Residential Energy and Water Conservation

The Green Roundtable
and

Energy & Water Conservation
Low-Hanging Fruit

(copyright © Green Roundtable 2007)

Green Roundtable

Consulting, education, training
and strategic planning

to create healthy environments by
integrating principles of
sustainability into mainstream
planning, design and construction.


Objectives
Discuss:
- Easy ways to reduce energy & water consumption in the
home (low-hanging fruit)
- Additional cost-effective measures (higher cost but
potentially big returns)
- Energy efficient lighting, appliances & equipment
- Conserving water in the landscape
- Improving performance of building envelope
(insulating & air sealing)
- Basic economics- incentives, payback time, etc.


General approaches

- Make simple lifestyle adjustments

- Take advantage of natural methods/ work with nature

- Improve maintenance routines

- Make simple upgrades to fixtures in the home

- Upgrade appliances and equipment

- Make improvements to the building envelope


Preventing heat loss (bldg envelope)
• Insulate

• Air seal (prevent infiltration)

• Use landscape features- vegetative shields, etc.

• Address lifestyle issues

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


Low-hanging Fruit


Low-hanging fruit- easy pickin’s
• Lower thermostat by 1 or 2 degrees- 1 degree
lower for 8 hour period saves about 1% on heating
energy use (simple math: 2 deg for 24 hrs = 6%)

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

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


Low-hanging fruit- easy pickin’s

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

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

• Clean heat pump and air conditioner coils


More easy pickin’s
• “If it’s yellow, let it mellow…”
• Use toilet tank water displacement ‘devices’
• Wash your clothes in cold water; don’t use a higher
water level or longer cycle than necessary
• Let bath water dissipate heat to room temperature
before letting water down drain- collect some of this
water for plants/ landscape/ toilet flushing. Do same
for dishwater- This also adds much-needed humidity
to winter air
•“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 hold
water from a full laundry load)

A little less convenient
• Collect water that would otherwise run down the
drain 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 thing
in morning
• Use this to water plants, fill your humidifier, or flush
your toilet. Laundry detergent jugs (large size) w/
spout removed are ideal for toilet flush water, as they
let you pour water out very quickly and they hold a
sufficient 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 to
water heater first)

• Add an insulation blanket to your hot water heater

• Install a low-flow shower head

• Install faucet aerators

• Install a programmable thermostat

• Change your furnace filter (forced hot air systems)


Using self-adhesive insulating
tape at bends & valves in piping
easier than cutting foam pipe
insulation to fit


Low cost, big return- continued
• Replace worn weatherstripping
• Use expanding foam insulation to plug obvious holes
in building envelope
• Add gaskets to electrical receptacle covers

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

• Install dimmer switches & occupancy sensors

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

• Use an auto shut-off electric kettle


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 gas
from power plant capacity needed to satisfy increased
demand from incandescent bulbs
• Must treat blown-out bulbs as hazardous waste

More energy conservation strategies
• Put radiant reflecting panels behind radiators

• Keep baseboard convectors clean

• Close off unoccupied areas of house and turn off
heat to those areas if possible; be careful if there are
pipe runs

• Regularly defrost refrigerators/ freezers

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


• Remove window A/C units in winter

• Use microwave oven for cooking

• Use ceiling fans w/ cathedral or high ceilings to
eliminate temperature stratification (both heating and
cooling season)

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

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


• Use deciduous vegetation on south, SW and west
sides of structure for summer shading; use vines on
trellises too

• Install awnings, overhangs and other shading
structures, such as pergolas

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

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


• Install white window shades to help keep house
cool in summer
• Make sure attic space is well vented
• Use whole-house fans to exhaust warm air from
house in summer; run mainly at night to flush w/ cool
air; close windows during very hot days
• Install radiant barriers on underside of roof rafters;
can help to warm in winter and cool in summer; don’t
interrupt ventilation pathways
• Use double-wall cellular reflecting window shades
w/ edge guides or “Energy Track” or window quilts


Green Practice:
HVAC/ Plumbing/ Lighting


HVAC & Plumbing Systems
• “Right-size” systems using analysis tools (Manual J)
rather than rule-of-thumb methods; a right-sized
system can be up to 40% smaller than a
conventionally-sized system
• Use zoned heating
• Use demand pumps in DHW supply system
(gothotwater.com
• Use heat recovery devices on DWV pipes
(gfxtechnology.com)
• Use instantaneous hot water heaters
• Use structured plumbing & PEX piping

