Embed Size (px)
Citation preview
U.S. Department of EnergyEnergy Efficiency and Renewable EnergyBringing you a prosperous future where energy is clean, abundant, reliable, and affordable
Building Technologies ProgramT OF ENER
GYD
EPA
RTMEN
U
E
NIT
ED
STAT S OFA
ER
ICA
M
November 2004 • NREL/SR-550-36474
Strategies for Energy-Efficient Remodeling:SEER 2003 Case Study ReportFebruary 27, 2003—October 31, 2004
S. Craig DrumhellerJoe WiehagenNAHB Research Center, Inc.Upper Marlboro, Maryland
November 2004 • NREL/SR-550-36474
Strategies for Energy Efficient Remodeling: SEER 2003 Case Study Report February 27, 2003―October 31, 2004
S. Craig Drumheller and Joe Wiehagan NAHB Research Center, Inc. Upper Marlboro, Maryland
NREL Technical Monitor: Ren Anderson Prepared under Subcontract No. ADO-3-32471-03
National Renewable Energy Laboratory 1617 Cole Boulevard, Golden, Colorado 80401-3393 303-275-3000 • www.nrel.gov
Operated for the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy by Midwest Research Institute • Battelle
Contract No. DE-AC36-99-GO10337
NOTICE
This report was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States government or any agency thereof.
Available electronically at http://www.osti.gov/bridge
Available for a processing fee to U.S. Department of Energy and its contractors, in paper, from:
U.S. Department of Energy Office of Scientific and Technical Information P.O. Box 62 Oak Ridge, TN 37831-0062 phone: 865.576.8401 fax: 865.576.5728 email: mailto:[email protected]
Available for sale to the public, in paper, from: U.S. Department of Commerce National Technical Information Service 5285 Port Royal Road Springfield, VA 22161 phone: 800.553.6847 fax: 703.605.6900 email: [email protected] online ordering: http://www.ntis.gov/ordering.htm
This publication received minimal editorial review at NREL
Printed on paper containing at least 50% wastepaper, including 20% postconsumer waste
iii
We would like to acknowl-edge the people and com-panies without whose helpthis project would not havebeen a success. A specialthanks is extended to BillAsdal, both as the propertyowner and general contrac-tor/remodeler for his never-ending commitment toproducing a showcaseenergy retrofit home. Specialrecognition is also given tothe companies who madethis major undertaking pos-sible with generous technicaland material support:
AstroPower
Bergy Windpower
Crane Performance Siding
Eastern Insulation
Energy Services Group
Fineline Energy Solutions
New Jersey Clean EnergyProgram
Rheem
SETS Systems
Simonton Windows
Solargenix Energy
Tamarack Technologies
TechBuilt Systems
Therma – Tru Doors
U.S. GreenFiber
VanNatta Mechanical
Vanguard Piping Systems
Waterfurnace International
Whirlpool Corporation
Appreciation is also given tothe U.S. Department of En-ergy (DOE) Building AmericaProgram and the NationalRenewable Energy Labora-tory (NREL) technical advisorsfor their consistent and com-petent support as well as theircommitment to improvingenergy efficiency in allhomes.
Thanks to the staff ofHousingzone.com who estab-lished, maintained andsupported the SEER websiteto widen the educationalcircle for energy efficiency inremodeling.
ACKNOWLEDGMENTSS E E R 2 0 0 3 C
A S E S T U
D Y R E P O
R T
v
TABLE OF CONTENTS
1. INTRODUCTION ...................................................................................... 12. THE FIRST SEER PROJECT – A CASE STUDY IN ALL OR NOTHING ........ 23. SYSTEMS ENGINEERING APPLIED TO ENERGY EFFICIENCY
RETROFIT – CHALLENGES AND CHOICES ............................................ 34. BENEFITS TO HOME REMODELING PROJECTS THAT INCLUDE
ENERGY EFFICIENCY STRATEGIES ......................................................... 45. STRATEGIES FOR ENERGY EFFICIENCY IN REMODELING ..................... 5
5.1 Wall Insulation System....................................................................................... 55.1.1 Wall Insulation – SEER Case Study ....................................................................................................................................... 5
5.2 Ceiling Insulation System.................................................................................. 85.2.1 Ceiling Insulation – SEER Case Study ............................................................................................................................... 8
5.3 Basement or Floor Insulation System............................................................... 85.3.1 Basement or Floor Insulation – SEER Case Study ................................................................................................ 9
5.4 Windows and Doors .......................................................................................... 95.4.1 Windows and Doors – SEER Case Study ...................................................................................................................... 9
5.5 Air Sealing ........................................................................................................ 105.5.1 Air Sealing – SEER Case Study .............................................................................................................................................. 10
5.6 Heating and Cooling Equipment ................................................................... 115.6.1 Heating and Cooling Equipment – SEER Case Study ................................................................................ 11
5.7 Water Heating System ..................................................................................... 135.7.1 Water Heating System – SEER Case Study.............................................................................................................. 14
5.8 Lights and Appliances .................................................................................... 155.8.1 Lights and Appliances – SEER Case Study ............................................................................................................. 15
5.9 Room Additions ............................................................................................... 155.9.1 Room Additions – SEER Case Study ............................................................................................................................... 15
5.10 Renewable Energy Systems ......................................................................... 165.10.1 Renewable Energy Systems – SEER Case Study ............................................................................................ 17
6. SUMMARY OF COST AND SAVINGS ESTIMATES ................................. 19ADDENDUM
FIRST SEER REMODEL SITE – LEBANON, NEW JERSEY......................... 23
S E E R 2 0 0 3 C A
S E S T U D
Y R E P O R T
vi
LIST OF TABLES AND FIGURES
TABLESTable 1 – Insulated Siding Cost Comparison ......................................................................................................................... 7
Table 2 – Energy Efficiency Cost Summary .......................................................................................................................... 19
Table 3 – Summary of SEER Case Study Energy Use and Costs/Savings .............................................. 21
Summary of Economic Analysis Based on Energy Value Only ....................................................................... 22
FIGURESThe site of the “gut rehab” ....................................................................................................................................................................... 1
The “gut rehab” one year later ........................................................................................................................................................... 1
The main house on the same property ....................................................................................................................................... 2
Insulation blown into wall cavities ..................................................................................................................................................... 6
Blown cellulose insulation ........................................................................................................................................................................... 6
Insulated siding trim ........................................................................................................................................................................................... 7
Insulated siding ....................................................................................................................................................................................................... 7
Floor insulation between joists ............................................................................................................................................................... 8
Energy efficiency windows and door in cottage ............................................................................................................ 9
Air sealing around windows .................................................................................................................................................................. 10
Air barrier on outside of house .......................................................................................................................................................... 11
Ground source heat pump in conditioned space ..................................................................................................... 12
All duct joints sealed ..................................................................................................................................................................................... 12
Manifold plumbing system ..................................................................................................................................................................... 13
Hot water system in cottage ............................................................................................................................................................... 14
Solar thermal collector with PV panel for pump........................................................................................................... 14
Addition construction using foam panels .............................................................................................................................. 15
Ridge and eave supports for roof panels ............................................................................................................................. 16
Addition constructed in 6 hours ....................................................................................................................................................... 16
R-50 roof and R-30 wall panels .......................................................................................................................................................... 17
Ridge beam for roof support ............................................................................................................................................................... 17
PV system on Cottage home ............................................................................................................................................................. 17
Aerial view of PV system .......................................................................................................................................................................... 17
Garage PV system for Cottage home ..................................................................................................................................... 18
PV system inverters .......................................................................................................................................................................................... 18
S E
E R
2 0
0 3
C
A S
E S
T U D
Y R
E P
O R
T
vii
DEFINITIONS
ACH air changes per hour
DOE US Department of Energy
LOW-E low emissivity
NAHBRC NAHB Research Center
NJCEP New Jersey Clean Energy Program
NREL National Renewable Energy Laboratory
PV photovoltaic
ROI return on investment
SEER Strategies for Energy Efficiency in Remodeling
1
S E E R 2 0 0 3 C A
S E S T U D
Y R E P O R T
INTRODUCTION
The goal of the Strategies forEnergy Efficiency in Remodel-ing (SEER)1 project is to pro-vide information, based onresearch and case studies, toremodelers and consumersabout opportunities to in-crease home energy perfor-mance. Opportunities toinclude energy efficiencyoften arise while undertakinggeneral remodeling work. Ofcourse, energy efficiencymay always be pursued as aremodeling project unto itselfto improve the comfort of thehome and reduce monthlyutility bills. A case study in themid-Atlantic region was
1 The SEER project was developed by the NAHBResearch Center (NAHBRC) as part of the DOEExisting Buildings Program under the BuildingAmerica umbrella.2 The Building America program is sponsored bythe Department of Energy (DOE) through theNational Renewable Energy Laboratory (NREL).
