The Energy Star HomeThe Energy Star Home

Drew TepperDrew Tepper

OverviewOverview

What is an energy star home?What is an energy star home? New HomesNew Homes Existing HomesExisting Homes

WindowsWindows HVACHVAC InsulationInsulation PlumbingPlumbing

ConclusionConclusion

What is an energy star What is an energy star home?home?

““More home for less money than standard homes.”More home for less money than standard homes.” Energy Star labeled homes are at least 30% more Energy Star labeled homes are at least 30% more

energy-efficient than standard homes.energy-efficient than standard homes. Use reliable and established technologies and Use reliable and established technologies and

building practices to operate significantly more building practices to operate significantly more efficiently than homes built to the efficiently than homes built to the Model Energy Model Energy CodeCode.. These technologies and practices save the owners of Energy These technologies and practices save the owners of Energy

Star homes money on their utility bills.Star homes money on their utility bills. They provide a home that’s more comfortable, more They provide a home that’s more comfortable, more

durable, environmentally friendly, and cheaper to own.durable, environmentally friendly, and cheaper to own. To receive an Energy Star label, homes must To receive an Energy Star label, homes must

undergo a undergo a third party evaluationthird party evaluation of their energy of their energy efficiency.efficiency.

Standard Standard HomeHome

Energy Star Energy Star Labeled Labeled HomesHomes

$200,000$200,000 List PriceList Price $203,000$203,000

$1,654$1,654 Monthly MortgageMonthly Mortgage $1,679$1,679

$155$155 Monthly UtilitiesMonthly Utilities $100$100

$1,809$1,809 Total Monthly CostsTotal Monthly Costs $1,779$1,779

Monthly SavingsMonthly Savings $30$30

Model Energy CodeModel Energy Code

The Energy Star standard for new homes is The Energy Star standard for new homes is measured by the Home Energy Rating System measured by the Home Energy Rating System (HERS) scoring.(HERS) scoring.

The HERS rating is a calculation of the energy The HERS rating is a calculation of the energy efficiency of a home compared to an identical efficiency of a home compared to an identical ‘house’ that meets the minimum requirements of ‘house’ that meets the minimum requirements of the Model Energy Code (MEC).the Model Energy Code (MEC). The HERS score will be between 0 and 100.The HERS score will be between 0 and 100. The reference ‘house’ will have a score of 80.The reference ‘house’ will have a score of 80.

Each 5% reduction in energy usage will result in Each 5% reduction in energy usage will result in an additional point on the HERS scale.an additional point on the HERS scale.

An Energy Star home must receive a score of at An Energy Star home must receive a score of at least 86 on the HERS score.least 86 on the HERS score.

Builder Option Packages (BOP Builder Option Packages (BOP Ratings)Ratings)

BOPs are a set of construction specifications for a BOPs are a set of construction specifications for a specific climate zone.specific climate zone.

These specifications include performance levels for These specifications include performance levels for the thermal envelope, insulation, windows, the thermal envelope, insulation, windows, orientation, HVAC systems, and water heating orientation, HVAC systems, and water heating efficiency.efficiency. The United States has been divided into 19 climate zones The United States has been divided into 19 climate zones

for purposes of BOP.for purposes of BOP. A home built to BOP specs is not rated by the HERS A home built to BOP specs is not rated by the HERS

system but still is subject to third party verification.system but still is subject to third party verification. BOP homes either pass or fail as Energy Star homes.BOP homes either pass or fail as Energy Star homes.

New ConstructionNew ConstructionTight Construction.Tight Construction. There are hundreds of holes that penetrate the There are hundreds of holes that penetrate the

outside of a house.outside of a house. These occur due to gaps and holes from These occur due to gaps and holes from

framing and penetrations for wiring, plumbing, framing and penetrations for wiring, plumbing, and ducts.and ducts.

Air sealing combined with proper ventilation Air sealing combined with proper ventilation can reduce energy bills and eliminate can reduce energy bills and eliminate unwanted drafts and pollutants. unwanted drafts and pollutants.

New Construction Cont.New Construction Cont.

Tight Ducts.Tight Ducts. Duct Sealing – typically ducts Duct Sealing – typically ducts

leak more than 35% of the air leak more than 35% of the air traveling through them before traveling through them before reaching a destination. Duct reaching a destination. Duct tape does not seal ducts tape does not seal ducts adequately.adequately.

Duct location – should only be Duct location – should only be placed where the air will be placed where the air will be heated and cooled. Attics can heated and cooled. Attics can reach above 150 F.reach above 150 F.

Duct insulation – if used Duct insulation – if used outside the living area.outside the living area.

Duct Sizing.Duct Sizing.

New Construction Cont.New Construction Cont.

InsulationInsulation.. A continuous boundary of insulation is A continuous boundary of insulation is

necessary between the inside and outside necessary between the inside and outside for a home to maintain temperature for a home to maintain temperature efficiently.efficiently.

Insulation must be installed carefully with Insulation must be installed carefully with no gaps, crimping, or compression, as no gaps, crimping, or compression, as these can allow unwanted air and heat these can allow unwanted air and heat exchange between the outside and inside. exchange between the outside and inside.

Old ConstructionOld Construction

Existing houses can be modified to Existing houses can be modified to meet Energy Star standards.meet Energy Star standards. Not necessary.Not necessary. Improvements can be made to increase Improvements can be made to increase

efficiency.efficiency. Windows.Windows. High-efficiency heating and cooling High-efficiency heating and cooling

systems.systems.

Replacement WindowsReplacement Windows

Windows typically Windows typically make up 10 – 25% make up 10 – 25% of a home's exterior of a home's exterior wall area.wall area.

