Illinois Energy Conservation Code Training and Support Program
2012 IECC - Frequently Asked Questions - 2012 IECC
III. BUILDING DIAGNOSTIC TESTS
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Q: Am I required to utilize diagnostic testing for assessing compliance with the 2012 IECC?
A: Yes, There are no longer two options for assessing compliance with the home air leakage requirements of the 2012 IECC. The visual inspection option of the 2009 IECC has been removed. Under the 2012 IECC, all new residential one- and two-family dwellings and townhouses and low-rise multi-family buildings shall be tested and verified as having an air leakage rate not exceeding 5 air changes per hour (ACH) at a pressure of 0.2 inches w.g. (50 Pascal), 5ACH50.
The common tool used for measuring air tightness is the blower door, which accurately measures air pressure difference and flow rate. The blower door, as its name implies, is affixed to the front door of the home and using a variable speed fan and manometer to measure the building or dwelling unit air leakage rate. A house air leakage rate can be quantified by inducing a pressure difference across the apparatus and between the interior and exterior of the house, measuring the airflow necessary to maintain this constant pressure difference. A home-performance contractor or field-inspector then locates air leakage sites requiring additional sealing. For compliance assessment, the blower door measurements, reported at 50 Pascal of pressure (representing a 20 mph wind), can be combined with a factor representing the dimensions of the home to yield the comparable air tightness value expressed in cfm/ft2 @ 50Pa (CFM50). (2012 IECC Section R402.4.1.2)
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Q: I noticed that Section R402.4.1.2, Testing, says "Where required by the code official, [blower door] testing shall be conducted by an approved third party." Does that mean that it's up to the code official to require that the blower door test be conducted or not?
A: The language “…where required by the code official…” excerpted from 2012 IECC below, refers only to whether an approved third party is required to conduct the test.
R402.4.1.2 Testing. The building or dwelling unit shall be tested and verified as having an air leakage rate of not exceeding 5 air changes per hour in Climate Zones 3 through 8. Testing shall be conducted with a blower door at a pressure of 0.2 inches w.g. (50 Pascals). Where required by the code official, testing shall be conducted by an approved third party.
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Q: Does the blower door test have to be done by a third party, or can the builder perform the test?
A: Yes, both the 2009 and 2012 IECC editions require blower door testing be conducted by an approved third party or an approved inspection agency. A review of Code Change EC13-09/10, Part I, to the 2012 IECC, which was Approved as Modified by Public Comments (AMPC) 5, 19, and 20 reveals the following:
- Closer scrutiny of the supporting statement to EC13-09/10, Part 1–PC19 shows that the public comment was submitted and approved to prevent an installing contractor from performing the blower door test on their own work. Specific reference to the test being performed by an approved third party is now referenced in the 2012 IECC with respect to these matters; along with citing third party inspection programs as a common practice that has worked well for design professionals, and required to employ approved special inspectors to conduct special inspections on the work. The supporting statement continues, “Nothing in the proposed language would deny the code official’s prerogative to do the blower door testing himself or using his own personnel, should any building department choose to develop this capability.”
- The Illinois Energy Office is currently identifying a baseline for approval of third parties which they believe will be of assistance to “Authorities Having Jurisdiction” in their pursuit of compliance assessment. Currently, certifications recognized by the IL DCEO, but still requiring approval by the local code official are:
1. BPI-BA/EP Certified,
2. RESNET – HERS Certified,
3. Illinois Association of Home Energy Raters & Performance Professionals – Duct and Envelope Tightness (DET) Verifier Training (New! In December 2012),
4. Southface Energy Institute – DET Verifier, or
5. Equivalent as verified by established training results.
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Q: Regarding duct leakage; I have a client who attended a seminar at which he believed he was told the only ducts that have to be measured for leakage are those ducts that are “outside” the thermal envelope. Is this correct?
A: A slight misunderstanding, only. A duct system is to be leak-tested only where the air handler or a portion of that duct system is located outside of the conditioned space. Ducts located within building thermal envelope components or outside of the pressure boundary are considered outside of the conditioned space.
For 2009 IECC:
Duct leakage (“total” or “to the outdoors”) is based on xx cfm/100 ft2 of conditioned floor area.
• Rough-in no air handler ……………… 4 cfm total leakage
• Rough-in with air handler ……………. 6 cfm total leakage
• Post construction with air handler ….. 8 cfm leakage to outdoors
• Post construction with air handler ….. 12 cfm total leakage
For 2012 IECC:
Total duct leakage is based on xx cfm/100 ft2 of conditioned floor area.
• Rough-in no air handler ……………… 3 cfm total leakage
• Rough-in with air handler ……………. 4 cfm total leakage
• Post construction with air handler ….. 4 cfm total leakage
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Q: IECC 2012 dropped the “duct leakage to outside” option for testing that was present in the IECC 2009. Did IL amend the code to include this?
A: No. The 2012 IECC (effective for Illinois Jan 1, 2013) removed the one instance where “leakage to outdoors” was a permissible option in the 2009 IECC, in its entirety.