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Opinion: Energy Code 7672

#1 Subject: 

Duct Sealing Materials

Code:

Part 7672.0500, Subpart 26  

Submitted By:

Bongard Corporation

Issue Date: 

May 12, 2000

Question:

Does the definition of "UL Standard 181 or equivalent" in Chapter 7672 exclude a cloth backed tape with rubber adhesive product which meets UL Standard 181? Does this definition appear in Chapter 7670?

Answer:

The state building code (UBC Section 101.3) requires in any specific case where different sections of the code specify different materials, methods of construction or other requirements, the most restrictive shall govern. The portion of the definition "It does not mean cloth backed tape with rubber adhesive" is the most restrictive. Thus, even if a product is cloth backed tape with rubber adhesive complies with UL181, it would not be an approved product under Chapter 7672. Neither a definition of "UL Standard 181 or equivalent" nor requirements referencing it appear in Chapter 7670, and thus the product could be used in a Category 1 home.

#2 Subject

Interior Air Barrier Protection Code: Part 7672.0600, Subpart 3, item F 

Submitted by:

Builders Association of Minnesota

Issue Date:

December 15, 1999

Question:

Does the requirement that the interior air barrier must be covered to protect against physical abuse permit the use of cross-laminated polyethylene material as an acceptable alternative?

Answer:

Yes, if approved by the Building Official. The intent of this provision is to prevent damage to the interior air barrier during construction causing loss of air barrier integrity. If the barrier material is durable enough to resist damage (as would be true for cross-laminated polyethylene) and the installation would adequately secure the edges, then it may be considered an alternate method, material, and design. Application of alternate materials which meet the intent of the rule may be considered by the Building Official under UBC section 104.2.8, Alternate Methods, Alternate Design and Methods of Construction.

#3 Subject:

Enclosed Three Season Porch Method Code: Part 7672.0800, Subpart 9

Submitted by:

Builders Association of Minnesota

Issue date:

December 15, 1999

Question:

Does the porch need to comply with all of the envelope requirements that the rest of the house must comply with, including fenestration products?

Answer:

No. This provision exempts the porch wall U-value from any maximum requirement if certain other conditions are met. Unlimited window area in the porch is possible. The maximum overall average U-value of 0.37 applies to the porch windows. The combined U-value of the porch wall and the wall separating the porch from the rest of the house must be no greater than U-0.11. The porch walls and the wall separating the porch from the rest of the house must meet the minimum criteria for air-barrier, vapor retarder, and other requirements of Part 7672.0600.

#4 Subject:

Three Season Porch Method Code: Part 7672.0800, Subpart 9

Submitted by:

Owens Company

Issue date:

December 15, 1999

Question:

Part 7672.0800, Subpart 9 does not specifically site Part 7672.0700 for window air leakage and determination of thermal performance, although Part 7672.0600 is cited. Does Part 7672.0700 apply when using the three-season porch method?

Answer:

Yes. Part 7672.0700 does apply to the three-season porch method even though it is not specifically sited.

#5 Subject:

Duct Vapor Retarder Requirements Code: Part 7672.0900 Subpart 3, and Subpart 4

Submitted by:

Biermann Homes

Issued date:

April 9, 2001

Question:

Does a metal duct running in an exterior wall outside of the vapor retarder, but inside of the insulation, need to be encapsulated in its own vapor retarder?

Answer:

No. Part 7672.0900, Subpart 3, states, "Ducts outside of the interior air barrier must be sealed with a product meeting UL 181 or equivalent." Part 1346.1005 of the mechanical code states, "Within conditioned spaces or in basements with insulated walls, a vapor retarder is not required." Even though the duct is on the exterior side of the vapor retarder/air barrier, it is still on the inside of the conditioned space.
 

#6 Subject:

Definition of Power Vented Appliance Code: Part 7672.0900, Subpart 8, item A, subitem (6)

Submitted by:

Several inquiries

Issued date:

April 13, 2001

Question:

Does a fan-assisted furnace (rated to operate with a nonpositive vent static pressure) qualify as a power vented appliance? Can a fan-assisted furnace be installed in a Category 1 house?

Answer:

No. Appliances rated to operate with a nonpositive vent static pressure are considered atmospherically vented. An atmospherically vented furnace would not be able to be installed in a Category 1 house.

#7 Subject:

Make-up Air Requirements Code: Part 7672.0900, Subpart 8, item B

Submitted by:

Builders Association of Minnesota

Issue date:

December 15, 1999

Question:

Can a clothes dryer rated at 225 cfm be considered to receive all required make-up air from passive infiltration?

