75+ Ways To Lower Cooling Costs — Without Replacing HVAC

-Plus Many Ways Also Lower Heating Costs-

This Is Part 2 Of Our 5-Part Article:  Click Here To Read Part 3: Part 3 of Our 5-Part Article

— Seal Air Leaks —

Air Leakage In Older Homes – Continued From Part 1.

(Page 23 of the report) **

The Berkeley National Lab (a respected research organization) Collected Air-Leakage Results From 147,000 Homes (8,512 were in Texas).

      Year Built       Air Leakage Rate 

  • Prior to 1960      70%   of (cooled/heated) indoor leaked from the home each hour (35% per hour is needed).  The home exchanges all indoor air (with outdoor air) every 1.3 hours
  • 1960–69              59%
  • 1970–79               58%
  • 1980–89              48%
  • 1990–99              37%  Homes built 1990-1999 leak just over the 35% needed.  No Weatherizing Needed.  If weatherized, the home would then need mechanical ventilation.
  • 2000 and after   31%  Homes built 2000 leak less than the 35% needed.  No Weatherization Needed.   These homes typically have mechanical ventilation.

** Source: (Berkely Report)

On A Side Note — Why Your Home Is Less Comfortable On Windy Days

  • The wind forces air into the side of the home facing the wind.
  • The wind pulls air out of the home on the opposite side.
  • These create negative pressure inside the home — which increases air leakage.

Most DFW Homes Have Attic Ductwork.  Attic Ductwork Homes Homes Typically Leak In More Air (than homes with ductwork inside living space)

ductwork for hvac system

Image Source: Shutterstock

When Attic Ductwork Leaks:

  • The furnace draws in Return-Air (through the large grills that can’t be turned off).
  • Some of the (newly cooled/heated) Supply-Air (that comes out vents than can be turned off) — leaks into the attic and is lost.
  • Then the home leaks in more outdoor air — to make up for air lost in the attic.

Note: To prevent this — you must seal ductwork air leaks.  There are many services that do this.

hvac return air grille  ceiling air supply vent for hvac Ceiling Supply-Air Vent

Leaking Attic Ductwork Increases Cooling/Heating Bills In 2 Ways

  • Newly Cooled/Heated air goes into the attic.
  • To make up for the air lost in the attic — the home leaks more air outdoor air in.  Then that air must cooled/heated.

Seal Air Leaks — Reduction In Air Leakage After Weatherization:

(Page 39 of report)

  • The intent of weatherization is to make the home as airtight as is realistically possible  ***
  • The more air a home leaked before weatherization — the more air it will still leak afterward.
  • This is because there’s a limit to how much any home can be tightened.
  • Based on initial blower door test results —  there is a suggested air leakage amount to expect after weatherization.  ***


  • No existing home can be made as airtight as a new home.
  • To be as airtight as a new home — an existing home would have to have been built differently.
  • This is because home-building practices have improved over time.

*** Source:

Seal Air Leaks.  A High-Profile Improvement In Home Building Practices Is The Addition Of “House Wrap”

Since 2006, House Wrap Has Been Required By International Building Code

The 2018 International Residential Building Code Says:

  • Exterior walls must prevent water from accumulating inside them.
  • If water gets inside the wall — the wall must allow the water to drain/evaporate.
  • House Wrap helps to create a water-resistant barrier under the exterior finish (brick, stucco, siding, and others).
  • House Wrap helps minimize water or moisture entering the exterior walls.
  • House wrap allows any moisture to exit the outside walls.
  • House wrap also helps to minimize air leaks.
  • This reduces air leakage into the home.
  • Most (if not all) House Wraps are made with some variation of spun-bonded, high-density, polyethylene fibers.

Before 2006 House Wrap was not required by building code — though some home builders chose to install it.

home with tyvek house wrap added

Image Source: Shutterstock

Shown: See The (white) House Wrap On This New Home Under Construction

1970's built home

Image Source: Shutterstock

Homes Built During 2005 And Earlier Were Not Required To Have House Wrap.