Tankless water heaters

• Brands: Rinnai, Noritz, Takagi

• Gas-fired typically more responsive and can provide
needed capacity more effectively

• Cost more than standard water heaters but last longer


High-efficiency heating
• Choose Energy Star! Right-size systems! (did I
mention that before?!)
• Make sure heating systems have Annual Fuel
Utilization Efficiency (AFUE) of at least 83% for oil-
fired and 90% for gas-fired, and Seasonal Energy
Efficiency Rating (SEER) of at least 13 for cooling
systems
• Boilers tend to have higher AFUE than furnaces
• Closed-cycle, condensing-type boilers and furnaces
are more efficient; they extract additional heat from
warm flue gases
• These systems often don’t need conventional flue pipe,
they can side vent, but they require a dedicated
combustion air source (coaxial flue pipe)

Lighting

• Use zone lighting

• Use solar landscape lights

• Use motion sensor outdoor lights

• Put timer switches on bathroom fans

• Use natural daylighting strategies


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


MWRA
A water conservation resource

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


Water conservation

• Use low-flow showerheads & faucet aerators
• Incorporate graywater systems
• Use demand pumps in supply system
• Use dual-flush or composting toilets; waterless
urinals
• Collect rainwater in rain barrels for landscape
irrigation


Coroma Dual-Flush Toilet Source

The Portland Group- Splash Showroom
244 Needham St.
Newton, MA 02164
617.332.6662


Green Systems:
Gray water


Gray water

• Collected from drain-waste-vent system other than
toilets & kitchen sinks with garbage diposals (“Black
water”)

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

• May be difficult to get local code approval


Gray water: A direct approach

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

Rainwater collection
• For 1000 sq ft roof area, 15 – 25,000 gallons of
rainwater can be collected annually in Eastern states
• Combined with drip-irrigation systems, collected
rainwater can keep landscaping vibrant even during
drought conditions
• Using rainwater helps to maintain aquifers and public
water supplies at adequate levels
• Rainwater does not contain chlorine so it is better for
plants, garden ponds, etc.
• Rainwater does not contain minerals, so it is
potentially better for use as laundry/ wash water
• 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 mulches
• Create water retention landscape features
• Use drip irrigation & soaker hoses
• Group plants
• Use plantings to create windbreaks & shade to
protect from drying winds and sun
• Use native plantings, they are better suited to natural
rainfall patterns


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 be
achieved through managing the demand side of
the equation, rather than the supply side.

In other words, you’ll get better bang for your buck
through energy conservation measures, like insulating
& minimizing air infiltration, than incorporating
expensive renewable energy systems such as wind
and solar.


An exception:

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

There are other compelling reasons to perform
upgrades like this, such as reduced reliance on
foreign energy resources, promotion of renewable
energy & local industry, passive survivability, etc.


Home energy use

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


Saving home energy, guidelines
• Use utility bills to establish energy use baseline
• Get energy audit/ assessment (MassSave.com;
Energystar.gov; Conservation Services Group:
csgrp.com)
• If your house is very leaky to begin with, don’t start
with an energy audit- do air sealing and insulating
first
• Verify improvements w/ blower door testing,
thermograph, etc.
• Verify improvements through future utility bills-
establish new baseline
• Make additional improvements as budget permits

Blower door
test to
measure air
leakage


Thermograph to check heat loss through walls (insulation effectiveness)


Building envelope, definition

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


Building envelope, functions
• Protect structural elements and interior of structure
from weather, esp. moisture

• Help to maintain proper thermal regime within
structure

• Help to maintain proper humidity regime within
structure

• Prevent infiltration of outside air and contaminants

• Acoustically isolate interior of structure from outside
noise

• 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
• Or monolithic masonry floors/ walls, with or without
insulation, exterior damp-proofing, etc.
• Interior wall finish


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 wall
cavities causing structural/ insulation failure & mold
• Excessive heat transfer from inside to outside


Codes and standards

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

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

• Better to follow Energy Star Homes or HERS
guidelines for maximum energy efficiency and code
compliance


Heat transfer (loss) mechanisms
• Radiation- like the way the sun heats you or the
way you feel heat directly from an electric heating
element (measured in infrared)
• Conduction- direct transfer of heat through a
material, like the direct transfer of heat from your
hand to a cold metal object!
• Convection- heat transfer by way of movement of a
fluid such as air or water- this is the way most central
heating systems distribute their heat from the
furnace/ boiler
• Infiltration- cold outside air leaks into structure and
mixes with indoor air, reducing its temperature


Preventing heat loss
• Insulate

• Air seal (prevent infiltration)

• Use landscape features- vegetative shields, etc.

