This article is about ENERGY STAR CERTIFIED HOMES.  Additionally, we compare Energy Star standards to existing DFW homes, and discuss ways to make your current home notably more energy efficient. 

Al’s Plumbing, Heating & A/C, in Plano, Texas provides full service plumbing maintenance, repairs and replacements for every plumbing component in your home.  Al’s sells and installs Rheem Professional Series gas & electric water heaters, and tankless water heaters.  Al’s Plumbing, Heating & A/C is near your home in Plano, Allen, and Frisco.  We service all homes in southern Collin and Denton Counties with no additional travel charge.

Image Source: Pixabay.com

Energy Star Homes

Energy Star Certified Homes are designed and built to keep energy bills low.  This is done with a combination of; insulation, air-leakage control, high efficiency windows & exterior doors, higher efficiency HVAC Sytem & appliances plus other energy saving measures.

New Energy Star Certified homes use up to 30% less energy than a typical new home.  Energy Star Certified homes undergo a process of inspections, testing, and verification to ensure they meet strict requirements set by the EPA.

To earn the ENERGY STAR Home Certification, the home must be meet certification requirements based on Regional Specifications.  The minimum standards for energy efficiency become more higher for each region farther north in the U.S.

Home Energy Rating System (HERS)

Part of the Energy Star Certified Home requirements is obtaining its HERS Score.  HERS stands for Home Energy Rating System. 

The HERS Score compares the specific HERS Certified home to a similarly-sized home built to today’s Building Codes.  The HERS Index calculates a home’s energy efficiency.  The lower the HERS score is, the higher the home’s energy-efficiency is.

Working with a Certified Home Energy Rating System (HERS) Home Energy Rater, Home Builders select the energy efficiency measures for the home.  Different homes, or homes in different areas of the U.S., will have different energy efficiency measures.

Example:  In southern states, most new homes have a Radiant-Heat Barrier in the attic.  This would not be added in the northern U.S.

Then the selected home’s proposed Energy-Saving Features are entered into a RESNET Home Energy Rating Software.  The resulting HERS Score is verified as meets or exceeds the HERS Index Target.   Once the home is completed, it is tested to ensure it meets or exceeds its HERS target score.

To get a HERS score, the completed house must be tested & verified by a certified RESNET Home Energy Rater.  The process is extensive and costs $1,500 — $3,000.  Energy-saving improvements leading to a good HERS score will lower the home’a energy bill and add to the home’s value.

Click Here To See A Comparison Of Heating / Costs For Various HERS Scores: Heating / Cooling Costs For Various HERS Scores

Click Here To See An Example Of A HERS Label Used By A Home Builder: HERS Label Used By A Home Builder

Image Source: Pixabay

Requirements For Energy Star Homes

In DFW (Climate Zone 3)

Copy The Link Below To See The Official Energy Star Certified Checklist From The U.S. Department Of Energy (DOE). 

https://www.energystar.gov/ia/partners/bldrs_lenders_raters/downloads/ES%20NPR%20v83%202015-07-07_clean_508.pdf?1b44-b5fd

Click Here To See The Blue Label An Energy Star Qualified Home Has: Label For Energy Star Qualified Home

Note 1: The Energy Star Certified Home Requirements Shown Below Can Assist You As To How To Upgrade Your Existing Home To Maximize Its Energy Efficiency.

Note 2: Older homes cannot not be upgraded to be as as air-tight as new Energy Star Certified homes.   In order for the home to be that air-tight, it would have had to be built much differently than homes were built in the past.

• The U.S. EPA states that air-sealing an existing home can result in up to a 15% reduction in cooling & heat costs.  Actual savings depends on the age of the home.

• The EPA states that adding insulation can result in up to a 10% reduction in cooling & heating costs.  Actual savings depends on the home’s age & existing insulation.

Note 3: With a Blower-Door Test, you can determine where your home is leaking air.  Sealing those leaks will result in a notable decrease in how much air the home leaks, and reduce cooling & heating costs.

Energy Star HVAC SYSTEM Requirements For Climate Zone 3 (Includes DFW)

Energy Star Certification allows the Home Builder the flexibility to select which Energy-Saving measures are used in each home.  The total of the Energy-Saving measures for any individual home must meet Energy Star requirements.  In the southern U.S. the home may have a higher efficiency A/C (SEER-14.5) than required by Building Code (SEER-14)  In the northern U.S., a home may have a higher efficiency furnace (92-96%) than required by Building Code (90%).

