Recommended Modified zone Method Correction Factor for Determining R-values of Cold-Formed Steel Wall Assemblies

Description:

Currently, ASHRAE has determined the zone method and modified zone method are appropriate calculation methods for materials with a high difference in conductivity, such as cold-formed steel (CFS) walls. Because there is currently no standard U-Factor calculation method for CFS walls, designers and code officials alike tend to resort to the zone method. However, the zone method is restricted to larger span assemblies because the zone factor coefficient is 2.0. This tends to overestimate the amount of surface area influenced by CFS. The modified zone method is restricted to C-shaped stud, clear wall assemblies with framing factors between 9 and 15%. The objective of the research is to narrow the gap of knowledge by re-examining the modified zone method in order to more accurately determine R-Values and U-Factors for CFS wall assemblies with whole wall framing factor percentages of 22% and above.

Creator(s): Black, John
Creation Date: May 2011
Partner(s):
UNT Libraries
Collection(s):
UNT Theses and Dissertations
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Past 30 days: 41
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Publisher Info:
Publisher Name: University of North Texas
Place of Publication: Denton, Texas
Date(s):
  • Creation: May 2011
Description:

Currently, ASHRAE has determined the zone method and modified zone method are appropriate calculation methods for materials with a high difference in conductivity, such as cold-formed steel (CFS) walls. Because there is currently no standard U-Factor calculation method for CFS walls, designers and code officials alike tend to resort to the zone method. However, the zone method is restricted to larger span assemblies because the zone factor coefficient is 2.0. This tends to overestimate the amount of surface area influenced by CFS. The modified zone method is restricted to C-shaped stud, clear wall assemblies with framing factors between 9 and 15%. The objective of the research is to narrow the gap of knowledge by re-examining the modified zone method in order to more accurately determine R-Values and U-Factors for CFS wall assemblies with whole wall framing factor percentages of 22% and above.

Degree:
Level: Master's
Discipline: Engineering Systems
Language(s):
Subject(s):
Keyword(s): R-value | framing factor | ASHRAE | cold-formed steel | conductivity | heat transfer | u-factor
Contributor(s):
Partner:
UNT Libraries
Collection:
UNT Theses and Dissertations
Identifier:
  • ARK: ark:/67531/metadc67960
Resource Type: Thesis or Dissertation
Format: Text
Rights:
Access: Public
License: Copyright
Holder: Black, John
Statement: Copyright is held by the author, unless otherwise noted. All rights reserved.