The “gut rehab” one year later
The site of the “gut rehab”
undertaken to developand test the applicationof energy efficiencystrategies, to evaluatethe benefits, and toidentify any weaknessesin their design or appli-cation. Taken togetheras a system, the strate-gies provide opportuni-ties for energy and costsavings, increaseddurability, and in-
creased comfort of the remod-eled home.
This case study report exam-ines the technologies, meth-ods and installation of specificenergy efficiency strategies.The information presentedhere stems from a “gut rehab”of a house in rural New Jerseyas part of the SEER projectthrough the Building AmericaExisting Buildings Program2. A“gut rehab” project allows forconsideration of a wide rangeof energy efficiency strategiesand, accordingly, is a goodbasis of this initial effort. Asother remodeling projects are
1
undertaken the knowledgebase will expand and becomemore complete. The evalua-tion of this extensive rehabproject provides many detailsof energy efficiency strategiesthat will lead to energy savingsand can be implemented byremodelers and consumersover months or years.
2
S E
E R
2 0
0 3
C
A S
E S
T U D
Y R
E P
O R
TTHE FIRST SEER PROJECT –A CASE STUDY IN ALL OR NOTHING
The gut rehab project devel-oped by remodeler Mr. BillAsdal is detailed in his sum-mary in the addendum andclearly demonstrates a remod-eling “all-or-nothing” ap-proach. The remodeler’schoice of the full renovation ofa home that would otherwisebe destined for the landfillprovides an opportunity todemonstrate the extent towhich existing housing can bemade comfortable andenergy efficient – while re-maining cognizant of thecosts. The remodeler selectedto fully renovate the homeand in so doing salvaged abuilding for continued usefullife. The SEER project providedtechnical services to focus onthe energy efficiency aspectsof the remodel and in sodoing is estimated to decreasethe heating and coolingenergy consumption byabout 60%.
The first case study remodelproject was part of a largerrenovation project to com-pletely rehab two homes anda barn on a section of farm-land in west-central NewJersey. The smaller of thehomes, referred to as thecottage house, is 1,400square feet and has beenunoccupied for 10 years. Thehome, shown above, was
The main house on the same property
uninhabitable when pur-chased. Many of the energyefficiency concepts applied tothe cottage are also beingimplemented in the larger4,000-square-foot home (whichwill serve as a Bed & Break-fast). The cottage house willserve as the case study hometo demonstrate strategies foran energy efficiency remodel.
2
3
S E E R 2 0 0 3 C A
S E S T U D
Y R E P O R T
SYSTEMS ENGINEERING APPLIED TO ENERGYEFFICIENCY RETROFIT – CHALLENGES AND CHOICES
The Building America modelfor a systems engineeringapproach states that newhomes “can be cost effectiveto build as well as energyefficient to live in. In fact, theenergy consumption of newhouses can be reduced by asmuch as 50% with little or noimpact on the cost of con-struction through a systemsengineering approach.”3 Thistheory is practiced throughuse of new building materialsand systems as well as de-signs that can be serviced bysmaller heating and coolingsystems than used in typicaldesigns. Through the processoften termed “value engi-neering,” any increased costsin one area of construction(e.g., insulation) can be offsetby savings in another area(e.g., downsized furnace).
However, existing homespresent a larger challenge toimplementing a systemsapproach to energy effi-ciency. Because remodelingjobs typically involve fewersystems (e.g., wall, window,mechanical systems) thannew construction, it is moredifficult to make value-engineering tradeoffs. Inaddition, since remodelingjobs often involve a limitedbudget, it is typically moreexpensive to retrofit energyefficiency solutions than it isto include them in newconstruction.
Still, a systems approach toenergy efficiency remodelingcan create not only opportu-nities for energy savings, butalso improvements in durabil-ity and comfort. For example,existing homes may presentmore opportunities for the
have far fewer opportunitiesto directly reduce coststhrough construction tradeoffsexcept for gut rehabs and,possibly, attic/basementconversions and additions.Otherwise, the home alreadyhas selected framing, insula-tion, and heating and coolingequipment installed. In thesecases, the remodeling workmay focus on increasing theefficiency of a particularbuilding system as it is beingremodeled, or in some casesas additional work along withthe general remodeling effort.
3 Information on the Building America program’sSystem Engineering approach can be found athttp://www.eere.energy.gov/buildings/building_america/system.shtml.
3
selection of energy efficiencyupgrades since efficiencycan often be included withother work being performed.One benefit to includingenergy efficiency in existinghomes is that, often, peopleundertake extensive renova-tions with the intention ofstaying in the home for a longtime. Therefore, savings fromenergy efficiency detailsbecome an investment fromwhich they are likely to reapbenefits. In addition, a majoradvantage is the opportunityto improve comfort, espe-cially if the consumer hasdirect experience withuncomfortable conditions inthe home.
Unlike new constructionwhere energy efficiencyupgrades can directly reducecosts in other areas, theexisting home market will
Throughout the design and construction process,the systems engineering approach considersthe interaction between the building site,envelope, and mechanical systems, as well asother factors. It recognizes that features of onecomponent in the house can greatly affectothers and it enables the teams to incorporateenergy-saving strategies at no extra cost.System trade-offs, like the tightened shell thatenables an engineer to recommend a smallerHVAC system, can improve the quality andperformance of a home without affecting itscosts—to the builders or to the consumers.
Building America Program, Systems EngineeringResearch
4
S E
E R
2 0
0 3
C
A S
E S
T U D
Y R
E P
O R
T
4Many homes constructed 30or more years ago have littleor no insulation in the wallsand roof, single-pane win-dows that allow largeamounts of air and heat loss,and inefficient (by today’sstandards) hot water systems,space conditioning equip-ment, lighting, and appli-ances. All of these factorsresult in large amounts ofwasted energy and higherthan necessary utility bills.While lowering monthly utilityexpenses is often a primemotivation for improving ahome’s energy efficiency,there are numerous otherbenefits to improving energyefficiency that are not asoften considered. Thesebenefits include the following:
• ComfortLeaky and poorly insulatedolder homes often feeluncomfortable due to coldwall temperatures and draftsfrom windows. To accom-modate, many homeownersturn up the thermostat in thewinter. In summer, thesehomes are often subjectedto large solar gains andhigh levels of humidity (fromthe outdoors), causing thehomeowner to turn thethermostat down. Whenthermostats are turned up(or down), in addition tothe additional energyrequired for heating andcooling the space, there isan associated increase inwasted energy throughduct or hydronic systemlosses. In addition, draftywindows, cold wall sur-faces, and poor duct
design often result in largetemperature variationsbetween rooms.
• DurabilityOlder, inefficient homes areoften subjected to largeindoor swings in tempera-ture and humidity, causingwall and ceiling materials toswell and shrink and reduc-ing durability of materials,paints, and caulk. In addi-tion, to accommodate thehigh-energy needs of aninefficient home, mechani-cal equipment may operatefrequently and for longerperiods causing excesswear and tear. Attention toenergy efficiency detailscan mitigate some dura-bility problems, includingthose from moisture andunwanted air infiltration.
• Environmental PerformanceWhile quantifying the valueof the environmental ben-efits of energy efficiencyupgrades is often difficult,the qualitative values arereadily apparent. Benefitssuch as reduced energy useultimately result in less airpollution and a slower rateof natural resources deple-tion. Some efficiency prod-ucts use recycled materials,such as cellulose insulation.Many new air-conditioningsystems use a refrigerant thatis not harmful to the ozonelayer. In addition, thesystems approach to effi-ciency, comfort, and dura-bility can make the existingspace sufficiently comfort-able and durable to extendthe life of the home itself.
