INSULATION STUDIESBy: Matthew Irvine and Cristina Belew
Introduction
Origination and Goals Partnership with Habitat for Humanity Their goal is to lower the overall cost to
owner Studied the effect of insulation on
energy costs Looked for the effects of different
insulations and insulating methods Recommend the insulations with the
lowest cost to owner
Four Different Areas Wall insulation types
Framing dimension selection
Attic insulation
Duct Insulation
Design Information
Design Modeling Assumptions h and k values
No thermal contact resistance
Siding geometry
No radiation in attic, theoretical venting
Decision of appropriate options Wall Insulation
Stud Sizing
Duct Insulation
Modeling Techniques We began with a square foot section
Moved to a larger section with other elements included
Completed our analysis by simulating an entire house (Woodruff House)
Studied Design Description Small and large wall section for 2X4 and
2X6
Attic Section
Duct Section
SUMMARY OF RESULTS
2 x 4 Stud, 1 x 1 m2 Section: Overview Equation for heat flux
Q = (T2 – T1)/Rtotal
Studied 3 times during the year January – 2.778 ºC April – 15.56 ºC July - 27.2 ºC
Desired inside temperature- 22.2 ºC
Drywall
Insulation
Plywood
Air Pocket
Hardiboard
2 x 4 Stud, 1 x 1 m2 Section: R-values R of Convection – 1/h*A
h- convection coefficient (W/m·°C) A- area of convection (m2)
R of a certain material – L/k*A k- thermal conductivity L- thickness of material (m) A- area of material (m2)
Rtotal = Routside,convection + Rdrywall + Rinsulation + Rhariboard + Rair pocket + Rsiding + Rinside,convection
R (W/m·°C)
Ri Rjanuary Rapril Rjuly Rhardiboard Rplywood Rinsulation Rdrywall Rair pocketR-Total January
R-Total April
R-Total July
0.042 W/m2·°C 0.100 0.0294 0.0353 0.0441 0.0567 0.106 2.12 0.0713 0.156 2.636 2.642 2.651
0.03 W/m2·°C 0.100 0.0294 0.0353 0.0441 0.0567 0.106 2.96 0.0713 0.156 3.483 3.489 3.497
0.046 W/m2·°C 0.100 0.0294 0.0353 0.0441 0.0567 0.106 1.93 0.0713 0.156 2.452 2.458 2.467
2 x 4 Stud, 1 x 1 m2 Section: Theoretical vs. Simulation Heat Flux Heat flux for each insulation and temperature difference
was calculated next with Solidworks and compared to the theoretical calculations done.
Heat Flux (W-theoretical) January April July
0.042 W/m2·°C 7.367 2.513 -1.886
0.03 W/m2·°C 5.577 1.904 -1.430
0.046 W/m2·°C 7.9200 2.701 -2.027
Heat Flux (W- simulation) January April July
0.042 W/m2·°C 7.4297 2.5393 -1.8999
0.03 W/m2·°C 5.6123 1.9192 -1.4372
0.046 W/m2·°C 7.9925 2.7312 -2.0429
Error (%) January April July
0.042 W/m2·°C 0.84% 0.63% 0.91%
0.03 W/m2·°C 0.76% 0.79% 1.11%0.046 W/m2·°C 0.73% 0.50% 0.78%
2 x 4 Stud, 1 x 1 m2 Section: FEA (January)
0.042 W/m2·ºC 0.03 W/m2·ºC 0.046 W/m2·ºC
2 x 4 Stud, 1 x 1 m2 Section: FEA (April)
0.042 W/m2·ºC 0.03 W/m2·ºC 0.046 W/m2·ºC
2 x 4 Stud, 1 x 1 m2 Section: FEA (July)
0.042 W/m2·ºC 0.03 W/m2·ºC 0.046 W/m2·ºC
2 x 6 Stud, 1 x 1 m2 Section: R-values Next Step: How does the heat flux change when
more insulation is added with a 2 x 6. The R-values were calculated again when a thicker
insulation.
