BBBD Rap it in Foam - Efficiency Vermont · 7.Cavity Insulation 8.Gypsum Wall Board Rap it in Foam...

Wrap it in Foam

Joseph Cincotta AIA & Joe Kohler PELinesync Archtiecture VT Kohler & Lewis NH

Rap it in FoamMC JC & MC JK

Choices

Structure TypesTraditional 2x6, ICF: Insulated Concrete Form, SIP: Structural Insulated Panels, Timber Frame, Balloon frame, Platform Frame, Modified Frame, Double stud, I Joist Stud

Insulation typesxps, eps, polyisocyanurate, fiberglass, cellulose, polyicynene, urathane, hemp, recycled fibers...

Rap it in Foam Better Buildings By Design 2008 Joseph Cincotta / LineSync Archtiecture Joe Kohler / Kohler & Lewis

Our (modest) Goals Foam Jacket Insulation

Does Wrapping a building in a continuous jacket of insulation make sense?

Insulation vs. FuelHow much insulation should we use today

to save on fuel in the future?



Materials Unit / PackageUnit Cost: sq ftLabor Cost: sq ftInstalled Cost / sq ft

Cost Worksheet


First foam jacket building for AOTRemove almost all Thermal BridgesTop rated performer

AOT Readsboro Highway Garage

Foam Jacket Thinking in 1998

Replace the Exterior Sheathing with Rigid Foam Insulation

"Replacing the exterior sheathing with 1 1/2 inch rigid foam insulation can reduce the risk of thermal bridging and increase the thermal resistance of the wall by 33%, although this is not recommended where the sheathing is needed for structural strength. It can have a significant effect in cold climates. ....The overall thermal resistance of the wall would be the same as that of the 2 x 6 frame, but the wall would be slightly narrower and the assembly process would be lighter and possibly quicker."

Common Building Science Recommendation ( of the time )


SIP Claims"The University of Tennesse (sic) and the US Deptartment (sic) Of Energy compared 5 different building systems for clear-wall R-value verses whole-wall R-value. The test concluded that SIPs maintain 88% of their clear-wall performance after whole-wall R-value is measured, 58% better than 2x6 stick-framing."

http://www.enercept.com

" I was really excited about using SIPs to build my house until I started digging into their costs." http://www.greenbuildingtalk.com


SIP Options

Details Structural SIPCurtain Wall SIP

Courtesy of Foard Panel


ICF ClaimsThe effective R-Value performance of [ICF] consists of three factors: (1) the R-Value of the expanded polystyrene, (2) the thermal stability of massive concrete walls reduces the temperature fluctuations, and, consequently, the heat load requirements, so common to stick-frame buildings. 3) air leakage (infiltration) can account for 20% to 40% of the heat load requirements of a stick-framed building. [ICF's] reduces this air infiltration by 75%


...guarantee, in writing, that a homeowner will save at least 33% of their energy costs over 2 X 6 construction with R-19 insulation http://www.polysteel.com/faqs.htm

Sample House1. 3000 sq ft2. 2 story3. Truss insulation4. Insulated foundation5. 30 x 50 x 18' high


Wall Types Studied1. Frame

with cavity fill fiberglasswith cavity fill cellulosewith cavity fill Icynene (polyicynene)

2. ICF - Insulated Concrete Forms 3. SIP Structural Insulated Panel


Frame WallFrom Outside to Inside:1. Siding 2. Insect screen3. rain-screen strapping4. Foam Jacket5. OSB Sheathing6. Studs7. Cavity Insulation8. Gypsum Wall Board


Options for Frame Walls:2x4 standard (not code)2x4 with foam jacket2x6 standard2x6 with foam jacket

ICF Wall

From Outside to Inside:1. Siding 2. Insect screen3. rain-screen strapping4. ICF5. Gypsum Wall Board


