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Lower Cooling Bill-2 Ductwork & Air Leaks Sealing

Without Replacing Your HVAC System

(Most Of These Ways Also Lower Heating Bills)

©

This Is Part 2 — Click Here To Read Part 1:  AlsPlumbing.com Lower Cooling Bills 50+ Ways – Part 1.

Lower Cooling Costs — 75+ Ways. This is Part-2 Of Our Article About How To Lower Cooling Bill Without Replacing Your HVAC System.  NOTE: Most of these efforts also Lower Heating Bills. 

Al’s Plumbing, in Plano, Texas Provides Full-Service Plumbing; Maintenance, Repairs, and Replacements For Every Plumbing Component In Your Home. We sell and install gas and electric water heaters.  Al’s is near your home in; Murphy, TX; Rowlette, TX; and Wylie, Texas.  We service all homes in southern Collin County, TX, and northeastern Dallas County, TX with no additional travel charges.

Call Al’s Today To Discuss Any Concerns Or Problems You Have With Your Home’s Plumbing. 

We will arrange an appointment at your convenience.

What’s Discussed In Part-2:

    • 4. Ductwork Sealing Products — Durability Test Results.
    • 5. Aerosol Ductwork Sealing (for existing homes) — seals from inside the ductwork.
    • 6. Typical Home Air Leakage — Shown By Decade The Home Was Built

4. A 2000 Report: Ductwork-Sealing Products Durability

Lower Your Cooling Bill By Up To 1/3 — By Sealing Ductwork That’s 10+ Years Old.

These Sealing Products Were Tested

NOTE: Acceptable Duct Sealants Must Meet 1 of These 2 Underwriters Laboratories (UL) Standards:

  • UL-181A: For Use With Rigid Ductwork.
  • UL-181B: For Use With Flexible Ductwork.

Commonly Used Duct Sealing Products

  • Typical Duct-Tape: Rubber-based adhesive with a vinyl or polyethylene backing + fiber reinforcement.  FAILED WITHIN DAYS.
  • UL181B Cloth Tape:  Looks similar to standard duct tape — BUT is UL Rated as a ductwork sealant.  FAILED WITHIN 2 MONTHS.
  • Clear UL181B Tape: Has an acrylic adhesive & clear polyester backing.  This looks like packing tape — but is better.  It has the UL Rating as a ductwork sealant.
  • Foil Tape: Has an acrylic adhesive + metal backing.
  • Butyl Tape: Has butyl (synthetic) adhesive + metal backing.
  • Mastic: A wet adhesive (usually applied with a brush) that fills gaps.  It dries to a semi-rigid state (remains a little flexible).
  • Aerosol Sealant:
  • It’s applied to the leaks inside the ductwork –by blowing aerosolized sealant throughout the ductwork.
  • The sealant exits ductwork at leaks.
  • The sealant particles build-up (at the leak) — until the leak becomes sealed.

Testing Process:

The testing process was designed to create more stress than normal operating conditions.  The goal was to accelerate the aging/failure process.

  • Air Pressure Between 100–200 Pascals.  100 pascals = 40 mph wind.  200 pascals = 80 mph wind.
  • A furnace blower creates only 25 pascals of pressure.

And/Or

  • Heated to 140–200f degrees.
  • A furnace outputs air at 125f degrees.

Sealing Ductwork May Lower Cooling Bill By 1/3 Or More. 

Ductwork Sealants Tested — Durability Results

The 2 Sealants Just Below Are Unacceptable:

Common Duct-Tape:   

  • Failed within 3 days. 

UL181B-FX Cloth Tape:  Similar to duct tape — BUT has UL Rating for duct sealant.

  • Failed within 10-60 days. 

 

The 3 Sealants Just Below Are Considered To Have GOOD Longevity:

Butyl Tape

Foil Tape

Clear UL181B Tape

  • These 3 Did not fail within the testing period.

 

The 2 Sealants Just Below Are Considered To Have EXCELLENT Longevity:

Mastic:

  • Mastic showed NO visible nor measurable signs of degradation during the testing period. 

Aerosol: 

  • Aerosol (blown inside ductwork) showed NO visible nor measurable signs of degradation during the testing period. 

Source: http://can-best.com/index_files/Wind%20Speed%20Pressure%20Conversion.pdf

Source: https://www.aceee.org/files/proceedings/2000/data/papers/SS00_Panel1_Paper23.pdf


5. Likely The Best Way To Seal (existing) Ductwork & Lower Cooling Bill 

Is To Seal Air Leaks From Inside The Ductwork. 