• Address lifestyle issues

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


Minimizing air infiltration
(sealing building envelope)

• Min .35 Air changes per hour (ACH) for good
ventilation; max .50 for energy efficiency (Energy
Star)
• Seal obvious openings- pipe penetrations, attic
scuttles, electrical receptacles, recessed lights, etc.
• Openings to attic spaces are some of worst offenders
• Any place where two building planes meet is good
candidate for air sealing
• For additions/ new construction, use exterior air
barrier to minimize infiltration


Housewrap to
minimize air
infiltration &
protect from
moisture


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 product
sources

• efi.org

• conservationtechnology.com


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

• Look for U-value of .35 or less

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

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

• Always look for Energy Star & NFRC labels

• Typical heat loss through windows about 20%


Insulating
• Resistance to heat flow (insulating ability) measured
in R-value; not important to know how this is derived;
mainly need to know that it’s a relative scale of
effectiveness, and the higher the R value, the better
the insulating value

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


Insulating guidelines
• Go for low-hanging fruit- e.g. add more attic
insulation first if it is accessible and is not well
insulated

• Remember that you are minimizing cooling expense
by buttoning up your house as well as heating
expense if you use A/C

• Try to eliminate bridging (perimeter) heat loss
through structural elements, as it greatly reduces
overall insulation effectiveness

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

Bridging heat loss

• Conductive heat loss through structural members

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


Bridging heat loss- snow melts over roof rafters

Bridging heat loss caused wall-staining over structural members


Bridging
heat
loss through
sill plates


Layer of foam
minimizes bridging
loss through sill;
top of concrete
foundation wall
will also receive
layer of foam


Fiberglass batt insulation

• R 3.3 – 3.5 per inch

• Relatively inexpensive

• May contain formaldehyde binders

• Need to avoid inhaling dust during insulation

• No inherent air-sealing characteristics

• Moderate to high embodied energy


Cellulose insulation
• R 3.5 per inch; 3.7 if wet blown

• Relatively inexpensive

• Usually contains high recycled content (made from
newsprint)

• Need to avoid inhaling dust during insulation

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

• Low embodied energy


Extruded polystyrene (XPS)
• R 5.0 per inch

• Relatively expensive

• Acts as vapor barrier at thicknesses > ¾ inch

• Can be difficult to install

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

• Good air-sealing characteristics if edges foamed and
seams taped

• High embodied energy

Polyisocyanurate rigid foam
• R 7.0 per inch

• Relatively expensive

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

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

• Can be difficult to install

• Good air-sealing characteristics if edges foamed and
seams taped

• High embodied energy


Icynene Spray foam

• R 3.6 per inch

• Expensive

• Does not produce harmful smoke; does not burn

• Professionally installed

• Very good air-sealing characteristics

• Relatively high embodied energy


Icynene
application


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 as
when you have exposed exterior wall cavities during
remodeling projects


Ventilation & Vapor Barriers

Issues:

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

• Indoor air quality (IAQ)


Vapor barriers/ Retardes
• Prevent transfer (and accumulation) of internal
moisture into wall/ ceiling cavities

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

• In this part of country, vapor retarders are generally
better than vapor barriers; vapor retarders allow wall
to dry from the inside as well as outside

• Asphalt-impregnated kraft paper is excellent vapor
retarder


Vapor barriers, continued

• Eliminating air leaks in inside wall finishes minimizes
vapor transfer into wall cavities

