Ventilating Cathedral Ceilings to Prevent Problematic Icings at Their Eaves
Building heat from an unventilated steep-slope roof system can cause bottom melting of snow on that roof's surface. This often creates icicles, ice dams, leaks and structural damage at cold eaves. A prior study of attics showed that, to minimize such problems, attic ventilation systems should b...
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ftdtic:ADA433980 2023-05-15T16:37:32+02:00 Ventilating Cathedral Ceilings to Prevent Problematic Icings at Their Eaves Tobiasson, Wayne Tantillo, Thomas Buska, James COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH 1999-09 text/html http://www.dtic.mil/docs/citations/ADA433980 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA433980 en eng http://www.dtic.mil/docs/citations/ADA433980 Approved for public release; distribution is unlimited. DTIC AND NTIS Snow Ice and Permafrost Air Condition Heating Lighting & Ventilating Structural Engineering and Building Technology *VENTILATION *ICE FORMATION *MELTING *ROOFS SKILLS DAMAGE AIR INSULATION GRAPHS STRUCTURES FREEZING ICE GLASS FIBERS BARRIERS MATHEMATICS RIGIDITY BOTTOM OPENINGS DAMS TASTE AIR BARRIERS AIRWAYS *CATHEDRAL CEILINGS Text 1999 ftdtic 2016-02-21T10:48:36Z Building heat from an unventilated steep-slope roof system can cause bottom melting of snow on that roof's surface. This often creates icicles, ice dams, leaks and structural damage at cold eaves. A prior study of attics showed that, to minimize such problems, attic ventilation systems should be sized to keep the underside of the roof below freezing when it is 22 F (-5.6C) outside. When it is colder than that, it is easier to ventilate with outside air, and when it is warmer than 22 F(-5.6 C) meltwater seldom refreezes at eaves. In this paper, mathematical expressions for sizing airways of cathedral ceilings of various slopes, lengths and insulating abilities are presented. Coldroom tests of 16 food- (4.9-m-) long airways, some undersized and some oversized, show that the mathematics produces airways that do indeed perform as expected. In some of these tests, airways were blocked by expanding fibrous glass insulation. Air barriers and rigid insulation boards are shown to offer solutions to this problem. Design guidelines in the form of graphs make the taste of sizing cathedral ceiling airways, as well as their inlet and exhaust openings, quick and easy. Proceedings of the North American Conference on Roofing Technology, pg 84-97, 1999. Text Ice permafrost Defense Technical Information Center: DTIC Technical Reports database |
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Open Polar |
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Defense Technical Information Center: DTIC Technical Reports database |
op_collection_id |
ftdtic |
language |
English |
topic |
Snow Ice and Permafrost Air Condition Heating Lighting & Ventilating Structural Engineering and Building Technology *VENTILATION *ICE FORMATION *MELTING *ROOFS SKILLS DAMAGE AIR INSULATION GRAPHS STRUCTURES FREEZING ICE GLASS FIBERS BARRIERS MATHEMATICS RIGIDITY BOTTOM OPENINGS DAMS TASTE AIR BARRIERS AIRWAYS *CATHEDRAL CEILINGS |
spellingShingle |
Snow Ice and Permafrost Air Condition Heating Lighting & Ventilating Structural Engineering and Building Technology *VENTILATION *ICE FORMATION *MELTING *ROOFS SKILLS DAMAGE AIR INSULATION GRAPHS STRUCTURES FREEZING ICE GLASS FIBERS BARRIERS MATHEMATICS RIGIDITY BOTTOM OPENINGS DAMS TASTE AIR BARRIERS AIRWAYS *CATHEDRAL CEILINGS Tobiasson, Wayne Tantillo, Thomas Buska, James Ventilating Cathedral Ceilings to Prevent Problematic Icings at Their Eaves |
topic_facet |
Snow Ice and Permafrost Air Condition Heating Lighting & Ventilating Structural Engineering and Building Technology *VENTILATION *ICE FORMATION *MELTING *ROOFS SKILLS DAMAGE AIR INSULATION GRAPHS STRUCTURES FREEZING ICE GLASS FIBERS BARRIERS MATHEMATICS RIGIDITY BOTTOM OPENINGS DAMS TASTE AIR BARRIERS AIRWAYS *CATHEDRAL CEILINGS |
description |
Building heat from an unventilated steep-slope roof system can cause bottom melting of snow on that roof's surface. This often creates icicles, ice dams, leaks and structural damage at cold eaves. A prior study of attics showed that, to minimize such problems, attic ventilation systems should be sized to keep the underside of the roof below freezing when it is 22 F (-5.6C) outside. When it is colder than that, it is easier to ventilate with outside air, and when it is warmer than 22 F(-5.6 C) meltwater seldom refreezes at eaves. In this paper, mathematical expressions for sizing airways of cathedral ceilings of various slopes, lengths and insulating abilities are presented. Coldroom tests of 16 food- (4.9-m-) long airways, some undersized and some oversized, show that the mathematics produces airways that do indeed perform as expected. In some of these tests, airways were blocked by expanding fibrous glass insulation. Air barriers and rigid insulation boards are shown to offer solutions to this problem. Design guidelines in the form of graphs make the taste of sizing cathedral ceiling airways, as well as their inlet and exhaust openings, quick and easy. Proceedings of the North American Conference on Roofing Technology, pg 84-97, 1999. |
author2 |
COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH |
format |
Text |
author |
Tobiasson, Wayne Tantillo, Thomas Buska, James |
author_facet |
Tobiasson, Wayne Tantillo, Thomas Buska, James |
author_sort |
Tobiasson, Wayne |
title |
Ventilating Cathedral Ceilings to Prevent Problematic Icings at Their Eaves |
title_short |
Ventilating Cathedral Ceilings to Prevent Problematic Icings at Their Eaves |
title_full |
Ventilating Cathedral Ceilings to Prevent Problematic Icings at Their Eaves |
title_fullStr |
Ventilating Cathedral Ceilings to Prevent Problematic Icings at Their Eaves |
title_full_unstemmed |
Ventilating Cathedral Ceilings to Prevent Problematic Icings at Their Eaves |
title_sort |
ventilating cathedral ceilings to prevent problematic icings at their eaves |
publishDate |
1999 |
url |
http://www.dtic.mil/docs/citations/ADA433980 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA433980 |
genre |
Ice permafrost |
genre_facet |
Ice permafrost |
op_source |
DTIC AND NTIS |
op_relation |
http://www.dtic.mil/docs/citations/ADA433980 |
op_rights |
Approved for public release; distribution is unlimited. |
_version_ |
1766027829854601216 |