SIPs: A Critical Component of Zero Energy Homes

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SIPs A Critical Component of Zero Energy Homes
April 21, 2009 2009 SIPA Annual Meeting, Chicago,
IL

• Jeff Christian

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From 5 small Habitat test Houses to medium spec
and Custom near ZEH developments

• TVA demographically selected house size, builder,
  developer, location, 225- 260K price range,
• Builder house, 2400 ft2, HERS 90, 5.7 ACH_at_50
  Pascals
• Retrofit house, 2400 ft2, HERS 66, 3.2 ACH_at_50
  Pascals
• nZEH, 2500 ft2, HERS 34, 2.63 ACH_at_50 Pascals
• Lead Builder in East Tennessee
• 3600 ft2, HERS 37, SIP
• 3600 ft2, HERS 39, Optimum Value Engineered
  Framing
• Two 2700 ft2, Exterior Insulated Finish System,
  Phase Change Materials

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US DOE Goal to develop an Affordable Zero Energy
Home by 2020

• Produces annually on-site solar energy equal to
  the energy requirements.
• Provides standard energy services typical
  expected energy using features (National
  Averages)
• Net ZEH is defined as HERS index 0 US
• Added first cost 30 year mortgage incremental
  payment off set by energy cost savings at end of
  first year

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Motivation

• In the U.S.
• 40 of US CO2 comes from buildings
• 71 of electric grid serves buildings
• Grid will be shared with plug-in-hybrids
• In developing countries, standards of living
  improving and energy demand increasing world wide
• 34 out of 37 Countries polled believe the US is
  the major contributor to Climate Change

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Energy Consumption of 5 Habitat for Humanity near
ZEH kWh and /day
20000
29-41 Solar
15000
kWh
SOLAR
10000
GRID
5000
0
3.36
1.04
0.91
0.81
0.77
0.69
Base
ZEH1
ZEH2
ZEH3
ZEH4
ZEH5
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ZEHcor
Premanufacture and ship to site, Just like SIPS
First cost savings potential 1000 to 3000
Energy savings 5 to 10
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Blower Door study of sticks with blown foam vs
SIPs in identical 1200 ft2 Habitat houses
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Envelope Air-tightness of sticks with foam as
good as SIPS
1.35 ACH50
4.0 ACH50
1.15 ACH50
1.7 ACH50
1.09 ACH50
1.64 ACH50
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Future ZEH will be aggregated to dispatchable
green power plants
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August 2007 The Hottest on Record
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In August 2007 TVA (Electric Utility servicing
Tennessee) all time Top 10 System Peaks
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39 oC
23 oC
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23.6 C
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TVA all time Critical Peak Period
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Summary of peak load savings from near zero
annual energy homes in East Tennessee
 
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100/mo mortgage
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Campbell Creek near Zero Energy House
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• Campbell Creek Research House, 2,500 ft2, HERS
  34 (Incl. Solar)
• Advanced framing (2 x 6) with DOWsis (R-2.74)
  sheathing rather than OSB
• R-49 attic with LP Techshield radiant barrier
  sheathing
• R-6 triple-pane gas-filled windows
• One 2-ton air-source heat pump, SEER 16, HSPF
  9.5, air-side zone control
• Fantech energy recovery ventilator (ERV)
• Advanced appliances, waste heat recovery, HPWH,
  2.5 kW solar PV, etc.

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TVA Three House Study House 3 Near Zero Energy,
HERs Index 34

• Advanced 2 X 6 Framing with DOWsis
• R-49 attic with LP Techshield radiant barrier
  sheathing
• R-7. Triple layer windows from Serious Materials
• R-10 vertical slab stem wall insulation
• One Amana 2-ton HP, SEER 16, HSPF9.5, zone
  control
• Fantech Energy Recovery Ventilator
• Advanced GE appliances
• Energy Star pin based High performance lighting
  design
• Solar drain-back water heater
• 2.5 kWh Solar PV system
• Greywater waste heat recovery
• Appliance waste heat recovery
• 70 heating energy savings