During the 1990s — Lawrence Berkeley National Lab (LBNL) scientist Dr. Mark Modera & engineer Duo Wang developed an easy way to seal ductwork.  It uses Airborne Adhesive Particles to seal leaks from inside the ductwork.   This provides an excellent opportunity to lower cooling cost in an existing home.

Ductwork is put under higher pressure than a furnace blower creates.  This forces the sealant’s adhesive particles into hard-to-find leaks and seals them.  This is at a lower cost, and with less disruption to the homeowner.

  • Dr. Modera’s startup company: Aeroseal licensed the system in 1997 for homes.
  • In 2003, the Aeroseal system was developed for commercial buildings.
  • Aeroseal’s System has been proven to seal from 70%–90% of ductwork leaks.
  • Aeroseal’s System comes with a 10-year guarantee.
  • Aeroseal has been durability-tested to 40+ years lifespan.

An AEROSEAL Case Study: A Cincinnati, OH Home

  • Before: 
    760 Cubic Feet per Minute (CFM) of air leaked from the home’s ductwork.
  • After AEROSEAL:
    46 Cubic Feet per Minute (CFM) of air leaked from the home’s ductwork.
  • Ductwork Air Leakage Was Reduced By -94%

The homeowner was on a fixed billing plan for both gas & electricity.

  • Before Ductwork Sealing:  She paid $275 / month.
  • After Ductwork Sealing:  She pays $159/ month.
  • Gas & Electric Monthly Bill Dropped by -58%

Source: https://aeroseal.com/case-study-cincinnati-ohio/

NOTES:

  • If ductwork has come apart — inside ductwork sealing can’t fix that (lower cooling costs won’t be achieved).
  • First, a visual inspection must be performed — before ductwork sealing.

Attic Ductwork That’s Come Apart. #1

Attic Ductwork That’s Come Apart. #2

Source: https://ipo.lbl.gov/berkeley-lab-duct-sealing-innovation-saves-energy-in-buildings-around-the-world/

NOTE: There Are Likely Other Companies/Brands with Ductwork-Sealing Services.

Al’s does not endorse any specific ductwork-sealing service or process — only because we don’t have first-hand knowledge of all that’s available.



6. Typical Home Air Leakage — Shown By Decade The Home Was Built

(NOTE: This Section Is Not About Ductwork Leakage.)

Reducing Air Leakage In A Pre-2009 Home.

Can Lower Cooling Bill (& heating costs) By Up To 1/2.

1970's built home

Image Source: Shutterstock

 Typical 1960s–1970s Built Homes Leak Nearly Double The Air That’s Needed For Acceptable Ventilation.

When The U.S. Homes Began Incorporating Energy-Saving Building-Materials & Construction-Standards (details below).

Energy Saving Efforts Began In The Mid 1970s:

  • In Oct. 1973 — The Oil Producing & Exporting Countries (OPEC) — placed a (politically inspired) oil embargo on the U.S.
  • Oil production was decreased — to increase oil prices, and maintain OPEC’s profits.
  • U.S. Crude Oil prices rose nearly 400% higher (than before the embargo  — from $2.90 to $11.75 per barrel).
  • In 1979 the 2nd Oil Crisis occurred.  It was caused by a drop in oil production due to the Iranian Revolution.
  • Over the next 12 months — crude oil prices rose nearly 100% (from around $20 to nearly $40 per barrel).
  • 41 Years Later: At the end of 2021 — crude oil prices were around $75.

How Warm Air Leaks Into/Out Of A Home — Based On The Season

  • Thermodynamics is the word used to explain that Heat Moves Toward Cold Year-Round — until everything’s the same temperature.
  • During Winter, heat exits the home through leaks in the ceilings (at light fixtures).
  • During Winter, cool air enters the home — where walls meet floors and at electrical outlets & light switches.
  • During Winter, heat radiates outward from ceilings, exterior walls, & windows.
  • In Summer — these 3 conditions reverse.

How Much Can Weatherization (add insulation & make a home more airtight) Help Lower Cooling Bill (and heating)?

These Government Agencys’ Numbers Below Speak For Themselves

NOTE: Higher Air Exchange Rates Occur Where Colder Winter Temperatures Are Common.

