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Hayati, A., Mattsson, M. & Sandberg, M. (2019). A wind tunnel study of wind-driven airing through open doors. The International Journal of Ventilation, 113-135
Open this publication in new window or tab >>A wind tunnel study of wind-driven airing through open doors
2019 (English)In: The International Journal of Ventilation, ISSN 1473-3315, E-ISSN 2044-4044, p. 113-135Article in journal (Refereed) Published
Abstract [en]

Temporarily enhanced natural ventilation of indoor environments can be achieved by opening windows and/or doors, i.e. airing. In this study, wind driven airing rate through doors was measured by tracer gas at a building model in a wind tunnel. Both single opening and cross flow airing was investigated, with doors placed in centrally on the long side of an elongated building model. It was found that cross flow airing yielded 4–20 times higher airing rate than single opening airing; lowest value occurring with opening surfaces perpendicular to wind direction. At single opening airing, windward positioned door yielded about 53% higher airing rate than leeward positioned. Inclusion of a draught lobby (extended entrance space) lowered airing rate by 27%, while higher wind turbulence increased it by 38%. Advection through turbulence appeared a more important airing mechanism than pumping. At cross flow, however, turbulence and draught lobby had practically no effect.

Place, publisher, year, edition, pages
Taylor & Francis, 2019
Keywords
Wind-driven flow, Single-sided ventilation, Cross flow, Tracer gas decay method, Wind turbulence, Churches
National Category
Building Technologies
Identifiers
urn:nbn:se:hig:diva-25112 (URN)10.1080/14733315.2018.1435027 (DOI)000469880200003 ()2-s2.0-85042108561 (Scopus ID)
Projects
Church project
Funder
Swedish Energy Agency, 2011-002440
Available from: 2017-08-28 Created: 2017-08-28 Last updated: 2019-08-22Bibliographically approved
Hayati, A., Akander, J. & Mattsson, M. (2019). Simulation of Ventilation Rates and Heat Losses during Airing in Large Single Zone Buildings in Cold Climates. In: Johansson, D., Bagge, H., Wahlström, Å. (Ed.), Cold Climate HVAC 2018: Sustainable Buildings in Cold Climates. Paper presented at Cold Climate HVAC 2018, The 9th International Cold Climate Conference, Sustainable new and renovated buildings in cold climates, Kiruna, Sweden, 12-15 March 2018. Springer
Open this publication in new window or tab >>Simulation of Ventilation Rates and Heat Losses during Airing in Large Single Zone Buildings in Cold Climates
2019 (English)In: Cold Climate HVAC 2018: Sustainable Buildings in Cold Climates / [ed] Johansson, D., Bagge, H., Wahlström, Å., Springer, 2019Conference paper, Published paper (Refereed)
Abstract [en]

Airing can be a solution to introduce extra ventilation in large single zone buildings, especially where there are large aggregations of people such as churches or atriums. In naturally ventilated domestic and ancient buildings, opening of a window or door can introduce extra fresh air and remove particles and other contaminants emitted from people and other sources such as lit candles in churches. However, the energy use might be an issue in cold climates, where airing might lead to waste of heated air, at the same time as indoor air temperatures can be uncomfortably low. In the present study, the energy loss and ventilation rate due to airing in a large single zone (church) building is investigated via IDA-ICE simulation on annual basis in cold weather conditions. The results can be used in order to prepare airing guidelines for large single zone buildings such as atriums, churches, industry halls and large sport halls. According to the results, one-hour of airing in the studied church building resulted in 40-50 % of exchanged room air and, if practiced once a week, an increase of around 1 % in heating energy.