Seal Air Leaks

23,100 Homes Had Air-Leakage Measured

Before & After Professional Weatherization Efforts

Year Home Was Built     Reduction In Air Leakage

Prior to 1960                          -124%

1960–69                                  –87%

1970–79                                  -83%

1980–89                                 -50%


1990–99                                 -15% Homes built 1990-99 leak 37% — just over the 35% needed.   If they were weatherized — then they would need mechanical-ventilation to be added.

2000 & later                     no change

  • The older the home — the more weatherization reduced air leakage.
  • In homes built in 1990 and later — there is no need for additional weatherization.   They were built tight enough.


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

  • Thermodynamics is the word used to explain that Heat Moves Toward Cold — until everything’s the same temperature.
  • During winter — heat exits the home through leaks in the ceilings (at light fixtures) & walls (at electrical outlets and light switches).
  • Also, heat radiates from ceilings into the attic — because the attic is cooler than inside the home.
  • Heat radiates from walls to outdoors — because outdoor air is cooler.
  • During summer — heat enters the home through leaks in the ceilings & walls.
  • Heat radiates through the ceilings and into the living spaces — because the attic is hotter than inside the home.
  • Heat radiates from walls to outdoors — because outdoor air is warmer.

If You Do Only 2 Things To Reduce Cooling & Heating Bills — Do These

photo of blown insulation in an attic

Image Source: Shutterstock

  • Insulate The Attic — To R-38.  R-38 is the Texas’ Building Code for attic insulation in newly built homes.

Click Here To See A Thermal-Image Showing An Attic Temperature Of 170 Degrees: Thermal Image Of Attic At 170 Degrees

Note: The 170 Degrees Reading Is Near The Right Side Of Image — Just Above Where The Image Turns From Yellow-Green TO Red.

  • During DFW summer — DFW attic temps can reach up to 170 degrees.  That’s +90–100 degrees hotter than inside a typical home.
  • More attic insulation (if needed) reduces the amount of heat radiating from the hot attic (into the home) during summer.
  • During winter — attic temps are similar to outdoor temps, especially at night.
  • More attic insulation (if needed) reduces the amount of heat radiating (from the home) into the cool attic during winter.

blower door test

Shown: Temporary “Blower-Door” Used To Test A Home For Air Leaks

Image Source: Shutterstock

  • Seal Air Leaks in the ceilings (at light fixtures) to prevent hot air entering the home during summer — and warm air exiting the home during winter.

WHERE Homes Leak Air — Locate & Seal Air Leaks At These Locations

  • 31% Seal Gaps or Openings in; Floors, Walls, & Ceilings.   Sealing ceiling openings provides the most benefit — plus ceilings have the least number of openings.
  • 15% Ductwork — Seal Attic Ductwork leaks to prevent cooled/heated air going into the attic.    TIP: There are many services that seal ductwork.
  • 14% Fireplace — Damper left open, or a damaged damper that can’t close correctly.  Always close the damper once the fireplace has completely cooled.
  • 13% Plumbing Penetrations Through Walls.
  • 11% Around Exterior Doors.
  • 10% Windows.  Note: Windows leak along the top, sides, & bottom of the moving parts (that open & close the window).
  •  2% Wall Electrical Outlets & Switches

Source: U.S. Department Of Energy (DOE)

Seal Air Leaks

Sometimes They’re Hidden — Sometimes They’re In Plain Sight

Seal Air Leaks At Recessed Ceiling Lights

recessed light

Image Source: ShutterStock

Older Recessed Lights Have Air Vents To Allow Heat (from the bulb) Out.  These lights leak air into/from the attic 24/7.  Newer Fixtures Are Sealed.

In The Photo Below — You Can Also See An Unsealed Gap Around The Entire Fixture.

Image Source: YouTube Embedded Link.

Click On White Arrow At The Center Of Image To View Video.

Shown: Old, Recessed, Ceiling Lights Have Vent Holes — To Allow Heat From The Bulb To Escape.

An Inexpensive & Easy Way To Retrofit Existing Recessed Light Fixtures

Image Source: Embedded Link

Click On Image To: View Product, Read Details, or Purchase From

Note: The home’s original recessed light fixture remains in place.

