When Is Duct Leakage Testing Required In Colorado?

Date Published: April 22, 2019

You may have heard of a duct leakage test in Colorado, and you might be wondering if it is required for your new home. In this article, we’ll discuss the test, when it is required, how it is performed, and what you’ll need to do to pass. Let’s get started.

Understanding When Duct Leakage Testing is Required In Colorado

Duct leakage testing is required in any county or city that enforces the new IECC 2015 building code. Because Colorado is adopting IECC 2015 building codes statewide, duct leakage testing is required for any new homes that are built in Colorado which has a duct system that is outside of the conditioned space, such as:

  • An attic
  • An uninsulated crawl space
  • A garage
  • An exterior utility room
  • A garage attic

Essentially, if any piece of the system is outside the heated space, you will need to perform the test. Even if there is just one flex line going through an attic, or an unconditioned crawl. However, this requirement is fairly new to many areas in Colorado. Be sure to check with your building department if your duct system fits this description.

Need a duct leakage test performed? Learn more and schedule one today!

How Is The Test Performed?

Using a special fan, air is pumped through your ducts at a specified pressure of 25 Pascals, equivalent to 0.1 inch w.g. (Water Gauge). All of your registers will be sealed during the test. The sealing is performed with special HVAC tape, but many times HVAC contractors will seal the ducts during construction as well. Learn about the best ways to prep for the test here.

By measuring the fan output and the amount of additional air pressure required to maintain the proper pressure in the ducts, the total amount of leakage in your duct work can be measured. When a duct leakage test is required in Colorado, these are the necessary steps taken.

When is duct leakage testing required in colorado

What Counts As A “Pass?”

To pass the test, your home must meet the following test results. These results are pulled from the 2015 IECC energy code.

  • Rough-in test – If the air handler has been installed, leakage must be less than 4 cubic feet per minute, per 100 square feet of conditioned floor area. If the air handler is not installed at the time of the test, leakage must be less than or equal to 3 cubic feet per minute, per 100 square feet of conditioned floor area.
  • Post-construction test – Total duct leakage must be less than or equal to 4 cubic feet per minute, per 100 square feet of conditioned floor area. In addition, building framing cavities cannot be used as ducts or plenums, and any mechanical piping carrying fluids over 105 degrees Fahrenheit, or under 55 degrees Fahrenheit, must have a minimum insulation level of R-3.

If you do not pass, your ducts may need to be reworked, or sealed, to reduce air leakage and ensure compliance with IECC 2015 standards. In many cases, installing AeroSeal can help seal the system, if the ducts have difficulty passing the test.

Know The Basics About Duct Leakage Testing – And If It’s Required For Your Home!

A properly-built new home will have no issues passing IECC 2015 duct leakage standards. So make sure you know what to expect from your duct leakage test, and prepare accordingly – you’re sure to pass with flying colors. We can help with fast scheduling and experienced technicians when you order a duct leakage test through Scott Home Inspection.

Colorado’s Top Rated Inspection Company:

Scott Home Inspection is Colorado’s highest rated inspection company offering home inspections, energy services, and Boulder Rental License Inspections. Click your service to learn more.

Home Inspection Services
Energy Services
Rental Inspections

About the Author: Joe Ophoff

Joe Ophoff has been working as an energy efficiency specialist since 2014. He is the Energy Services Manager at Scott Home Inspection in Colorado.

Recent Posts

2302, 2024

Home Inspections in Lafayette CO

About Lafayette Lafayette, CO is a quaint city situated in the southeastern region of Boulder County. It was originally established in 1889 by Marie E. [...]

Ready For A Great Inspection Experience?

Experience quality with the top rated Colorado based company for home inspections, energy services, and rental inspections.



Visit Our Ask Your Inspector page to see all our posts, find great Colorado contractors, and ask us questions about your home. 

Ask Your Inspector