Place, publisher, year, edition, pages
Springer, 2019
Series
Springer Proceedings in Energy, ISSN 2352-2534
Keywords
Airing (single-sided ventilation), IDA-ICE simulation, Large single zones.
National Category
Building Technologies Energy Systems
Identifiers
urn:nbn:se:hig:diva-26260 (URN)978-3-030-00661-7 (ISBN)978-3-030-00662-4 (ISBN)
Conference
Cold Climate HVAC 2018, The 9th International Cold Climate Conference, Sustainable new and renovated buildings in cold climates, Kiruna, Sweden, 12-15 March 2018
Note

Forthcomming March 2019

Available from: 2018-03-21 Created: 2018-03-21 Last updated: 2018-12-06Bibliographically approved
Björling, M., Mattsson, M. & Akander, J. (2018). Infiltration of Air into two World Heritage Farmhouses in Sweden during Winter Conditions. In: Risto Kosonen, Mervi Ahola, Jarkko Narvanne (Ed.), Roomvent & Ventilation 2018: Excellent Indoor Climate and High Performing Ventilation. Paper presented at Roomvent & Ventilation 2018 'Excellent Indoor Climate and High Performing Ventilation', 2-5 June, 2018, Espoo, Finland (pp. 1079-1084). Helsinki, Finland
Open this publication in new window or tab >>Infiltration of Air into two World Heritage Farmhouses in Sweden during Winter Conditions
2018 (English)In: Roomvent & Ventilation 2018: Excellent Indoor Climate and High Performing Ventilation / [ed] Risto Kosonen, Mervi Ahola, Jarkko Narvanne, Helsinki, Finland, 2018, p. 1079-1084Conference paper, Published paper (Refereed)
Abstract [en]

As a part of an ongoing study, we report measurements of air infiltration during winter conditions into two Decorated Farmhouses of Hälsingland designated as UNESCO World Heritage Sites. In winter these two-storied farmhouses are rarely heated, except for special occasions. In this measurement one farmhouse  was  unheated,  whereas  one  room  was  heated  for  a  brief  period  in  the  other  one.  The observed local mean ages of air measured with tracer gas techniques generally increase with height, both  locally  within  each  room  and  between  floors.  The  average  temperature  and  humidity  also increases from the first to the second floor. The indoor temperature follows the outdoor temperature with a time lag. The differences in water content between inside and outside air correlate with changes of the indoor relative humidity. The correlation is stronger for humidity increase than for humidity decrease, possibly due to moisture absorption by interior text.

Place, publisher, year, edition, pages
Helsinki, Finland: , 2018
Keywords
World Heritage, preservation, moisture, relative humidity, air infiltration, PFT tracer
National Category
Other Civil Engineering
Identifiers
urn:nbn:se:hig:diva-28778 (URN)978-952-5236-48-4 (ISBN)
Conference
Roomvent & Ventilation 2018 'Excellent Indoor Climate and High Performing Ventilation', 2-5 June, 2018, Espoo, Finland
Available from: 2018-12-07 Created: 2018-12-07 Last updated: 2018-12-07Bibliographically approved
Falk, A. B., Lindström, S., Mattsson, M. & Wright, S. A. I. (2018). Influence of some weather parameters on the susceptibility of apple fruit to postharvest grey mould attack. In: Proceedings 2018: . Paper presented at 18th International Conference on Organic Fruit Growing; University of Hohenheim, Germany; 19-21 February 2018 (pp. 124-127).
Open this publication in new window or tab >>Influence of some weather parameters on the susceptibility of apple fruit to postharvest grey mould attack
2018 (English)In: Proceedings 2018, 2018, p. 124-127Conference paper, Published paper (Refereed)
Abstract [en]

Several cultural and weather factors during the season influence the susceptibility of apple fruit to post-harvest pathogens. In the present study, the effect of different weather parameters on postharvest susceptibility of apples of the cv. ‘Ingrid Marie’ to grey mould was investigated. In 2015, apple fruit were collected from orchards in Southern Sweden, where local weather stations monitored different parameters. After harvest, the fruit were tested for susceptibility to grey mould by artificially inoculating them with%FLQHUHD. Lesion development was monitored over a 10-day-period. Analysis of results for a few orchards showed that cold weather for over a month preceding harvest and a low total number of growth degree days gave apples that were more susceptible to grey mould. This study was carried out in conventional orchards, but the conclusions can be important also for organic production, since they deal with the general effect of sunshine, temperature and rain, factors that may strengthen fruit during cultivation, regardless of production type. Future studies may focus on organic production to investigate whether these effects are general and also apply to organic production.

