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SIPs
Outperform Stick & Batt
(Oak
Ridge National Labs R-Value Test)
When someone says "R-value", what they're really talking about is
resistance to heat flow in a given medium, such as fiberglass insulation.
The higher the number, the greater the resistance. So when a builder is
asked "What's the R-value of this wall?", the natural lination is to
think of the material that most commonly specifies its rating. More often
than not, it's the insulation, and the response is something along the lines
of "Oh, that wall has an R-value of 24" - fairly impressive, but also
strikingly inaccurate.
It's not that the builder is intentionally misleading his client or
associate, but that he's just following common practice. In reality, this
reasoning doesn't take into account all the other components that go into
making a wall: wood or steel studs every 16" or 24", bracing, nails or
screws, wiring and switch boxes - any number of things that are not
insulation, and in all likelihood, have R-values that fall well short of the
stated R-24.
A new study by
the Oak Ridge National Labs (ORNL) proves that a 4-h SIP wall outperforms
2"x4" stick and batt construction, and even edges out 2"x6" construction in
terms of thermal performance. Because SIPs are the structural elements,
there are no studs or braces to cause breaks in the insulative action. The
end result is a more comfortable, energy efficient structure that performs
up to spec in real-world conditions. Unlike stick and batt construction,
which can be subject to poorly installed - even missing - insulation, the
nature of SIPs is such that the structural and insulative elements are
joined as one. There are no hidden gaps, because a solid layer of foam
insulation is integral to panel construction.
By contrast, state-of-the-art technical analysis of whole wall
performance indicates that the losses in a stud wall are much greater than
you might think: on average, the other standard components in stick and batt
construction can reduce R-values in as much as 30% of the wall area.
Fortunately, that's not the case with structural insulated panels. The ORNL
study found that SIPs perform at approximately 97% of their stated R-value
overall, losing only 3% to nail holes, seams, splines, and the like. Wiring
chases are precut or preformed into the foam core, providing a continuous
layer of insulation keeping the elements at bay and the interior free of
drafts and cold spots.
A SIP wall also outperforms stick and batt when it comes to maintaining
consistent interior temperatures, and that translates to improved occupant
comfort. As shown in the graph below, the interior surface temperature of
frame construction drops precipitously at every stud, while the SIP wall
remains consistent across its entire surface. No temperature dips mean
improved occupant comfort, regardless of where you are in the room. That's a
big part of what people are talking about when they say they can immediately
"feel the difference" in a SIP-built residential or commercial space. With
SIPs, thermal efficiency and comfort are built in at the factory, and now
the lab results prove it.

Interior surface temperature comparisons indicating constant temperature
for SIP wall and reductions in temperature at stud locations for 2"x 4' and
2" x 6" wood frame walls (ORNL).
Energy Savings
"If you are not using SIPs as your core building
material you are not serious about energy efficiency."
Michael Morley, Builder & Author -
"Building with Structural Insulated Panels"
Energy Payback
There are five reasons foam-panel homes should have lower heating
and cooling bills than homes insulated with common wall and ceiling
insulation materials:
- Structural Insulated Panels achieve thermal ratings of between
R-4 and R-7 per h; batt and loose-fill materials are about half
that.
- With less wood, panels reduce thermal bridging (the transfer
of heat into or out of a structure through a solid piece of
lumber). A 16-foot SIP wall section with one 3 x 4-foot window
contains 5 percent wood and 95 percent Insulation. The same wall
framed with 2 x 4s 16 o.c. has 20 percent wood and a variable
amount of insulation.
- If not installed properly, batt insulation is susceptible to
voids. Batts are either jammed into narrow cavities, improperly
split around wiring or around electrical boxes, or cut too short
or too long. In some remodeling jobs, insulation is removed, but
not replaced. When used with a trussed roof system, batts won't
cover up the bottom chords, allowing heat to transfer directly
from the interior of the house into the attic area in the winter
and from the attic into the house in the summer. A solid foam
panel eliminates these problems.
