Field Study and Energy-Plus Benchmarks for Energy Saver Homes

Authors

Dr. William Miller, Dr. Som Shrestha and Ken Childs of ORNL Eric Stannard of Univ. of Tennessee

SUMMER STUDY ON ENERGY EFFICIENCY IN BUILDINGS

August 16, 2012

William (Bill) Miller, Ph.D

N

Pair of Homes• Two-story with

Basement

Pair of Homes• Two-story on

Crawlspace

Project consists of four houses with different equipment and envelope systems

Wolf Creek Subdivision, Oak Ridge, TN

“Structural Insulated Panel” SIP Strategy “Advanced Framing” OVF Strategy “Dynamic Insulation - Phase Change Material” PCM Strategy “Exterior Insulation Finishing EIFS Strategy

Footprint in square feet1 Key Envelope Feature Basement 1st Floor 2nd Floor Total (ft2)

Structural Insulated Panels (SIP home) 1518 1518 677 3713 Optimal Value Framing (OVF home) 1518 1518 677 3713 Dynamic Envelope (PCM home) NA 1802 919 2721 Exterior Insulation Finish System (EIFS home) NA 1802 919 2721

1 Conversion: m2 = 9.290304E-02 * ft2

SIP House

OVF House

PCM House

EIFS House

ZEBRAlliance established to promote Cost-Effective Energy Efficiency in Buildings

Functions as a public-private research project to promote an energy-efficiency education campaign

Miller, et al. 2009 “Advanced Residential Envelopes for Two Pair of Energy-Saver Homes,” ACEEE Summer Study, 2009.

Objectives

· DOE Building Technologies (BT) program Residential Building Integration

Accelerate progress toward Zero-Energy-Home (ZEH) Whole-house 50% saver homes in mixed humid climate

· DOE BT: Building Envelope R&D Showcase different envelope approaches Best practices portfolio: materials and construction

· DOE BT: Analysis Tools and Designs Data acquisition for Foundation Heat Exchanger (FHXs) Benchmark FHX data against analytical tools

· DOE BT: Space Conditioning and Refrigeration Characterize HVAC, Water heating and Appliance systems Accelerate for-sale status to better penetrate market

Demonstration Homes in Oak Ridge, TNSIP and OVF Pair of Homes

Blower Door Tests Tracer Gas Experiments IR Thermography Diagnostics

Construction Verified Using IR Thermography

SIP

Kaushik Biswas, Kosny and Miller. “Thermal Integrity Assessment of Building Envelopes of Experimental Houses Using Infrared Thermography,” InfraMotion 2010, Las Vegas, Nevada.

FLIR Systems S65 HS IR CameraASTM Standard C1060

• ΔT >10°C for 4 hrs• No Irradiance for 3 hrs• Wind Speed < 15 mph

Min -7.2 Max 1.2 Min -4.4 Max -1.5

Min -7.8 Max -5.9

Min -11.1 Max 4.6Min -3.7 Max -0.7

SIP House

OVF House

SIP House

OVF House

Min -11.5 Max 2.0

Min -6.1 Max -3.4

Min -5.7 Max 2.0

Min -7.4 Max 1.8

Min -5.9 Max -2.8

Min -7.9 Max 1.,3

Revenue Meter Readings Verify all Homes used 50% less energy than Home Built to IECC 2006

DescriptionSIP

StrategyOptimal Value

Framing StrategyPCM Envelope EIFS

EnvelopeBuilders House1

HERS 46 47 47 50 101

Annual (kWh per ft2 per year) 4.66 4.50 5.43 5.70 11.14

ACH2 at 50 Pa 1.23 1.74 3.18 2.18 5.7

Tracer Gas3ACH 0.05/0.09 0.05/0.13 0.11/0.14 0.08/0.07 NA

1 International Energy Conservation Code (2006).2 Air exchanges per hour (ACH) measured by blower door testing conducted at 50 Pa.3 Tracer gas test using concentration decay method and R-134a refrigerant. Measured values in summer/winter 2011.