Keywords
sun, temperature, apple, Botyris cinerea, prediction
National Category
Food Science Biological Sciences Meteorology and Atmospheric Sciences
Identifiers
urn:nbn:se:hig:diva-28730 (URN)
Conference
18th International Conference on Organic Fruit Growing; University of Hohenheim, Germany; 19-21 February 2018
Available from: 2018-11-30 Created: 2018-11-30 Last updated: 2018-11-30Bibliographically approved
Hayati, A., Mattsson, M. & Sandberg, M. (2017). Single-sided ventilation through external doors: measurements and model evaluation in five historical churches. Energy and Buildings, 141, 114-124
Open this publication in new window or tab >>Single-sided ventilation through external doors: measurements and model evaluation in five historical churches
2017 (English)In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 141, p. 114-124Article in journal (Refereed) Published
Abstract [en]

Ventilation through open doors is a simple way to temporarily enhance ventilation of indoor spaces, with the purpose to evacuate indoor air pollutants or to adjust the indoor temperature. In churches and other historical buildings, which otherwise are ventilated only through air infiltration, temporarily enhanced ventilation through open doors or windows may be a prudent deed after e.g. services involving large congregations and burning of candles or incense. In the present study, the air exchange occurring at single-sided ventilation through the external doors of five historical churches is measured by tracer gas decay method. Further, air velocity measurements and smoke visualization in a doorway are performed. Measurement results are compared with predictions attained from four previously developed models for single‐sided ventilation. Models that include terms for wind turbulence yielded somewhat better predictions. According to the performed measurements, the magnitude of one hour single-sided open-door airing in a church is typically around 50% air exchange, indicating that this is a workable ventilation method, also for such large building volumes. A practical diagram to facilitate estimation of a suitable airing period is also presented. The study adds particularly knowledge to the issue of airing through doors, in large single zones.

Keywords
Natural ventilation, Single-sided ventilation, Historical buildings, Tracer gas field measurements, Model evaluation, Airing
National Category
Building Technologies
Identifiers
urn:nbn:se:hig:diva-23675 (URN)10.1016/j.enbuild.2017.02.034 (DOI)000400212400009 ()2-s2.0-85013648580 (Scopus ID)
Projects
Church project
Funder
Swedish Energy Agency, 2011-002440
Available from: 2017-02-24 Created: 2017-02-24 Last updated: 2018-03-13Bibliographically approved
Hayati, A., Mattsson, M. & Sandberg, M. (2016). A Study on Airing Through the Porches of a Historical Church – Measurements and IDA-ICE Modelling. In: ASHRAE and AIVC IAQ 2016 - Defining Indoor Air Quality: Policy, Standards and Best Practices, 2016. Paper presented at ASHRAE and AIVC IAQ 2016 — Defining Indoor Air Quality: Policy, Standards and Best Practices, 12–14 September 2016, Alexandria, Virginia, USA (pp. 216-223). ASHRAE, Article ID C029.
Open this publication in new window or tab >>A Study on Airing Through the Porches of a Historical Church – Measurements and IDA-ICE Modelling
2016 (English)In: ASHRAE and AIVC IAQ 2016 - Defining Indoor Air Quality: Policy, Standards and Best Practices, 2016, ASHRAE, 2016, p. 216-223, article id C029Conference paper, Published paper (Refereed)
Abstract [en]

In churches, intentional airing may be a measure to evacuate temporarily high levels of contaminants that are emitted during services and other occasions. Crucial contaminants include moisture and other emissions that may deteriorate and/or soil painted surfaces and other precious artefacts. Most old churches do not have any mechanical ventilation system or any purpose provided openings for natural ventilation, but the ventilation is governed by air infiltration. Enhanced airing may be achieved by opening external windows or doors. Thus, models provided in energy simulation programs should predict this kind of air flows correctly, also in order to get a proper estimation of the total energy use. IDA-ICE is examined here and the model for air flow through a large vertical opening used in the program is investigated. In the present study, field measurements were performed for airing rate in a historical church. In comparison with measured air flow rates, the simulated results were of the same magnitude, but the effect of wind direction was less considered by the simulation program.