SIP Wall

From Outside to Inside:1. Siding2. Insect screen3. rain-screen strapping4. SIP5. Gypsum Wall Board



2x4 Fiberglass: Wall Types Worksheet


2x4 Cellulose: Wall Types Worksheet


2x4 Icynene: Wall Types Worksheet


ICF: Wall Types Worksheet


SIP: Wall Types Worksheet

Analytical MethodologyEnergy Use

1. Calculate total R value of wall systems2. Account for thermal bridging

3. Exclude thermal dynamics4. Exclude infiltration


Calculation of Wall R Value

Resistance Diagram:T AmbientR1 Outdoor Air Film R2 SidingR3 StrappingR4 Strapping air film R5 Rigid InsulationR6 SheathingR7 StudsR8 Cavity InsulationR9 Gypsum Wall Board GWBR10 Inside Air Film

T Conditioned


Annual Energy Use AEU = UA * 24 * Degree Days

(DD)For A = 1 SF

AEU = (1/R )* 24 * DD

Analytical MethodologyCost Benefit

1. Net Present Value: Cost of Money Now and Later2. Inflation Rate 3%3. Discount Rate 6%

4. Savings in Present Day Fuel Costs 5. Savings in anticipated fuel costs

6. Lifetime of Building7. Green Energy


http://www.eia.doe.gov/emeu/cabs/AOMC/images/chron-june2007.gif

Cost /Benefit AnalysisThe economic optimum insulation levels can be defined as the point at which the cost to save an additional Btu/year over the live of the building through conservation is equal to the present value of the cost to purchase a Btu/year over the life of the building.


Present Value of Growing AnnuityIn this case the each cash flow grows by a factor of (1+g). Similar to the formula for an annuity, the present value of a growing annuity (PVGA) uses the same variables with the addition of g as the rate of growth of the annuity (A is the annuity payment in the first period). This is a calculation that is rarely provided for on financial calculators.

Inflation (CPI) vs. Oil Cost


http://www.eia.doe.gov/emeu/cabs/AOMC/images/chron-june2007.gif

CostsCost of Oil: [$3/gal (1 million Btu) ] / [ (140,000 Btu/gal)(.83) ] = $25.80


Cost of Electricity: [ ($.13/kwh)(1 million Btu) ] / [ 3413 Btu/kwh ] = $38.08

CostsHeat Pump with a COP of 2.5 = $15.23


Green Electricity [ ($.17/kwh)(1 million Btu) ] / [ 3413 Btu/kwh ] = $49.80

Costs

xRap it in Foam Better Buildings By Design 2008 Joseph Cincotta / LineSync Archtiecture Joe Kohler / Kohler & Lewis

Green Electricity with a heat pump COP of 2.5 =$19.92

Cost of Photovoltaic Energy

xRap it in Foam Better Buildings By Design 2008 Joseph Cincotta / LineSync Archtiecture Joe Kohler / Kohler & Lewis

Assume $10,000 per installed kilowatt, and 1200 kWh/yr energy production/kW.$10,000/ (1,200 kWh * .003413 Btu/kW * 1 MM Btu) = $2442/MM Btu.Energy Cost with a heatpump with a COP of 2.5= $2442/2.5 = $976/MM Btu


ICF: Wall Types Worksheet


SIP: Wall Types Worksheet


Optimum Wall Types Worksheet Ranking of optimuim wall options of each construction type in terms of increasing cost

Findings

1. Infiltration - better data is required. 2. Heat Pump: the post oil solution?

3. If you choose PV energy invest in more Insulation4. 4" of XPS is about right

5. ICF is impressive 6. and...


...maybe the three little pigs were right


BBBD Rap it in Foam - Efficiency Vermont · 7.Cavity Insulation 8.Gypsum Wall Board Rap it in Foam...

Documents

Transcript of BBBD Rap it in Foam - Efficiency Vermont · 7.Cavity Insulation 8.Gypsum Wall Board Rap it in Foam...