nexus: buttoning up your home for the winter

The Green Roundtable

Buttoning up for the winter-

Basics of home energy

conservation

and

Green Roundtable

Consulting, education, training and strategic planning

to create healthy environments by integrating principles of

sustainability into mainstream planning, design and construction.

Objectives

- Easy ways to reduce energy consumption in the home

(low-hanging fruit)

- Additional cost-effective measures (higher cost but

potentially big returns)

- Energy efficient lighting, appliances & equipment

- Improving performance of building envelope

(insulating & air sealing)

Discuss:

- Basic economics- incentives, payback time, etc.

The Green Roundtable(copyright © Green Roundtable 2007)

Home energy use

Space heating represents about 50% of

the average home’s energy use

>90 percent of the embodied life-cycle

energy in the typical home is attributable to

operating energy (heating, cooling,

lighting, appliances, 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


Building envelope, definition

All of the elements of a building that separate and

isolate the unconditioned, sometimes hostile

outdoor environment from the conditioned indoor

environment. This may include walls and wall

finishes, roofs and roof finishes, doors, windows,

skylights and basement floors and walls.


But first…

• Lock sashes; adjust closers on storm doors so that

the doors latch properly

• Close storm windows if you have them!

• Repair broken windowpanes; re-putty windows if

necessary

• Install hooks on older (wooden) storm doors to make

sure weatherstripping makes tight seal

• Remove window A/C units in winter

• The old familiar mantra: “Do you live in a barn?!…”

– Educate your children!


If you can‟t replace

broken window panes

right away, seal cracks

with a clear/ translucent

caulking material or

cellophane tape!


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



• Close off a section of the house for the season if

practical (e.g. multi-zone heating); don‟t lower

thermostat below 55 deg.

• Close window shades if you have them…all the way to

window sills (interrupts convection loops)



• Drain a few quarts of water from your water heater

(at least 4 times per year). This improves efficiency

and extends tank life.

• Bleed radiators if valve is open & no heat


More low-hanging fruit…

• If it‟s too inconvenient to turn off your computer

between daytime 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

• Use ceiling fans w/ cathedral or high ceilings to

eliminate temperature stratification (both heating and

cooling season)

• Regularly defrost refrigerators/ freezers


More low-hanging fruit…

• Wash your clothes in cold water; do full loads;

otherwise, 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.

• Use a „solar clothes dryer‟

• Do same for dish water- This also adds much-

needed humidity to winter air


Low cost, big return

• Insulate your hot water pipes (pipes closest to

water 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)

• Fix leaky faucets, especially hot water


Don‟t insulate top of

gas-fired water

heaters; leave access

panels & valves at

base clear as well


Don‟t waste too much

time trimming pipe

insulation to fit tightly

around elbows & valves;

wrap a few times with

wide (1 ½ - 2”) foam

self-adhesive

weatherstripping tape &

secure w/ electrical tape

if necessary


An example of a foam

weatherstripping tape

option for sealing pipe

insulation at elbows &

valves


Low cost, big return- continued

• Install dimmer switches & occupancy sensors

• Control groupings of consumer electronics, like

entertainment 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 holes

in 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 www.estarlights.com, www.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

http://www.estarlights.com/

http://www.efi.org/


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.


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

• Interior wall finish

• Or monolithic masonry floors/ walls, with or without

insulation, exterior damp-proofing, etc.


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


Air leakage pathways


Minimizing air infiltration (sealing building envelope)

• Openings to attic spaces are some of worst offenders

• Seal obvious openings- pipe penetrations, attic

scuttles, electrical receptacles, recessed lights, etc.

• 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 proportion through various pathways


Attic hatches/ scuttles are a major leakage pathway


A commercial solution for attic openings

See also www.efi.org


A home-brew solution


Rim joist between floors:

A significant air-leakage &

heat loss pathway.

Expanding foam insulation

a good solution here


Seal joint between baseboards and

floors/ walls. Add molding if necessary

to conceal caulking.


Seal joints between intersecting planes w/ expanding foam


Electrical receptacles can be a

significant air leakage pathway.

Seal cover plates w/ foam gaskets.

Seal joint between electrical box &

wall with caulking, spackle or

drywall compound.


Some commercial alternatives

to gaskets/ sealing mentioned

previously.


Don‟t run insulation up to

and over canister

(recessed) light fixtures

unless they are “IC”

(Insulation Contact)- rated;

Otherwise maintain

minimum 3” clearance at

all sides


Fireplaces are usually NOT an effective heating appliance!

They lead to excessive heat loss via drafts up chimney, especially

when you have a roaring fire! Use glass doors & outside

combustion air source if practical. Close damper when not in use!


