Residential Energy and Water Conservation

The Green Roundtable(copyright © Green Roundtable 2007)

The Green Roundtable

Energy & Water ConservationLow-Hanging Fruit

and


Green Roundtable

Consulting, education, trainingand strategic planning

to create healthy environments byintegrating principles of

sustainability into mainstreamplanning, design and construction.


Objectives

- Easy ways to reduce energy & water consumption in thehome (low-hanging fruit)

- Additional cost-effective measures (higher cost butpotentially big returns)

- Energy efficient lighting, appliances & equipment

- Conserving water in the landscape

- Improving performance of building envelope(insulating & air sealing)

Discuss:

- Basic economics- incentives, payback time, etc.


General approaches

- Make simple lifestyle adjustments

- Improve maintenance routines

- Make simple upgrades to fixtures in the home

- Upgrade appliances and equipment

- Make improvements to the building envelope

- Take advantage of natural methods/ work with nature


Preventing heat loss (bldg envelope)

• Air seal (prevent infiltration)

• Best bang for buck (aside from lifestyleadjustments) through air sealing! Begin here!

• Insulate

• Use landscape features- vegetative shields, etc.

• Address lifestyle issues


Low-hanging Fruit


Low-hanging fruit- easy pickin’s

• Lower thermostat by 1 or 2 degrees- 1 degreelower for 8 hour period saves about 1% on heatingenergy use (simple math: 2 deg for 24 hrs = 6%)

• Add humidity to the air; it makes a given temperaturefeel warmer

• Lower your water heater to 120 deg. F, especially ifyou have a newer dishwasher


Low-hanging fruit- easy pickin’s

• If it’s too inconvenient to turn off your computerbetween use, at least turn it off overnight

• Clean the coils on your refrigerator; clean doorgasket and mating surfaces

• Clean heat pump and air conditioner coils


More easy pickin’s

• “If it’s yellow, let it mellow…”

• Let bath water dissipate heat to room temperaturebefore letting water down drain- collect some of thiswater for plants/ landscape/ toilet flushing. Do samefor dishwater- This also adds much-needed humidityto winter air

• Use toilet tank water displacement ‘devices’

•“Harvest” additional water from laundry slop sink(Important note: if you plug sink to capture energy/water, make sure it’s of sufficient capacity to holdwater from a full laundry load)

• Wash your clothes in cold water; don’t use a higherwater level or longer cycle than necessary


A little less convenient

• Collect water that would otherwise run down thedrain while you’re waiting for hot water to come up-collect in jugs or in sink

• Collect cold water that you flush from pipes first thingin morning

• Use this to water plants, fill your humidifier, or flushyour toilet. Laundry detergent jugs (large size) w/spout removed are ideal for toilet flush water, as theylet you pour water out very quickly and they hold asufficient volume.

• Use a ‘solar clothes dryer’

• Fix leaky faucets (esp. hot water!) and toilets


Low cost, big return

• Insulate your hot water pipes (pipes closest towater heater first)

• Install faucet aerators

• Add an insulation blanket to your hot water heater

• Install a low-flow shower head

• Install a programmable thermostat

• Change your furnace filter (forced hot air systems)


Using self-adhesive insulatingtape at bends & valves in pipingeasier than cutting foam pipeinsulation to fit


Low cost, big return- continued

• Install dimmer switches & occupancy sensors

• Control groupings of consumer electronics, likeentertainment centers from central power strip

• Use an auto shut-off electric kettle

• Buy Energy Star anything! (if it affects energy use)

• Replace worn weatherstripping

• Use expanding foam insulation to plug obvious holesin building envelope

• Add gaskets to electrical receptacle covers


Low cost, big return- continued

• Use CFLs!-Don’t mix w/ incandescent in enclosed fixtures-Long payback time in little-used fixtures-Use higher than incand. wattage-equivalent

(you’re still saving over incandescent)-Don’t use in dimmed fixtures unless rated

“dimmable”

• See estarlights.com, efi.org

• Mercury in bulbs far less than mercury in stack gasfrom power plant capacity needed to satisfy increaseddemand from incandescent bulbs

