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SLS Construction & Building Solutions LLC

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You are here: Home / New Construction / Illinois Duct Leakage Testing (DET Verification)

Illinois Duct Leakage Testing (DET Verification)

The Duct Tightness (AKA Duct Leakage or Duct Blaster Test) is only required for new systems when the entire HVAC system and duct work is not completely contained inside the buildings thermal envelope for those permitted before January 1st, 2024. Depending on which Compliance Path you chose when initially pulling your permit will determine the allowable leakage rate – is it 3%, 4%, or does it just need to be tested?

UPDATE: Illinois has adopted 2021 IECC which means that for homes permitted after January 1st, 2024 – all new systems are required to be tested. For ducts & systems located completely inside the building envelope one is allowed a maximum rate of 8%. One amendment that was adopted (your welcome) is a minimum floor value – so the allowable amount is either 60 CFM or the percentage listed above – whichever is higher. This does apply to all systems whether located in the envelope or not.

To schedule: Please call us at (815) 200-3688 or reach out via Email

As an FYI, we don’t simply show up for your duct leakage test, give you your result, & bolt; we include up to 30 minutes for diagnostic time which allows for additional sealing work to be completed before getting you your final result. If additional time is required to pass & our schedule allows, that time will be billed out as Diagnostic & Training Time, saving you not only time later but a retest fee.

Base Cost’s:

Single Package System Test …………………………………………………….……. $300
Additional Systems ……………………………………………………………….. $225 each
Supply & Return Registers over 10′ up (need notification) ……….. Please Call
Combined DET Verification (Blower Door W/ 1 HVAC system) ….……. $550
Combined DET Verification (W/ LTO) …………………………………………… $600
**On Site Training, Consulting, Diagnostic Time…………………………..$150 hr.
Exhaust System Verification (in combination w/above testing) …….$25 each
Rush / Emergency Charge (aka same day charge) ……..…………….. Please Call
System Retest …………………………………………………….. Same charges as Above

Curious on best options, ways to keep the ducts inside the thermal envelope or just what that means? Consider doing a virtual consultation with us as early in the process as you can. We can easily help you save money and aggravation. (HVAC Virtual Consultation $65 for 30 minutes via smart phone or tablet)

FYI – some helpful articles from our blog site: The HTRC are located at the bottom

Effective July 1st, 2019: The only change made from prior codes is that the Building Department / AHJ may require an independent third party to conduct the test whereas previously a “certified” installer or their company could do it.

The Duct Leakage Test:

Duct leakage measurements are used to diagnose and demonstrate leakage & efficiency problems with the entire system and to certify the quality of the installation. These tests are based off the Conditioned Floor Area or CFA. In all cases we seal up all the registers and then hook up a calibrated fan (as seen above) and pressurize the duct system to 25 Pascals (Pa). The CFM required to keep the system at that pressure is considered the leakage amount. This number is then divided by the CFA which gives us your percentage.

For example, using a typical 2 story w /basement house layout with two systems in a 3000 SF house; one located in the basement & the other located in the attic (or at least some portion of the ducts are). To make life easy we will say each floor is 1000 SF in size. As the basement is considered conditioned no test is necessary on that system which would be serving the basement and 1st floor, but one is required for the 2nd floor system.

Let’s say the test shows 50 CFM of air leakage – dividing 50 into 1,000 gives you a 5% leakage rate. Not bad, but not good enough for those using the prescriptive path. In this case you would need to be at 40 CFM or less to hit 4% and pass. Depending on when you tested you might be able to remedy that, or you might have to go to more extreme measures. What happens if you selected another route, well in that case it “doesn’t matter” as far as the codes are concerned.

What types of testing can I do & when?

While there are four common tests (for residential & some small commercial situations), only three are recognized under the EEB Act. Depending on test determines when you can do it.

  • The “Total Duct Leakage” or “Post-Construction” test is done after all the finishes are completed – house is painted, vent covers are on, etc… and we cover over the registers themselves
  • The “Rough-In Test” is done when the system is fully installed (minus register covers) but before the drywall goes up. In this case we simply seal up the vent openings. The best thing about this test, is it allows you to make needed corrections before the finishes are installed and is the most popular option.
  • If the air-handler is not installed, a “Rough-In” test may still be completed but you are only allowed 3 CFM per 100 SF as compared to 4 CFM for the other two. Please note all the ducts must be in place including the ones that “bolt onto” the air handler.
  • The “Leakage to Outdoors Test” is not acceptable for code compliance but is a specialty test required by certain programs like ENERGY STAR and must be done “Post-Construction.” This requires pressurizing the house (using a blower door) & duct system (see above) to 25 Pa & measuring how much CFM of air is required to bring the system up to 25 Pa.

Additional Info: Duct Testing 101 — Dust Testing FAQ’s for Homeowner’s — Common Duct Leakage Area’s & Methods (aka how to pass the first time (Note: specific area’s and methods start 1/2 way down)

To schedule: Please call us at (815) 200-3688 or reach out via Email

Service Area: Remote & Virtual

Nice thing about remote and  virtual assessments, 2nd opinions, design assistance, etc… is that you can be located almost anywhere.

One word of warning is if you are “shopping” or just looking for advice, make sure that the individual or company understands your specific climate challenges or environment beyond just the climate zone chart.

  • Very Hot & Dry?
  • Hot & Humid?
  • Coastal / Lake Region?
  • High Mountain?
  • Wind, Fire, or Other Zone?

 

Having lived, worked & built in many of these environments has helped me understand what the issues can be and how to work around them.

 

For example, unless you live in a place which uses an AC unit for 10 or fewer hours a year, you don’t want someone talking about installing a vapor barrier on the inside unless you want rot issues.

Local Service Area

  • Addison
  • Aurora
  • Batavia
  • Bolingbrook
  • Carol Stream
  • Darien
  • Downers Grove
  • Eola
  • Fox Valley
  • Geneva
  • Glen Ellyn
  • Glendale Heights
  • Lemont
  • Lisle
  • Lombard
  • Montgomery
  • Naperville
  • North Aurora
  • Oakbrook Terrace
  • Oswego
  • Saint Charles
  • Villa Park
  • Warrenville
  • West Chicago
  • Westmont
  • Wheaton
  • Winfield
  • Woodridge

Extended Service Area

Not considered local? No worries as we cover most of Northern Illinois*. Some common locations we have served include:

  • Algonquin
  • Barrington
  • Coal City
  • Darien
  • Des Plaines
  • Elgin
  • Grayslake
  • Kingston
  • La Grange
  • La Grange
  • Lake County
  • Lake in the Hills
  • McHenry
  • Mokena
  • New Lenox
  • Niles
  • North Barrington
  • Oak Brook
  • Romeoville
  • Round Lake
  • Schaumburg
  • St Charles
  • Yorkville

 

*Additional travel time & charges beyond the stated price on our site will apply.

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30W153 Argyll Ln, Naperville, IL 60563 --- PH: (815) 200-3688