R (W/m·°C) Ri Rjanuary RApril Rjuly Rhardiboard Rplywood Rinsulation Rdrywall Rair pocket
R-Total January
R-Total April
R-Total July
0.042 W/m2·°C 0.100 0.0294 0.0353 0.0441 0.0567 0.106 3.33 0.0713 0.156 3.846 3.852 3.860
0.03 W/m2·°C 0.100 0.0294 0.0353 0.0441 0.0567 0.106 4.66 0.0713 0.156 3.483 3.489 3.497
0.046 W/m2·°C 0.100 0.0294 0.0353 0.0441 0.0567 0.106 3.04 0.0713 0.156 2.452 2.458 2.467
2 x 6 Stud, 1 x 1 m2 Section: Theoretical vs. Simulation Heat Flux Here are the heat flux numbers for the SolidWorks simulations
compared to the theoretical calculations done:
Heat Flux (W-theoretical) January April July
0.042 W/m2·°C 7.367 2.520 -1.8860.03 W/m2·°C 5.577 1.904 -1.430
0.046 W/m2·°C 7.920 2.701 -2.027
Heat Flux (W- simulation) January April July
0.042 W/m2·°C 7.4297 2.5393 -1.89990.03 W/m2·°C 5.6123 1.9192 -1.4372
0.046 W/m2·°C 7.9925 2.7312 -2.0429
Error (%) January April July
0.042 W/m2·°C 0.61% 0.80% 0.51%
0.03 W/m2·°C 0.47% 0.69% 0.38%0.046 W/m2·°C 0.65% 0.85% 0.55%
2 x 6 Stud, 1 x 1 m2 Section: FEA (January)
0.042 W/m2·ºC 0.03 W/m2·ºC 0.046 W/m2·ºC
2 x 6 Stud, 1 x 1 m2 Section: FEA (April)
0.042 W/m2·ºC 0.03 W/m2·ºC 0.046 W/m2·ºC
2 x 6 Stud, 1 x 1 m2 Section: FEA (July)
0.042 W/m2·ºC 0.03 W/m2·ºC 0.046 W/m2·ºC
Conclusions from Theoretical and SolidWorks Studies of 1 x 1 m2 Section
Based upon this data, fiberglass is the insulation to choose. The heat flow through the section of wall is the lowest compared to the other insulation choices.
3 Sections of Wall with 2 x 4 Studs: Overview The next step: A bigger
section of wall with studs included.
The R-values had to be calculated for the sections of wall next to the studs and next to the insulation. Drywall
Insulation
Studs
Plywood
Hardiboard
3 Sections of Wall with 2 x 4 Studs: R-values
Ri RJanuary RApril RJuly Rhardiboard Rplywood Rinsulation Rdrywall Rstuds1/R-Total January