• Must treat blown-out bulbs as hazardous waste


More energy conservation strategies

• Put radiant reflecting panels behind radiators

• Regularly defrost refrigerators/ freezers

• Close off unoccupied areas of house and turn offheat to those areas if possible; be careful if there arepipe runs

• Keep baseboard convectors clean

• Keep gas appliances tuned, including stoves; lookfor blue flame; see mfgr for adjusting burners



• Use ceiling fans w/ cathedral or high ceilings toeliminate temperature stratification (both heating andcooling season)

• Use microwave oven for cooking

• Remember that A/C units also dehumidify, so youmay feel comfortable at a higher temperature

• Shade air conditioner and heat pump condensers w/vegetation or artificial shading (be careful w/deciduous vegetation)

• Remove window A/C units in winter



• Install awnings, overhangs and other shadingstructures, such as pergolas

• Use retrofit heat-reflecting window films on west-facing windows (look for NFRC label); for newwindows, choose units w/ low solar heat gaincoefficient (SHGC)

• Close all curtains and shades at night during winter(can help to break convection loops even if loose-fitting)

• Use deciduous vegetation on south, SW and westsides of structure for summer shading; use vines ontrellises too



• Make sure attic space is well vented

• Use double-wall cellular reflecting window shadesw/ edge guides or “Energy Track” or window quilts

• Install radiant barriers on underside of roof rafters;can help to warm in winter and cool in summer; don’tinterrupt ventilation pathways

• Use whole-house fans to exhaust warm air fromhouse in summer; run mainly at night to flush w/ coolair; close windows during very hot days

• Install white window shades to help keep housecool in summer


Green Practice:HVAC/ Plumbing/ Lighting


HVAC & Plumbing Systems

• “Right-size” systems using analysis tools (Manual J)rather than rule-of-thumb methods; a right-sizedsystem can be up to 40% smaller than aconventionally-sized system

• Use structured plumbing & PEX piping

• Use demand pumps in DHW supply system(gothotwater.com

• Use heat recovery devices on DWV pipes(gfxtechnology.com)

• Use instantaneous hot water heaters

• Use zoned heating


Tankless water heaters

• Brands: Rinnai, Noritz, Takagi

• Gas-fired typically more responsive and can provideneeded capacity more effectively

• Cost more than standard water heaters but last longer


High-efficiency heating

• Boilers tend to have higher AFUE than furnaces

• Make sure heating systems have Annual FuelUtilization Efficiency (AFUE) of at least 83% for oil-fired and 90% for gas-fired, and Seasonal EnergyEfficiency Rating (SEER) of at least 13 for coolingsystems

• Choose Energy Star! Right-size systems! (did Imention that before?!)

• Closed-cycle, condensing-type boilers and furnacesare more efficient; they extract additional heat fromwarm flue gases

• These systems often don’t need conventional flue pipe,they can side vent, but they require a dedicatedcombustion air source (coaxial flue pipe)


Lighting

• Use natural daylighting strategies

• Use zone lighting

• Use solar landscape lights

• Use motion sensor outdoor lights

• Put timer switches on bathroom fans


Appliances

• Buy Energy Star!

• Upgrade refrigerator if more than 10 years old

• Buy horizontal axis washing machines

• Buy dishwashers w/ booster heater

• Don’t buy oversized air-conditioners


Green Practice:Water conservation


Order a free water saving kit at:www.mwra.com/04water/html/watsense.htm

MWRAA water conservation resource


Water conservation

• Use low-flow showerheads & faucet aerators

• Collect rainwater in rain barrels for landscapeirrigation

• Incorporate graywater systems

• Use demand pumps in supply system

• Use dual-flush or composting toilets; waterlessurinals


The Portland Group- Splash Showroom244 Needham St.Newton, MA 02164617.332.6662

Coroma Dual-Flush Toilet Source


Green Systems:Gray water


Gray water

• Collected from drain-waste-vent system other thantoilets & kitchen sinks with garbage diposals (“Blackwater”)