BENEFITS TO HOME REMODELING PROJECTS THATINCLUDE ENERGY EFFICIENCY STRATEGIES
• AffordabilityEnergy efficiency upgradeshave often been evaluatedin relation to the monthlycost of ownership. Lightbulbs are a good examplewhere the highly efficientfluorescent bulbs are com-pared to the higher energyand replacement costs ofincandescent bulbs, result-ing in a relatively shortpayback period. Althoughthe cost of energy efficiencyupgrades raises the totalremodeling project cost,monthly utility savings aremeasurable and continuethroughout the life of thehome – eventually resultingin a payback on the initialinvestment.
Although some remodelingelements could be arguedas a recouped investmentwhen one considers theresale market value of thehome (e.g., kitchen andbath upgrades), mostremodeling projects do notrecoup their total invest-ment. In addition, most newproducts used in the remod-eling will age and depreci-ate. Improving energyefficiency is the one remod-eling element that as aninvestment will have acontinued annual returnregardless of the resalemarket value.
5
S E E R 2 0 0 3 C A
S E S T U D
Y R E P O R T
5Although any one strategy toenhance the energy effi-ciency of the home may beperformed independently ofthe others, this case studycombines many differentstrategies into a system thatworks together to achieve thegoal of at least 30% energysavings. The strategy listevaluates each energy effi-ciency feature, comparing the“typical” approach with the“SEER” approach, to enhancethe energy performance of thehome. The overall energyefficiency features that wereconsidered in the case studyinclude the following:
• Insulation• Windows and doors• Air sealing• Heating and cooling
equipment• Water heating system• Lighting and Appliances• Additions• Renewable energy systems.
Each feature has within itstrategies to achieve thegoals of reduced energyconsumption, increasedcomfort and durability, and ifpossible, energy productionfrom renewable sources. Anexamination of specificstrategies shows the effective-ness of incorporating thesestrategies into a remodelingproject.
5.1 WALL INSULATIONSYSTEMThe home originally had noinsulation in the walls. Framedwith full 2x4 construction, thewood siding on the outsideand interior 1x6 sheathingprovided the wall structure
STRATEGIES FOR ENERGY EFFICIENCY INREMODELING
that stood for more than 100years. Since the home wasunoccupied for almost 10years, a prime goal was toremove the deterioratedsiding and replace it withsheathing and house-wrap toprotect the home’s interiorduring construction. Thiseffectively left the exteriorwall system with coverings onboth sides of the framing. Thiscondition made use of battinsulation materials nearlyimpossible. In addition, theirregular framing dimensions,including depth, meant thatbatt products would have anirregular fit.4
Based on the existing wallconditions, two wall cavityinsulation choices becameclear – the use of blowninsulation materials such asfiberglass, cellulose androckwool, or use of a foam-in-place insulation. Blown orfoamed insulation materialsprovide more of an opportu-nity to completely fill irregularwall cavities and may beinstalled through small open-ings in the framing bay. Theblown or foamed insulationproducts are particularlyadaptable to insulating wallsections that have coveringson both the exterior andinterior of the framing mem-bers.
Additional insulation on theexterior of the framing wasalso considered since thesiding was being replaced. Inolder homes, the framingmaterial accounts for more ofthe wall area than newhomes today, so use of anexterior insulation can add alarge benefit to the overall R-value of the wall system.
Typical products include sheetfoam board of various thick-nesses. However, anotherapproach is to use productsthat combines the sidingmaterials with the insulation.
5.1.1 WALL INSULATION –SEER CASE STUDY
The approach taken in theSEER case study was basedon the wall conditions thatwere
• covered on both the interiorand exterior of the framing
• constructed of rough cut,irregular framing members
• typical of large framing-to-cavity ratio (i.e., largeamounts of framing).
Based on the wall structuralassessment, the following wallinsulation options wereselected:
• Use blown or foamedinsulation in the wallcavities
• Use sheet insulation underthe siding.
The two most commonoptions for insulating existingwall cavities with coveringson both the exterior andinterior of the framing arespray foam and blown fibrousinsulations, such as fiberglassand mineral wool, or blownloose-fill insulation, such ascellulose5. Blown cellulosewas selected for this casestudy based on the followingcriteria:
• The much higher installedcost of foamed-in-placeinsulation6
4 However, the irregular fit could be overcomewith careful attention to batt installation details.5 Other blown insulation materials are manufac-tured but much less common and available.6 Based on estimates received by the remodeler.
6
S E
E R
2 0
0 3
C
A S
E S
T U D
Y R
E P
O R
T
7 Cost data primarily from RSMeans, 2004 with“Location Factors” applied.8 All R-value units in °F·hr·ft2/Btu.9 The insulated vinyl siding CraneBoard, ismanufactured by Crane Performance Siding.
Insulation blown into wall cavities
• The capability of dense-pack cellulose to signifi-cantly decrease infiltrationloses
• The availability of contrac-tors and equipment toinstall blown insulation
• The ready availability of thematerial.
The estimated installationcosts7 for blown celluloseinsulation is approximately$0.43/sf with an additional$1.74/sf to drill holes for blow-ing access. The total installedcosts then for installed blowncellulose insulation is about$2.17/sf of insulated wall area.Further, the estimated in-stalled cost of the wall insula-tion of the case study house
with 1338 sf of retrofittedinsulated wall area is $2,900.
In addition to the insulation inthe wall cavity, insulatedsheathing was selected forapplication to the exterior ofthe framing. This is advanta-geous since in many older
Blown cellulose insulation
homes large portions of thewall are wood membersproviding an R-value8 ofabout 4. Compared with theinsulated cavity of aboutR-14, this represents a largeportion of the wall with anR-value of only about one-
third of the cavity. To mitigatesome of these framing ef-fects, rigid insulation is usedunder the siding. Two choicesare available: board insulationapplied over the framing (orexisting wood sheathing) orinsulated siding. In the casestudy, insulated vinyl sidingwas selected.
Features of the insulated vinylsiding9 include a coverage of19" vertical per horizontal run(standard vinyl at 7.5" to 10")and an insulated core ofexpanded polystyrene. The R-value as a tested system fromthe manufacturer data is R-4.A comparison of the cost ofinstalling insulated vinyl sidingwith standard vinyl siding overa rigid foam board is shownin Table 1.
7
S E E R 2 0 0 3 C A
S E S T U D
Y R E P O R T
Insulated siding trim
Insulated siding
Based on the cost estimatesand primarily the labor sav-ings with a larger coveragearea, there is virtually nodifference between theinstalled costs of each system.The cost of installing theboard insulation to provide athermal break for the framingadds approximately $970, butwith the selection of theinsulated vinyl siding, theadditional cost is about $900.
Table 1 – Insulated Siding Cost Comparison
All values are normalized to a 100 square foot basis.Cost estimates based on interviews or cost estimate tables.
Cost of standard 9" or 10" siding $60
Labor to install $81
¾” foam sheathing (~ R4) $26
Labor to install sheathing $22
Total for vinyl siding over R4 rigid insulation $189 per 100 sf
Cost of integrated insulated siding (R4) $132
Labor to install (40% faster) $49
Total for R4 integrated siding $181 per 100 sf
8
S E
E R
2 0
0 3
C
A S
E S
T U D
Y R
E P
O R
T
5.2 CEILINGINSULATION SYSTEMAs with the wall system, therewas no insulation in theceiling or attic of the existinghome. Similar choices ofinsulating materials is avail-able for the ceiling or atticspace, with blown, foamed orbatt insulation products beingapplicable and easily in-stalled.
Blown or foamed insulationproducts are often used inceiling spaces following theinstallation of the ceilingcovering. These products canbe installed to various thick-nesses depending on thelevel of insulation required.The blown insulation productscan also be installed over anyexisting insulation.
Cathedral ceilings, however,pose more challenge to theblown insulation productssince netting would benecessary to hold the insula-tion between the rafters. If theceiling covering is in place, asimilar installation method asexisting walls can be used.Foam insulation products canbe used easily in the rafterspace since it can be applieddirectly to the underside ofthe sheathing and in variousthicknesses.