Answer:

Yes, under two make-up air paths. subitem (6) of the same subpart, the aggregate make-up air path, allows up to 425 cfm of exhaust capacity provided by infiltration. Item D, the performance path, contains no exhaust capacity limit on any appliance.

#8 Subject:

Alternate Ventilation Performance Path Code: Part 7672.1000, Subpart 1, item

Submitted by:

Research Products

Issued by:

April 13, 2001

Question:

Subpart 1, item C says that the ventilation performance path (Subpart 7) may be used as an alternative to the requirements of Subparts 3 through 6. Subpart 7 does not mention several of the requirements of subparts 3 through 6, including performance testing at ventilation design conditions, complying with UL1812 requirements, and heat recovery ventilator labeling. Does this mean these items and others in subpart 4 are not required under Subpart 7?

Answer:

Yes, with the exception that Subpart 7 item E does require ventilation systems to be tested and balanced.
 

#9 Subject

Heat Recovery Ventilator Performance Testing Requirements Code: Part 7672.1000, Subpart 4, item C, subitem (1)  

Submitted by:

Research Products Corporation

Issue date:

March 13, 2001

Question:

Does the requirement to test the performance of heat recovery ventilators require more than measuring airflow rates? Does it require testing of other performance characteristics such as sensible recovery efficiency?

Answer:

Heat recovery ventilator performance must be tested in accordance to the standard CAN/CSA-439, which includes (from section 4.1 of the standard):

 

determining the effectiveness of the ventilator in transferring sensible and total heat from one air stream to another, under equal and unequal mass flow rates; determining the ventilation performance under specified test conditions; determining the percentage of the exhaust air carried over into the supply air under specified test conditions; and determining the air leakage of the casing under specified test conditions. An exception is provided where the testing required in parts 10.6 and 10.7 of CAN/CSA-439 need not be done when the manufacturer provides specified certifications.

#10 Subject:

Heat Recovery Ventilator Testing Requirement Exception Code: Part 7672.1000, Subpart 4, item C, subitem (1)

Submitted by:

Research Products Corporation

Issue Date:

March 13, 2001

Question:

To be eligible for the exception under the required heat recovery ventilator testing, the manufacturer must provide a specified certification.

 

a) What is meant by the word "certify? b) Can the manufacturer perform testing at their own facility to develop that certification?

Answer:

a) Webster's first definition of the word is "To declare a thing true, accurate, certain, etc. by formal statement, often in writing." The intent of this requirement is that the manufacturer provide a written certification of the specified values.
b) Yes.

#11 Subject:

Pipe Insulation for Domestic Water Heating Systems Code: Part 7672.1100 and Part 7674.0900

Submitted by:

Rheem Manufacturing

Issue Date:

May 12, 2000

Question:

Do Chapters 7672 and 7674 require service water heating pipes to be insulated over their entire pipe length if the water heater is not equipped with factory installed heat traps?

Answer:

No. For non-recirculating systems where the water heater is not equipped with factory installed heat traps, both supply and return piping must be insulated for a distance of three feet from the water heater.

#12 Subject:

Reducing Air Leakage with Window Replacement Code: Part 7672.1200, Subpart 2

Submitted by:

Andersen Corporation

Issue date:

October 13, 1999

Question:

What happens if the building already fails before any of the windows are replaced, and is the permit holder still responsible for bringing that building into compliance?

Answer:

There is no effect on compliance requirements. The word "fails" in the question refers to the testing provision of the subpart, which is only an alternate path for compliance and does not describe the minimum requirement for compliance. The only requirement is that combustion air be installed in the specified circumstances, and yes, the permit holder is responsible for that requirement.

#13 Subject:

Worst Case Draft Test Compliance Option Code: Part 7672.1200, Subpart 2

Submitted by:

Andersen Corporation

Issued by:

October 13, 1999

Question:

What information will be required to verify that the home passes the draft test?

Answer:

Since the Worst Case Draft Test does not specify what documentation is required, minimum documentation would be a signed statement that the home passes the draft test. Whether this meets the requirement of the code for documentation would be up to the Building Official.

#14 Subject:

Additions and Alterations Roof / Ceiling Envelope Requirements Code: Part 7672.1200 (Additions) as it references Part 7672.0600

Submitted by:

Builders Association of America

Issued by:

December 15, 1999

Question:

Do the requirements in 7672.0600, Subpart 3, for a six inch heel and R-19 at the inside edge of the top plate always apply when an addition is built that must meet the requirements of the entire chapter as outlined in 7672.1200, subpart 3?

Answer:

No. The intent is to require a high R-value for additions within practical limitations and design considerations. Alternate details which meet this intent may be considered by the Building Official with respect to practical difficulties under UBC Section 104.2.7, Modifications.

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