Transcript Geothermal Alliance of Illinois Consider the Entire Package… “HVAC and Building Shell Working Together”

Geothermal Alliance of Illinois
Consider the Entire Package…
“HVAC and Building Shell
Working Together”
What Makes a Comfortable Home?
1. Building Shell – (first priority)!
 Complete thermal & pressure boundaries
2. Mechanicals – (sized to building shell)
 Heating, air conditioning & duct systems
3. Ventilation – (controlled air leakage)
 Bath and kitchen exhaust
 Moisture source control
 35 to 40% humidity in the winter
Tightest Home in the World
“Net Zero
Energy Ready”
Home In
Dillingham,
Alaska
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R90 Walls, R140 Attic…..
R140 Ceiling
R90 Walls
R20 Perimeter
R35 Under Slab
Factors that Affect Insulation Performance
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Convection through the insulation
Air leakage through the insulation
Density of the insulation
Gaps and voids
Thermal bridging across the envelope
Humidity
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Thermal Bridging
Thermal bridging is conductive heat loss through a solid
assembly with a temperature difference on each side causing
heat to flow. House framing is a good example.
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Wall Cavities with Six Sides
1. Top plate
2. Bottom plate
3. Left side
4. Right side
5. Ext. sheeting
6. Drywall
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Fiberglass Batt Insulation
Fiberglass batt insulation
is an air permeable
insulation that must be
installed in reasonable air
tight vertical wall cavities
to perform close to its
advertised R-value.
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Batt Insulation Installation
Voids mean less R-value!
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Fiberglass Batts Not Installed Properly
Air permeable insulation be in full
contact with the warm side of the drywall!
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Damp Spray Cellulose – New Const.
Damp spray is a new construction application when the walls
are open. Water is injected into the stream of cellulose as it
comes out of the hose. Causing it to stick in the wall cavities.
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Industry Solution to Air Sealing
(Knauf Insulation's EcoSeal spray)
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Horrible Insulation!
50% reduction in
R-value at design
temperatures!
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Under Performing “Overblown” Fiberglass
R42 fiberglass on a 45° day
70° inside
Convective heat
loss through the overblown
fiberglass attic insulation
Convection Within Attic Insulation
Overblowing or “Fluffing” fiberglass insulation
will cause convective heat loss through the
insulation no matter the thickness
Fluffed Fiberglass Attic Insulation
Heated Living Space
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Insulation Chutes & Wind Blocks
WIND BLOCK
INTERIOR DRYWALL
EXTERIOR
STUD WALL
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Wind Washing in the Eaves
Insulation
blown out of the
eaves leaving
the drywall
ceiling
uninsulated.
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Wind Washing in the Eaves
Insulation
blown out of the
eaves leaving
the drywall
ceiling
uninsulated.
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Standard Truss R50 (w/ tapered insulation)
Full Height
Average Height
Minimum Height
Energy Truss R38 (w/ full height insulation)
Full Height
Never Use Batts on the Attic Floor!!
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Gap in Pressure Boundary
Thermal Boundary
Air Leaks in through
spaces between Drywall
and Top Plate
Thermal Boundary
“Complete pressure boundary”
is a Tell Tale
StopDirty
theInsulation
convective
loop
Sign of Air Leaks
Convective Loop occurs in wall
cavity and warm air leaks out
into attic carrying moisture
Electrical Penetrations
from Basement
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Sealed Top Plates Short Knee Wall
Sealed and insulated short
knee wall and top plates
Perfectly sealed top plates
with 2-part spray foam
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IC Rated Recessed Light Fixtures
“Complete pressure boundary”
IC Rated
Air-Loc
“Incomplete pressure boundary”
Conditioned Attic Space, or is it????
Incomplete Wall Assembly
75%
reduction
in R-value!
Bonus Room Trusses – Problems!
• No top plate
• No bottom plate
• Usually no sheathing on the attic side of wall
• No blocking under the knee wall in the floor joists
• Batts in the sloped ceiling
Insulated Basement, or is it????
Conductive Heat Transfer
Q = U x A x ΔT
(Q = Heat Flow in btu’s / hr)
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Conductive Heat Loss in One Hour
Q = U x A x ΔT
(U-value x Area x Temperature Difference)
Example: 1,200 sq/ft attic with an 8 sq/ft pull down ladder
(R50) .02 x 1,192 sq’ x 60º = 1,430 btu/hr
(R.5) 2 x 8 sq/ft x 60º =
960 btu/hr
Total heat loss 2,390 btu/hr
60% loss from ceiling
40% loss from pull down ladder!
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Uninsulated Attic Hatch
Attic hatch
551
Uninsulated 2’ x 2’attic hatch
R30 insulated attic hatch
2 x 4 x 70 = 560 btu/hr
.033 x 4 x 70 = 9 btu/hr
551 btu/hr
551
Wind Blown Insulation
Attic hatch
Missing insulation
551
1,400
2 x 10 x 70 = 1,400 btu/hr
1,951
Poorly Insulated Rim
R4 rim joist (reduce by 70%)
R13 rim joist
.25 x 200 x 70 = 3,500 btu/hr
.076 x 200 x 70 = 15 btu/hr
3,485 btu/hr
Attic hatch
Missing insulation
Rim Joist
551
1,400
3,485
5,436
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Attic Insulation
R25 Insul-Safe insulation
R50 Insul-Safe insulation
.04 x 2100 x 70 = 5,880 btu/hr
.02 x 2100 x 70 = 2,940 btu/hr
2,940 btu/hr
Attic hatch
Missing insulation
Rim Joist
Attic insulation
551
1,400
3,485
2,940
8,376
Knee Wall Insulation
R4 knee wall insulation
R13 knee wall insulation
.25 x 160 x 70 = 2,880 btu/hr
.076 x 160 x 70 = 851 btu/hr
2,029 btu/hr
Attic hatch
Missing insulation
Rim Joist
Attic insulation
Knee walls
551
1,400
3,485
2,940
2,029
10,405
32 - Recessed Lights
32 recessed lights (12 sq/ft)
.2 x 32 x 70 = 448 btu/hr
.02 x 32 x 70 = 45 btu/hr
403 btu/hr
Attic hatch
Missing insulation
Rim Joist
Attic insulation
Knee walls
32 recessed lights
551
1,400
3,485
2,940
2,029
403
10,808
Thermal Bypasses
20 sq’ bypasses R5
20 sq’ bypasses R50
1 x 20 x 70 = 1,400 btu/hr
.02 x 20 x 70 = 28 btu/hr
1,372 btu/hr
Attic hatch
Missing insulation
Rim Joist
Attic insulation
Knee walls
32 recessed lights
Thermal bypasses
Total btu/hr loss
551
1,400
3,485
2,940
2,029
403
1,372
12,180
Is Your Mirror Foggy After A Shower?
You Should Never Have a Foggy Mirror
4” Dia. Duct
6”
Prescriptive Duct Sizing for Ventilation
Source: ASHRAE Standard 62.2-2007
This table assumes no elbows. Deduct 15 ft of allowable duct length for each elbow.
NL = no limit on the duct length of this size
THERMAL IMAGING SERVICES
of Central Illinois, Inc.
“Improving Home Performance”
Brian Kumer
Thermal Imaging Services, Inc.
Peoria, IL
309-547-5000 office
309-251-1719 cell
[email protected]
www.improvinghomeperformance.com