the value of r-value

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 energy efficiently •Heating and cooling equipment

•Transport•Lighting and appliances

Use clean sources •Solar

•Geothermal•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 w

ith m

a-jor

air

leaka

ge o

r ins

ulat

ion

prob

lems

Aver

age

cold

clim

ate

hom

es

Aver

age

tem

pera

te c

limat

e ho

mes

Well

insu

lated

hom

es w

ith

low a

ir lea

kage

Very

well

insu

lated

and

air

tight

hom

es w

ith h

eat-

reco

very

ven

tilat

ors

0

20

40

60

BTUs per Hour per Square Foot

0400800

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