- Any air moving within a conventionally insulated wall or
ceiling decreases the energy performance of batt insulation. When
properly sealed, foam panels do not allow air movement.
- Depending on proper installation and effective sealing of
joints and openings, Structural Insulated Panel (SIP) construction
lends itself to tighter-than-average construction. This is
especially true when SIPs are used for both walls and ceiling
because the systems are engineered to connect to each other easily
and tightly.
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Energy Tables |
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R Value |
Panel Thickness |
Weight (PSF) |
16.87 |
4.50" |
3.31 |
25.60 |
6.50" |
3.47 |
33.20 |
8.25" |
3.61 |
41.90 |
10.25" |
3.78 |
50.60 |
12.25" |
3.95 |
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CASE STUDY 1
Place: Watertown, S.D.
Heating degree days: 9,000
Size of home: 1,040
square feet with a full basement, identical floor plans
Energy source: Natural gas, forced-air furnace |
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Conventional frame |
Panel frame |
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Walls |
6' fiberglass batts with 1"
foil sheathing; R-24 |
5"EPS-core panels, R-24 |
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Ceiling |
12" fiberglass; R-38 |
71/2" EPS-core panels, R-32 |
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Heated
area |
Main floor |
Main floor and basement |
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Heating bill
Jan.-March |
$263 |
$85 |
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Source: Enercept, ., Watertown,
SD |
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CASE STUDY 2 Place: El Jebel,
Colo.
Heating degree days: 7,635
Size of home: 1,336 square feet
Heating source: Electric baseboard; HRV |
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Conventional 2 x 6
frame |
Panel frame |
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Walls |
51/2" fiberglass batts plus
1/2"exterior Insulated, R-22 with airtight drywall (5/8") |
R-22 |
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Ceiling |
Fiberglass batts, R-38 (R-30 in
slope) |
R-38 |
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Heated area |
Whole House |
Whole House |
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Heating bill
Oct.-Dec. |
$450 |
$112 |
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Source: Big Horn Construction Services,
Carbondale, Colo. |
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CASE STUDY 3 Place: Ludlow,
Mass
Heating degree days: 5,600
Size of home: 2400 square feet
Heating source: Electric |
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Conventional 2 x 6 frame |
Panel frame |
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Walls |
51/2" fiberglass
batts, R-19 |
R-25 |
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Ceiling |
9"Fiberglass batts, R-30 |
R-33 |
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Heated area |
Whole House |
Whole House |
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Heating bill
Oct.-Dec. |
$131/mo |
$30/mo |
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Source: Waverly Heights Development
Corporation, Ludlow, Mass. |
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The walls of this Idaho State Liquor Store in
Nampa, Idaho (pictured above the tables) are 6.5" thick (R 25.6) and 9'
high. Most panels measured 8' wide x 9' high. The total square footage
of this building is 2,990 square feet and the walls were installed in
one day. The General Contractor on this project was Sage Construction of
Caldwell, Idaho.
According to the Idaho State Liquor Dispensory, the
building saves them operating expenses every month. There is a similar
building located approximately 10 miles away in Caldwell, Idaho that has
a total of 3,010 square feet and was framed using 2 x 6 studs at 16" on
center. Below is the comparative energy costs for the (2) buildings
during the winter of 1997 / 1998:
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Building 1 |
Building 2 |
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2 x 6 Stick Frame |
6.5" Precision
Panel |
December 1997 |
$158.92 |
$38.45 |
January 1998 |
$176.46 |
$64.85 |
February 1998 |
$112.85 |
$29.36 |
March 1998 |
$72.81 |
$22.07 |
Totals |
$521.04 |
$154.73 |
Savings over a 4 month period =
$366.31 |
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Sips Homes &
Houses for sale, Expanded
Polystyrene Steel framed
Buildings; Manufacturers of Sips
Homes Houses & Buildings |
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Contact form:
Please provide the
following contact information; |
Sips
Home Manufacturers.. Sips Homes for
sale.. SIPs Buildings for sale,
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Contact
at info@advancedstructuralbuildingsystems.us for more information
on SIPs Homes & Houses: |
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