Duct Leakage Testing<\/span><\/p>\n<\/div> Duct Leakage Testing for new IECC construction requirements <\/span>and Boulder SmartRegs.<\/span><\/p>\n<\/div> Duct Leakage testing has become a requirement in many jurisdictions and counties throughout Colorado. The purpose of duct leakage testing is to evaluate how well a home’s duct system can hold air. The idea behind it is that the more air that leaks out of the duct system, the more potential energy loss can occur.<\/span><\/p>\n Because of this, a pressure test is performed on the duct system itself to determine if the duct system is meeting the standards of today’s building codes.<\/span><\/p>\n Most CO municipalities have now adopted the 2018 IECC<\/a> or the 2021 IECC<\/a>. The 2018 IECC code is stated as follows:<\/strong><\/em><\/span><\/p>\n First of all, you need to check the current code in your building jurisdiction. If its a IECC 2021 code, all duct systems must be tested inside and out<\/em> of the conditioned space. If you are on the IECC 2018 or earlier, duct testing is only required when parts of the HVAC system are outside of the conditioned envelope. This includes areas like unconditioned attics, garages, and crawlspaces. If any supply or return duct chases, flexible lines or air handler units are in these areas, by IECC 2015 code, a duct leakage test is required. If a crawlspace is conditioned, then no test is required.<\/span><\/p>\n A duct leakage test (duct testing) can be performed at rough-in before drywalling, or post-construction. In both cases, the requirements are the same. The system will need to achieve a leakage rate of less than 4 CFM (cubic feet per minute) per 100 square feet of the home. Here is an example:<\/span><\/p>\n 40 CFM moving through the ducts when put under pressure.<\/em><\/span><\/p>\n 1000 sqft house.<\/em><\/span><\/p>\n 38CFM \/ 1000sqft = 0.38 x 100 sqft = 3.8 CFM<\/strong><\/em><\/span><\/p>\n This is commonly referred to as a 4% leakage rat<\/em>e.<\/span><\/p>\n Testing the ducts requires sealing all the openings of a duct system. This includes all supply and return registers. We do this by using large HVAC tape to cover and seal the openings. This process can take some time as we try to create the best seal possible. Our fan is then sealed to the air handler or a large return opening.<\/span><\/p>\n The fan is run to depressurize the duct system to -25 pascals. The amount of air moving through our fan is then measured. The number generated under 25 pascals of pressure is known as CFM@25. This CFM number is the number used in the calculation.<\/span><\/p>\n<\/div> After performing thousands of tests, we have come up with a list to help you easily past our test.<\/span><\/p>\nDuct Leakage Testing:<\/span><\/h1>\n
Ducts shall be pressure tested to determine air leakage by either of the following:<\/strong><\/span><\/h3>\n
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The 2021 IECC is similar to the 2018 IECC except\u00a0<\/em>that it also requires duct leakage testing within the building thermal envelope.\u00a0<\/strong><\/span><\/h3>\n<\/div>\n<\/div>
How a Duct Leakage Test Works:<\/span><\/h1>\n
Duct Testing Process:<\/span><\/h2>\n
![\"Sealing](\"https:\/\/scotthomeinspection.com\/wp-content\/uploads\/2018\/11\/DSC05868-1024x684.jpg\" "\\"DSC05868\\"")
<\/span><\/div>Testing Preparation:<\/span><\/h2>\n
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