• May be difficult to get local code approval

• Generally used for flushing toilets, landscapeirrigation & other non-potable, utility purposes


http://www.gaiam.com/product/eco-home-outdoor/energy-efficient-climate-control/energy-saving-tools/toilet+lid+sink.do

Gray water: A direct approach


Rainwater collection

• For 1000 sq ft roof area, 15 – 25,000 gallons ofrainwater can be collected annually in Eastern states

• Using rainwater helps to maintain aquifers and publicwater supplies at adequate levels

• Combined with drip-irrigation systems, collectedrainwater can keep landscaping vibrant even duringdrought conditions

• Rainwater does not contain minerals, so it ispotentially better for use as laundry/ wash water

• Rainwater does not contain chlorine so it is better forplants, garden ponds, etc.

• Rainwater is free, and inexpensive to collect & store!


http://www.cleanairgardening.com/33galrainbar.html


Xeriscaping (low-water-landscaping)

• Two major aspects:-Making maximum use of available precipitation-Selecting species with low water requirements

• Use drip irrigation & soaker hoses

• Use mulches

• Create water retention landscape features

• Group plants

• Use native plantings, they are better suited to naturalrainfall patterns

• Use plantings to create windbreaks & shade toprotect from drying winds and sun


Drip emitters


Soaker Hose


Green Practice:Improving the Building Envelope


Key Principle- Saving home energy

As a general rule, for the average home/homeowner, the greatest energy savings will beachieved through managing the demand side of

the equation, rather than the supply side.

In other words, you’ll get better bang for your buckthrough energy conservation measures, like insulating

& minimizing air infiltration, than incorporatingexpensive renewable energy systems such as wind

and solar.


An exception:

Exceptions to this may include passive solar, andsituations where you qualify for a substantial rebateand/or credit for other renewable energy systems(keep in mind the embodied energy of systemsthough!)

There are other compelling reasons to performupgrades like this, such as reduced reliance onforeign energy resources, promotion of renewableenergy & local industry, passive survivability, etc.


Home energy use

Space heating represents about 50% of the averagehome’s energy use


Saving home energy, guidelines

• Use utility bills to establish energy use baseline

• If your house is very leaky to begin with, don’t startwith an energy audit- do air sealing and insulatingfirst

• Verify improvements w/ blower door testing,thermograph, etc.

• Get energy audit/ assessment (MassSave.com;Energystar.gov; Conservation Services Group:csgrp.com)

• Verify improvements through future utility bills-establish new baseline

• Make additional improvements as budget permits


Blower doortest tomeasure airleakage


Thermograph to check heat loss through walls (insulation effectiveness)


Building envelope, definition

All of the elements of a building that separate andisolate the outdoor environment from the indoorenvironment. This may include walls and wall finishes,roofs and roof finishes, doors, windows, skylights andbasement floors and walls.


Building envelope, functions

• Protect structural elements and interior of structurefrom weather, esp. moisture

• Help to maintain proper thermal regime withinstructure

• Help to maintain proper humidity regime withinstructure

• Prevent infiltration of outside air and contaminants

• Acoustically isolate interior of structure from outsidenoise

• In essence, act as ‘membrane’ for the structure


Building envelope components

• Exterior finish- wood siding, vinyl siding, brick, etc.

• Weather membrane/ air barrier/ drainage plane-building paper, Tyvek, Typar, etc.

• Exterior sheathing- usually plywood

• Wall/ ceiling cavities (inc. structural members &insulation)

• Vapor retarders/ barriers

• Interior wall finish

• Or monolithic masonry floors/ walls, with or withoutinsulation, exterior damp-proofing, etc.


Building envelope failure

• External water leaks leading to:-Damaged structural elements-Damaged interior finishes-Insulation failure-Damaged interior furnishings and appliances-Mold problems

• Air leaks leading to:-Infiltration of unconditioned air/ Drafts-Direct escape of conditioned air to outside-Infiltration of outdoor contaminants

• Excessive accumulation of interior moisture in wallcavities causing structural/ insulation failure & mold

• Excessive heat transfer from inside to outside


Codes and standards

• Sixth edition of MA building code was officiallysuperseded by 7th edition as of January 1st, 2008

• New MA energy code based on 2006 InternationalEnergy Conservation Code; more stringent

• Better to follow Energy Star Homes or HERSguidelines for maximum energy efficiency and codecompliance


Heat transfer (loss) mechanisms

• Radiation- like the way the sun heats you or theway you feel heat directly from an electric heatingelement (measured in infrared)

• Conduction- direct transfer of heat through amaterial, like the direct transfer of heat from yourhand to a cold metal object!