An important issue to consideris the air space between theinsulation and the sheathing.An air space under thesheathing is often requiredper the building code orshingle manufacturers. Ifvented soffit is used, the roofventilation should extend tothe ridge vent. In any case,sealing of air leakage into theattic (or rafter space if insu-lated) should be provided.
5.2.1 CEILING INSULATION– SEER CASE STUDY
Since the walls are beingblown with cellulose insula-tion, the same material wasselected for the ceiling of theexisting home. Based on theinstallation of a nominal R-19in the exposed attic floor, thecost for installing fiberglassbatt insulation and cellulose isvirtually identical. Otherbenefits such as air sealingfavor the installation of blowncellulose insulation over battproducts in some locations.The estimated cost for install-ing blown cellulose insulationin the existing home ceiling isapproximately $0.62/sf for anR-19 coverage (comparedwith $0.67/sf for batt insula-tion). The cost for insulatingthe 560 sf existing ceiling withfiberglass batts is about $375.
For the case study, however,the recommended R-valuefor the ceiling in this coldclimate is R-38. Based on costestimates, the cost of install-ing cellulose insulation in thecase study ceiling is about$672. The additional cost forthe case study home isapproximately $297 to in-crease the ceiling insulationto R-38 over R-19.
5.3 BASEMENT ORFLOOR INSULATIONSYSTEMMany remodeling projectsinvolve basement or crawlspaces that were originallyuninsulated, as is true for thiscase study. Though con-structed with a basement, thefoundation space was andwill continue to be uncondi-tioned. Isolating the uncondi-tioned basement space fromthe conditioned house wasachieved simply by insulatingthe floor joist space. The mostcommon insulation methodfor the floor joist space is battinsulation, using unfacedbatts. However, this is also anexcellent location for spray-applied foam insulationproducts, especially thosewith a low permeability.
Floor insulation between joists
9
S E E R 2 0 0 3 C A
S E S T U D
Y R E P O R T
For unconditioned basementsand some crawl spaces,addition of wall insulationover the above-grade sectionof walls can help to temperthe basement temperature.Rigid foam insulation at-tached by vertical gluebeads is a simple method ofinstalling the foam board.Check with local buildingcodes for any requirementsfor installing foam in uncondi-tioned basements andcrawlspaces.
5.3.1 BASEMENT ORFLOOR INSULATION – SEERCASE STUDY
For the case study home,where the basement is poten-tially subject to regular dampconditions, the floor waschosen for insulation ratherthan the basement walls. Thefloor insulation options includeblown or foamed insulationand batt insulation. In thislocation, use of batt insulationis preferable due to thehigher cost of installing blownor foamed insulation prod-ucts. The typical insulationlevel required for this locationwould be at least R-19. Use ofR-30 is preferable if the floorjoists are nominal 2x10’s as isthe case with the case studyhouse. The additional cost ofupgrading the floor insulationfrom the minimum R-19 to R-30 is approximately $328.
5.4 WINDOWS ANDDOORSThe use of energy efficientwindows and doors in theremodeling effort is verysimilar to that of new homes –
with the primary limitation totheir use being simply theknowledge of availableproducts. Information con-cerning appropriate windowsfor a given climate is easilyavailable on the Internet andthrough window manufactur-ers. Use of low-e coatings, anenergy benefit in most allclimates, is commonplace forwindow glass yet must still bespecifically requested inmany locations, as is theaddition of an inert gas forthe space between thepanes. Both the low-e andgas-fill options for windows willsignificantly increase theefficiency of the windowwhile increasing the comfortof the room.
Similarly, doors have a rangeof energy efficiency perfor-mance, but the energyefficiency ratings are moredifficult to identify directly onthe product. A minimalamount of research will
identify doors with a betterinsulating value than another.Foam-core doors with littleglazing will have the bestenergy performance.
5.4.1 WINDOWS ANDDOORS – SEER CASESTUDY
The additional cost of select-ing energy efficiency featuresfor the windows varies signifi-cantly between manufactur-ers. Generally, the added costof low-E coatings and gas fillranges from a low of a fewdollars per window to nearly$100. But many manufacturersoffer an energy efficientoption that includes low-ecoatings or a combination oflow-e coatings and gas fill, fortheir windows at a cost ofabout $2/sf of window area.For the case study house with196 sf of windows then, theadditional cost for energyefficient windows is about$400.
Energy efficiency windows and door in cottage
10
S E
E R
2 0
0 3
C
A S
E S
T U D
Y R
E P
O R
T
5.5 AIR SEALINGAir sealing to prevent energylosses due to infiltration is animportant part of the overallenergy performance of thehome, new or remodeled.Though this strategy is notspecifically addressed incurrent building codes,significant improvement inenergy savings and comfortcan be achieved throughsimple and inexpensivetechniques. Any place whereair can leak from inside theconditioned area to otherareas, including uncondi-tioned basements,crawlspaces, attics, garages,etc., are points where energyis lost to the outdoors. Airsealing can be done when-ever any part of the home isbeing remodeled, or on itsown, to simply increase theefficiency and comfort of thehome.
Many options are available tothe remodeler when airsealing homes. Foams, insula-tions, caulks, gaskets, andsheet goods are all productssuitable for achieving thegoal of lowering infiltrationlosses in the home. Ideally,multiple strategies should beimplemented during theconstruction phase. This willbetter ensure adequatesealing is achieved.
In choosing methods for thecase study, preference wasgiven to inexpensive solutionsthat could be executedduring multiple phases of theremodeling process. A pri-mary concern to the teamwas to reduce the migrationof moisture-laden air from the
foundation areas and out-doors into the thermal en-velop.
5.5.1 AIR SEALING – SEERCASE STUDY
For this “gut” remodel project,the air sealing effort is fairlyextensive. Since the housewas framed nearly 100 yearsago, there are ample oppor-tunities to fill gaps and holeswhere the
• framing adjoins block orstone
• top plate and ceiling joistsintersect
• window and door roughopenings are framed andirregular
• wires and pipes passthrough to the attic, base-ment, and walls
• interior stairway exists to thebasement.
Several trades were utilizedduring the remodeling phases
to achieve sealing of thebuilding. These included aprofessional air-sealing con-sultant, the insulation contrac-tor, the drywall contractor,and the remodeler’s owncrew. The following techniqueswere utilized for the project:
• Exterior plywood sheathingwas glued to framing
• Window frames werecaulked to the framing
• Wallboard was glued toframing
• Sill seam and band joistareas were foamed
• Floor and wall penetrations(including at stairway) werefoamed.
Though the choice of insula-tion was primarily made forother reasons, dense-packedinsulation will also aid incontrolling infiltration byreducing airflow within wallcavities. If air-sealing strate-gies had been ignored duringthe gut-rehab, it is estimated
Air sealing around windows
11
S E E R 2 0 0 3 C A
S E S T U D
Y R E P O R T
that an additional 60% ofheating and cooling energywould have been required tooperate the home10.
An expeditious method todetail all of the air-sealingopportunities in existinghomes is to obtain the ser-vices of specialized contrac-tor. Costs for such servicesvary depending on the sizeand complexity of theproject. Many times special-ized energy contractors offertesting and guarantees ofperformance with their air-sealing service. For manyremodeling projects, air-sealing costs will be low sincethere will be little addedlabor and materials if tech-niques are performed duringthe construction process withthe same work crews. In thisgut-rehab, the insulationcontractor charged anadditional $500 to performthis work.
Air barrier on outside of house
5.6 HEATING ANDCOOLING EQUIPMENTThough complicated in theirdesign, the equipment toheat and cool the home canbe installed with attention toa few basic principles:
• Install a highly efficientcooling and heating sys-tem, maximizing efficiencywith installation and opera-tion costs
• Place all ducts and equip-ment in conditioned space
• Size the equipment perACCA Manual J or otherrecognized sizing tool, useACCA manual D to deter-mine duct sizing
• Seal ducts preferably withmastic or silver11 (not duct)tape
• Install passive returns whereducted returns are non-existent or impractical.