1/R-Total April
1/R-Total July
0.042 W/m2·°C 0.038 0.0113 0.0136 0.0170 0.0649 0.041 0.81 0.0275 1.002 0.9833 0.9966
0.03 W/m2·°C 0.038 0.0133 0.0136 0.0170 0.0649 0.041 1.14 0.0275 0.7545 0.7543 0.7524
0.046 W/m2·°C 0.038 0.0133 0.0136 0.0170 0.0649 0.041 0.74 0.0275 1.077 1.076 1.073
Studs 0.2764 0.0813 0.0975 0.1218 0.4663 0.2925 0.1972 1.7551 0.3259 0.3241 0.3216
𝑅𝑠𝑡𝑢𝑑𝑠 = 1ℎ𝑜𝑢𝑡𝑠𝑖𝑑𝑒 ∗𝐴𝑠𝑡𝑢𝑑𝑠 + 𝐿𝑑𝑟𝑦𝑤𝑎𝑙𝑙𝑘𝑑𝑟𝑦𝑤𝑎𝑙𝑙 ∗𝐴𝑑𝑟𝑦𝑤𝑎𝑙𝑙 ,𝑠𝑡𝑢𝑑𝑠 + 𝐿𝑝𝑙𝑦𝑤𝑜𝑜𝑑𝑘𝑝𝑙𝑦𝑤𝑜𝑜𝑑 ∗𝐴𝑝𝑙𝑦𝑤𝑜𝑜𝑑 ,𝑠𝑡𝑢𝑑𝑠 + 𝐿ℎ𝑎𝑟𝑑𝑖𝑏𝑜𝑎𝑟𝑑𝑘ℎ𝑎𝑟𝑑𝑖𝑏𝑜𝑎𝑟𝑑 ∗𝐴ℎ𝑎𝑟𝑑𝑖𝑏𝑜𝑎𝑟𝑑 ,𝑠𝑡𝑢𝑑𝑠 + 𝐿𝑠𝑡𝑢𝑑𝑠𝑘𝑠𝑡𝑢𝑑𝑠 ∗𝐴𝑠𝑡𝑢𝑑𝑠 + 1ℎ𝑖𝑛𝑠𝑖𝑑𝑒 ∗𝐴𝑠𝑡𝑢𝑑𝑠
𝑅𝑖𝑛𝑠 = 1ℎ𝑜𝑢𝑡𝑠𝑖𝑑𝑒 ∗𝐴𝑖𝑛𝑠 + 𝐿𝑑𝑟𝑦𝑤𝑎𝑙𝑙𝑘𝑑𝑟𝑦𝑤𝑎𝑙𝑙 ∗𝐴𝑑𝑟𝑦𝑤𝑎𝑙𝑙 ,𝑖𝑛𝑠 + 𝐿𝑝𝑙𝑦𝑤𝑜𝑜𝑑𝑘𝑝𝑙𝑦𝑤𝑜𝑜𝑑 ∗𝐴𝑝𝑙𝑦𝑤𝑜𝑜𝑑 ,𝑖𝑛𝑠 + 𝐿ℎ𝑎𝑟𝑑𝑖𝑏𝑜𝑎𝑟𝑑𝑘ℎ𝑎𝑟𝑑𝑖𝑏𝑜𝑎𝑟𝑑 ∗𝐴ℎ𝑎𝑟𝑑𝑖𝑏𝑜𝑎𝑟𝑑 ,𝑖𝑛𝑠 + 𝐿𝑖𝑛𝑠𝑘𝑠𝑡𝑢𝑑𝑠 ∗𝐴𝑖𝑛𝑠 + 1ℎ𝑖𝑛𝑠𝑖𝑑𝑒 ∗𝐴𝑖𝑛𝑠
3 Sections of Wall with 2 x 4 Studs: Heat Flux Comparisons
Heat Flux (W-simulation) 0.042 W/m2·°C 0.03 W/m2·°C 0.046 W/m2·°C
January 25.79 20.98 27.24
April 8.680 7.161 9.300
July -6.590 -5.370 -6.971
Heat Flux (W-Theoretical) 0.042 W/m2·°C 0.03 W/m2·°C 0.046 W/m2·°C
January 25.85 21.57 27.57
April 8.880 7.414 9.414
July -6.685 -5.585 -7.138
Error (%) 0.042 W/m2·°C 0.03 W/m2·°C 0.046 W/m2·°CJanuary 0.21% 2.73% 1.20%
April 2.25% 3.41% 1.21%
July 1.43% 3.85% 2.34%
𝑄= ሺ𝑇𝑜𝑢𝑡𝑠𝑖𝑑𝑒 − 𝑇𝑖𝑛𝑠𝑖𝑑𝑒ሻ∗( 1𝑅𝑠𝑡𝑢𝑑𝑠 + 1𝑅𝑖𝑛𝑠𝑢𝑙𝑎𝑡𝑖𝑜𝑛 )
3 Sections of Wall with 2 x 4 Studs: FEA (January)
0.046 W/m2·ºC 0.03 W/m2·ºC 0.042 W/m2·ºC
3 Sections of Wall with 2 x 4 Studs: FEA (April)
0.046 W/m2·ºC 0.03 W/m2·ºC 0.042 W/m2·ºC
3 Sections of Wall with 2 x 4 Studs: FEA (July)
0.046 W/m2·ºC 0.03 W/m2·ºC 0.042 W/m2·ºC
Duct Insulation: Overview Next step: Determine what
size fiberglass insulation is best
Assumptions: Air flowing through is 22.2
°C Air surrounding duct is the
temperature of the outside since placed in attic
Three fiberglass insulation size choices of 2 inches, 4 inches and 6 inches.