Click Here To See The U.S. Map Of Climate Zones:  Climate Zone Map For U.S.

• SEER-14.5 Central A/C.   SEER-14 is minimum efficiency a newly installed A/C in DFW.
• 80% Efficient Gas Furnace — this is a Standard-Efficiency Furnace.   High-Efficiency furnaces are 90% — 96% efficient.

• The EPA states that attic ductwork accounts for 25% of lost heated / cooled air. **
• A notable portion of heated / cooled air is lost due to leaking ductwork in the attic.
• Energy Star Certification allows ductwork to be located in the attic in Climate Zone 3 (includes DFW).
• Energy Star requires attic ductwork to have at least R-8 insulation.  This is the same as Texas Building Code.

One New Home Design Has Ductwork Located Between

The Rooms’ Ceilings & The Attic Floor (with attic insulation above).

Copy This Link To See A Photo Of A Home Under Construction Being Built This Way:  https://www.probuilder.com/lessons-learned-bringing-ducts-inside

In A Typical DFW Home, The Ceilings Are Also The Attic’s Floor.

Click Below To See A Thermal Image Of A Ceiling Showing Were Insulation Is Missing Or Not Adequate:

Ceiling Thermal Image Shows Missing / Insufficient Attic Insulation

The thermal image was taken during summer.  Yellow is where the ceiling is hottest.  Dark Purple is where the ceiling is coolest.

During summer in DFW, attic temperatures can reach 170 degrees.  If there are areas of missing insulation, only the ceiling drywall is between the attic and living space which is as much as -100 degrees cooler.

Why Attic Insulation Is So Important In Your Existing Home. 

Today’s building code requires R-38 insulation value for the attic.  A DFW home built in the 1950’s was not required to have any attic insulation.  A DFW home built in 1970’s required only R-19 attic insulation.    Additionally, blown insulation settles over time, plus it’s common for workers to kick insulation out of their way while in the attic.

The EPA states that adequate attic insulation will lower cooling & heating bills by up to 10%.  The savings will pay for the insulation over time.  Additionally, your HVAC System will also last longer because it doesn’t need to run as much.  You will also be more comfortable, with fewer hot / cold spots in your home.

Current New Home Building Codes In Texas

• Most older DFW homes have ductwork (and many have the furnace) in their attic.
• The 2018 International Energy Conservation Code (IECC) allows both the furnace & ductwork to be in the attic. ***
• Texas Building Code is based upon the 2018 IECC.
• Supply-Air ducts in attics must be insulated to a minimum of R-8 (same as Energy Star). ***

** Source: https://www.energycodes.gov/sites/default/files/documents/cn_ducts_in_conditioned_spaces.pdf

*** Source: https://www.probuilder.com/lessons-learned-bringing-ducts-inside

WATER HEATER

• Energy Star Home Gas 50-Gallon Water Heater: 0.59 EF.    EF stands for Energy Factor.
• Energy Star Home Electric 50-Gallon Water Heater:  0.92 EF.
• These are standard efficiency water heaters.

* Source: http://hes-documentation.lbl.gov/calculation-methodology/calculation-of-energy-consumption/water-heater-energy-consumption/water-heater-energy-factor

AIR LEAKAGE & VENTILATION

SHOWN: Blower Door Testing Equipment

• Energy Star Homes must have Comprehensive Air Sealing.
• The test for air leakage is called the “Blower-Door Test” — which refers to the equipment used to test the home.
• Energy Star Homes in CZ-3 Must Have No More Than 5 Air Changes Per Hour (ACH) during a Blower Door Test.
• A DFW home built during the 1970’s ranges from 17 — 50 Air Changes Per Hour (ACH) during a Blower-Door Test. *3

Notes:

• A home cannot be completely air-tight.  This would cause pollutants & humidity to build up, resulting in unacceptable Indoor Air-Quality.
• If a home is too air-tight, mechanical ventilation is required to ensure adequate ventilation for acceptable Indoor Air-Quality.

This Is Why It’s Important To Insulate & Seal Air Leaks In Your Existing Home. 