The type of heating andcooling equipment, its effi-
10 Based on the reduction of infiltration losses from1.0 ACH to 0.25 ACH with ventilation added.11 Typically listed UL 181 tape.
ciency and its location aremost often at the recommen-dation of the installer. How-ever, various types oftechnology can be consid-ered as part of the evaluationof energy efficient heatingand cooling equipment:
• Condensing overatmospheric furnacetechnology
• SEER ratings of greater than10 for air-conditioningequipment
• HSPF ratings of greater than7.0 for heat pump units
• Ground-source heat pumptechnology
• Active solar heatingtechnologies
• Combined hot water/heating technologies.
The installation of the HVACsystem including ducts orpipes is as important as theequipment itself. Attention tothe entire process fromequipment selection, toinstallation, to controls willshow benefits long after theremodeling project is com-plete.
5.6.1 HEATING ANDCOOLING EQUIPMENT –SEER CASE STUDY
In the case study home, theplan had called for a SEER-10air-conditioner compressorwith an AFUE-80 propanefurnace located in the base-ment. High electric prices($0.11-0.15/ kWh) and asignificant heating seasoneliminated the option of anair-to-air heat pump system.
12
S E
E R
2 0
0 3
C
A S
E S
T U D
Y R
E P
O R
T
Natural gas was not availableon the property, and thebuilder desired not to useheating oil.
Since the site had a high watertable, a ground source heatpump was investigated. Aftersome consultations withseveral manufacturers, instal-lation contractors, and en-ergy modeling, this systemwas chosen for its low annualoperational costs. The largelot enabled a cost-effectivehorizontal closed-loop con-figuration that was trenchedand installed by the remodeler(with HVAC contractor) andserved a total of three pack-aged units for the two homeson the site. The 2-ton compres-sor and air handler unit in thestudy home, as well as allsupply and return ducts, arelocated within conditionedspace. This dramaticallyreduces system loses through-out the year. In addition, allductwork was rigid metal, and
Ground source heat pump in conditioned space
All duct joints sealed
mastic was installed on allduct connections. Theseimprovements to efficiencyof the distribution systemallowed the unit to bedownsized by 1/2 ton. Even
though the original designrecommended ducted returnson both levels, the builderchose to install passive wallreturns between all bedroomsand the open stairway wherethe central return was located.
The original estimate to heatand air condition the buildingusing a single 3-ton SEER-10system and AFUE 80% pro-pane furnace was $9,100 forall labor, equipment, andductwork. The cost to installthe 2-ton geothermal systemwas $12,300, including alllabor, equipment, ductwork,and ground piping. An addi-tional cost estimate of $600would have been expectedfor the ground excavationwork, but in this case wasperformed by the remodeler.
13
S E E R 2 0 0 3 C A
S E S T U D
Y R E P O R T
5.7 WATER HEATINGSYSTEMThe energy efficiency waterheating system in the SEERcase study involves allaspects of water heating, fromcold water inlet to the hotwater outlets andincludes pre-heat systems,primary water heating equip-ment, and piping to theoutlets. The primary goal of anefficient water heating systemis to reduce energy losses inthe water heating equipmentand in the piping. To achievethis goal, a demand waterheater and parallel pipingsystems are considered to bethe best option in this climate.Other systems that wouldinclude, for example, a heatpump water heater or distrib-uted water heaters at eachoutlet would increase effi-ciency even more, but atprohibitive costs at this time.
Demand water heaters, eitherfuel-fired or electric, are limitedby the input energy that in turnlimits the maximum tempera-ture rise that can be achievedat a given flow rate. Tankwater heaters do not sufferfrom this limitation since thevolume of stored water can besupplied to the outlet at(theoretically) any flow rate.Tanks, however, cannot supplyheated water beyond thecapacity of the tank, and theoutlet temperature of thewater will decrease as it mixeswith the incoming cold water.Also, tanks have a limitedamount of input energy sothat the recovery to bring thetank back to full temperatureis over many minutes. Inaddition, tank storage of hot
water manifold is used for thispurpose.
The system design in this casestudy uses an electric de-mand water heater feeding aparallel piping system. Electricdemand heaters are typicallylimited to lower temperaturerises at typical flow rates inhomes. Therefore, to decreasethe necessary size of thedemand water heater whileproviding adequate hot waterdelivery, a pre-heat systemcan be used. The choice ofdemand heater is importantwhen using this strategy,however, since not all prod-ucts will properly account forvariable input temperatures.
There are a number ofchoices to preheat the coldwater prior to the demandwater heating equipment:
• Desuperheater from theground-source heat pump
• Solar thermal• Waste heat from the drain.
Manifold plumbing system
water will lose energy to thesurroundings, so that periodi-cally the water will need to bereheated even if no water isused. If a demand heater cansupply the anticipated hotwater needs, it is almostalways more efficient thantank storage heaters.
The hot water piping is an-other part of the overallwater heating system thatcan be designed to reducewasted energy by supplyinghot water outlets with as smalla diameter pipe as possiblewhile maintaining the desiredflow rate. This design results ina lesser volume of water inthe pipe to the outlet with lessenergy wasted as the pipecools to ambient tempera-ture. Smaller diameter pipes,however, can not flow largequantities of water. Therefore,the piping system is designedas a parallel system so thatonly one outlet is suppliedfrom a dedicated piping runfrom the water heater. A hot
14
S E
E R
2 0
0 3
C
A S
E S
T U D
Y R
E P
O R
T
Among the options, the mostconsistent source throughoutthe year, in this area, is thesolar system, specifically, anactive solar thermal systemthat charges a pre-heat tank.
The entire hot water system,taken together, can providehot water to the outlets withfewer losses and with perfor-mance similar to that ofmuch larger tank systems.
5.7.1 WATER HEATINGSYSTEM – SEER CASESTUDY
As with other systems in thehome, the water distributionand heating systems requiredreplacement. An estimate of$2,700 was obtained for thesupply and installation ofcopper supply lines for thehot and cold water in thehome. In comparison, a priceof $2,200 was secured tosupply and install a singlecentral manifold and PEXpiping for all the supply linesin the home. This savings wasprimarily due to the reducedlabor costs associated withrunning the flexible supplylines since the materials costswere very similar.
The original design for thewater heating system was toinclude a “typical” propane-fired storage tank with anenergy factor of approxi-mately 0.56 located in thebasement. While this wouldhave been a relatively inex-pensive option to purchaseand install, the performanceof this equipment, and ex-pected standby loses due toit’s location in unconditionedspace, would have costsignificantly more to operateover it lifetime. The choice of
a solar preheated tank andtankless demand heaterlimited the storage tank lossesto energy generated only bythe solar system. The solarcontribution is expected torepresent approximately 57%of the annual hot water load.The estimate for the cost of
the supply and installation ofthe solar preheat system withtankless backup heater is$4,400. This, of course, issignificantly more than the$500 – $700 cost to install astandard residential electricor propane tank.
Hot water system in cottage
Solar thermal collector with PV panel for pump
15
S E E R 2 0 0 3 C A
S E S T U D
Y R E P O R T
5.8 LIGHTS ANDAPPLIANCESEven energy efficient homesutilize many electrical devicesthat add to the energyconsumption “bottom line.”Minimizing energy use is left tothe consumer who mustdecide on individual appli-ances and select energyefficient options. Two mainareas where this is easily doneare larger appliances, such asrefrigerators and washingmachines, and lighting.
Efficient appliances are easilyidentified under the federalgovernment’s ENERGYSTAR®
program. The ENERGYSTAR®
marked appliances havebeen tested to be the mostefficient appliances available.Likewise, lighting providesanother opportunity to ex-tract large energy savings.Use of fluorescent fixtures orlamps are the best optiontoday to save lighting energy.Newer technologies such asLED lighting are not yet widelyavailable for general use inthe home, but show promisefor even more savings thanfluorescent.
5.8.1 LIGHTS ANDAPPLIANCES – SEER CASESTUDY
The remodeler for this homemade a bulk purchase ofcompact fluorescent replace-ment light bulbs that he willuse in all the light fixtures ofthe home. Since he tookadvantage of special pricingon these units, his estimatedcost increase over incandes-cent bulbs is approximately$12 for all the fixtures in the
home. The appliances for thehome are being chosen withan eye toward efficiency. Therefrigerator, dishwasher, andclothes washer will all beENERGYSTAR® rated. Theestimated additional cost toprovide these ENERGYSTAR®
rated appliances is $320.