The analysis in Solidworks was performed on a three foot section of duct.
Reflective Barrier
Fiberglass insulation
Aluminum Core
Air Flow
Duct Insulation: R-values For a cylinder, the equation for the total r-value changes. It
is dependent on the radius of each section of material.
R-Values Rconvection, inside Raluminum Rfiberglass Rreflective barrier Rouside,convection
2 inch 0.1371 0.0007076 3.529 0.00002453 0.1523
4 inch 0.1371 0.0007076 5.714312 1.69064E-05 0.1054695
6 inch 0.1371 0.0007076 7.298 0.00001219 0.08072
𝑹𝒕𝒐𝒕𝒂𝒍 = 𝟏𝒉𝒂𝒊𝒓 𝒇𝒍𝒐𝒘∗𝒂+ 𝐥𝐧൬𝒓𝒂𝒍𝒖𝒎𝒊𝒏𝒖𝒎𝒓𝒂𝒊𝒓 𝒇𝒍𝒐𝒘 ൰𝟐𝝅∗𝒌𝒂𝒍𝒖𝒎𝒊𝒏𝒖𝒎 ∗𝑳+ 𝐥𝐧ቀ𝒓𝒇𝒊𝒃𝒆𝒓𝒈𝒍𝒂𝒔𝒔𝒓𝒂𝒍𝒖𝒎𝒊𝒏𝒖𝒎ቁ𝟐𝝅∗𝒌𝒇𝒊𝒃𝒆𝒓𝒈𝒍𝒂𝒔𝒔 ∗𝑳+ 𝐥𝐧൬𝒓𝒓𝒆𝒇𝒍𝒆𝒄𝒕𝒊𝒗𝒆 𝒃𝒂𝒓𝒓𝒊𝒆𝒓𝒓𝒇𝒊𝒃𝒆𝒓𝒈𝒍𝒂𝒔𝒔 ൰𝟐𝝅∗𝒌𝒓𝒆𝒇𝒍𝒆𝒄𝒕𝒊𝒗𝒆 𝒃𝒂𝒓𝒓𝒆𝒓 ∗𝑳+ 𝟏𝒉𝒂𝒕𝒕𝒊𝒄 𝒂𝒊𝒓 ∗𝒂
Duct Insulation: Heat Flux
Heat Flux- Simulation January April July
2 inch 5.074 1.735 1.3057
4 inch 3.3025 1.1323 0.8393
6 inch 2.584 0.883 0.6652
Heat Flux- Theoretical January April July
2 inch 5.090 1.744 1.304
4 inch 3.260 1.115 0.8492
6 inch 2.6202 0.89835 0.67376
Error (%) January April July
2 inch -0.31% -0.52% 0.13%
4 inch 1.30% 1.55% -1.17%
6 inch -1.38% -1.71% -1.27%
𝑄= 𝑇𝑜𝑢𝑠𝑡𝑖𝑑𝑒 − 𝑇𝑖𝑛𝑠𝑖𝑑𝑒𝑅𝑡𝑜𝑡𝑎𝑙
Duct Insulation: FEA Simulation (January)
January Analysis: Temperature flow through the center at 22.2 ºC and the surrounding temperature 2.778 ºC
2 inches
4 inches 6 inches
Duct Insulation: FEA Simulation (April)
6 inches 4 inches
2 inches
April Analysis:Temperature flow through the center at 22.2 ºC and surrounding temperature at 15.56 ºC
Duct Insulation: FEA Simulation (July)
July Analysis: Temperature flow through the center at 22.2 ºC and the surrounding temperature 27.2ºC
2 inches
4 inches 6 inches
Attic Insulation: Overview Next Step: Which
insulation is the best choice for the attic
Assumptions: Attic temperature is the
outside temperature Inside temperature is
22.2 °C
Drywall
Insulation
Attic Insulation: R-values
R-Values Rinside Rjanuary Rapril RJuly Rinsulation RdrywallR- Total January
R- Total April R-Total July
0.042 W/m2·°C 0.108 0.108 0.108 0.163 2.12 0.0713 2.407 2.407 2.518
0.03 W/m2·°C 0.108 0.108 0.108 0.163 2.96 0.0713 3.247 3.247 3.358
0.046 W/m2·°C 0.108 0.108 0.108 0.163 1.93 0.0713 2.217 2.217 2.328
𝑅𝑡𝑜𝑡𝑎𝑙 = 1ℎ𝑖𝑛𝑠𝑖𝑑𝑒 ∗𝐴+ 𝐿𝑑𝑟𝑦𝑤𝑎𝑙𝑙𝑘𝑑𝑟𝑦𝑤𝑎𝑙𝑙 ∗𝐴𝑑𝑟𝑦𝑤𝑎𝑙𝑙 + 𝐿𝑖𝑛𝑠𝑢𝑙𝑎𝑡𝑖𝑜𝑛𝑘𝑖𝑛𝑠𝑢𝑙𝑎𝑡𝑖𝑜𝑛 ∗𝐴+ 1ℎ𝑎𝑡𝑡𝑖𝑐 ∗𝐴
Attic Insulation: Heat Flux
Heat Flux- Theoretical January April July
0.042 W/m2·°C 8.068 2.758 -1.986
0.03 W/m2·°C 5.981 2.045 -1.489
0.046 W/m2·°C 8.759 2.995 -2.148
Heat Flux- Simulation January April July
0.042 W/m2·°C 8.0884 2.7731 -1.9886
0.03 W/m2·°C 5.9816 2.0508 -1.4877
0.046 W/m2·°C 8.7592 3.003 -2.1457
