Energy Conservation

February 8, 2011

Steve Wilson, MBA, CEM, CDSM, BEP

The Energy Guy

How We Use Energy in Our Homes

Heating & Cooling

Water HeaterRefrigerator

Dish Washing 2%

Clothes Washing

Lighting

Other: TV, VCR, Computer, DVD, chargers, video games, Etc.

45%

19%

7%

10%

6% 11%

Climate Zone

Ames is in climate zone 5.

Residential Building Code

2009 IECC – (International Energy Conservation Code).

Ceiling R38

Wall R20

Floor R30

Basement R10/13

Slab R10 (2 ft)

Crawlspace R10/13

Window U factor .35

Heat Transfer

We lose heat from our homes in winter and gain it during summer

HVAC equipment used to maintain comfort– Replaces heat lost in winter and cools heat

gained in summer

Build to take advantage of the sun

Use materials that resist heat transfer

Heat Loss/Gain

How does a home lose/gain heat?– Conduction

Low levels of insulation

Windows

– ConvectionConvection currents

– Drafts by windows

– Upstairs warmer than downstairs

– RadiationWarm home radiating heat to surrounding atmosphere and ground

Home Heat Loss

10% lost through floor (rim joist)20% through windows and doors25% lost through

walls35% lost through

ceilings10% lost through

infiltration

Reducing Heat Loss From The Home

Heat can be lost through many places at home. These include:– Roof– Walls– Gaps around doors and windows– Floors– Windows

Reducing Heat Loss From The Home

Insulate (conduction)– Double pane windows, attic and wall Insulation– Building materials

Seal (convection)– Caulk– Weatherstrip

Orient (radiation)– Maximize winter solar gain– Minimize summer solar gain

Windows

Metal is a conductor, wood an insulator.– Metal conducts heat away from your hands. Wood

does not. – The wood feels warmer than metal.

Wood framed windows are better than metal.

Windows

Cold air coming through cracks and gaps sinks and is warmed by the air in the room setting up a convection

current.

Window Heat Loss

About 10%-15% of a homes total energy is lost through windows

Want to reduce loss through windows– Install fewer windows– Use multiple panes with an air space and low

emittance coating to reflect infrared rays and a high solar gain coefficient to allow the sun’s heat in

Window ConstructionThe window industry measures U-factor– Measures the rate of heat transfer through the window– Lower is better– .35 is good

Also solar heat gain coefficient– Measures how well the window blocks heat from the sun– Lower is better– .32 is good

Visible transmittance– Measures how much light comes through the window– Higher is better– .51 is good

Air leakage– Measures air coming through the window– Lower is better– .2 is good

Insulation

Types & R value:– Fiberglass rolls 3.14– Loose fill fiberglass 2.2– Loose fill cellulose 3.6– Extruded polystyrene 5– Polyurethane 6.25– Polyisocyanurate 7.2– 8” concrete block (whole) 1.11– 4” brick (whole) .8– Plywood 1.25– Drywall .9– Ashpalt shingles .44– Single pane window .91– Double pane window 2.8– Triple pane window 3.23– Air space 1

Insulation

How do you know if your insulation is working?– Infrared camera– Temperature gun

Preventing Air Leakage

Caulk or foam all wall openings– Plumbing, wiring, exhaust fans, etc.

Caulk and weatherstrip windows and doors

Caulk around recessed lighting and attic hatchway

Caulk foundation, roof, and wall connections– Maintain air exchange of 25%-35%

Air Leakage

Air Leakage

Orientation

Passive solar design– Block summer sun but allow winter sun

West

North

East

South

Green Materials

Proven sustainability– Clean manufacturing process– High percentage of recycled content– Ability to recycle at end of life– Long product life cycle (lasts a long time)– Made in sizes that produce less waste

May come from design

Wall and Roof Color

Dark exterior walls may help heat the home in winter but will make it harder to cool the home in summer

Energy Star supports light colored roofs– Reduce roof surface temp by 100ºF– Lower cooling energy requirement by 15%

Most homes have dark roofs – Availability of materials – We live in a heating dominated environment– Some don’t understand the value of light colored roofs

Home Testing

Home Energy Rating System (HERS) audit– Score of 100 equals current energy code

(2009 IECC) – Score of 85 or lower qualifies as Energy Star

Blower door testing can identify where air leaks are and determine overall home tightness

Payback

We have to spend money in order to make our homes efficientPayback time compares the amount of money that we spend on materials to the amount of money that we saveFor example if we spend $2,000 on double pane windows and it saves us $100 a year it will be 20 years before we save as much money as we spentMust be considered against the budgetTrade offs may be required

Web SitesWeb Sites

www.state.ia.us/dnr/energy/MAIN/renewablewww.state.ia.us/dnr/energy/MAIN/renewable

www.BLM.gov/energy http://www.iccsafe.org/Pages/default.aspxwww.doi.gov/greening/energy www.city.ames.ia.us/electricwebwww.city.ames.ia.us/electricwebwww.energy.iastate.eduwww.energy.iastate.eduwww.eia.doe.govwww.eia.doe.govwww.fypower.orgwww.fypower.org

Questions?