5.9 ROOM ADDITIONSA remodel project involving acomplete addition is anexcellent opportunity toinclude energy efficiency“from the ground-up.” Wall,roof, and foundation construc-tion can be performed usingnew-construction methods thatprovide energy upgrades fromnormal practices. Many ofthese upgrades can be em-ployed with little extra costsince the main work wasalready being performed.Also, some energy upgradescan actually result in con-tained costs – for examplewith the heating and coolingsystem. An efficient addition
may be able to be servicedfrom the existing HVAC systemwhere a standard, less effi-cient addition might haverequired a separate heatingand cooling system for theaddition.
Many of these issues alsopertain to room conversions,for example an attic orbasement space. Use of moreefficient methods and tech-nologies can result in a morecomfortable space, at a nearequal cost, but with lowermonthly bills.
5.9.1 ROOM ADDITIONS –SEER CASE STUDY
The addition is made frompre-manufactured structuralEPS foam and steel tubepanels and, therefore, doesnot require any additionalstructural supports. The floor ofthis addition is made ofconventional solid woodenjoists and plywood decking.The original design called fora conventionally framed
Addition construction using foam panels
16
S E
E R
2 0
0 3
C
A S
E S
T U D
Y R
E P
O R
T
Addition constructed in 6 hours
Ridge and eave supports for roof panels
addition with a vented attic.The choice to use structuralpanels allowed for the cre-ation of a cathedral ceiling inthe room and dramaticallydecreased the close-in timefor the project. Once theconventional wooden deckhad been built, it took theremodeler’s crew of three,plus two support techniciansfrom the panel manufacturer,
only 5 hours to construct thestructure.
Mr. Asdal estimated that toconstruct this addition usingconventional framing (2x4walls) would have cost him$3,000. The costs for thestructural foam panel addi-tion were $5,700. While hesaw the speed of the con-struction being an advantage
in some situations, in thiscase he thought the problemshe had with scheduling thejob with the supplier’s crewcountered any savings hehad in the speed ofconstruction.
5.10 RENEWABLEENERGY SYSTEMSLast, but not least, are thoseopportunities in the remodel-ing project to include renew-able energy systems that canprovide a portion of thehome’s energy needs. Thesesystems tend to be morecostly and require larger roofor ground areas, but alsoprovide large amounts ofenergy that is, in its operation,pollution and waste free. Themost prominent systems aresolar photovoltaics thatconvert sunlight to electricityand wind generators thatconvert wind energy toelectricity.
Solar thermal systems for hotwater, briefly describedabove, are most often usedto raise the efficiency of thehot water or heating system.Passive solar systems, such assunrooms or trombe walls, alsouse solar energy to reduce theheating loads in the house.
Use of renewable energysystems not only reduce theconsumption from non-renewable utility energysupplies, but provides a bufferagainst fluctuating costs ofenergy. When a renewableenergy system is purchasedand installed, a portion of thecost is considered as the “fuel”purchase. Unlike engine
17
S E E R 2 0 0 3 C A
S E S T U D
Y R E P O R T
PV system on Cottage home
Ridge beam for roof supportR-50 roof and R-30 wall panels
generators, for example, thatcan provide an alternative toutility energy supply, theengine systems still requireregular purchase of fuel suchas diesel or gasoline – thatcan change in price, some-times dramatically andquickly.
Renewable energy systemstypically have required theservices of a solar systemdesigner and installer andspecial attention to utilityinterconnections andmetering.
5.10.1 RENEWABLEENERGY SYSTEMS – SEERCASE STUDY
An onsite photovoltaic (PV)solar system was investigatedfor the site. Since there wasno significant shading, goodroof orientation, and ampleroof area, the home wasdeemed suitable for a PVarray. The major factors thatled to the decision to pur-chase a system were thesignificant financial incentivesavailable and the simplifiedutility interconnection proce-
Aerial view of PV system
dures. There isa statewideresidentialgrant pro-gram in placeand operatedby the Boardof PublicUtilitiesthrough theNew JerseyClean EnergyProgram(NJCEP).Through thisprogram, thesolar installerwill receive an incentive worthup to $5.50 per rated DC Wattof solar equipment that allowshim or her to offer a substan-tially lower price to the home-owner for the installed system.This dealer is also handling therebate application processand in turn, finances therebate amount for the home-owner.
A 3.0-kW mono-crystallinesystem is located directly onthe Cottage roof with a4.2-kW system located on thegarage roof also feeding intothe building’s utility service.
18
S E
E R
2 0
0 3
C
A S
E S
T U D
Y R
E P
O R
T
The power-conditioninginverters are located insideboth in the garage andbasement of the home. Theout-of-pocket expenses for thehomeowner are approxi-mately $15,120. The NJCEPrebate paid for 70% of thesystem ($35,280). The system isexpected to produce approxi-mately 9,000 kWh per year.
Garage PV system for Cottage home
PV system inverters
19
S E E R 2 0 0 3 C A
S E S T U D
Y R E P O R T
A summary of the energyefficiency feature costs isdescribed in Table 2. The costshave been derived from acombination of constructioncost estimates and actual bidsfrom trade contractors andfrom the remodeler. Theadded costs (or savings) forthe energy efficiency featureas described in the “Net”column represent a bestestimate at adding the desiredenergy efficiency improvementin this home over standardpractice.
6SUMMARY OF COST AND SAVINGS ESTIMATES
Adding the energy featuresto the existing home (BaseRetrofit) costs approximately$23,000 over leaving thehome “as-is” and performingonly basic renovations tomaintain the home, butincluding new appliances aspart of the energy features.With the SEER project, addi-tional upgrades to the energyefficiency features are in-cluded to significantly de-crease the energy used in the
home. These additionalfeatures represent an addi-tional cost of about $14,000or 60% more.
In conjunction with theadditional energy efficiencyfeatures, a solar electric(photovoltaic) system is alsoincluded. The system’s fullprice is about $50,000, butwithin the NJ Clean EnergyProgram will cost the home-owner about $15,000. Conse-quently, the total cost for the
Table 2 – Energy Efficiency Cost Summary
Technology Base Retrofit SEER Retrofit Net Cost or Savings
Wall Insulation–Cavity $1,4561 $2,900 $1,444
Wall Insulation–Continuous $2,8482 $3,656 $808(w/ Siding)
Ceiling Insulation $375 $672 $297
Floor Insulation $470 $798 $328
Windows $2,420 $2,820 $400
Air Sealing $0 $500 $500
HVAC System $9,100 $12,900 $3,800(inc. $600 for excavation)
Water Heating System $700 $4,400 $3,700
Water Distribution System $2,700 $2,200 $-500
Lighting (bulbs only) $11 $23 $12
Fixed Appliances $1,630 $1,950 $320
Addition Framing and $3,000 $5,700 $2,700Insulation
Solar Electric System (PV) $0 $15,120 $15,120
Total with PV3 $23,080 $52,009 $28,929
Total without PV3 $23,080 $36,889 $13,809
1 Includes $733 for sheathing removal and disposal and $723 for R-13 batt insulation.2 Costs for uninsulated vinyl siding were used here to provide an accurate comparison.3 Without added cost for new minimum-efficiency appliances.
20
S E
E R
2 0
0 3
C
A S
E S
T U D
Y R
E P
O R
T
12 The actual benefit is a net-gain to the utility, butthe economic value of the net-electricity fedback to the utility is not recoverable at this time.
SEER energy efficiency featuresand including a PV system isabout $54,000. For this cost,the home is expected toachieve a zero energy utilitybill on an annual basis.
Based on energy simulations,estimates of energy use andsavings for the SEER CaseStudy house have beendeveloped and aresummarized in Table 3.
For the base home remodel,the estimated energy costs(w/o service charges) showan annual energy savings ofabout $500 over the existing(before) home, including theadded energy cost for cen-tral air-conditioning. CentralA/C would only be feasiblegiven the minimal energyfeatures included in the baseretrofit. Had central A/C notbeen included, the annualsavings would have beenabout $665.
