1 deterioration of trusses and roof systems of livestock farm buildings by yves choinière ing.,...
TRANSCRIPT
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Deterioration of Trusses and Roof Systems of Livestock Farm
Buildings
By Yves Choinière
Ing., agr., P. Eng.
CSBE: 08-117
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Case study
#1: Finishing swine barn, Ontario– Power-natural ventilation versus 100 % natural
ventilation #2: Nursery-finishing, Ontario
– Mechanical ventilation #3: Finishing swine barn, Quebec
– 100 % natural ventilation #4: Pullet rearing barn
– Mechanical ventilation
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Case #1: Finishing swine barn
Barn A– Power-natural ventilation, 1996– Winter pit fans– Modular ceiling air inlets– Deep pit over slatted floor– Summer natural ventilation
Barn B– 100 % natural ventilation, 1995– Similar to barn A
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Table of results, power-natural 1996
November 21, 2007
Exterior T° = 5°C, rain
Attic measurements In-barn
T° 6-7° C 15-16° C
R.H. % 60-65 % 80-85 %
NH3 2-4 ppm 15 ppm
CO2 600-700 ppm 3 000 ppm
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Table of results, 100 % natural 1996
Attic measurements In-barn
T° 6-7° C 15-16° C
R.H. % 70-75 % 70 %
NH3 N\D 15 ppm
CO2 400-500 ppm 3 000 ppm
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Observations
Attic space contamination from the barn to the attic by :– Modular air inlets– Fan exhaust– Eave openings– Vapor barrier failure
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Case #2: Nursery-finishing
Mechanical ventilation– Ceiling modular air inlets– Sidewall fans– Open eave
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Table of results, 1997-1998
Attic measurements In-barn
T° 7-8° C 21-22° C
R.H. % 75-80 % 70-75 %
NH3 6-7 ppm 16-17 ppm
CO2 700-800 ppm 2 800-3 000 ppm
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Observations
Attic space contamination :– Modular air inlets– Fan exhaust– Eave openings– Vapor barrier failure
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Case #3: Finishing swine naturally ventilated barn
Natural ventilation– Alley scrappers– Eave openings– Attic ventilation
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Observations
Eave opening desing; minimum space Vapor barrier Chimney vapor tightness Ridge ventilator, snow + rain
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Case #4: Pullet rearing barn, 1976
Sidewall air inlets without attic contact Sidewall fan exhaust with wind stoppers
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Conclusion
Ceiling modular air inlets– Risk of attic backdraft– Sealed or negative pressure
Sidewall exhaust fans– No eave openings above winter fans– Fans with winter hoods– Eave opening desing