A sampling of window sealing/ insulating options

• Shrink film w/ double-stick tape - one season use

• Rigid plastic (like Plexiglas™ sheet acrylic) with

weatherstripping & clips or magnetic tape – whole

system can be re-used from year to year – one of most

aesthetically pleasing options; magnetic tape option

allows easy escape

• Plastic (or shrink) film w/ bead or spline track (“Tiger

track”); track can be painted to match woodwork – whole

system reusable from season to season if non-shrink

plastic sheeting used

• Rope caulking to eliminate air leaks (provides no

insulating value) – can be re-used if carefully removed

• Important note: Always provide at least one unsealed window

per bedroom & living level to allow fast escape in fire/ emergency


Air sealing, online product

sources

• www.efi.org

• www.conservationtechnology.com

http://www.efi.org/

http://www.conservationtechnology.com/


Plexiglas retrofitted

to exterior of upper

sash; lower sash

gets retrofitted on

inside to assure

proper operation of

window


Interior storm window retrofit; made

from ceiling light diffuser panel;

provides additional privacy as well


Creative solutions:

Bubble-pack between

sash & storm window to

provide insulating value

(& additional privacy)


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; Diminishing

returns 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


NFRC Label


Seal gap between rough opening and

window sill/ jambs when installing new windows


Insulating guidelines

• Button up your house to minimize cooling (A/C)

loads as well as heating loads

• Go for low-hanging fruit- e.g. add more attic

insulation first if it is accessible and is not well

insulated

• Look for additional opportunities to insulate (other

than typical wall/ ceiling cavity insulation)

• Try to eliminate bridging heat loss through wall framing,

etc, as it greatly reduces overall insulation effectiveness,

e.g., cross-band attic insulation

• Don‟t forget the basement! It‟s often overlooked; heat

loss to ~50 deg. F ground surrounding uninsulated

foundation is assured according to the laws of physics!


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


Bubble pack-

style radiant

insulation

stapled to back

of attic door


Ventilation

• It‟s generally difficult to make an old house too tight

(inadequate outdoor make-up air)

• Even in a tight house, a bathroom fan is often enough

to provide adequate ventilation; cycle on periodically w/

timer switch (and/or humidistat; see efi.org)

• Provide dedicated (outside) combustion air sources for

large combustion appliances like furnaces & fireplaces

• Control internal sources of excessive moisture

• 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


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 (& seal) ducts in unconditioned spaces; for

cooling (A/C) ductwork, make sure insulation has

external vapor barrier to minimize condensation on duct

surfaces

• Keep inside of ductwork clean

• When insulating ducts in unconditioned basement,

you may make basement too cold; may want to

insulate basement walls instead


Appliances

• Buy Energy Star!

• Upgrade refrigerator if more than 10 years old

• Buy horizontal-axis washing machines

-They save water and energy (and soap!)

• Buy dishwashers w/ booster heater

• Don‟t buy oversized air-conditioners


More energy conservation strategies

• Put radiant reflecting panels behind radiators

• Keep baseboard convectors clean

• Keep gas appliances tuned, including stoves; look

for blue flame; see mfgr for adjusting burners

• Employ manufacturer-recommended maintenance

routines for heating & cooling equipment. This may

include adjusting burners, lubricating motors and

changing filters.

• Close all curtains and shades at night during winter

(can help to break convection loops even if loose-

fitting); install closed-top window cornices if you are

using curtains or drapes



• Use microwave oven for cooking; in addition to

consuming less power for cooking, they may help to

reduce summer cooling loads

• Remember that A/C units also dehumidify, so you

may feel comfortable at a higher temperature

• Shade air conditioner and heat pump condensers w/

vegetation or artificial shading (be careful w/

deciduous vegetation)



• 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) for west-facing walls

• Use deciduous vegetation on south, SW and west

sides of structure for summer shading; use vines on

trellises too



• Make sure attic space is well vented

• Use double-wall cellular reflecting window shades

w/ 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‟t

interrupt ventilation pathways

• 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 white window shades to help keep house

cool in summer


Next steps- Home energy saving

• Use utility bills to establish energy use baseline

• 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.

• 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 door

test to

measure air

leakage


Thermograph to check heat loss through walls (insulation effectiveness)


Funding conservation & renewable

energy projects


Rebates and incentives

• Energy efficient mortgages

• MA state renewable energy tax credit

• Mass Technology Collaborative‟s Commonwealth

Solar Initiative

• MA state sales tax exemption

• Federal Energy Policy Act of 2005

• See DSIRE database (Database of State

Incentives 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 performed

in 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 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

• 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/commonw

ealth_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_dishwashe

rs

http://www.energystar.gov/index.cfm?c=clotheswash.pr_clothes

_

washers

http://www.energystar.gov/index.cfm?c=boilers.pr_boilers

Energy Star savings calculators

http://www.energystar.gov/index.cfm?c=dishwash.pr_dishwashers

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

• 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 the

pipeline)

• Local green building community

Use NEXUS as your green resource!


Local Resources


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.

www.greenroundtable.org

[email protected]

617-374-3740

www.nexusboston.com38 Chauncy Street, Boston

Located in downtown Boston, NEXUS

welcomes all to come ask questions,

research topics, and attend tours and

events on green building and

sustainable design innovation.

THANK YOU

http://www.greenroundtable.org/

http://www.nexusboston.com/

nexus: buttoning up your home for the winter

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