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Attic Insulation Level — A/C Running Non-Stop When It’s Quite Hot? (Part 2 of 4)

IF Your A/C Temperatures Difference Passed The Test (See Part 1 of 4),  Your A/C Running Non-Stop Means It’s Doing All It Can do to keep you cool.  Here are some things which may be causing the problem.

The First Thing To Check Is Attic Insulation Level.

Newer homes have the minimum attic required by current Building Codes.  Many older homes do not have the insulation required.  Current TX Building Code for attic insulation is R-38.

attic insulation thickness diagram

The horizontal lumber in the attic (what the ceiling drywall is nailed to) is about 7-1/2 inches thick — this represents R-22 if the insulation comes to the top of this lumber.  R-38 insulation is about 13 inches thick and R-49 is about 18″.

TIP:  If you are adding insulation, be sure to ask the contractor the difference in cost between 13″ and 18″ — it’s likely not than much to add more insulation while they are there.  Insulation above R-49 / 18″ will have little additional effect.

The biggest problem many older homes have is insulation which has been kicked aside so someone could walk in the attic.

missing attic insulation

Thermal-Analysis reveals that if you have only 5% missing insulation in an attic (bare sheetrock) you’ll have a slightly more than a 50% drop in total attic insulating R-value!


thermal image of missing attic insulation

This Thermal-Image shows how hot the room’s ceiling is where attic insulation is missing.  Yellow is hot and purple is cool.

You can check your own ceilings for insulating value with a Thermal Heat Gun (thermometer).

thermal heat gun

Thermal Heat Gun from under $15

This device will allow you to check for under-insulated areas above your ceilings.  It will show you the room ceilings’ temperatures which are directly influenced by the amount of attic insulation overhead.

SUMMARY:  Attic insulation is key in minimizing DFW cooling and heating costs.  You can purchase the most efficient a/c made and still have huge cooling bills because the home has too little insulation.  Adding attic insulation is a great home improvement which rewards you with lower energy bills and increased comfort year round.

Al’s Plumbing, Heating & A/C does not sell or install attic insulation.

We do provide HVAC Maintenance, Repair and Replacement services for your DFW home.  We also perform ductwork inspection and repair services.  Al’s can maximize your HVAC system’s performance and efficiency, increasing your home’s comfort-level year round.  Call Al’s today for any HVAC or Plumbing issues or concerns you have.

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