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IECC要求R-60屋顶

罗伯特·宾德(Robert Binder)|Posted inBuilding Code Questionson

它在https://thehtrc.com/2020/sunsulation-requirements-2021-iecc新的(2021年)IECC代码将为5区屋顶至少需要R-60的绝缘材料,而其他区域和结构元素的更改可比。

这个论坛中的任何人都可以评论此主张吗?

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答复

  1. 专家成员
    Zephyr7||#1

    我也听说过这件事,现在已经谈论了一段时间,但是我会等待看看真正发表的内容。

    I think the roof/attic insulation levels are well into the diminishing returns here up over R49. I thought the same when they went from R10 for basement walls in CZ5 to R15. I'm actually pretty sure why that basement change was done, and it's a little on the silly side. Anyway, I'm not opposed to the higher levels in general, I just think they are excessive when mandated as code minimums. Going overboard in the codes drives up building costs, which is an especially big problem for smaller projects with lower income homeowners. There is eventually a point where the energy savings from the extra insulation can't really justify the cost of that additional insulation, and I think we're into that range now. I would rather see tighter air sealing standards instead of higher R value minimums.

    账单

  2. 兰迪·威廉姆斯||#2

    2021年IRC已更改阁楼绝缘要求,将要求4-8区具有R-60。如果在您所在地区采用2021年未经修改的情况下,这将被执行。您可以在此处查看2021能源代码:
    https://codes.iccsafe.org/content/irc2021p1/chapter-11-re-energy-energy-energy-efcipical-circ2021_pt04_pt04_ch11_secn1101

  3. Jay M||#3

    是否有任何迹象表明2021年未压缩的阁楼价值将是什么?据我了解,如果在桁架中内置了能量脚跟,则代码只需要R-38。使用新的2021代码,而不是R-60,我应该期望与R-49“未压缩”值的线一样?

    1. 专家成员
      迈克尔·梅纳斯||#4

      周杰伦,如果完整的深度阁楼绝缘层延伸到顶板 - 即,您的脚跟凸起 - 您可以从R-60降至R-49:https://codes.iccsafe.org/content/irc2021p1/chapter-11-re-energy-energy-energy-efcipical-circ2021_pt04_pt04_ch11_secn1102.1

  4. Jon R||#5

    And R 41.67 on a U-factor basis.

    显然,R60拥有118年的回报,超出了财务意义。希望地方当局能够修改R49。

    https://www.nahb.org/advocacy/top-priorities/building-codes/code-adoption-kits/2021-international-enternational-energy-corservation-code-code-code

    1. 芝加哥||#6

      我倾向于看到NAHB对增加首先成本的任何东西都非常有偏见,即使房主长期有好处。

      During Illinois state review a few resources said only 15-20 years pay back for R60.

      易于根据所使用的模型倾斜以一种或另一种方式。

      1. Jon R||#7

        很高兴从这些来源看到更多信息。显然,NAHB并没有批评绝大多数代码 - 即使在增加成本的地方也是如此。

        1. 芝加哥||#9

          Definitely not what I’ve seen in Illinois. There is a proposed amendment by the builders to revert all residential envelope requirements back to 2018 values.

  5. Peter L||#8

    我惊讶的是,第4区正在推动R-60。我现在只需要R-40才能天花板。应更强调适当的空气密封,而不是阁楼中的R值。房屋的30-40%的能源损失是由于空气泄漏。

    1. 道格·梅斯弗斯(Doug McEvers)||#10

      我在同样的线条上思考。与泄漏的R-60相比,气密R-30天花板的性能效果很好或更好。此外,阁楼绝缘材料的回报必须考虑到特定物业的加热燃料成本。

      1. 专家成员
        马尔科姆·泰勒(Malcolm Taylor)||#11

        I'm just guessing, but they probably saw adding more blown insulation to trussed roofs as fairly simple, inexpensive, low-hanging fruit. The alternatives - better windows and walls - both become complicated or pricey quite quickly.

        Our code makes the distinction between the levels of insulation required in attics and cathedral ceilings for much the same reason.

        并不是说这可能的解释回答了R-60是否有意义的问题。

    2. Jon R||#13

      > 30-40% of a homes energy loss is due to air leaks

      当前代码的空气密封级别不正确。

  6. 安德鲁c||#12

    如果该代码的结果是意外或其他方面的结果,就是让建筑商在能量高跟鞋和R-49上设计以避免R-60,那么我是粉丝。

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