Energy Star labeled Energy Star labeled windows are twice windows are twice as efficient as the as efficient as the average window average window produced just ten produced just ten years ago.years ago.

U-factor, R-value and Solar U-factor, R-value and Solar Heat Gain CoefficientHeat Gain Coefficient

U-factor is the measurement of heat U-factor is the measurement of heat transfer through a given building material transfer through a given building material (such as glass).(such as glass).

R-value depicts the resistance a material R-value depicts the resistance a material has to heat transfer.has to heat transfer.

U-factor = 1/R-valueU-factor = 1/R-value The solar heat gain coefficient (SHGC) is a The solar heat gain coefficient (SHGC) is a

measure of the amount of solar energy measure of the amount of solar energy that a glazing material allows to pass.that a glazing material allows to pass.

Window FactsWindow Facts

In heating-dominated climates, windows In heating-dominated climates, windows account for up to 25% of a typical house’s account for up to 25% of a typical house’s heating load.heating load.

In cooling-dominated climates, windows In cooling-dominated climates, windows account for up to 50% of the same house’s account for up to 50% of the same house’s cooling load.cooling load.

In recent years, many technological advances In recent years, many technological advances have improved the thermal performance of have improved the thermal performance of windows.windows. These advances include low-emissivity and solar These advances include low-emissivity and solar

control coatings, low-conductance gas fills, control coatings, low-conductance gas fills, improved thermal breaks and edge spacers, and improved thermal breaks and edge spacers, and better edge sealing techniques.better edge sealing techniques.

What’s a good window?What’s a good window?

Windows can improves the thermal Windows can improves the thermal performance of homes by minimizing heat loss performance of homes by minimizing heat loss in heating-dominated climates and by in heating-dominated climates and by minimizing solar heat gain in cooling-minimizing solar heat gain in cooling-dominated climates.dominated climates.

Windows with lower U-factors (higher R-Windows with lower U-factors (higher R-values) perform better in heating-dominated values) perform better in heating-dominated climates while windows with lower solar heat climates while windows with lower solar heat gain coefficients (SHGC) perform better in gain coefficients (SHGC) perform better in cooling-dominated climates.cooling-dominated climates.

Thermal Window

“Vacuum” can be filled with other gases

Windows Cont.Windows Cont.

Air tightness (unconditioned air leakage into a Air tightness (unconditioned air leakage into a house).house). A rating of 0.2 cfm/ft (cubic foot per minute of A rating of 0.2 cfm/ft (cubic foot per minute of

air leakage per linear foot of window edge) or air leakage per linear foot of window edge) or lower is considered good.lower is considered good.

The best windows have a rating of 0.1 cfm/ft or The best windows have a rating of 0.1 cfm/ft or lower.lower.

High-Performance™ Low Emissivity, Argon Blend Filled Window:Air Leakage: 0.15 cfm/ftU-Factor: 0.28.Solar Heat Gain Coefficient (SHGC): 0.43

Insulation (R-values put to Insulation (R-values put to use)use)

Insulation SpecsInsulation Specs

Insulation MaterialInsulation Material R-value per inch of R-value per inch of ThicknessThickness

Batt-typeBatt-type 3.1 to 3.53.1 to 3.5

Loose fillLoose fill 2.9 to 3.72.9 to 3.7

Board stockBoard stock 3.5 to 6.23.5 to 6.2

Spray-typeSpray-type 3.5 to 6.03.5 to 6.0

Rigid Foam InsulationRigid Foam Insulation

HVACHVAC

The average air conditioned home uses 2000 kWh The average air conditioned home uses 2000 kWh per year.per year.

The efficiency of Central A/C units is governed by The efficiency of Central A/C units is governed by U.S. law and regulated by the U.S. Department of U.S. law and regulated by the U.S. Department of Energy.Energy.

The Seasonal Energy Efficiency Ratio (SEER) is The Seasonal Energy Efficiency Ratio (SEER) is defined as the total cooling output (in Btu-British defined as the total cooling output (in Btu-British thermal units) provided by the unit during its normal thermal units) provided by the unit during its normal annual usage period divided by its total energy annual usage period divided by its total energy input (in Watt-hours) during the same period.input (in Watt-hours) during the same period.

The minimum SEER allowed by law for a central A/C The minimum SEER allowed by law for a central A/C is 10.is 10.

The best available SEER is about 18.The best available SEER is about 18.

Water (not addressed in the energy star Water (not addressed in the energy star program)program)

When buying shower heads, look for low When buying shower heads, look for low GPM (gallons per minute).GPM (gallons per minute).

ToiletsToilets

Light Bulbs – Compact Light Bulbs – Compact Florescent Bulbs (CFLs)Florescent Bulbs (CFLs)

25 watts used is the equivalent of a 100 W

bulb

ConclusionConclusion

New construction Energy Star Homes make sense New construction Energy Star Homes make sense because during construction upgrade costs are because during construction upgrade costs are nominal.nominal.

Upgrades to existing homes have a cost benefit if the Upgrades to existing homes have a cost benefit if the life of the product is taken into account.life of the product is taken into account.

Keep in mind that Energy Star Homes take advantage Keep in mind that Energy Star Homes take advantage of current technologies used in efficient ways; no solar of current technologies used in efficient ways; no solar or wind power (but maybe back at the power plant!)or wind power (but maybe back at the power plant!)

Energy Star improvements will increase resale value Energy Star improvements will increase resale value of homes.of homes.

With a hybrid in the driveway and an energy star With a hybrid in the driveway and an energy star home, who wouldn’t want to be your friend?!home, who wouldn’t want to be your friend?!