SIP House Equipment Characteristics

WAHP: 2-ton (7kW) capacity – Cooling COP 4.0 high-

stage– Heating COP 5.4 high-

stage– 2-Stage scroll compressor– Rated as per

ANSI/AHRI/ISO 13256-1– Brine Pump (1/6)hp (147

W)

WWHP: 1.5-ton (5.3 kW)– COP 3.1 (based on EWT

32oF (0oC)and load EWT 100oF (37.8oC)

– 1-Speed rotary compressor

– Brine Pump (1/6)hp (147W)– DHW Pump (1/25)hp (30W)

Water Tank: 80 gal (303L) – ~60 g/d (220L/d) water @

120oF (49oC)

Heating Capacity vs. Entering Water Temperature (EWT)

M. Ally, J. Munk, V. Baxter, A. Gehl

ASHRAE Summer Meeting San Antonio, TX, June 23-27, 2012

High Stage: 5% of total run time

Cooling Capacity versus EWT

M. Ally, J. Munk, V. Baxter, A. Gehl

ASHRAE Summer Meeting San Antonio, TX, June 23-27, 2012

High Stage: 3% of total run time

OVF Home Salient Features· OVF House

– 2x6 stick-built wood-framing– 24-in on center with ½” OSB– House air tight using Carlisle’s Barritech VP liquid membrane – Walls contain R-21 flash and batt fiberglass– Cathedral ceiling using SIP based phenolic foam design (R8 /

in)

Exterior Insulation Finishing System

The EIFS has 2x4 stick-built wood-framing, 16-in on center with 5-in of EPS exterior insulation on all exterior walls to reduce thermal bridging losses.

A trowel applied weather resistive barrier minimizes the infiltration and/or exfiltration heat and moisture loads.

Crawlspace of the home is insulated and sealed (not vented to the outdoor ambient).

Weather Resistive Barrier PerformanceAfter a full year of exposure to the elements both WRB systems are adequately protecting the sheathing on the south-facing wall

E+ Model of PCM HomePhase Change Material (PCM) Home

Exterior Double Wall Assembly

2 by 4 studs

ZIP Panel

Gypsum board

Fabric Mesh

PCM - Cellulose

Cellulose24” OC

24” OC

PCM applied in the insulation will provide thermal buffering in wall

Summer Temperatures Measured in the East and South Wall of the PCM Home

Temperatures Measured in Blown Fiber Insulation in the Attic of the PCM Home

Winter Field Data Summer Field Data

E+ Benchmarks of Attic Floor Heat FluxSIP and OVF Homes have cathedral ceilingsPCM and EIFS Homes have conventional ventilated attics

E+ predicted roof heat flux (W/m2) better for summer data than for winter

Avg Seasonal Differences

SIP OVF EIFS

Summer (W/m2) 0.22 0.25 0.54

Winter (W/m2) 1.73 0.28 0.85

E+ Benchmarks of East Wall Heat FluxWinter data shows continual heat loss to the cold outdoorsE+ predicted SIP and OVF wall flux better than EIFS (low-e foil)

E+ differences between measured and predicted east wall heat flux (W/m2)

Avg Seasonal Differences

SIP OVF EIFS

Summer (W/m2) 0.30 0.11 NA

Winter (W/m2) 0.24 0.36 NA

Rising SunHeating Wall

Conclusions· HERS scores and revenue meter data prove all

homes consume only about half the energy consumed by conventional IECC (2006) compliant house

· Driving rains do not penetrate the WRB which provide good protection from moisture intrusion

E+ (v7.0) predicted heat flux through the roofs and attics matched better with summer field measured data compared to that in winter

– does an acceptable job in matching the trends in summer and winter

PCM in East Tennessee’s climate showed the PCM fully active in an east oriented wall but only partially active in the south-facing wall

South Wall East Wall

Fully Active1 Partially Active2

Fully Active1

Partially Active2

Days out of Year 0 130 31 140

Percent of Days out of Year

0% 36% 8% 38%

Actual and Standard costs for the Four ZEBRA Houses

House 1 SIP House

House 2 OVF House

House 3 PCM House

House 4 EIFS House

Costs Items Actual Costs $

Standard Costs $

Actual Costs $

Standard Costs $

Actual Costs $

Standard Costs $

Actual Costs $

Standard Costs $

Labor~ 11,659 6,750 8,222 6,750 7,376 6,750 5,455 6,750 Supervision/ Administration~

74,115 27,000 36,326 27,000 46,639 27,000 39,181 27,000

Architectural* 14,880 26,566 1,502 25,795 260 21,227 158 20,094 Engineering° 2,455 4,735 2,035 3,537 2,686 2,945 2,894 3,052 Total Costs 596,000 557,900 526,700 541,700 444,800 445,800 412,800 422,000

House 1 SIP House

House 2 OVF House

House 3 PCM House

House 4 EIFS House

Total Costs ($) $557,900 $541,700 $445,800 $422,000 Total Square Footage 3,713 3,713 2,721 2,721 Total Cost Per Square Foot ($) 150 $145 $163 $155