• Convection- heat transfer by way of movement of afluid such as air or water- this is the way most centralheating systems distribute their heat from thefurnace/ boiler

• Infiltration- cold outside air leaks into structure andmixes with indoor air, reducing its temperature


Preventing heat loss

• Air seal (prevent infiltration)

• Best bang for buck through air sealing! Begin here!

• Insulate

• Use landscape features- vegetative shields, etc.

• Address lifestyle issues


Minimizing air infiltration(sealing building envelope)

• Min .35 Air changes per hour (ACH) for goodventilation; max .50 for energy efficiency (EnergyStar)

• Openings to attic spaces are some of worst offenders

• Seal obvious openings- pipe penetrations, atticscuttles, electrical receptacles, recessed lights, etc.

• Any place where two building planes meet is goodcandidate for air sealing

• For additions/ new construction, use exterior airbarrier to minimize infiltration


Housewrap tominimize airinfiltration &protect frommoisture


Air leakage pathways


Air leakage proportion through various pathways


Attic hatches/ scuttles are a major leakage pathway


A commercial solution for attic openings

See also www.efi.org


Insulate header/ rim joists w/ rigid foam & expanding foam


Seal joints between intersecting planes w/ expanding foam


Fireplaces are usually NOT an effective heating appliance!They lead to excessive heat loss via drafts up chimney.


Air sealing, online productsources

• efi.org

• conservationtechnology.com


Windows

• ‘Low-e’ coating reflects heat back into structure

• Performance measured in “U-value”; inverse of R-value; measure of material’s ability to conduct heat;the lower the U-value, the better

• Double-glazed, argon filled preferred; Diminishingreturns with triple glazing

• Typical heat loss through windows about 20%

• Look for U-value of .35 or less

• Always look for Energy Star & NFRC labels


Insulating

• Resistance to heat flow (insulating ability) measuredin R-value; not important to know how this is derived;mainly need to know that it’s a relative scale ofeffectiveness, and the higher the R value, the betterthe insulating value

• Code represents absolute minimum; newer codehas more stringent requirements; tied to window area;R-49 ceiling, R-21 walls, R-30 floors, R-13 basementtypical


Insulating guidelines

• Remember that you are minimizing cooling expenseby buttoning up your house as well as heatingexpense if you use A/C

• Go for low-hanging fruit- e.g. add more atticinsulation first if it is accessible and is not wellinsulated

• Look for additional opportunities to insulate (otherthan typical wall/ ceiling cavity insulation)

• Try to eliminate bridging (perimeter) heat lossthrough structural elements, as it greatly reducesoverall insulation effectiveness


Bridging heat loss

• Eliminate with:-Double wall construction (very expensive!)-Foam skin-Cross-banding attic batt insulation

• Conductive heat loss through structural members


Bridging heat loss- snow melts over roof rafters


Bridging heat loss caused wall-staining over structural members


Bridgingheatloss throughsill plates


Layer of foamminimizes bridgingloss through sill;top of concretefoundation wallwill also receivelayer of foam


Fiberglass batt insulation

• R 3.3 – 3.5 per inch

• No inherent air-sealing characteristics

• Relatively inexpensive

• May contain formaldehyde binders

• Need to avoid inhaling dust during insulation

• Moderate to high embodied energy


Cellulose insulation

• R 3.5 per inch; 3.7 if wet blown

• Provides air-sealing characteristics if wet blown(professionally installed)

• Relatively inexpensive

• Need to avoid inhaling dust during insulation

• Low embodied energy

• Usually contains high recycled content (made fromnewsprint)


Extruded polystyrene (XPS)