When considering the addedcosts for the energy features,including a new furnace andduct system and a newaddition to replace thedeteriorated existing addition,but not including replace-ment of the appliances, thetotal cost is estimated at$23,080. Evaluating the addedcosts for the energy featuresonly in terms of energy sav-ings reveals a lengthy 46-yearsimple payback. However, thisnarrow approach ignores theadded longevity of the homeand the significant increase incomfort and durability basedeven on the modest energyefficiency upgrades.
However, when looking at theincrease in the energy perfor-mance of the home from the
SEER energy efficiencyapproach, a much differentpicture emerges. Ignoring thesolar electric (PV) system forthe moment, the value of theenergy savings for the SEERenergy retrofit is about $2,800over the existing home’senergy costs and about $2,300from the base case retrofit.This dramatic improvementresults from an integrated(systems) design utilizingenergy efficiency technologiesthat are selected based on theparticular site characteristicsand a knowledgeableremodeler and trades contrac-tor. Even with the increasedcosts of 60% over the baseenergy efficiency retrofit, thesimple payback approaches13 years for the existing homeand about 6 years over thebase case.
When adding the PV systeminto the economic valuationof the SEER retrofit case, theresulting electricity costs go tozero12. The simple paybackthen is about 14 years fromthe existing home and 9 yearsfrom the base case. Thisapproach values the PVsystem solely for its energybenefit, while adding no valuefor the reduction in pollution,security from rising energycosts, and reduced demandfor fossil fuels.
Other economic valuationsare possible. When consider-ing a loan of about $52,000to pay for the full SEER energyefficiency remodel includingthe PV system, an interestrate of 6% over 30 yearswould show a monthly break-even cost based on theenergy savings. And thisassumes that the energy costsremain fixed over the term.
Still yet another approach isto consider the return oninvestment (ROI) of the savingswhen investing a similaramount as the energyefficiency upgrades. In thiscase, the ROI is over 7% whencomparing the upgrades fromthe existing home and over11% when considering theupgrades from the base caseremodel. Again, this ROIassumes fixed utility rates overthe useable lifetime of theenergy efficiency systems.A summary of the economicanalysis is shown on page 22.
21
S E E R 2 0 0 3 C A
S E S T U D
Y R E P O R T
Table 3 – Summary of SEER Case Study Energy Use1 and Costs/Savings
Performance Before Base Base SEER SEER SEERCharacteristic Retrofit Retrofit Savings Energy Savings Savings
Over Efficient Over OverBefore Retrofit Base Before
Heating Peak Load 65,400 45,400 31% 15,900 65% 76%(Btuh)
Cooling Peak Load 0 26,400 — 13,400 49% —(Btuh)
Annual Heating Load 134.3 71.0 47% 24.3 66% 82%Annual Cooling Load 0.0 12.7 — 10.9 14% —Totals (Million Btu) 134.3 83.8 38% 33.2 60% 75%
Heating Cost2 $2,660 $1,794 33% $179 90% 93%Cooling Cost $0.0 $163 — $61 — —
Total Heating and $2,660 $1,957 26% $240 88% 91%Cooling Costs
Water Heating Use 30.5 27.4 10% 5.6 80% 82%(Million Btu)Appliance/Lighting 19.6 19.6 0% 13.3 32% 32%Use (Million Btu)
Water Heating Cost- $364/O $556/P -53% $193/E 65% 47%Oil/Propane/Elect
Appliances/Plug Loads $672 $682 -1% $455 33% 32%
Estimated Annual $3,696 $3,195 $888Energy Costs
Solar PV System (kWh) 0 0 8,899Value of kWh @ utility — — —rates ($) $0 $0 $1,043
Total Estimated Annual $3,756 $3,304 13.7% $-95($0)4 103% 103%Energy Costs3
HERS Score 39.3 77.6 49% 93.1
Notes:1 Energy Use Estimates based on simulation software2 Electricity Rates: Applies to Before, Base and SEER energy estimates
Monthly Service Charge = $5.00Jun-Sep, 0-600 kWh @ $0.1246/kWh
> 600 kWh @ $0.1508/kWhOct-May, 0-1000 kWh @ $0.1134/kWh
> 1000 kWh @ $0.1107/kWhPropane Rates: Applies to Base energy estimates for heating and water heating
Monthly Service Charge = $4.00/monthJan-Dec, @ $1.85/gallon
Fuel Oil Rates: Applies to Before energy estimates for heating and water heatingMonthly Service Charge = $0.00/monthJan-Dec, @ $1.69/gallon
3 Including service charges and PV net-savings.4 Currently, there is no payment required by the utility for annual net-production.
22
S E
E R
2 0
0 3
C
A S
E S
T U D
Y R
E P
O R
T
Summary of Economic Analysis Based on Energy Value Only
Cost to add Base energy efficiency features to the Existing home remodel $23,080
Annual Energy Savings (including the addition of A/C) $501
Annual Energy Savings (without the addition of A/C) $664
From existing-to-Base (with A/C) Retrofit - Simple payback 46 years
From existing-to-Base (without A/C) Retrofit - Simple payback 35 years
Return-On-Investment (with A/C) 2.2%
Return-On-Investment (without A/C) 2.9%
Cost to add SEER energy efficiency features to the Existing home remodel(without PV) $36,889
Annual Energy Savings $2,808
From Existing-to-SEER Retrofit – Simple payback 13 years
Return-On-Investment 7.6%
Cost to add SEER features to the Base home remodel (without PV) $13,809
Annual Energy Savings $2,307
From Base-to-SEER Retrofit - Simple payback 6 years
Return-On-Investment 16.7%
Cost to add SEER energy efficiency features to the Existing home remodel(with PV) $52,009
Annual Energy Savings $3,696
From Existing-to-SEER Retrofit – Simple payback 14 years
Return-On-Investment 7.1%
Cost to add SEER features to the Base home remodel (with PV) $28,929
Annual Energy Savings $3,195
From Base-to-SEER Retrofit - Simple payback 9 years
Return-On-Investment 11.0%
Loan Payment – SEER and PV system (7%, 15 years, $28,929) $260.02
Monthly utility savings ($3,195 annual cost) $266.25
23
S E E R 2 0 0 3 C A
S E S T U D
Y R E P O R T
Adapted from comments ofthe builder/remodeler, BillAsdal
The first SEER remodel site is ina rural setting. It is very typicalof many of the housesthroughout the countryside,not only here, but near andafar. The average age ofhousing in the country is 32 or33 years. This one is 100+ years.Regionally, these averagescan be as high as 55 or 60.And in the not too distantPennsylvania and the AmishCountry it gets up to 60 – 70years, so there is a very largeidentifiable housing stock thatis deficient in its energy effi-ciency and its mechanicalsystems. But quite frankly,houses of this vintage havevery contemporary squarefootage and design attributes.For example, this one thoughit was built between 1898 and1903 (about 100 years ago),has 10-foot ceilings on the firstfloor and 9-foot ceilings on thesecond floor. There are twohomes on the site. One ofwhich is very close to4,000 sq. ft. The other, whichwe’re calling the Cottagehouse, runs just shy of 1,500 sq.ft. So these are not unusualstructures, but based on theirage (unlike the post warhomes of 1,100 or 1,200 sq. ft.)have the square footage thatcontemporary buyers arelooking for. They are verymuch serviceable for another100 years if kept dry. I thinkthese attributes, in addition tothe fact that we are com-pletely gut rehabbing bothhouses, give us a good oppor-tunity to be proactive and saythat these houses should notbe abandoned.
As an aside, the state of NewJersey led the country inintroducing the rehab codein 1998, recognizing thatneglected urban, maturesuburban, and the old ruralhomes were three categorieswherein you could find a largehousing stock that not onlyneed code upgrades, but areperfectly serviceable. In thisproject, we find the opportu-nity to look at energy conser-vation and use of renewablesas a primary part of the homeremodeling project. I think thecombination of property andphysical attributes lends itselfwell for a 2003 SEER projectsetting.