Place, publisher, year, edition, pages
ASHRAE, 2016
Keywords
Airing, Single-sided ventiltion, Simulation, IDA-ICE, Churches.
National Category
Building Technologies
Identifiers
urn:nbn:se:hig:diva-22747 (URN)978-1-939200-48-8 (ISBN)
Conference
ASHRAE and AIVC IAQ 2016 — Defining Indoor Air Quality: Policy, Standards and Best Practices, 12–14 September 2016, Alexandria, Virginia, USA
Projects
Church project
Funder
Swedish Energy Agency, 2011-002440
Available from: 2016-11-11 Created: 2016-11-11 Last updated: 2018-03-13Bibliographically approved
Hayati, A., Akander, J. & Mattsson, M. (2016). Development of a Numerical Air Infiltration Model Based On Pressurization Test Applied On a Church. In: ASHRAE and AIVC IAQ 2016 — Defining Indoor Air Quality: Policy, Standards and Best Practices, 2016. Paper presented at ASHRAE and AIVC IAQ 2016 — Defining Indoor Air Quality: Policy, Standards and Best Practices, 12–14 September 2016, Alexandria, Virginia (pp. 224-231). ASHRAE, Article ID C030.
Open this publication in new window or tab >>Development of a Numerical Air Infiltration Model Based On Pressurization Test Applied On a Church
2016 (English)In: ASHRAE and AIVC IAQ 2016 — Defining Indoor Air Quality: Policy, Standards and Best Practices, 2016, ASHRAE, 2016, p. 224-231, article id C030Conference paper, Published paper (Refereed)
Abstract [en]

Pressurization (blower door) test is a well-established standardized method, performed in order to quantify the total leakage in a building envelope. However, blower door results are not adequate to use when air leakage through the building envelope during natural conditions (non-pressurized) is to be estimated. A common assumption made when estimating air leakage during natural conditions, is that air leakage paths are evenly distributed in the areas of the building envelope. This assumption gives quite poor calculation results since different leakage configurations are often situated unevenly in the envelope. In order to improve the correspondence between Blower door and air leakage model results, more information on the types and locations of the leakage paths are required as input to simulation models. 

This paper investigates if additional information from visual inspection and IR-thermography observations at site can increase the precision when simulating air change rates due to air leakage in natural conditions.  A numerical model is developed in this study by allocating leakage in various parts of the building envelope. The leakage allocation is based on visual inspection and IR-thermography observations at the site during the blower door test.

This procedure is tested in the case study of a large single zone church. Blower door, neutral pressure level measurement and leakage allocation results are used as input in the numerical model. Model results are compared with tracer gas measurements and result accuracy is compared with results from the Lawrence Berkeley Laboratory model (LBL) and the Alberta Air Infiltration Model (AIM-2) for the same church. 

Place, publisher, year, edition, pages
ASHRAE, 2016
Keywords
Air infiltration, Air leakage, Modeling, Churches.
National Category
Building Technologies
Identifiers
urn:nbn:se:hig:diva-22734 (URN)978-1-939200-48-8 (ISBN)
Conference
ASHRAE and AIVC IAQ 2016 — Defining Indoor Air Quality: Policy, Standards and Best Practices, 12–14 September 2016, Alexandria, Virginia
Projects
Church project
Funder
Swedish Energy Agency, 2011-002440
Available from: 2016-11-11 Created: 2016-11-11 Last updated: 2018-03-13Bibliographically approved
Mattsson, M. & Linden, E. (2016). Test av luftrenare i Visby domkyrka.
Open this publication in new window or tab >>Test av luftrenare i Visby domkyrka
2016 (Swedish)Report (Other academic)
Abstract [sv]

