Hey there George! Thanks for the kind wishes.
This is in response to your correspondence with the Illinois Energy Office, regarding provisions of The Illinois Energy Efficient Building Act [“the Act” 20 ILCS 3125]. I have been asked by to respond on their behalf. In addition to your questions, I offer additional clarifying commentary which follows:
1. Does the parenthetical phrase (Mandatory) require the installation of a recirculation system for service hot water?
No. You are correct, George. WHEN the residential domestic service hot water system is provided with a recirculation system, ONLY THEN are the provisions of Section R403.4.1 applied. The parenthetical language (Mandatory), and its application, are explained by way of Section R401.2 which reads, “Projects shall comply with Sections identified as “mandatory” and with either sections identified as “Prescriptive” or the performance approach in Section R405.”
2. Regarding Table R403.4.2 maximum run length, Is this a cumulative length of piping 1’’ reducing to ¾ ‘’ reducing to ½’’ [Yes.] or does each pipe size have to travel the stated distance before requiring insulation? [No.] For example, a 1-inch line 2 feet long connected to a ¾-inch line 9 feet long [Total length of ¾-inch or greater pipe = 2 + 9 è 11. Eleven is greater than 10, therefore insulation is required.] connected to a ½-inch line 18 feet long [Total length of ½-inch or greater pipe = 2 + 9 + 18 è 39. 39 is greater than 20, therefore insulation is required.]. Would this pipe be required to be insulated?
3. I have understood this table to imply that when the distance exceeds the 5 foot point from the heat source the line needs insulation to the end of the line (the terminal point of use). George, This is a good “rule” to use, as it correctly represents the intent of the code.
4. Here is how the State Energy Office has answered similar questions:
a. Do the run lengths of Table R403.4.2 apply to a trunk with the branch lines combined or each separately? Example: A ¾-inch DHW supply trunk extends 6-feet from the W.H. outlet collar (say 3-feet vertical then 3-feet horizontal. At points along the length of the horizontal portion of the ¾-inch trunk line, six (6) additional ½-inch branch lines extend as follows:
i. Branch line one extends to the 2nd floor Master Bath, an additional 4-feet horizontal then 15-feet vertical: Total run length of ¾-inch = 6’. See Table R403.4.2 (no need to insulate as 6’ is less than 10’). However, the total run length of ½-inch = 6 + 4 + 15 è 25’. See Table R403.4.2 (25’ is greater than 20’). Therefore, insulate R-3 from W.H. outlet collar to 2nd floor Master bath point of use.
ii. Branch line two extends to the 2nd floor Bath 2, an additional 12-feet horizontal then 15-feet vertical: Total run length of ¾-inch = 6’. See Table R403.4.2 (no need to insulate as 6’ is less than 10’). However, the total run length of ½-inch = 6 + 12 + 15 è 33’. See Table R403.4.2 (33’ is greater than 20’). Therefore, insulate R-3 from W.H. outlet collar to 2nd floor Master bath point of use.
iii. Branch line three extends to the 1st floor powder room, an additional 3-feet vertical: Total run length of ¾-inch = 6’. See Table R403.4.2 (no need to insulate as 6’ is less than 10’). Total run length of ½-inch = 6 + 3 è 9’. See Table R403.4.2 (9’ is less than 20’). Therefore, no need to insulate powder room branch.
iv. Branch line four extends to the 1st floor laundry, an additional 9-feet horizontal then 4-feet vertical: Total run length of ¾-inch = 6’. See Table R403.4.2 (no need to insulate as 6’ is less than 10’). Total run length of ½-inch = 6 + 9 + 4 è 19’. See Table R403.4.2 (19’ is less than 20’). Therefore, no need to insulate laundry branch.
v. Branch line five extends to the 1st floor kitchen serving both the sink and dishwasher, an additional 9-feet horizontal then 4-feet vertical: Total run length of ¾-inch = 6’. See Table R403.4.2 (no need to insulate as 6’ is less than 10’). Total run length of ½-inch = 6 + 9 + 4 è 19’. See Table R403.4.2 (no need to insulate as 19’ is less than 20’). However, Item 3 requires all piping from W.H. to “kitchen outlets” to be insulated R-3. Thus, dishwasher/kitchen sink branch shall be insulated.
b. The other question that begs to ask, is does the piping have to be insulated continuously? Yes (see our answer to c., below).
c. Can the insulation be interrupted where it passes thru supports or where the pipe enters or exits a wall? Yes, as the pipe and insulation pass through cuts and notching in studs or support beams. However, no – The insulation cannot be interrupted simply because it enters or exits a wall. Perhaps the question is specific to residential retrofit applications; in which case the AHJ’s judgment should be exercised.
We hope this answers your question in full. This opinion is that of the Illinois State Energy Office, and offered for the purpose of technical assistance in support of the International Energy Conservation Code® (IECC®) as it applies to the State of Illinois. The above opinion is based solely on the information which you have provided. We have made no independent effort to verify the accuracy of your submitted information nor have we conducted a review beyond the scope of your question. Remember that only the code official has the authority to administer and enforce the code, and that the opinions of IECC LLC and the Illinois State Energy Office are advisory.
Thank you for your inquiry. Holiday Best, -Darren
International Energy Conservation Consultants, (IECC LLC)
Darren B. Meyers, P.E., CEM, BPI-BA/EP, HVAC-QAP
A BuildRIGHT Illinois Partner
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