• R 5.0 per inch

• Good air-sealing characteristics if edges foamed andseams taped

• Relatively expensive

• Acts as vapor barrier at thicknesses > ¾ inch

• Can be difficult to install

• High embodied energy

• Must be protected from flame with min. ½ in drywallor equivalent


Polyisocyanurate rigid foam

• R 7.0 per inch

• Good air-sealing characteristics if edges foamed andseams taped

• Relatively expensive

• Acts as vapor barrier if foil faced (and edges sealed)

• Can be difficult to install

• High embodied energy

• Acts as radiant barrier if foil faced (and facing ¾”min. air space)


Icynene Spray foam

• R 3.6 per inch

• Very good air-sealing characteristics

• Expensive

• Does not produce harmful smoke; does not burn

• Professionally installed

• Relatively high embodied energy


Icyneneapplication


A new (and promising)technology

• Soy-based spray foam insulation


Additional Insulating Opportunities

• Be creative!

• Examples:- Behind built-in bookcases- Behind cabinets- Closet walls & ceilings

• Capitalize on opportunities to insulate, such aswhen you have exposed exterior wall cavities duringremodeling projects


Ventilation & Vapor Barriers

• Moisture control as it relates to:-Mold potential-Structural failure-Insulation failure-Aesthetic issues

Issues:

• Indoor air quality (IAQ)


Vapor barriers/ Retardes

• Prevent transfer (and accumulation) of internalmoisture into wall/ ceiling cavities

•Always on warm side of insulation (winter) for thispart of country

• Asphalt-impregnated kraft paper is excellent vaporretarder

• In this part of country, vapor retarders are generallybetter than vapor barriers; vapor retarders allow wallto dry from the inside as well as outside


Vapor barriers, continued

• Eliminating air leaks in inside wall finishes minimizesvapor transfer into wall cavities

• For retrofit of vapor barrier (w/ blown-in insulation forinstance), consider a vapor barrier paint

• New ‘smart’ materials like Certainteed’s Membraincreate variable vapor barrier


Ventilation

• It’s almost impossible to make an old house tootight

• Even in a tight house a bathroom fan is generallyenough to provide adequate ventilation; control w/timer (and/or humidistat)

• Provide dedicated combustion air sources for largecombustion appliances like furnaces & fireplaces

• Control internal sources of excessive moisture

• Proper attic ventilation may extend life of roof andhelp to eliminate ice dams

• Extremely tight houses may need heat-recovery ormulti-port supply (or exhaust) ventilation systems


Other ventilation strategies

• Heat recovery ventilators

• Multi-port exhaust (or supply) ventilation


Install continuous soffit ventshere

Provide continuous vent (ridge) here

Attic living space

Insulation baffle(green)

Continuous airflow (blue) from soffitto ridge; minimizes risk of ice dams,minimizes moisture accumulation inrafter cavities, keeps living spacecooler in summer and may extend lifeof roof

2” XPS foam boardinsulation

Rafter cavity insulation(fiberglass typical.)


Insulation Baffle


Ductwork

• Move duct runs into conditioned spaces (thermalenvelope) if possible

• Seal ducts; use duct mastic for this if possible,otherwise make sure duct tape is UL listed

• Insulate ducts in unconditioned spaces; for cooling(A/C) ductwork, make sure insulation has externalvapor barrier to minimize condensation

• Keep ductwork clean

• When insulating ducts in unconditioned basement,you may make basement too cold; may want toinsulate basement walls


Design Strategies: Natural daylighting

• Can reduce lighting loads and cooling loads

• Residential systems typically consist of skylights ortubular daylighting devices (TDD’s; “sun tubes” or“light tubes”

• Improves indoor environmental quality

• Also achieved with clerestory windows

• Skylights in south, southwest and west-facing roofscan contribute to summer overheating

• Skylights in more north-facing roof surfaces cancontribute more light on cloudy days

• TDDs may contribute less to overheating


Natural daylighting

• Light-colored walls reflect light deeper into structure

• Light shelves can serve the same purpose, andaccomplish this w/o excessive glare; they provideshading as well

• Combine daylighting strategies with photo-resistorcontrolled lights to avoid excessive lighting duringdaytime