Error (%) January April July
0.042 W/m2·°C 0.25% 0.55% 0.13%
0.03 W/m2·°C 0.01% 0.28% -0.09%
0.046 W/m2·°C 0.00% 0.27% -0.11%
House Model: Overview Next Step: Move from
a small section of wall or attic to a full wall or ceiling.
Each section of wall was simulated separately and then the heat flux of all were added together.
House Model: Layout
House Model: Layout
House Model: Layout
House Model: FE Analysis Here are the results for the heat flux traveling
through each wall of the house model.
Heat Flux (W) 0.042 W/m2·ºC for January
0.042 W/m2·ºC for April
0.042 W/m2·ºC for July
Back Wall 329.03 110.04 -80.303
Front Wall 276.64 93.284 -68.72
Left Wall 489 164.81 -121.35
Right Wall 484.78 163.55 -120.32
Ceiling 852.16 292.7 -210
Heat Flux Total 2431.61 824.384 -600.693
House Model: FEA Simulation
Right and Left Walls
House Model: FEA Simulation
Front Wall
Quantitative Results Insulation Type (30%)
Duct Thickness (36% compared to 20%)
Stud Sizing (~30%)
Future Work
Future Work Determine thermal conductivities for
each insulation
Find quantitative difference of heat flux for different insulation choices
Compare cost difference between insulations with energy savings or loses
Result Details
Values (W/m^2*C) hi hjanuary hapril hjuly khardiboard kplywood kcellulose kdrywall kair pocket kfiberglass kmineral wool
10 34 28.35 22.7 0.14 0.12 0.042 0.178 0.026 0.03 0.046Hardiboard Plywood Insulation Drywall Air Pocket
Thickness (2x4) (m) 0.0079375 0.0127 0.0889 0.0127 0.004064 Temperature (Celcius) January April JulyThickness (2x6) (m) 0.0079375 0.0127 0.1397 0.0127 0.004064 Outside 2.778 15.56 27.2
Inside 22.2 22.2 22.2l/ka
Ri Rjanuary Rapril Rjuly Rhardiboard Rplywood Rcellulose Rdrywall Rair pocket R-Total for January R-Total for April R-Total for JulyR-Values 0.100 0.0294 0.0353 0.0441 0.0567 0.106 2.12 0.0713 0.156 2.636 2.642 2.651
Heat Flux (W) 7.367 2.513 -1.886Ri Rjanuary Rapril Rjuly Rhardiboard Rplywood Rcellulose Rdrywall Rair pocket R-Total R-Total for April R-Total for July
R-Values 0.100 0.0294 0.0353 0.0441 0.0567 0.106 3.33 0.0713 0.156 3.846 3.852 3.860Heat Flux (W) 5.050 1.724 -1.295
Ri Rjanuary Rapril Rjuly Rhardiboard Rplywood Rfiberglass Rdrywall Rair pocket R-Total for January R-Total for April R-Total for JulyR-Values 0.100 0.0294 0.0353 0.0441 0.0567 0.106 2.96 0.0713 0.156 3.483 3.489 3.497
Heat Flux (W) 5.577 1.903 -1.430Ri Rjanuary Rapril Rjuly Rhardiboard Rplywood Rfiberglass Rdrywall Rair pocket R-Total for January R-Total for April R-Total for July
