1. Single Family Residential Amanda Webb & Omar Swei Feb 04, 2011 CONCRETE SUSTAINABILITY HUB

2. Major Model Changes CONCRETE SUSTAINABILITY HUB CategoryAug 2010 ModelJan 2011 Model Reference StandardASHRAE Standard 90.2-2007Building America House Simulation Protocol (based on IECC 2009) Envelope (small differences) ICF – R-26 Attic Floor –R-60 (Chi) ICF – R-20 Attic Floor – R-40 (Chi) Internal GainsSingle InputHighly Detailed Input (based on BAHSP) Infiltration & Ventilation - Infil difference - No nat vent - HVAC Outdoor Air - No infil difference - Nat vent - No HVAC Outdoor Air Domestic Hot WaterNo DHW SystemDetailed DHW System

3. Chicago - 28.8% Phoenix - 5.6% Greater savings in Phoenix than Chicago P REVIOUS R ESULTS [A UG 2010 M ODEL ] Updated model shows this is b/c of infiltration

4. Infil Rates Same R-values Different

5. The mass does make a difference…

6. Peaks reduced What if we add more concrete?

7. What if we expose the concrete inside?

8. Better in PHX Could get better with more exposed surface area?

11. Energy Model Conclusions Infiltration, R-value, and mass benefits of ICF should be considered separately Infiltration highly climate dependent; mass somewhat climate dependent Mass makes a small difference CONCRETE SUSTAINABILITY HUB

14. Heating-dominated (G) in Chicago vs. Cooling- dominated in Phoenix (E)

15. Work Through Aug 2011 What is the role of concrete in very low energy houses? –Trend in housing research (Bldg. America, BEOpt) –Trend in legislation (Greening the Codes, CA AB32) Two targets: Net Zero Energy, Passivhaus Two research questions to contextualize role of concrete… CONCRETE SUSTAINABILITY HUB

16. Work Through Aug 2011 Q1: How does mass shift the ‘PV Start Point”? –Christensen, et. al., 2004 –Consider LCA (embodied energy) – CONCRETE SUSTAINABILITY HUB Enough to prove significance, Don’t have to build

17. Work Through Aug 2011 Q2: Does mass make a difference in a Passivhaus? –Suggestion that thermal behavior is different –Combine Q1 & Q2: Is there a “curve” that describes the optimal use of mass? Overall: Industry able to make intelligent decisions about how to promote use of concrete in very low energy houses. CONCRETE SUSTAINABILITY HUB