You can achieve an energy-efficient home by reducing the presence of leaks and gaps, which often cause the heating and air conditioning systems to work harder. One way to identify air leakages and problem spots is through an energy audit, where professionals will perform a series of tests throughout your home – including a blower door test. Here’s an explanation of how this energy-efficiency analysis is done.

What Is a Blower Door Test?

During a blower door test, a heating and air contractor will install a doorway seal and a variable-speed fan attached to a manometer, which measures pressure and how much air flows out. In calibrating the fan to decrease pressure from your home, outside air has to flow inside through any small gaps or hidden cracks. Inversely, cranking up the pressure inside will reveal areas where indoor air is leaking out.        

How to Read the Numbers

The blower door test shows results using specific figures. ACH at 50 (air changes per hour at 50 pascals), for instance, shows the number of times the volume of air was replaced in an hour at a specific test pressure. The lower the number, the better. Ideally, this figure should range from ACH5 to ACH9, as anything higher indicates a leaky home while a lower number suggests an overly sealed structure.  

On the other hand, CFM at 50 (cubic feet per minute of air at 50 pascals) pertains to the volume of indoor air moving towards the outside through the fan. Sealed homes typically have below 1250 CFM at 50 pascals, while structures with air leaks will record 1300 to 3000 CFM at 50. If the reading exceeds 3000, then it’s likely that you have a loose home and need to plug in those leaks.

Why It Matters

With a blower door test, you can determine if you have a properly sealed or leaky home. A few gaps or cracks are normal, but if these become bigger, your heating and air conditioning system may wear out earlier than expected. Imperceptible holes can leak out warm air during winter and let in hot air in the summer, making it more difficult for your system to maintain the right indoor temperature and driving up energy costs.  

Have a professional check for inefficiencies in your heating and air conditioning system using a blower door test. Preston Reeves Heating & Air Conditioning in Nassau County, FL, is a leading contractor when it comes to HVAC repair, installation, and AC maintenance. Call (904) 845-3338 today to schedule an appointment for energy-efficiency analysis or visit their Facebook page.