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House 3 Advanced Framing
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24 inch on center Advanced Framing
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Insulated headers above windows
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DOWsis, R-2.74/ ½ inch, 3 in. nail spacing at
perimeter, 6 in in the field, avoid ladder marks
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Two stud corners rather than 3 or 4
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Two inches vertical XPS Slab insulation
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Before the wall is pushed up 1. stable sill seal
to pressure treated bottom plate
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2. Stable 6 inch aluminum flashing
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3. Stable second layer of sill sealer
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Air seal, termite barrier and capillarity break
sandwich
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Knee walls Classic over sight
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Bonus knee walls all foamed up ready for spider
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Added 2X6s to allow R-41 in bonus cathedral
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Bonus Room means lots of extra blocking
Bonus Room Floor above Garage
Knee walls
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Blocking behind tub and shower
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Master bath well sealed insulated and ventilated
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Blocking adds costs back in
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Behind the fireplace chase
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Foam at least air sealling framing trouble spots
still leaves thermal shorts
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Cantilevered floor
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Flash all sides of cantilevered floor truss cavity
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Cantilevered floor remaining space filled up
with Spider
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Blocking between garage and dining
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Blocking needed to air seal
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Blocking between garage and kitchen
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Taped DOWsis board and flash serves as the air
barrier for this house
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Spider men
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Envelope Air-tightness of the Builder, Retrofit
and the NZEH
5.7 ACH_at_50
3.27 ACH_at_50
2.6 ACH_at_50
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Envelope Air-tightness of other NZEH prototypes
1.35 ACH50
1.64 ACH50
4.0 ACH50
2.6 ACH50
1.15 ACH50
1.7 ACH50
1.09 ACH50
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Retrofit is 4/ft2 floor area more than the
Builder and NZEH is 21/ft2 more?
Total cost K
Includes some cost of installing instrumentation
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Insulation alone in the NZEH is 1.67/ft2 more
than the Builder

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Measured heating energy kWh from January 24 until
February 4, 2009
35 Saver
kWh
65 Saver
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Projected energy costs per year 0.65/ft2
savings for NZEH compared to Builder
Save 444/yr

Save 1544/yr

• Assumes TVA solar buy back is 0.10 kWh
• more than residential rate

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Key Features for near ZEH

• SIPS with drainage plane or Optimum Value
  Engineered 2X6 with foam sheathing air barrier
• High Performance Windows (U-value 0.2-0.34, SHGF
  0.35)
• Air tight (1.5 ACH_at_50) infiltration)
• Ducts inside the conditioned space
• ASHRAE 62.2 mechanical ventilation
• Raised metal seam roof (no roof penetrations)
• Geothermal\Exterior Foundation insulation
• 2.5 kW PV Solar system
• House daily reminds you how precious it is to
  collect energy from the sun and how easy it is to
  shut of a light U.S. News World Report April
  22, 2008

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Schaad, DOE Builder Challenge, 4 HERS 40-30
energy saver test houses
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SIPS vs Optimum Value Framing (framing fraction
13)
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Seeking Affordable 50 Energy Saving Envelope
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• RD lineage springs from SIPA and ORNL
  partnership
• Purpose of projects
• Low-HERS Research affordable ways to go lower
  (new/retrofit)
• Low-HERS Education build consumer demand,
  builder/contractor capacity

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Double layer of papers eliminates cost for
furring strips and ½ inch drainage layer over SIPS
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Foundation geothermal loop
Electrical
Water
Sewer Line
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ZEHcor
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ZEHcor for basement of 3 story ZEH
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FHX
ZEHcor
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ZEHcor Interior Utility Wall

• Saves energy
• Imposes floor plan discipline
• Reduces hot water distribution losses
• Enables integration that could never be done
  reliably on-site
• ERV-to-FHX
• Appliances grey water to FHX
• Reduces cost
• Pre-fabrication in a controlled environment
• Greater labor productivity
• Less materials waste

ZEHcor
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Thank you!
?

• Jeff Christian
• ChristianJE_at_ORNL.gov