The EPA States:

• Sealing air leaks will reduce cooling & heating bills by as much as 15%.
• Adequate Insulation (R-38 in attic in DFW) will reduce cooling & heating bills by as much as 10%.
• These two measures can how an existing DFW home’s energy consumption by up to 25%.  The older the home, the higher your savings will be.

DFW Insulation Building Codes Over The Years

Today:

• R-38 in the attic
• R-15 in the walls
• R-19 in the floors

Notes:

• Blown attic insulation settles over time.  More may be needed to ensure adequate insulating value.
• Workers often kick attic insulation out of their way while working in the attic.  Check your attic to see if this has occurred.

Attic Insulation                Wall Insulation

• 1950’s:     None           None
• 1965-70: R-13             R-6
• 1970’s:    R-19             R-6    *3
• 1980’s:   R-30             R-13  *4
• 2014:      R-38             R-15   *5

*3 Source: https://snuggpro.com/blog/item/many-homes-built-prior-to-1980-were-built-without-insulation-in-the-walls

*4 Source: https://www.jlconline.com/how-to/insulation-code-change_o

*5  As required by the 2012 Edition of the International Building Code (IBC)

ENERGY STAR HOMES WINDOWS

• Energy Star Home Window U-Value: 0.30 in CZ 3.  U-Value represents how much heat exits the home through the window (glass + frame). **
• This means Energy Star home’s windows cannot allow more than about 30% heat-loss during the winter.

• Window SHGC: 0.25 in CZ 3    SHGC indicates how much of the sun’s heat striking the window enters the home. **
• This means Energy Star home’s windows cannot allow more than 25% of the sun’s heat to enter the home through the windows.

• Converting U-Value + SHGC-Value TO R-Value, an Energy Star window is approximately R-3. **

• For older existing homes, the EPA states:
• 10%–15% of a home’s total energy loss is through its windows.
• 30% of a home’s total heat is lost through windows during winter.
• 75%+ of of the sun’s heat enters the home through the windows during summer.

A Typical 1970’s DFW Home:

• Has single-pane glass & aluminum-frame windows.
• U-Value = 1.1  This means the windows allow nearly 90% heat-loss during winter. 
• SHGC =.71  This means the windows allow 71% of the sun’s heat into the home through the windows during summer.
• A 1970’s DFW home’s common windows have a R-Value of <1 (R-0.9).   Note: R-0 would be a hole in the wall.
• This comparison does not take into consideration older windows that leak air due to worn out weatherstripping.

* Source: https://www.architectmagazine.com/technology/products/the-latest-highly-insulating-windows-are-almost-as-efficient-as-a-wall_o

** Source: https://www.energy.ca.gov/title24/archive/2001standards/residential_manual/res_manual_form_s.PDF

*** Source: https://www.greenbuildermedia.com/buildingscience/window-film-a-cost-effective-window-retrofit

**** Source: https://www.energy.gov/energysaver/energy-efficient-window-attachments

Should You Replace Or Upgrade Your Existing Windows?

• Replacing windows will have less effect on cooling & heating bills than increasing attic insulation or sealing air leaks.
• There are modestly priced Energy Star Rated, Low-E, Windows Available From Window World Of Dallas for $265.00 each.
• This price includes installation & full size screens.

Note: This is not an endorsement for Window World only because we don’t have knowledge of all replacement window offerings.

Upgrades To Existing Windows:

• Adding Solar-Film to existing single pane glass windows (that face south or west) can reduce the sun’s heat gain from 71% to as low as 45%. ***
• This would be a 2/3 reduction in heat gain through the glass.  The heat gain through the metal frame remains the same.
• Solar film blocks the amount of light coming through the glass.  If there is a 2/3 reduction in heat gain, there is a 2/3 reduction in light coming through.
• This is why north and east facing windows are not ideal for solar film.

To reduce heat gain through both the glass + frame, full size solar-screens are available (instead of solar film on only the glass).

• One website (*5) offers screens that reduce heat gain through the windows by; 65%, 80%, 90% & 95%.
• The full-size screen also minimizes heat gain or loss through the metal frame.
• The more sun is blocked, the more the screen darkens the room:
• The 65% Solar Screen states it’s 32% open.  So it’s blocking 2/3 of the light.
• The 95% Solar Screen states it’s  5% open.  It’s blocking 95% of the light.

Note: This is not an endorsement for Metro Screen Works only because we don’t have knowledge of all replacement window offerings.