• Wide windowsills/ shelves can reflect light as well,but may contribute to glare

• Landscape features can be utilized for reflectinglight into interior as well (paved surfaces, waterfeatures, etc)


Light shelves shade windowwhile providing natural daylightvia light reflected from topsurface


Sky tube


Suggested Room SurfaceReflectances:Ceilings: > 80%Walls: 50%-70%Floors: 20%-40%Furnishings: 25%-45%


Funding conservation & renewableenergy projects


Rebates and incentives

• Energy efficient mortgages

• MA state renewable energy tax credit

• Mass Technology Collaborative’s CommonwealthSolar Initiative

• MA state sales tax exemption

• Federal Energy Policy Act of 2005

• See DSIRE database (Database of StateIncentives for Renewables & Efficiency):http://www.dsireusa.org/

• Utility incentives


Federal Energy Policy Act of 2005

Examples:

• Energy Star windows/ skylights: 10% of cost up to$200 for all windows

• Exterior/ Storm doors: 10% of cost up to $500

• Insulation: 10% up to $500

• Geothermal heat pump: $300

• http://www.energy.gov/taxbreaks.htm

• Credits good only for upgrades performedin 2006/ 2007


Energy Efficient Mortgages

• Remodelers/ Refinancers:-Owner gets all the EEM benefits without moving.-Make improvements which will actually save

money.-Increase the potential resale value .

• Allows you to increase your debt-to-income ratio

• Home Energy Rating System (HERS) report mustindicate that home will save money as a result of theimprovements- http://www.energy.ca.gov/HERS/;http://www.energyratings.org/

• For more info:http://www.pueblo.gsa.gov/cic_text/housing/energy_mort/energy-mortgage.htm


MA Renewables Tax Credit

• Solar Water Heat, Solar Space Heat, Photovoltaics,Wind

• 15% of cost up to $1000

• Excess credit may be carried forward three years

• http://www.state.ma.us/doer/programs/renew/renew.htm#taxcred

• Personal tax credit


MA State Sales Tax Exemption

• 100% of sales tax exempt; no maximum

• Solar Water Heat, Solar Space Heat, Photovoltaics,Wind, Geothermal Heat Pumps

• http://www.state.ma.us/doer/programs/renew/renew.htm#taxcred


MTC Small Renewables Initiative

• Rebates up to $50,000

• PV, wind, microhydro

• See http://www.masstech.org


MTC Commonwealth Solar

• $68 M Funding

•http://www.masstech.org/renewableenergy/commonwealth_solar/index.html


•High-efficiency space heating equipment

•High-efficiency indirect water heating equipment

•ENERGY STAR® qualified windows

•ENERGY STAR® qualified thermostats

•ENERGY STAR® qualified central air conditioning

•ENERGY STAR® air source heat pump systems

Typical utility rebates


http://www.energystar.gov/index.cfm?c=dishwash.pr_dishwashershttp://www.energystar.gov/index.cfm?c=clotheswash.pr_clothes_washershttp://www.energystar.gov/index.cfm?c=boilers.pr_boilers

Energy Star savings calculators


Rating Systems/ Resources

• LEED - www.usgbc.org

• Energy Star Homes- www.energystar.gov

• International Energy Conservation Code (IEEC)-http://www.iccsafe.org/

• HERS (http://www.energy.ca.gov/HERS)


• Upcoming workshops

• Reference library

• Samples library

• Cyber Lounge

• Online resources at nexusboston.com (in thepipeline)

• Local green building community

Use NEXUS as your green resource!


Local Resources


The Green Roundtable, Inc. (GRT) is an independent non-profitorganization whose mission is to mainstream green building andsustainable design and become obsolete. We work toward this goal bypromoting and supporting healthy and environmentally integrated buildingprojects through strategic outreach, education, policy advocacy andtechnical assistance.

[email protected]

617-374-3740

www.nexusboston.com38 Chauncy Street, Boston

Located in downtown Boston, NEXUSwelcomes all to come ask questions,research topics, and attend tours andevents on green building and sustainabledesign innovation.

THANK YOU

Residential Energy and Water Conservation

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