  • Remove & discard the ceiling trim-ring of the old fixture.
  • The new fixture screws into the old fixture — just like a light bulb.
  • Then the new light is pushed into place (inside the old fixture).
  • For best results – add caulk for an air-tight seal.

If Adding Caulk:

  • Apply the caulk along the inside edge of the new LED fixture — where the downward slope toward the bulb begins.
  • Push the fixture into place — and the caulk provides an air-tight seal.
  • Should you ever need to remove the fixture, the caulk will damage the “popcorn” texture on the ceiling — but you won’t see it when you’re finished.
  • Replace the LED fixture and remove any caulk stuck to the ceiling.
  • Recaulk the new light along the inside edge — and push the new light into place.


  • Avoid adding caulk at the outside edge of the new light fixture.
  • If you remove the LED fixture — the caulk will remove the ceiling’s popcorn texture where you’ll see it.

Gap Between Flooring And Wall 

When older homes were built — builders left a gap between the floor and the drywalled walls.   In newer homes (1990 & newer) — that gap is sealed.

Click Here To See A Gap Between Drywall & Floor

Plus, in older homes — home builders raised the base-trim in carpeted rooms.  This was so the base-trim in carpeted rooms looked the same size as in rooms with hard-surface flooring.

  • In carpeted rooms, the gap between floor and walls can be sealed with caulk.
  • To do this — the carpet must be pulled back and out of the way.
  • An easy time to add caulk is when new carpet is installed — and old carpet has been removed.

Also, many carpet installers will restretch existing carpet.

  • If your carpet has raised spots — it needs to be restretched.
  • This provides an opportunity to seal the gap below the base trim.

Click Here To See Carpet That Needs To Be Restretched: Carpet Needing To Be Restretched

If Changing From Carpet To Hard-Surface Flooring

Close the gap at the bottom of the base trim with a trim-molding to reduce air leaks.

Additional Trim-Molding Can Be Installed In Front Of Base-Trim: Additional Trim-Molding At Base-trim

The type & size of trim molding required is based on the size of the gap.

An Easy Peel & Stick Solution To Close The Gap Between A Floor And Wall

Insta-Trim is a peel & stick, flexible product to close baseboard trim gaps.  Click on the image below for additional photos showing how the product is applied.   This product comes in 1/2″ or 3/4″ and in several colors.  It’s paintable, and can be cut with scissors.

Amazon’s Web Page Says:  “Use InstaTrim as an alternative to wood moldings at baseboards.  No special tools are needed.”

Shown: InstaTrim 

Image Source: Amazon Embedded Product Link

Click On Image To; View Product, See It Installed,  Read Details, or Purchase From

Hidden Holes In Ceilings & Walls

When older homes were built — there was an unsealed gap around everything that came through the drywall (examples below).   In today’s new homes — these gaps are sealed.

These Air-Leaks Are Often Not Readily Seen.  Everywhere the ceilings or walls are penetrated (an opening was created) — they leak air unless the air gaps are sealed.

TIP: To know if gaps were sealed by the builder — remove the covers from some electrical switches and outlets.

  • Seal small gaps with caulk.
  • Large gaps can be sealed with weatherstripping.
  • For large holes — add drywall to cover the opening.
  • If the opening can’t be seen (like under the kitchen sink) — you can caulk gaps around the new drywall to seal them.
  • If the opening Can Be Seen — the gaps have to be repaired with drywall tape and then drywall mud.

Photos Of Air-Leaks That Can’t Be Seen Without Removing What’s Covering Them:

  • Wall Electrical Box: Electrical Outlet Box With Gap At Drywall.
  • TIP: It’s easier to close the gap with caulk and add a “jumbo” (larger) outlet cover.
  • TIP: Foam gaskets, for beneath outlet & switch covers, are readily available.  They close the gap around the outlet or light switch.


Plumbing Penetrations

NOTE: If Your DFW Home Had Burst Water Pipes Repaired During Texas’ February Winter Storm In 2021

Plumbers Often Had To Cut Drywall Openings To Repair The Water Pipes. 