*5 Source:  https://www.metroscreenworks.com/solar-screens-for-windows/?gclid=Cj0KCQjwrdjnBRDXARIsAEcE5Ym5UAQSBr5f3E4RiOOVm8EQxO2pmkE4nlARNDwASJOQ9pjQjebOR5UaAtaOEALw_wcB

APPLIANCES

• Energy Star rated refrigerator required.   An Energy star model will save $6.00 per year as compared to a new, non-certified model.
• Energy Star rated dishwasher required.   An Energy Star model with save $35.00 per year as compared to a new, non-certified model.
• Energy Star rated ceiling fans required.

Click Here For An Article About Energy Star Products For Homes: AlsPlumbing Energy Star Products For Homes

ENERGY STAR HOMES LIGHTING

• Energy Star LED light bulbs (85% efficiency) are required:

Shown: Incandescent, Fluorescent & LED Light Bulb

Image Source: ShutterStock

Does It Really Make Much Difference Which Type Of Light Bulbs You Use? 

YES.  The details are below, with the Total Cost shown for 25,000 hours.

NOTE:  The electricity cost shown below is for only the light bub(s).  Add to that the cost of having A/C remove the heat created by the light bulbs.

Incandescent Bulbs:

• Incandescent Bulbs convert 10% of the electricity into light.   10% is converted to light.  90% is converted to heat.   That heat must be removed by the A/C.
• 60 watts of light requires a 60-watt bulb.
• $150.00 to power the 60-watt incandescent bulb for 25,000 hours (at 10 cents per kWh).
• Incandescent bulbs last around 1,200 hours.
• 21 incandescent bulbs will be used to provide 25,000 hours of service.
• $21.00 for 21 bulbs to provide 25,000 hours (@ $1.00 per bulb).
• $171.00 Total Cost for electricity + 21 incandescent bulbs = $197 Total Cost for 25,000 hours.

CFL Bulbs:

• Compact Fluorescent (CFL) bulbs create heat from 80% of electricity consumed.  20% is converted to light.  80% is converted to heat.
• 60 watts of light requires a 14-watt CFL bulb.
• Compact Fluorescent (CFL) bulbs use 25-35% less electricity than incandescent bulbs.
• $35.00 to power the 60-watt (equivalent) CFL bulb for 25,000 hours (at 10 cents per kWh).
• These bulbs last around 10,000 hours.
• 2.5 CFL bulbs needed to provide 25,000 hours of service.
• $5.00 for 2.5 bulbs to provide 25,000 hours (@ $2.50 per bulb)
• $40.00 Total Cost for electricity + 2.5 CFL bulbs = $40.00 Total Cost for 25,000 hours.

LED Bulbs: 

• LED bulbs create heat from 15% of the electricity consumed.  85% is converted to light. 15% is converted to heat.
• 60 watts of light requires an 8.5-watt LED bulb.
• LED bulbs use around 85% less electricity than incandescent bulbs.
• $21.25 to power the 60-watt (equivalent) LED bulb for 25,000 hours (at 10 cents per kWh).
• These bulbs last around 25,000 hours.
• 1 LED bulb needed to provided 25,000 hours of service.
• $5.00 for 1 bulbs to provide 25,000 hours (@ $5.00 per bulb).
• $26.00 Total Cost for electricity + 1 LED bulb = $ 31.00 Total Cost for 25,000 hours. 

While the cost for LED bulbs is higher at first, they save 3/4 of the electricity that would be used by incandescent bulbs.  Because LED bulbs last far longer, the cost for the bulbs becomes much lower over time.

Note: Today, LED bulbs are notably less expensive than what’s shown in this comparison.  WalMart sells a 4 Bulb Package Of 60-watt LED bulbs for $5.98 ($1.50 each).

**Source: https://learn.eartheasy.com/guides/led-light-bulbs-comparison-charts/

Al’s Plumbing, Heating & A/C, in Plano, Texas provides full service plumbing maintenance, repairs and replacements for every plumbing component in your home. Al’s sells and installs Rheem Professional Series gas & electric water heaters, and tankless water heaters.  Al’s Plumbing, Heating & A/C is near your home in Wylie, Murphy, and  Rowlette, TX.  We service all homes in southern Collin & Denton Counties with no additional travel charge.