Blower Door Testing in Middle Tennessee: What It Is, Why It Matters, and How to Prepare

A blower door test by Middle Tennessee Blower Door measures your home’s airtightness to improve comfort, save energy, and meet Tennessee building code requirements.

If you’ve ever wondered why your home feels drafty in winter or your energy bills keep climbing, the answer might be escaping through tiny, invisible cracks. A blower door test is the best way to find out exactly where your home is leaking air, and it’s now a required step for most new homes in Middle Tennessee.

At Middle Tennessee Blower Door, we specialize in helping homeowners, builders, and inspectors ensure every home meets modern energy-efficiency standards while improving comfort and safety.

What Is a Blower Door Test?

A blower door test measures how airtight your home is. Think of it as a “check-up” for your house’s envelope—the barrier that separates indoor air from outdoor air.

During the test, a certified technician installs a powerful variable-speed fan into an exterior doorway. The fan gently pulls air out of the home to create a small pressure difference (50 Pascals, about the same as a strong wind). This controlled pressure allows us to measure how quickly outside air sneaks in through leaks and openings.

The main number you’ll hear about is ACH50, short for air changes per hour at 50 Pascals. It tells us how many times the entire volume of air in your home is replaced in one hour when the house is depressurized.

Lower ACH50 = tighter, more efficient home.

How the Process Works

  1. Setup – All windows and exterior doors are closed, and interior doors are opened. The fan assembly is placed in a front or back doorway and sealed in place.
  2. Depressurization – The fan pulls air from the home, creating a pressure difference. Instruments record airflow rates and pressure data.
  3. Leak Detection – As air rushes through cracks and gaps, we use tools like smoke pencils or infrared cameras to pinpoint exactly where leaks occur—around windows, attic hatches, outlets, and baseboards.
  4. Results & Recommendations – You receive a detailed report showing your home’s ACH score and guidance on how to seal problem areas for better performance.

Why a Blower Door Test Matters in Tennessee

1. Code Compliance

Since December 2020, the 2018 International Energy Conservation Code (IECC) adopted by Nashville and surrounding Middle Tennessee areas requires blower door testing for all new residential construction.
Passing the test ensures builders meet the required energy-efficiency threshold before a final inspection.

2. Energy Efficiency

Air leaks are silent money-drainers. Sealing them can cut heating and cooling costs by up to 20–30%. The blower door test quantifies how tight your home really is so improvements can be made before you move in, or before your energy bills skyrocket.

3. Comfort

Fewer leaks mean fewer drafts. Homeowners notice more even temperatures and quieter interiors once leaks are sealed.

4. Indoor Air Quality & Safety

Too much leakage lets dust, pollen, and humidity in. Too little airflow without proper ventilation can trap pollutants inside.
Our technicians help you strike the right balance for healthy, comfortable living.

How to Prepare for Your Blower Door Test

  • Ensure access to all areas: attics, crawl spaces, and closets.
  • Close all exterior doors and windows, but leave interior doors open.
  • Turn off HVAC systems and close fireplace dampers.
  • Secure pets and remove valuables that could shift slightly during the test.
  • Notify the tester if your home contains older materials like asbestos so precautions can be taken.

The entire process usually takes about one hour for an average-sized home.

Who Performs the Test

At Middle Tennessee Blower Door, every test is conducted by a trained and certified energy professional who understands both code requirements and real-world building science. We serve builders, homeowners, and inspectors throughout Nashville, Franklin, Brentwood, Columbia, Murfreesboro, and the surrounding areas.

Schedule Your Test

Whether you’re finalizing a new build or improving your existing home, a blower door test is a simple, affordable step that pays for itself through energy savings and comfort.

📞 Call Middle Tennessee Blower Door 615-613-5447 or visit www.middletennesseeblowerdoor.com to schedule your test today.