The Value of R-Value

Home Energy Use

School Energy Use

Natural Gas Electricity

Energy Efficiency

Whole House Approach

Reduce

energy

demand

•Behavior changes

•Air sealing

•Insulation

•Landscaping and windows

Use energ

y efficiently

•Heating and cooling equipment

•Transport

•Lighting and appliances

Use clean sourc

es

•Solar•Geothe

rmal•Wind

Comfort and the Building Shell

Solar heatAir

Leakage

Internal Heat

Trans-mission

Heat Removed by Cooling System

Ceiling Transmission

Wall, Fenestration, Foundation

Transmission

Air Leakag

e

Heat Supplied by Heating System Internal and Solar Heat

Source: Residential Energy, 5th Edition

Cold

clim

ate

hom

es

wit

h m

a-jo

r air

leakag

e o

r in

sula

tion

p

rob

lem

s

Avera

ge c

old

clim

ate

hom

es

Avera

ge t

em

pera

te c

limate

h

om

es

Well

insu

late

d h

om

es

wit

h

low

air

leakag

e

Very

well

insu

late

d a

nd

air

tig

ht

hom

es

wit

h h

eat-

recovery

ven

tila

tors

0

20

40

60

BTUs per Hour per Square Foot

0

400

800

1200

Square Feet Cooled per Ton

Variations in Load

Source: Residential Energy, 5th Edition

Insulating Materials

Source: www.ornl.gov

Recommended R-Values for Colorado

Source: Colorado Governor’s Energy Office

Space Recommended R-Value

Attic 49

Wall 18

Floor 25

Crawlspace 19

Basement 11

Which is better?

Passivhaus