Section 12-I4-RE03. R403 - SYSTEMS

Strike Section R403.2 (including Subsections R403.2.1 through R403.2.3) of the International Energy Conservation Code in its entirety and insert new Section R403.2 in the Energy Conservation Code in its place to read as follows

 

R403.2 Ducts. Ducts and air handlers shall be in accordance with Sections R403.2.1 through R403.2.3.

 

R403.2.1 Insulation (Prescriptive).  Supply ducts located in attics shall be insulated to a minimum of R-8. All other ducts shall be insulated to a minimum of R-6.

 

Exception:  Ducts or portions thereof located completely inside the building thermal envelope.

 

R403.2.2 Sealing (Mandatory).  Ducts, air handlers, and filter boxes shall be sealed. Joints and seams shall comply with either the Mechanical Code or Residential Code, as applicable.

 

Exceptions:

 

1. Air-impermeable spray foam products shall be permitted to be applied without additional joint seals.

 

2. Where a duct connection is made that is partially inaccessible, three screws or rivets shall be equally spaced on the exposed portion of the joint so as to prevent a hinge effect.

 

3. Continuously welded and locking-type longitudinal joints and seams in ducts operating at static pressures less than 2 inches of water column (500 Pa) pressure classification shall not require additional closure systems.

 

Duct tightness shall be verified by either of the following:

 

1. Postconstruction test: Total duct leakage shall be less than or equal to 8 cfm (113.3 L/min) per 100 square feet (9.29 m2) of conditioned floor area when tested at a pressure differential of 0.1 inches w.g. (25 Pa) across the entire system, including the manufacturer’s air handler enclosure.  All register boots shall be taped or otherwise sealed during the test.

 

2. Rough-in test: Total leakage shall be less than or equal to 8 cfm (113.3 L/min) per 100 square feet (9.29 m2) of conditioned floor area when tested at a pressure differential of 0.1 inches w.g. (25 Pa) across the system, including the manufacturer’s air handler enclosure.  All registers shall be taped or otherwise sealed during the test. If the air handler is not installed at the time of the test, total leakage shall be less than or equal to 4 cfm (85 L/min) per 100 square feet (9.29 m2) of conditioned floor area.

 

Testing shall be conducted in accordance with a method approved by the code official, including, but not limited to, an approved sampling protocol.

 

Exceptions to testing requirements: 

 

1. The total leakage test is not required for ducts and air handlers located entirely within the building thermal envelope.

2. Existing duct systems that are part of an addition, alteration, renovation, or repair shall not be subject to the testing requirements set forth in this section.  New duct systems that are part of an addition, alteration, renovation or repair shall be subject to the testing requirements set forth in this section. 

 

R403.2.2.1 Sealed air handler.  Air handlers shall have a manufacturer’s designation for an air leakage of no more than 2 percent of the design air flow rate when tested in accordance with ASHRAE 193.

 

R403.2.3 Building cavities (Mandatory).  Building framing cavities shall not be used as ducts or plenums.

 

 

authority

Section 10 of the Construction Codes Approval and Amendments Act of 1986 (Act), effective March 21, 1987 (D.C. Law 6-216; D.C. Official Code § 6-1409 (2012 Repl.)) and Mayor’s Order 2009-22, dated February 25, 2009, as amended.

source

Final Rulemaking published at 61 DCR 3322 (March 28, 2014 – Part 2).

EditorNote

The District of Columbia Energy Conservation Code (2013), referred to as the “Energy Conservation Code,” consists of the 2012 edition of the International Energy Conservation Code, published by the International Code Council, as amended by the District of Columbia Energy Conservation Code Supplement (2013)(12 DCMR I). The International Energy Conservation Code is copyrighted by the ICC and therefore is not republished here. However, a copy of the text may be obtained at: http://publicecodes.cyberregs.com/icod/iecc/2012/index.htm?bu=IC-P-2012-000014&bu2=IC-P-2012-000019.