The construction approvalprocess here, as in many otherareas, is much constrained inthe permitting of new homes.There is a tremendous demandon older homes to fill a needfor new family or for move-upbuyers who in can’t get newlyapproved lots or when thesenew lots simply don’t exist.We’ve gone from wetlandsconstraints to planning con-straints to proximity to waterconstraints with the result thatour new housing production isabout 40% of its high, whichwas achieved almost 15 yearsago. Again, there is lots ofpressure on these old buildingsto produce at today’s stan-dards and with a gut rehab Ithink we have a chance toshow how to do just that. Wehave applied for anENERGYSTAR® rating on thelarger of the two homes andhope to do so on the cottage.For the larger home, we havehad an evaluation and think
that with a couple of clevertwists we will be able toachieve an 86 score, which willgive us an ENERGYSTAR® homein the shell of a 100-year-oldbuilding. And that is very veryexciting to know that these oldhomes could actually achievethat if you do a gut rehab.
FIRST SEER REMODEL SITE - LEBANON, NEW JERSEY ADDENDUM
REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188
The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, to Department of Defense, Executive Services and Communications Directorate (0704-0188). Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ORGANIZATION. 1. REPORT DATE (DD-MM-YYYY)
November 2004 2. REPORT TYPE
Subcontract Report 3. DATES COVERED (From - To) February 27, 2003—October 31, 2004
5a. CONTRACT NUMBER DE-AC36-99-GO10337
5b. GRANT NUMBER
4. TITLE AND SUBTITLE Strategies for Energy-Efficient Remodeling: SEER 2003 Case Study Report
5c. PROGRAM ELEMENT NUMBER
5d. PROJECT NUMBER NREL/SR-550-36474
5e. TASK NUMBER BET5.8004
6. AUTHOR(S) S.C. Drumheller and J. Wiehagen
5f. WORK UNIT NUMBER
7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) NAHB Research Center, Inc. Upper Marlboro, Maryland
8. PERFORMING ORGANIZATION REPORT NUMBER
10. SPONSOR/MONITOR'S ACRONYM(S) NREL
9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) National Renewable Energy Laboratory 1617 Cole Blvd. Golden, CO 80401-3393 11. SPONSORING/MONITORING
AGENCY REPORT NUMBER NREL/SR-550-36474
12. DISTRIBUTION AVAILABILITY STATEMENT National Technical Information Service U.S. Department of Commerce 5285 Port Royal Road Springfield, VA 22161
13. SUPPLEMENTARY NOTES NREL Technical Monitor: R. Anderson
14. ABSTRACT (Maximum 200 Words) The goal of the Strategies for Energy Efficiency in Remodeling (SEER) project is to provide information, based on research and case studies, to remodelers and consumers about opportunities to increase home energy performance. Opportunities to include energy efficiency often arise while undertaking general remodeling work. This case study report examines the technologies, methods, and installation of specific energy efficiency strategies. The information presented here stems from a "gut rehab" of a house in rural New Jersey as part of the SEER project through the Building America Existing Buildings Program.
15. SUBJECT TERMS Energy efficient homes; U.S. Department of Energy; Building America; NAHB Research Center; systems engineering; strategies for energy efficiency in remodeling; Existing Buildings Program
16. SECURITY CLASSIFICATION OF: 19a. NAME OF RESPONSIBLE PERSON a. REPORT
Unclassified b. ABSTRACT Unclassified
c. THIS PAGE Unclassified
17. LIMITATION OF ABSTRACT
UL
18. NUMBER OF PAGES
19b. TELEPONE NUMBER (Include area code)
Standard Form 298 (Rev. 8/98) Prescribed by ANSI Std. Z39.18
Bringing you a prosperous future where energy is clean, abundant, reliable, and affordable
A Strong Energy Portfolio for a Strong AmericaEnergy effi ciency and clean, renewable energy will mean a stronger economy, a cleaner environment, and greater energy independence for America. Working with a wide array of state, community, industry, and university partners, the U.S. Department of Energy’s Offi ce of Energy Effi ciency and Renewable Energy invests in a diverse portfolio of energy technologies.
Research and Development of Buildings
Our nation’s buildings consume more energy than any other sector of the U.S. economy, including transportation and industry. Fortunately, the opportun-ities to reduce building energy use—and the associated environmental impacts—are signifi cant.
DOE’s Building Technologies Program works to improve the energy effi ciency of our nation’s buildings through inno-vative new technologies and better building practices. The programfocuses on two key areas:
• Emerging Technologies Research and development of the next generation of energy-effi cient components, materials, and
equipment
• Technology IntegrationIntegration of new technologies with innovative building methods to optimize building performance and savings
For more information contact:EERE Information Center1-877-EERE-INF (1-877-337-3463)www.eere.energy.gov
An electronic copy of this factsheet is available on the Building America Web site at www.buildingamerica.gov
U.S. Department of Energy
Energy Effi ciencyand Renewable Energy
Building America ProgramGeorge S. James • New Construction • 202-586-9472 • fax: 202-586-8134 • e-mail: [email protected] Logee • Existing Homes • 202-586-1689 • fax: 202-586-4617 • e-mail: [email protected] Pratsch • Integrated Onsite Power • 202-586-1512 • fax: 202-586-8185 • e-mail: [email protected] America Program • Offi ce of Building Technologies, EE-2J • U.S. Department of Energy • 1000 Independence Avenue, S.W. • Washington, D.C. 20585-0121 • www.buildingamerica.gov
Building Industry Research Alliance (BIRA)Robert Hammon • ConSol • 7407 Tam O’Shanter Drive #200 • Stockton, CA 95210-3370 • 209-473-5000 • fax: 209-474-0817 • e-mail: [email protected] • www.bira.ws
Building Science Consortium (BSC)Betsy Pettit • Building Science Consortium (BSC) • 70 Main Street • Westford, MA 01886 • 978-589-5100 • fax: 978-589-5103 • e-mail: [email protected] • www.buildingscience.com
Consortium for Advanced Residential Buildings (CARB)Steven Winter • Steven Winter Associates, Inc. • 50 Washington Street • Norwalk, CT 06854 • 203-857-0200 • fax: 203-852-0741 • e-mail: [email protected] • www.carb-swa.com
Davis Energy GroupDavid Springer • Davis Energy Group • 123 C Street • Davis, CA 95616 • 530-753-1100 • fax: 530-753-4125 •e-mail: [email protected] • [email protected] • www.davisenergy.com/index.html
IBACOS ConsortiumBrad Oberg • IBACOS Consortium • 2214 Liberty Avenue • Pittsburgh, PA 15222 • 412-765-3664 • fax: 412-765-3738 •e-mail: [email protected] • www.ibacos.com
Industrialized Housing Partnership (IHP)
Subrato Chandra • Florida Solar Energy Center • 1679 Clearlake Road • Cocoa, FL 32922 • 321-638-1412 • fax: 321-638-1439 • e-mail: [email protected] • www.baihp.org
National Association of Home Builders (NAHB) Research CenterTom Kenney • National Association of Home Builders (NAHB) Research Center • 400 Prince George’s Boulevard • Upper Marlboro, MD 20774 • 301-430-6246 • fax: 301-430-6180 • toll-free: 800-638-8556 • www.nahbrc.org/
National Renewable Energy LaboratoryRen Anderson • 1617 Cole Boulevard, MS-2722 • Golden, CO 80401 • 303-384-7433 • fax: 303-384-7540 • e-mail: [email protected] • www.nrel.gov
Tim Merrigan • 1617 Cole Boulevard, MS-2722 • Golden, CO 80401 • 303-384-7349 • fax: 303-384-7540 • e-mail: [email protected] • www.nrel.gov
Oak Ridge National LaboratoryPat M. Love • P.O. Box 2008 • One Bethel Valley Road • Oak Ridge, TN 37831 • 865-574-4346 • fax: 865-574-9331 • e-mail: [email protected] • www.ornl.gov
Produced for the U.S. Department of Energy (DOE) by the National Renewable Energy Laboratory, a DOE national laboratory.
November 2004 • NREL/SR-550-36474
Printed with a renewable-source ink on paper containing at least 50% wastepaper, including 20% postconsumer waste.
Visit our Web sites at:www.buildingamerica.gov www.pathnet.org www.energystar.gov