R-Values 0.100 0.0294 0.0353 0.0441 0.0567 0.106 4.66 0.0713 0.156 5.176 5.182 5.191Heat Flux (W) 3.752 1.281 -0.963
Ri Rjanuary Rapril Rjuly Rhardiboard Rplywood Rmineral wool Rdrywall Rair pocket R-Total for January R-Total for April R-Total for JulyR-Values 0.1 0.0294 0.0353 0.0441 0.0567 0.106 1.93 0.0713 0.156 2.452 2.458 2.467
Heat Flux (W) 7.921 2.701 -2.027R-Values Ri Rjanuary Rapril Rjuly Rhardiboard Rplywood Rmineral wool Rdrywall Rair pocket R-Total for January R-Total for April R-Total for July
0.1 0.0294 0.0353 0.0441 0.0567 0.106 3.04 0.0713 0.156 3.556 3.562 3.571Heat Flux (W) 5.461 1.864 -1.400
Thickness (attic-m) Insulation Drywall0.0889 0.0127
Ri Rjanuary Rapril Rjuly Rcellulose Rdrywall R- Total January R- Total April R-Total JulyR-Values 0.108 0.108 0.108 0.163 2.12 0.0713 2.407 2.407 2.518R-Values Ri (july) 0.163 Heat Flux (W) 8.068 2.758 -1.986
Ri Rjanuary Rapril Rjuly Rfiberglass Rdrywall R- Total January R- Total April R-Total JulyR-Values 0.108 0.108 0.108 0.163 2.96 0.0713 3.247 3.247 3.358R-Values Ri (july) 0.163 Heat Flux (W) 5.981 2.045 -1.489
Ri Rjanuary Rapril Rjuly Rmineral wool Rdrywall R- Total January R- Total April R-Total JulyR-Values 0.108 0.108 0.108 0.163 1.93 0.0713 2.217 2.217 2.328R-Values Ri (july) 0.163 Heat Flux (W) 8.759 2.995 -2.148
Values (W/m^2*C) hi hjanuary hapril hjuly khardiboard kplywood kcellulose kdrywall kfiberglass kmineral wool R (2x4) R(2x6)10 34 28.35 22.7 0.14 0.12 0.042 0.178 0.03 0.046 0.14 0.98
L Hardiboard Plywood Insulation Drywall Stud Area Hardiboard Plywood Insulation Drywall StudsThickness (2x4) (m) 0.02362 0.0127 0.0889 0.0127 0.0889 Thickness (2x4) (m2) 2.5977 2.5977 2.5977 2.5977
0.3618 0.3618 0.3618 0.3618Thickness (2x6) (m) 0.02362 0.0127 0.1397 0.0127 0.1397 Thickness (2x6) (m2)
Ri Rjanuary Rapril Rjuly Rhardiboard Rplywood Rcellulose Rdrywall Rstuds R-Total for January R-Total for April R-Total for JulyR-Values (ins) 0.038 0.0113 0.0136 0.0170 0.0649 0.041 0.81 0.0275 1.002 0.9833 0.9966R-Values (studs) 0.2764 0.0813 0.0975 0.1218 0.4663 0.2925 0.1972 1.7551 0.3259 0.3241 0.3216
Heat Flux (W) 25.79 8.68 -6.591Ri Rjanuary Rapril Rjuly Rhardiboard Rplywood Rcellulose Rdrywall Rstuds R-Total for January R-Total for April R-Total for July
R-Values (ins)R-Values (studs)
Heat Flux (W)Ri Rjanuary Rapril Rjuly Rhardiboard Rplywood Rfiberglass Rdrywall Rstuds R-Total for January R-Total for April R-Total for July
R-Values (ins) 0.038 0.0133 0.0136 0.0170 0.0649 0.041 1.14 0.0275 0.7545 0.7543 0.7524R-Values (studs) 0.2764 0.0813 0.0975 0.1218 0.4663 0.2925 0.1972 1.7551 0.3259 0.3241 0.3216