Efter den senaste renoveringen av Visby domkyrka, som bl a innefattade rengöring av innerväggar (våren 2014), noterades en oväntat snabb försmutsning av rengjorda väggytor, orsakad av avsättning av partiklar i inneluften. Med syfte att minska försmutsningstakten installerades två fristående luftrenare av elektrostatisk modell i kyrkan i oktober 2015. Föreliggande studie har haft som främsta syfta att utvärdera dessa luftrenares effektivitet i att rena inneluften på luftburna partiklar, framför allt från levande ljus. Utvärderingen har gjorts genom att mäta hur partikelhalten i kyrksalen förändrades vid olika driftfall på luftrenarna. Två olika flödesinställningar på luftrenarna provades: maxflöde resp. lågflöde, där maxflödet provades med både horisontellt och vertikalt riktat utblås av den renade luften. Anledningen till att även ett lägre luftreningsflöde provades var att luftrenarna bullrade så mycket vid maxflöde att detta driftförhållande endast torde bli aktuellt utanför besökstid. Studien har även inkluderat luftomsättningsmätning med spårgasteknik, luft- och yttemperaturmätningar, samt kallrasmätning vid vägg. Även ett vädringstest via portöppning har ingått. 

Resultaten tyder på att luftrenarna har en klart renande effekt avseende luftburna partiklar i kyrksalen. Den minskning i antalet partiklar som luftrenarna åstadkom (partikelrenings-effektiviteten) varierade emellertid med partikelstorleken. I lågflödesfallet erhölls en reduktion av de minsta partiklarna (ultrafina, 0,02-0,3 µm) med ca 31 %, medan den för större partiklar (0,3-10 µm) var av storleksordningen 65‑75 %. I maxflödesfallet blev motsvarande siffror ca 58 % för de minsta partiklarna och 80‑90 % för de större. I välbesökta kyrkor där levande ljus ofta tänds – som i Visby domkyrka – utgör emissionerna från ljusen förmodligen den största partikelkällan. För dessa tycks de minsta partiklarna dominera avseende partikelyta (som kan tänkas täcka/försmutsa invändiga ytor), varför den sammantagna partikelreningseffektiviteten avseende försmutsning hamnar närmare den för de minsta partiklarna. Det är dock troligt att partikelreningseffektivitet blir något högre sommartid, då de riktigt stora besökarskarorna kommer i fallet Visby domkyrka.

Riktningen på utblåset på luftrenarna hade ingen nämnvärd inverkan på partikelrenings-effektiviteten. Dock indikerade mätningarna av kallras (nedfallande luft) längs yttervägg i kyrkan att detta blir något större vid uppåtriktat utblås på luftrenarna, vilket riskerar att öka partikelavsättningstakten vid ytan. Detta fenomen behöver dock studeras närmare. Testet med vädring genom portöppning indikerade att ett avsevärt luftutbyte erhölls med denna metod, och att tillfällig vädring därför kan vara en lämplig åtgärd (även som komplement till luftrenare) vid tillfällen med många besökare och/eller mycket ljusbränning. Både partikel- och spårgasmätningarna påvisade god luftomblandning i kyrksalen, vilket är positivt för spridningen av den renade luften, och detta bidrar till att placeringen av luftrenarna är mindre kritisk. Sommartid kan dock luftomblandningen bli sämre; detta kan behöva undersökas närmare. Förutom minskad försmutsning kan luftrenarna förväntas bidra till en hälsosammare innemiljö ett minskat städbehov i kyrkan.

Publisher
p. 30
Keywords
Luftrenare, Kyrkor, Försmutsning, Luftomsättning, Temperaturfördelning
National Category
Civil Engineering
Identifiers
urn:nbn:se:hig:diva-21343 (URN)
Projects
Church project
Note

Forskningsstudie gjord på uppdrag av Visby domkyrkoförsamling, Samfälligheten Gotlands kyrkor, Gustaf Vasa församling och Visby stift.

