rapid fire
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Rapid Fire. The thermal mass benefits of concrete in Insulated Concrete Forms (ICF). Amanda L. Webb, SMArchS Graduate Student. ▪ Objective: Understand the role of concrete portion of ICF in reducing building energy use - PowerPoint PPT PresentationTRANSCRIPT
Rapid Fire
▪ Objective: Understand the role of concrete portion of ICF in reducing building energy use
▪ Approach: Whole-building energy model for typical commercial and residential buildings
▪ Key findings: Small overall, but reduced peak heat transfer; mass via ICF not optimized
▪ Impact: Focus on optimized use of concrete for thermal benefit
Amanda L. Webb, SMArchS Graduate Student
The thermal mass benefits of concrete in Insulated Concrete Forms (ICF)
With L. Norford and J. Ochsendorf
Afternoon Presentation
Residential BuildingsSingle Family & Multifamily
Amanda WebbFeb 17, 2011
CONCRETE SUSTAINABILITY HUB
Major Model Changes
CONCRETE SUSTAINABILITY HUB
Category Single Family Multifamily
Reference Standard Building America House Simulation Protocol*(IECC 2009 equiv.)
DOE Benchmark Midrise Apartment
Envelope ICF – R-26 -> R-20Attic Floor –R-60 -> R-40 (Chi)
ICF with concrete interior -> ICF with wood/gyp interior
Internal Gains Detailed Input No Change
Infiltration & Ventilation - No infiltration difference**- Nat vent- No HVAC Outdoor Air
No Change
Domestic Hot Water Detailed DHW System No Change
= Most significant changes
*From DOE’s National Renewable Energy Laboratory
**Focus in this analysis on mass benefits of ICF
Infil rates same – focus on mass, insul. benefitsR-values different
Mass portion of ICF does make a difference
Peaks reducedWhat if we add more concrete?
What if we expose the concrete inside?
e.g., ThermomassBetter in PHXCould be better with optimized use of interior mass
Infiltration sensitivity dependent on climate
Operational energy dominates for benchmark building
Embodied energy matters more in very low energy building
Energy Model/LCA Conclusions
• Very solid model specifications• Better contextualize our work – NREL, etc. • Infiltration, R-value, and mass benefits of ICF
should be considered separately• Infiltration highly climate dependent; mass
somewhat climate dependent• Look at optimized use of mass – balance
changes for low energy buildings
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Work Through Aug 2011
• Energy benefits of concrete. Focus: low energy houses.– Analysis to find optimum curve for use of concrete
in envelope, interior [Hacker 2008, Zhu 2009]– Mass vs. insulation tradeoff– Range of climates, thermal performance
• Comfort benefits of concrete [beyond Aug]– Control algorithm testing to understand role of
concrete in comfort-based HVAC controls
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