Heat Flux (W) 20.98 7.161 -5.370Ri Rjanuary Rapril Rjuly Rhardiboard Rplywood Rfiberglass Rdrywall Rstuds R-Total for January R-Total for April R-Total for July
R-Values (ins)R-Values (studs)
Heat Flux (W)Ri Rjanuary Rapril Rjuly Rhardiboard Rplywood Rmineral wool Rdrywall Rstuds R-Total for January R-Total for April R-Total for July
R-Values (ins) 0.038 0.0133 0.0136 0.0170 0.0649 0.041 0.74 0.0275 1.077 1.076 1.073R-Values (studs) 0.2764 0.0813 0.0975 0.1218 0.4663 0.2925 0.1972 1.7551 0.326 0.324 0.322
Heat Flux (W) 27.24 9.300 -6.971Ri Rjanuary Rapril Rjuly Rhardiboard Rplywood Rmineral wool Rdrywall Rstuds R-Total for January R-Total for April R-Total for July
R-Values (ins)R-Values (studs)
Heat Flux (W)
Radius (meter) Air Core Steel Duct Insulation Reflective Barrier hi ho,jan ho,april ho,july ksteel kfiberglass kreflective barrier
0.0508 0.0605 0.111125 0.1143 25 10 10 10 43 0.03 200Length 0.914
Rconv Rsteel Rfiber Rreflective Rconv,o Rtotal Temperature Tinside Tjanuary Tapril Tjuly
0.1371 0.0007076 3.529 0.00002453 0.1523 3.819 22.22 2.778 15.56 27.2
Heat Flux (W) January April July5.090 1.744 -1.304
Radius (meter) Air Core Steel Duct Insulation Reflective Barrier hi ho,jan ho,april ho,july ksteel kfiberglass kreflective barrier
0.0508 0.0605 0.161925 0.1651 25 10 10 10 43 0.03 200Length 0.914
Rconv Rsteel Rfiber Rreflective Rconv,o Rtotal
0.1371 0.0007076 5.714312 1.69064E-05 0.1054695 5.957605963
Heat Flux (W) January April July3.260 1.115 -0.8393
Radius (meter) Air Core Steel Duct Insulation Reflective Barrier hi ho,jan ho,april ho,july ksteel kfiberglass kreflective barrier
0.0508 0.0605 0.212725 0.215725 25 10 10 10 43 0.03 200Length 0.914
Rconv Rsteel Rfiber Rreflective Rconv,o Rtotal
0.1371 0.0007076 7.298 0.00001219 0.08072 7.517
Heat Flux (W) January April July2.584 0.883 -0.6652
Duct Insulation Calculation
2 inch Insulation (Fiberglass)
4 inch Insulation (Fiberglass)
6 inch Insulation (Fiberglass)
2 x 6 Theoretical Calculations Mineral Wool
Attic Insulation Calculation Fiberglass
Attic Insulation Calculation Mineral Wool
2 x 4 Theoretical Calculations Mineral Wool
2 x 4 Theoretical Calculations Cellulose
2 x 6 Theoretical Calculations Cellulose
2 x 4 Theoretical Calculations Fiberglass
2 x 6 Theoretical Calculations Fiberglass
2 x 4 Theoretical Calculations Cellulose
2 x 6 Theoretical Calculations Cellulose
2 x 4 Theoretical Calculations Fiberglass
2 x 4 Theoretical Calculations Mineral Wool
2 x 6 Theoretical Calculations Fiberglass
Attic Insulation Calculation Cellulose
2 x 6 Theoretical Calculations Mineral Wool
