The Energy Star Home by bjdpkx

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									The Energy Star Home

     Drew Tepper
                     Overview
   What is an energy star home?
   New Homes
   Existing Homes
       Windows
       HVAC
       Insulation
       Plumbing
   Conclusion
    What is an energy star home?
   “More home for less money than standard homes.”
   Energy Star labeled homes are at least 30% more
    energy-efficient than standard homes.
   Use reliable and established technologies and building
    practices to operate significantly more efficiently than
    homes built to the Model Energy Code.
       These technologies and practices save the owners of Energy
        Star homes money on their utility bills.
       They provide a home that’s more comfortable, more durable,
        environmentally friendly, and cheaper to own.
   To receive an Energy Star label, homes must undergo a
    third party evaluation of their energy efficiency.
Standard Home                           Energy Star
                                      Labeled Homes
$200,000             List Price       $203,000

$1,654          Monthly Mortgage      $1,679

$155             Monthly Utilities    $100

$1,809          Total Monthly Costs   $1,779

                 Monthly Savings      $30
                Model Energy Code
   The Energy Star standard for new homes is measured by
    the Home Energy Rating System (HERS) scoring.
   The HERS rating is a calculation of the energy efficiency
    of a home compared to an identical ‘house’ that meets
    the minimum requirements of the Model Energy Code
    (MEC).
       The HERS score will be between 0 and 100.
       The reference ‘house’ will have a score of 80.
   Each 5% reduction in energy usage will result in an
    additional point on the HERS scale.
   An Energy Star home must receive a score of at least 86
    on the HERS score.
Builder Option Packages (BOP Ratings)

   BOPs are a set of construction specifications for a
    specific climate zone.
   These specifications include performance levels for the
    thermal envelope, insulation, windows, orientation,
    HVAC systems, and water heating efficiency.
       The United States has been divided into 19 climate zones for
        purposes of BOP.
   A home built to BOP specs is not rated by the HERS
    system but still is subject to third party verification.
   BOP homes either pass or fail as Energy Star homes.
           New Construction
Tight Construction.
 There are hundreds of holes that penetrate the
  outside of a house.
 These occur due to gaps and holes from framing
  and penetrations for wiring, plumbing, and ducts.
 Air sealing combined with proper ventilation can
  reduce energy bills and eliminate unwanted drafts
  and pollutants.
         New Construction Cont.
Tight Ducts.
 Duct Sealing – typically ducts leak
   more than 35% of the air traveling
   through them before reaching a
   destination. Duct tape does not
   seal ducts adequately.
 Duct location – should only be
   placed where the air will be heated
   and cooled. Attics can reach
   above 150 F.
 Duct insulation – if used outside
   the living area.
 Duct Sizing.
      New Construction Cont.
Insulation.
 A continuous boundary of insulation is necessary
  between the inside and outside for a home to
  maintain temperature efficiently.
 Insulation must be installed carefully with no
  gaps, crimping, or compression, as these can
  allow unwanted air and heat exchange between
  the outside and inside.
               Old Construction
   Existing houses can be modified to meet
    Energy Star standards.
       Not necessary.
       Improvements can be made to increase
        efficiency.
   Windows.
   High-efficiency heating and cooling
    systems.
         Replacement Windows
   Windows typically
    make up 10 – 25% of
    a home's exterior wall
    area.
   Energy Star labeled
    windows are twice as
    efficient as the
    average window
    produced just ten
    years ago.
    U-factor, R-value and Solar Heat
            Gain Coefficient
   U-factor is the measurement of heat transfer
    through a given building material (such as
    glass).
   R-value depicts the resistance a material has to
    heat transfer.
   U-factor = 1/R-value
   The solar heat gain coefficient (SHGC) is a
    measure of the amount of solar energy that a
    glazing material allows to pass.
                   Window Facts
   In heating-dominated climates, windows account
    for up to 25% of a typical house’s heating load.
   In cooling-dominated climates, windows account
    for up to 50% of the same house’s cooling load.
   In recent years, many technological advances
    have improved the thermal performance of
    windows.
       These advances include low-emissivity and solar
        control coatings, low-conductance gas fills, improved
        thermal breaks and edge spacers, and better edge
        sealing techniques.
        What’s a good window?
   Windows can improves the thermal performance
    of homes by minimizing heat loss in heating-
    dominated climates and by minimizing solar heat
    gain in cooling-dominated climates.
   Windows with lower U-factors (higher R-values)
    perform better in heating-dominated climates
    while windows with lower solar heat gain
    coefficients (SHGC) perform better in cooling-
    dominated climates.
                 “Vacuum” can be filled with other gases
Thermal Window
                      Windows Cont.
     Air tightness (unconditioned air leakage into a house).
        A rating of 0.2 cfm/ft (cubic foot per minute of air
         leakage per linear foot of window edge) or lower is
         considered good.
        The best windows have a rating of 0.1 cfm/ft or lower.




High-Performance™ Low Emissivity, Argon Blend Filled
Window:
Air Leakage: 0.15 cfm/ft
U-Factor: 0.28.
Solar Heat Gain Coefficient (SHGC): 0.43
Insulation (R-values put to use)
              Insulation Specs
   Insulation Material      R-value per inch of
                                Thickness
Batt-type                3.1 to 3.5

Loose fill               2.9 to 3.7

Board stock              3.5 to 6.2

Spray-type               3.5 to 6.0
Rigid Foam Insulation
HVAC
   The average air conditioned home uses 2000 kWh per
    year.
   The efficiency of Central A/C units is governed by U.S.
    law and regulated by the U.S. Department of Energy.
   The Seasonal Energy Efficiency Ratio (SEER) is defined
    as the total cooling output (in Btu-British thermal units)
    provided by the unit during its normal annual usage
    period divided by its total energy input (in Watt-hours)
    during the same period.
   The minimum SEER allowed by law for a central A/C is
    10.
   The best available SEER is about 18.
Water (not addressed in the energy star program)


   When buying shower heads, look for low GPM
    (gallons per minute).
Toilets
Light Bulbs – Compact Florescent
Bulbs (CFLs)



                           25 watts used is the
                        equivalent of a 100 W bulb
Conclusion
   New construction Energy Star Homes make sense
    because during construction upgrade costs are nominal.
   Upgrades to existing homes have a cost benefit if the life
    of the product is taken into account.
   Keep in mind that Energy Star Homes take advantage of
    current technologies used in efficient ways; no solar or
    wind power (but maybe back at the power plant!)
   Energy Star improvements will increase resale value of
    homes.
   With a hybrid in the driveway and an energy star home,
    who wouldn’t want to be your friend?!

								
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