  • The average weatherized home lowered energy costs from -19% to -42%.

Source: (Vermont) https://www.healthvermont.gov/sites/default/files/documents/pdf/ENV_CH_WxHealthReport.pdf

  • Participating homeowners in a Home Energy Savings Program (HESP) will lower their heating bills by up to -41%.

Source: (Maine) https://www.efficiencymaine.com/energy-efficiency-best-way-to-save-on-heating-expenses/

  • A weatherized home reduces energy by an average of -35%.

Source: (Missouri) https://www.spireenergy.com/weatherization

  • Participating households average nearly -35% lower home energy costs. 

Source: (Utah) https://jobs.utah.gov/housing/scso/wap/index.html

  • Weatherization reduced home energy costs by -20 to -30%

Source: (Ohio) https://hapcap.org/housing/weatherization/

  • Low-Income Home Energy Assistance Program reduced home energy costs by -23%.

Source: (Vermont) https://auditor.vermont.gov/sites/auditor/files/documents/Keeping%20Warm%20Report%20-%202002.pdf

  • On a typical low-income home — weatherization lowers home energy costs by -35%.

Source: https://www.nrel.gov/docs/fy11osti/51242.pdf


HOW MUCH Air Existing Homes Leak — By Decade Built

ACHn = Air Change per Hour naturally (through air leaks). 

(This number isn’t the Blower-Door Test result.)

Lower Cooling Bills (and heating costs) — By 1/2 Or More By Reducing Air Leakage.

  .35    Slightly Over 1/3 Of An Air Change (indoor air exchanged with outdoor air) is required each hour — To Ensure Acceptable Indoor Air Quality (IAQ)

ACH Decade Home Was Built  

1.29  Before 1940 (just over 1-1/4 ACHn — or nearly 4 times what’s needed)

  .7        1941–1959  (double what’s needed)

  .6       1960–1969   (175% of what’s needed)

  .6       1970–1979   (175% of what’s needed)

  .475  1980–1989  (125% of what’s needed).

 .375   1990–1999   Weatherization isn’t needed.  Seal obvious leaks (like under exterior doors).

  .15    2000-2011  Home Built too Airtight. (Consider leaving a bathroom vent fan on 24/7).  Some 2000-2011 homes may have Mechanical Ventilation.

 .35    2012  Mechanical Ventilation Became Required By Building Code.  To ensure .35 (just over 1/3) Air Changes per Hour (ACH).

 

Today’s Building Codes Dictate That No More Than 3 Air Changes per Hour (ACH) — During A Blower Door Test 

  • A Blower Door Test — simulates a 20 mph wind blowing on 1 side of the home.
  • BUT — how does a Blower Door Test result convert to air change per hour value under natural conditions (at various wind speeds, or when no wind is blowing?
  • The term for that is “Natural” air leakage.  It’s represented as Air Change per Hour naturally (ACHn)
  • Blower Door Test Result DIVIDED By 20 = Air Changes per Hour – natural (ACHn).
  • Example: ACH50 (during blower door test) = 3ACH Divided By 20.15 ACHn
  • Building Codes require today’s new homes to be built too tight to ventilate themselves enough.
  • This is why new homes must have Mechanical Ventilation (more on this later within this article).

Source: https://inspectapedia.com/Energy/Pascal_Calculations.php


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Lower Cooling Bill-2 Ductwork & Air Leaks Sealing

Without Replacing Your HVAC System

(Most Of These Ways Also Lower Heating Bills)

This Is Part 2 — Click Here To Read Part 1:  AlsPlumbing.com Lower Cooling Bills 50+ Ways – Part 1.

This was Part-2 Of Our Multi-Part Article That Details 75+ Ways To Lower Cooling Cost Without Replacing Your HVAC System.   Al’s Plumbing, in Plano, Texas provides full-service plumbing; maintenance, repairs, and replacements for every plumbing component in your home.

We sell and install gas and electric water heaters.  Al’s is near your home in; Plano, TX; Allen, TX; Frisco, TX; and McKinney, Texas.  We service all homes in southern Collin County, TX, and northeastern Dallas County, TX with no additional travel charges.

Call Al’s Today To Discuss Any Concerns Or Problems You Have With Your Home’s Plumbing. 

We will arrange an appointment at your convenience.

This Is Part 2 Of Our Article:  Click Here To Read Part 1: AlsPlumbing.com 75 Ways To Lower Cooling Costs Part 1