Plumbers don’t repair drywall — only the pipes. 

Image Source: YouTube embedded video link

Shown: A huge opening in the drywall where plumbing enters.


Standard-Depth Wall Cabinets That Were Recessed Into Bathroom Exterior Walls

In older homes, some home builders used a standard-depth kitchen cabinet — and recessed it into a bathroom wall.  This created a proper depth cabinet above the toilet, so you don’t bang your head.

On outside walls — there’s no room for insulation behind the cabinet.   Plus, most cabinets have holes for different shelf placements — creating multiple air leaks.   To solve these problems, replace the existing kitchen wall cabinet with one designed to be over a toilet.  It’s shallower and attaches to the wall.

Shown: Shallow-Depth Cabinet Designed To Be Over A Toilet 

Click On Image To; View Product, See Details, or Purchase From

Image Source: Amazon Product Link

The Only Way To Remedy This In An Outside Wall:

  • Remove the existing cabinet.
  • Add lumber (if needed) for new drywall to attach to.
  • Insulate + drywall + air seal gaps with caulk.
  • Install an over-the-toilet cabinet where the opening was.  These cabinets are around 7 inches deep — See illustration above.

Air Leaks At Exterior Doors

brick home

Image Source: ShutterStock

Exterior doors are often a source of substantial air leaks.  Gaps  can be along the sides or at the top.  The worst gaps are at the bottom.

Click To See A Gap Under An Entry Door: Air Leak Under Outside Entry Door

Click To See A Thermal-Image Of Cold Air Coming Under An Entry Door:  Thermal-Photo Shows Air Leak Under Door

Many newer door-thresholds (under the door) — can’t be used on older DFW homes.   If there’s an existing threshold — it can only be replaced with a similar height product.

In an older DFW home — you can weatherstrip a gap under a door with a “door sweep” that attaches to the door (on the inside).  The best door sweeps are made of metal & rubber.  The metal holds the rubber more tightly in place.  The one shown below is installed with screws.

Shown: White Indoor Door Sweep For Entry Doors 

Click On Image To; View Product, See Details, or Purchase From

Image Source: Amazon Embedded Link

The product below can be used in addition to a door sweep — to provide insulation when there are large gaps under the door.  This product is 39″ wide (exterior doors are up to 36″ wide).  This product is soft vinyl with a foam core (it’s black — see photo below).

NOTE: If you have a room(s) that is not heated, this product can be used on interior doors too.

Shown: Indoor Draft Stopper For Entry Doors 

Click On Image To; View Product, See Details, or Purchase From


Weather Stripping At Corners Of Exterior Doors

It’s common for air to be leaking in at the lower corners of exterior doors — you can often see daylight at the corners.

Click To See An Example: Air Leak At Bottom Corner Of Exterior Door

There are weatherstrip products specifically designed for this need.  They are typically foam + a vinyl cover.   Most self-stick into place.

Shown: Door-Corner Weatherstrip

Click On Image To; View Product, See Details, or Purchase From


Weather Strip For Bottom Of STORM Door

Many storm doors have a gap at the bottom.  When new, there’s a weatherstrip that wears out.   If you have this need, there is a replacement weather strip.


Shown: Weatherstrip For Bottom Of STORM Door 

Click On Image To; View Product, See Details, or Purchase From

Image Source: Amazon Embedded Link


This Was Part 2 Of Our 5-Part Article:  Click Here To Read Part 3: Part 3 of Our 5-Part Article



Al’s Plumbing, Heating & A/C in Plano, Texas provides maintenance & repairs for all brands of Central A/C, Gas & Electric Furnace, and Heat Pumps.  Additionally we sell and install new HVAC Systems from American Standard (same company as Trane), Ameristar (same company as American Standard) and Coleman HVAC (same company as York HVAC).

Al’s also 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 is near your home in Allen, TX; Frisco, TX; and McKinney TX.  We service all homes in southern Collin County TX with no additional travel-charges.

Call Al’s today to discuss any concerns or problems you have with your HVAC System or Plumbing.  We will arrange an appointment at your convenie