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

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


Ventilation
• It’s almost impossible to make an old house too
tight
• Even in a tight house a bathroom fan is generally
enough to provide adequate ventilation; control w/
timer (and/or humidistat)
• Control internal sources of excessive moisture
• Provide dedicated combustion air sources for large
combustion appliances like furnaces & fireplaces
• Proper attic ventilation may extend life of roof and
help to eliminate ice dams
• Extremely tight houses may need heat-recovery or
multi-port supply (or exhaust) ventilation systems

Other ventilation strategies

• Heat recovery ventilators

• Multi-port exhaust (or supply) ventilation


Provide continuous vent (ridge) here

Continuous airflow (blue) from soffit
to ridge; minimizes risk of ice dams,
minimizes moisture accumulation in
Insulation baffle
rafter cavities, keeps living space
(green)
cooler in summer and may extend life
of roof

Rafter cavity insulation
(fiberglass typical.)

2” XPS foam board
insulation
Attic living space

Install continuous soffit vents
here


Insulation Baffle


Ductwork
• Move duct runs into conditioned spaces (thermal
envelope) 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 external
vapor barrier to minimize condensation
• Keep ductwork clean
• When insulating ducts in unconditioned basement,
you may make basement too cold; may want to
insulate basement walls

Design Strategies: Natural daylighting
• Can reduce lighting loads and cooling loads
• Improves indoor environmental quality
• Residential systems typically consist of skylights or
tubular daylighting devices (TDD’s; “sun tubes” or
“light tubes”
• Also achieved with clerestory windows
• Skylights in south, southwest and west-facing roofs
can contribute to summer overheating
• Skylights in more north-facing roof surfaces can
contribute 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, and
accomplish this w/o excessive glare; they provide
shading as well
• Wide windowsills/ shelves can reflect light as well,
but may contribute to glare
• Combine daylighting strategies with photo-resistor
controlled lights to avoid excessive lighting during
daytime
• Landscape features can be utilized for reflecting
light into interior as well (paved surfaces, water
features, etc)

Light shelves shade window
while providing natural daylight
via light reflected from top
surface


Sky tube


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


Funding conservation & renewable
energy projects


Rebates and incentives
• Federal Energy Policy Act of 2005
• Energy efficient mortgages
• MA state sales tax exemption
• MA state renewable energy tax credit
• Mass Technology Collaborative’s Commonwealth
Solar Initiative
• Utility incentives
• See DSIRE database (Database of State
Incentives for Renewables & Efficiency):
http://www.dsireusa.org/


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 performed
in 2006/ 2007


Energy Efficient Mortgages
• Allows you to increase your debt-to-income ratio
• Remodelers/ Refinancers:
-Owner gets all the EEM benefits without moving.
-Make improvements which will actually save
money.
-Increase the potential resale value .
• Home Energy Rating System (HERS) report must
indicate that home will save money as a result of the
improvements- 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

• Personal 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


MA State Sales Tax Exemption

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

• 100% of sales tax exempt; no maximum

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


MTC Small Renewables Initiative

• PV, wind, microhydro

• Rebates up to $50,000

• See http://www.masstech.org


MTC Commonwealth Solar

• $68 M Funding

•http://www.masstech.org/renewableenergy/commonw
ealth_solar/index.html


Typical utility rebates

•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


Energy Star savings calculators

http://www.energystar.gov/index.cfm?c=dishwash.pr_dishwashers
http://www.energystar.gov/index.cfm?c=clotheswash.pr_clothes_
washers
http://www.energystar.gov/index.cfm?c=boilers.pr_boilers


Rating Systems/ Resources

• Energy Star Homes- www.energystar.gov

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

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

• LEED - www.usgbc.org


Use NEXUS as your green resource!

• Upcoming workshops

• Reference library

• Samples library

• Cyber Lounge

• Online resources at nexusboston.com (in the
pipeline)

• Local green building community


Local Resources


THANK YOU
www.greenroundtable.org
info@greenroundtable.org
617-374-3740

The Green Roundtable, Inc. (GRT) is an independent non-profit
organization whose mission is to mainstream green building and
sustainable design and become obsolete. We work toward this goal by
promoting and supporting healthy and environmentally integrated building
projects through strategic outreach, education, policy advocacy and
technical assistance.

Located in downtown Boston, NEXUS
welcomes all to come ask questions,
research topics, and attend tours and
www.nexusboston.com events on green building and sustainable
38 Chauncy Street, Boston design innovation.

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