Blower Door Testing and Home Inspection

New housing requirements:

  • Blower door testing
  • Duct pressure testing

South Carolina requires a certified DET technician to perform blower door testing on new homes before a certificate of occupancy can be issued for the protection of lives and your home. 

Air Concept Solutions is certified DET through BPI and professionally licensed and insured.
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Blower Door Testing

Have you ever felt pesky drafts around your home or higher than normal humidity issues. Drafts and air leakage can be a concern for a lot of homeowners. It’s especially frustrating when your heating or cooling bills skyrocket in the middle of the most intense seasons. The most effective way to determine the location and extent of the air leakage is a blower door test.

So what is a blower door test?

The blower door test measures the air tightness of the building by depressurizing it and measuring the rate at which air infiltrates through imperfections in the building envelope. The test involves:
  • Closing off or sealing all exterior openings
  • Activating a powerful, variable-speed fan to blow air out of the house
  • Measuring the higher outside air pressure that flows in through any unsealed cracks or openings
  • The test can help determine the level of air leakage and the exact sources causing the air leaks

Whether you’re looking to reduce your heating and cooling bills, you want a more comfortable home throughout all the seasons, or you want a more energy efficient home, a blower door test is truly a small investment to make. The information provided by a blower door test is absolutely invaluable. A blower door test is the most effective tool for pinpointing areas of your home that could see improvement, and will provide you with a roadmap to get there!

What does a blower door test measure?

A blower door test measures how airtight your home is. Your home’s air tightness plays a major role in the overall energy efficiency of your home! During a blower door test, your Registered Energy Advisor will run a fan that sits in the main exterior door frame of your home. The fan draws air from the inside of your home to the outside. The air then rushes back into the home through any cracks, gaps, or leaks. As the fan is running, your energy advisor will collect data from the pressure gauge that is used to calculate the airtightness of your home.

After the blower door test has been conducted, your Registered Energy Advisor will provide you with a list of recommended upgrades for your home. The list of recommended upgrades will outline how much your home could improve, should you wish to complete those renovations!

What numbers are required for what (Building Code, Net Zero, Passive House, Building Code, a home built to today’s standards would test at less than 2.5-3.5 ACH (Air Changes per Hour is a measurement of how many times the inside (conditioned) air is replaced with outside (unconditioned) air at a certain pressure. In most cases, ACH is read using 50 pascals of pressure. In other words, a home that has tests 1.0 ACH50 would see its total volume of air exchanged with outdoor air once every hour at 50 pascals of pressure.

A net zero home is up to 80% more efficient than a conventional home! As such, a net zero home must be exceptionally airtight to maintain its level of efficiency. In order to meet net zero. In most cases they may require outside fresh air or a foam of dehumidication.

A passive house is a home that is even more efficient than a net zero home. A passive house must meet strict air sealing requirements of 0.7 ACH at 50 pascals pressure. A passive house has extreme insulation levels and a completely airtight building envelope.

What is the average blower door test result?

The average blower door test result depends largely upon the age of the home, the insulation levels, and the age of the windows and doors. Generally, a new home should test less than 3.5 ACH50, as the insulation levels and efficiency of the windows/doors would make for a fairly airtight home. An older home, however, can vary immensely depending on a number of the aforementioned factors. If an older home is lacking in insulation and has inefficient windows, it can test anywhere from 5 ACH50 and up. A home that is very leaky would likely test somewhere around 10-20 ACH50.

How long does a blower door test take?

A blower door test will vary based on the size of the home. Generally, a blower door test, when combined with a whole home energy audit, should take approximately 1-4 hours.

The blower door test itself can run for about 2 hours. You may want to walk around your home with your energy advisor as the test is running! It’s a great way to physically feel the movement in the air and pinpoint exactly where the leakage is coming from.

What about fresh air?

While having an airtight home is integral to an overall energy efficient home, it’s important to remember that for indoor air quality, you must have fresh air circulating throughout your home. Think of it like the human body, without sufficient fresh air, your home isn’t able to breathe. It’s like trying to breathe through your skin rather than your mouth.

Reducing air infiltration and lowering the humidity inside your home will help lower your monthly energy bills and offer you more comfort.
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Preparing for a Blower Door Test

  • Take the following steps to prepare your home for a blower door test:
  • Close windows and open interior doors
  • Turn down the thermostats on heaters and water heaters
  • Cover ashes in wood stoves and fireplaces with damp newspapers
  • Shut fireplace dampers, fireplace doors, and wood stove air intakes
  • Please call us today to help you resolve any energy leakage…

DUCT PRESSURIZATION TESTING

Why should do I do duct pressurization testing? 

  • Increase the energy efficiency of your system
  • Find air leakage and eliminate drafts
  • Reduce humidity inside your home
  • For code compliance for new construction

Requirements for Duct Leakage Testing

Duct pressurization (or duct leakage) testing is mandatory in South Carolina for all new construction where any part of the duct system is on the outside of the building. The test helps ensure that the ductwork meets predetermined leakage limits to ensure that the system performs efficiently.

Test Methods and Limits

Rough-In Test: This test is done before drywall or sealing registers are installed.  The whole system is tested along with the air handler enclosure (if that is installed). For the Rough-in test, the leakage limit must be less than or equal to 6 cubit feet per minute per 100 square feet (6 CFM/100 sq ft) of a conditioned space. This test must be done at a pressure of .1 inches water column (or 25Pal).

Post-Construction Test: This test is done after all the construction has been finished.  This includes the sealing registers and the air handler enclosure for the entire system. The leakage limit for post-construction testing is usually 12 CFM/100 sq feet or if outdoors, the limit is 8 CFM/100 sq feet.

Construction in South Carolina must show it is compliant with the duct leakage requirements. Usually a Duct Seal Certificate is given.

Duct leakage testing must be done by a DET certified professional like Air Concept Solutions.

There are two types of blower doors: calibrated and uncalibrated. It is important that auditors use a calibrated door. This type of blower door has several gauges that measure the amount of air pulled out of the house by the fan. Uncalibrated blower doors can only locate leaks in homes. They provide no method for determining the overall tightness of a building. The calibrated blower door’s data allow the auditor to quantify the amount of air leakage and the effectiveness of any air-sealing job.

Preparing for a Blower Door Test

Take the following steps to prepare your home for a blower door test:

  • Close windows and open interior doors
  • Turn down the thermostats on heaters and water heaters
  • Cover ashes in wood stoves and fireplaces with damp newspapers
  • Shut fireplace dampers, fireplace doors, and wood stove air intakes

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Please call us today to help you resolve any energy leakage.

Office: (843) 323-8814 Fax: (843) 771-3632 E-mailinfo@airconceptsllc.com

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South Carolina Blower Door Testing Requirements

You can meet the state energy code requirement via a documented visual inspection checklist or through a passing blower door test. Ideally, you’ll find someone who is RESNET- or BPI-certified, which means they should have the right equipment and experience to help you not only get a leakage number, but also identify where the leakage is coming from.

Starting January 01, 2013, All new Residential construction will have to adhere to the 2009 IECC Home Energy Code. This requires Blower Door Testing and Duct Leakage Testing be performed before Certificate of Occupancy can be issued.

Air Concept Solutions, LLC. has a full time HERS Certified Rater on Staff to conduct all Home Energy Audits, Rating, and Code Compliance Testing.

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