Available from: 2016-03-22 Created: 2016-03-22 Last updated: 2018-12-03Bibliographically approved
Sandberg, M., Mattsson, M., Wigö, H., Hayati, A., Claesson, L., Linden, E. & Khan, M. (2015). Viewpoints on wind and air infiltration phenomena at buildings illustrated by field and model studies. Building and Environment, 92, 504-517
Open this publication in new window or tab >>Viewpoints on wind and air infiltration phenomena at buildings illustrated by field and model studies
Show others...
2015 (English)In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 92, p. 504-517Article in journal (Refereed) Published
Abstract [en]

Ventilation and infiltration caused by wind are difficult to predict because they are non-local phenomena: driving factors depend on the surrounding terrain and neighbouring buildings and on the building orientation with respect to the wind direction. Wind-driven flow through an opening is complex because wind can flow through the opening or around the building, in contrast to buoyancy driven flow. We explored wind and air infiltration phenomena in terms of pressure distributions on and around buildings, stagnation points, flow along façades, drag forces, and air flow through openings. Field trials were conducted at a 19th-century church, and wind tunnel tests were conducted using a 1:200 scale model of the church and other models with openings.

 

The locations of stagnation points on the church model were determined using particle image velocimetry measurements. Multiple stagnation points occurred. The forces exerted on the church model by winds in various directions were measured using a load cell. The projected areas affected by winds in various directions were calculated using a CAD model of the church. The area-averaged pressure difference across the church was assessed. A fairly large region of influence on the ground, caused by blockage of the wind, was revealed by testing the scale model in the wind tunnel and recording the static pressure on the ground at many points. The findings of this study are summarized as a number of steps that we suggest to be taken to improve analysis and predictions of wind driven flow in buildings.

Place, publisher, year, edition, pages
Elsevier, 2015
Keywords
Infiltration, Wind, Particle Image Velocimetry, Openings, Stagnation points, Drag force
National Category
Building Technologies
Identifiers
urn:nbn:se:hig:diva-19278 (URN)10.1016/j.buildenv.2015.05.001 (DOI)000358807800046 ()2-s2.0-84930645066 (Scopus ID)
Projects
Church project
Funder
Swedish Energy Agency, 34964-1
Available from: 2015-05-04 Created: 2015-05-04 Last updated: 2018-12-03Bibliographically approved
Hayati, A., Mattsson, M. & Sandberg, M. (2014). Evaluation of the LBL and AIM-2 air infiltration models on large single zones: three historical churches. Building and Environment, 81, 365-379
Open this publication in new window or tab >>Evaluation of the LBL and AIM-2 air infiltration models on large single zones: three historical churches
2014 (English)In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 81, p. 365-379Article in journal (Refereed) Published
Abstract [en]

Air infiltration in ancient churches and other historical and monumental buildings is of great importance considering moisture transfer, energy consumption, thermal comfort and air pollutants that induce surface soiling. Two of the most established models for predicting air infiltration rate in buildings are the Lawrence Berkeley Laboratory (LBL) model and the Alberta air Infiltration Model (AIM-2). Being originally developed mainly for dwellings, their applicability to large single zone buildings is evaluated in this study by comparing model predictions with field measurements in three historical stone churches that are naturally ventilated only through infiltration. The somewhat more developed AIM-2 model yielded slightly better predictions than the LBL model. However, an LBL version that allows inclusion of the Neutral Pressure Level (NPL) of the building envelope produced even better predictions and also proved less sensitive to assumptions on air leakage distribution at the building envelopes. All models yielded however significant overpredictions of the air infiltration rate. Since NPL may be difficult to attain in practice, the AIM-2 model was chosen for model modification to improve predictions. Tuning of this model by varying its original coefficients yielded however unrealistic model behaviors and the eventually suggested modification implied introducing a correction factor of 0.8. This reduced the median absolute prediction error from 25% to 11%. Thus, especially when the NPL is not at hand, this modification of the AIM-2 model may suit better for air infiltration assessment of churches and other buildings similar to the tested kind.

Keywords
Air infiltration, LBL model, AIM-2 model, Large single zones, Churches, Model optimization
National Category
Building Technologies
Identifiers
urn:nbn:se:hig:diva-17371 (URN)10.1016/j.buildenv.2014.07.013 (DOI)000342532200035 ()2-s2.0-84907334554 (Scopus ID)
Projects
Church project
Funder
Swedish Energy Agency, 2011-002440
Available from: 2014-08-18 Created: 2014-08-18 Last updated: 2018-03-13Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-0337-8004

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