ftXft study (4") Outside Temperature Indoor Temperature Inside Convection Outside Convection Cellulose (.042W/°C·m2) Fiberglass (.03W/°C·m2) Mineral Wool (.046 W/°C·m2)
January 37 72 8.333 34 7.4297 5.6123 7.9925April 60 72 8.333 28.35 2.5393 1.9192 2.7312July 81 72 8.333 22.7 -1.8999 -1.4372 -2.0429
Theoretical: 7.367 5.577 7.922.52 1.904 2.701
-1.886 -1.43 -2.027
% Difference: 0.84% 0.63% 0.91%0.76% 0.79% 1.11%0.73% 0.50% 0.78%
ftXft study (6") Outside Temperature Indoor Temperature Inside Convection Outside Convection Cellulose (.042W/°C·m2) Fiberglass (.03W/°C·m2) Mineral Wool (.046 W/°C·m2)January 37 72 8.333 34 5.0809 3.7696 5.4967
April 60 72 8.333 28.35 1.7378 1.2898 1.8798July 81 72 8.333 22.7 -1.3016 -0.96665 -1.4077
Theoretical 5.05 3.752 5.4611.724 1.281 1.864
-1.295 -0.963 -1.4
% difference 0.61% 0.47% 0.65%0.80% 0.69% 0.85%0.51% 0.38% 0.55%
ftXft study (attic) Outside Temperature Indoor Temperature Upper Convection Lower Convection Cellulose (.042W/°C·m2) Fiberglass (.03W/°C·m2) Mineral Wool (.046 W/°C·m2) Theo Theo TheoJanuary 37 72 9.26 9.26 8.0884 5.9816 8.7592 8.068 5.981 8.759
April 60 72 9.26 9.26 2.7731 2.0508 3.003 2.758 2.045 2.995July 81 72 6.13 6.13 -1.9886 -1.4877 -2.1457 -1.986 -1.489 -2.148
% Error 0.25% 0.01% 0.00%0.55% 0.28% 0.27%
Wall Section (2x4) Outside Temperature(F) Indoor Temperature(F) Cellulose (.042W/°C·m2) Fiberglass (.03W/°C·m2) Mineral Wool (.046 W/°C·m2) 0.13% -0.09% -0.11%January 37 72 25.79 20.98 27.24
April 60 72 8.680 7.161 9.300July 81 72 -6.590 -5.370 -6.971
Theoretical: 25.85 21.57 27.578.880 7.414 9.414
-6.685 -5.585 -7.138
% Difference: -0.21% -2.73% -1.20%-2.25% -3.41% -1.21%-1.43% -3.85% -2.34%
Duct Insulation (Fiberglass) 2 in Fiberglass 4 in Fiberglass 6 in FiberglassJanuary 5.074 3.3025 2.584
April 1.735 1.1323 0.883July 1.3057 0.8393 0.6652
Theoretical 5.090 3.260 2.62021.744 1.115 0.898351.304 0.8492 0.67376
% Difference -0.31% 1.30% -1.38%-0.52% 1.55% -1.71%0.13% -1.17% -1.27%
Wall Simulations Cellulose for January Cellulose for April Cellulose for JulyBack Wall 329.03 110.04 -80.303Front Wall 276.64 93.284 -68.72Left Wall 489 164.81 -121.35Right Wall 484.78 163.55 -120.32Ceiling 852.16 292.7 -210Heat Flux Total 2431.61 824.384 -600.693
References Heat and Mass Transfer (Cengel; McGraw-Hill) www.engineeringtoolbox.com www.matweb.com www.energysavers.com Engineering Analysis with SolidWorks Simulation 2010 (Kurowski; SDC
Publications) http://www.ornl.gov/sci/roofs+walls/insulation/ins_01.html http://www.jameshardie.com/ www.lowes.com Habitat for Humanity