maximums of the CO2 concentration in some rooms indicate an imbalance in the mechanical ventilation systems. During a regular school week of mixed operation, which includes both high and low operation modes, it is found that mainly the low operation modes show up in the results. The dynamics of the highly varying airflows in the building cannot be identified using the passive sampling technique.

Place, publisher, year, edition, pages
Springer, 2017 Edition: 1
Keywords
Homogeneous tracer gas emission technique, Local mean age of air, Air change rate, Air leakage, School building
National Category
Energy Systems
Identifiers
urn:nbn:se:hig:diva-24006 (URN)10.1007/978-3-319-30746-6_47 (DOI)2-s2.0-85029047826 (Scopus ID)978-3-319-30745-9 (ISBN)978-3-319-30746-6 (ISBN)
Note

Entire publication doi: 10.1007/978-3-319-30746-6

Available from: 2017-05-12 Created: 2017-05-12 Last updated: 2018-03-13Bibliographically approved
Björling, M., Akander, J. & Steen Englund, J. (2016). On Measuring Air Infiltration Rates Using Tracer Gases in Buildings with Presence Controlled Mechanical Ventilation Systems. In: E. Van Kenhove, J. Laverge, P. De Vlieger (Ed.), Indoor Air 2016: The 14th International Conference of Indoor Air Quality and Climate, July 3-8 2016, Ghent, Belgium: Conference Proceedings. Paper presented at Indoor Air 2016, 14th International Conference of Indoor Air Quality and Climate, Ghent, Belgium, 3-8 July 2016. ISIAQ, Article ID 875.
Open this publication in new window or tab >>On Measuring Air Infiltration Rates Using Tracer Gases in Buildings with Presence Controlled Mechanical Ventilation Systems
2016 (English)In: Indoor Air 2016: The 14th International Conference of Indoor Air Quality and Climate, July 3-8 2016, Ghent, Belgium: Conference Proceedings / [ed] E. Van Kenhove, J. Laverge, P. De Vlieger, ISIAQ , 2016, article id 875Conference paper, Published paper (Refereed)
Abstract [en]

The ventilation and air leakage of a school building was investigated. Information was collected from the parameters of the mechanical ventilation system and from measurements of the local mean age of air using the homogeneous emission method. While the average local mean ages of air can be accurately measured by passive integrative samplers, the estimation of the average room specific air change rate by taking the inverse of the measured average local mean age of air did not give correct results. The main problem is that integrative sampling represents a linear averaging process that is inappropriate to capture the average of nonlinearly related properties. This problem is accentuated when the ventilation rates for different periods differ a lot. A simple computational model was developed to discuss the system behavior. A partial solution to the measurement problem is to actively sample the different populations of air change rates separately.

Place, publisher, year, edition, pages
ISIAQ, 2016
Keywords
air infiltration, local mean age of air, room specific ventilation rate, ACH
National Category
Environmental Analysis and Construction Information Technology
Identifiers
urn:nbn:se:hig:diva-22676 (URN)978-0-9846855-5-4 (ISBN)
Conference
Indoor Air 2016, 14th International Conference of Indoor Air Quality and Climate, Ghent, Belgium, 3-8 July 2016
Available from: 2016-11-11 Created: 2016-10-28 Last updated: 2018-03-13Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0002-5822-4838

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