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SmartWall?
Smart Design!
SmartWall Systems
provides significant thermal savings. The savings will often completely
pay for the block, if not more, over the life of the building. That
why smart designers specify and use SmartWall Systems.
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Wall
Construction: Single wythe 8" CMU with polyurethane foam
core insulation. Location: Omaha, NE Fall, 1999.
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Density
of Concrete Masonry Unit |
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Normal
Weight
135 lb/ft3
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ASTM
C 90 Lightweight
105
lb/ft3
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SmartWall
Systems
90
lb/ft3
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Wall
Weight, lb/ft2
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39.2 |
30.9 |
26.7 |
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R
Value
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3.40 |
5.60 |
7.30 |
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U
Value
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0.29 |
0.18
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0.14 |
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Compared
to a 135 lb/ft3
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|
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Difference
in U values
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--- |
0.12 |
0.16 |
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Heating
Energy Savings: $/sq ft/yr
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$0.10 |
$0.13 |
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Cooling
Energy Savings: $/sq ft/yr
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|
$0.01 |
$0.01 |
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Present
Worth over 10 year period: $/block
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$0.84 |
$1.15 |
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Present
Worth over 30 year building life: $/block
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$2.10 |
$2.86 |
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See the
following example calculation details.
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Designing with
SmartWall Systems can provide significant savings in heating and
cooling. Even when used as backup in insulated cavity walls, the
energy savings are still notable-. For more information on SmartWall
energy savings in cavity walls, other types of block core insulation,
or for other geographic locations, contact Buildex Inc. or your
local SmartWall Systems block producer.
SmartWall
has benefits for everyone involved in building construction —
the Owner/Occupant, the Designer, the Masonry Contractor, the Block
Producer, and their suppliers.
We at Buildex
are proud and excited to be part of this program. We welcome the
opportunity to visit with you about all the benefits of using SmartWall
Systems.
Life
Cycle Energy Cost Analysis Present
Value of Annual Energy Cost Savings Using SmartWall Systems Over
a Thirty Year Period
Wall
construction: Single wythe 8" w/foamed in place core insulation
Location:
Omaha, Nebraska
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R
Value Data
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CMU
Density
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|
.
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135 lb/ft3
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105 lb/ft3
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90 lb/ft3
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R
value (3)
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3.40
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5.60
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7.30
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Calc:
U value
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0.294
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0.179
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0.137
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Calc:
Difference in U values
(vs 135 lb/ft3)
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---
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0.116
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0.157
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| R-value
in (hr • ft2 • ºF) / BTU. U value
in BTU / (hr • ft2 • ºF) |
The following analysis makes two comparisons. The left column
compares lightweight units meeting ASTM C90 at 105 lb/ft3
to ordinary 135 lb/ft3
units. The second comparison (in the right hand column) is between
a SmartWall Systems unit at 90 lb/ft3
and the same 135 lb/ft3
unit. All units are conventional 8" x 8" x 16" size. The analysis
Shows that SmartWall Systems units save substantial energy costs
when compared to both ordinary 135 lb/ft units and regular ASTM
C 90 lightweight units.
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Heating
Cost Calculations
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ASTM
Lightweight
105 lb / ft3
CMU
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SmartWall
90 lb / ft3
CMU
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U
value difference vs. 135 lb / ft3
cmu (from above)
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0.116
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0.157
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Natural
Gas Cost (2) per mcf
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$4.53
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$4.53
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Furnace
efficiency
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0.80
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0.80
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Calc:
$ Cost per Btu output
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5.66E — 06
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5.66E — 06
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Heating
Degree Days for This Location (1)
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6201
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6201
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Calc:
Energy Savings: $ / sq ft / yr
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$0.0974
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$0.1324
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Calc:
Energy Savings: $ / block / yr
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$0.0866
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$0.1177
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Present
Worth of Heating Savings n (years)
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30
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30
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i
(nominal rate — energy and money)(4)
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2.00%
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2.00%
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Calc:
Present Worth of Heating Energy Savings, $ / block
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$1.94
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$2.64
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Cooling
Cost Calculations
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.
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.
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Electricity
Cost (2) per kwh
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$0.0538
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$0.0538
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SEER
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10
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10
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Cooling
Degree Hours for This Location (1)
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13180
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13180
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Calc:
Energy Savings: $ / sq ft / yr
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$0.0082
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$0.0111
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Calc:
Energy Savings: $ / block / yr
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$0.0073
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$0.0099
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Present
Worth of Cooling Savings n (years)
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30
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30
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i
(nominal rate — energy and money) (4)
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2.00%
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2.00%
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Calc:
Present Worth of Cooling Energy Savings, $ / block
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$0.16
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$0.22
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Calc:
Present Worth of Total Energy Savings, $ / block
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$2.10
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$2.86
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See
ESCSI Information Sheet No. 3530 for references and information
on energy savings in other major US cities. Wall weights are from
Concrete Masonry Design Tables, TR-121, Table 7.2, National
Concrete Masonry Association, 1993.
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