图片来源：图像＃1和＃2：Peter Yost
图片来源：图像＃1和＃2：Peter Yost A home inspector told my client that this mold in her attic was the result of insufficient ventilation. But the pattern is targeted and distinct, not generalized throughout the attic. This sure looked like the result of an air leak to me, as indeed it turned out to be.
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几乎每周，我都会收到一个通话或一封电子邮件，该电子邮件变成建筑科学难题。尽管问题有所不同，但如何解决问题并不会改变。
First, you understand how heat and moisture move through building assemblies. Second, you follow the advice of your spouse.
My wife of 27 years is a real master at jigsaw puzzles, and she would laugh to learn that I think of myself as a puzzle master of any sort, since I am useless at the jigsaw ones. But she completely agrees that I should use her method of solving jigsaw puzzles in my work on building science problems.
这是她的拼图游戏与我的建筑科学之间令人困惑的燕尾尾。
步骤1：什么都不假
- Jigsaw:确保您拥有所有的拼图。
- 建筑科学:确保您拥有有关建筑物和问题所需的所有信息。
It’s almost funny how hard it can be to get folks to provide complete information; many want to stay focused on the expression of the problem and not “waste time” on full context. The easiest way to get the puzzle wrong is to “solve” it without all the pieces.
步骤2：建立边界
这意味着将与手头问题有关的建筑物分开。有时，这是关于收集测量或进行检查以完成手头建筑科学问题的“边缘”。
Can you imagine doing a jigsaw puzzle while blindfolded? Surprisingly, I have completed quite a few building science puzzles without ever visiting the project. I can only do this when I have confidence in the client’s abilities and willingness to send lots of images and accurate measurements.
Step 3: Find patterns
- Jigsaw:Group interior puzzle pieces by colors and patterns.
- 建筑科学:Use the puzzle clues to characterize heat and moisture flows.
Invariably, the client wants to focus on the spot where the moisture problem is being expressed. But you need to start with finding the source of the moisture. The pattern of the moisture expression can be linked to the wetting mechanism — bulk water, wicking, air leaks, or diffusion. The pattern could be visual or based on multiple measurements.
Step 4: Zoom out
- Jigsaw:Flip back and forth from focused detail to big picture puzzling.
- 建筑科学:Switch between building-level to site- and climate-level considerations.
No matter where you have set the boundary conditions for each project, it’s a good idea to step back and consider what role, if any, the site or climate could play in the building science puzzle.
步骤5：作弊
- Jigsaw:Use the picture on the box. (It’s not cheating!)
- 建筑科学:将手头的难题与您解决的类似难题进行比较。
步骤6：解决，以便您可以品尝
- Jigsaw:品尝最后一块。
- 建筑科学:The real last piece is finding the source.
可以在不识别其来源的情况下“解决”建筑科学难题。But if that’s your approach, there is always one missing piece at the end, and that should drive you crazy till you drop it in. It’s also what keeps you from being called back days, months, or even years later by a less-than-happy client.
在照片中所示的房子的顶部page, there were two distinct mold blooms that exactly coincided with uninsulated and un-air-sealed kneewall doors (see Image #2, below). We “solved” the problem of warm, moist air leaking into the attic through these doors during the winter by doing a blower door-guided air-sealing package for the whole home.
But the mold spots in the attic were pretty intense, so I thought I should follow up with the homeowner about interior relative humidity levels during the winter. They intentionally maintain it at about 55%. I was shocked: that’s very high for winter in their climate.
我发现，房主是音乐家，需要在干旱季节保护他们的大键琴和大提琴。学习水分的真正来源，导致关于如何保护其乐器和房屋的更彻底的对话。
I savored fitting that last piece into place.
In addition to acting as GBA’s technical director, Peter Yost is the Vice President for Technical Services atBuildingGreen在佛蒙特州的布拉特伯勒。他一直在建造，研究，教学，写作和咨询高性能房屋已有二十多年了。他是一位经验丰富的培训师和顾问，被公认为是年度NAHB教育家。您有建筑科学难题吗？在这里联系皮特。你也可以注册BuildingGreen的电子邮件新闻通讯获取有关避免有毒绝缘材料以及彼得的常规帖子的免费报告。
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5条评论
加湿到55％对房屋或乘员不利！
55％的相对湿度甚至高于最佳人类健康范围。
大多数医疗保健专业人员建议将其保持在30％和50％的相对湿度之间。（即使Ashrae曾经推荐40％-60％，甚至25％-65％，它们是错误的。）超过50％的人允许尘螨蓬勃发展，增加了皮肤和肺真菌感染的患病率，并增加细菌感染的风险。虽然对于大多数人来说，有55％的人没有风险（即使是60％，大多数对尘螨都不过敏的人都可以），但没有意义地维持它很高，而且并不是真正的最佳选择。
Keeping a house at 55% RH all winter in a colder climate will raise the springtime mold spore counts by quite a bit, due to the increased moisture content of the structure, which becomes an aggravating factor for asthma and those allergic to molds.
并非总是那么整洁
Peter,
It sounds like you mostly put together puzzles that are fresh from the store shelf, with the shrink wrap still on the box at the beginning. Maybe it's just that I'm not as good at assembling the pieces as you are, but the building science puzzles I deal with don't seem as neat and tidy as yours. I seem to deal with more puzzles that are missing pieces, that have pieces from other puzzles mixed in, that are missing the box cover with the picture on it. I often don't get the satisfaction of putting that last piece in. So we frequently have to make a guess at the root cause, implement some measures that we're pretty sure will mitigate the symptoms, and monitor the results to see if we guessed well enough. Not nearly as fun as your analogy.
保罗
observation
为什么提供的两张照片似乎与图片中的房屋不匹配，或者所示的房屋的另一侧有一个陡峭的添加功能与阁楼图片一致？
将RH保持在55％
达纳,事实上你是正确的, I spent some time with the client on this issue and the need to avoid RH this high. They were not really set on that number; it's just that as they don't air condition in the summer, that RH seemed to work best year round for their instruments, as an approximate target. And the hygrometer they were using was not all that accurate, as it turns out so they were plus or minus 5% (and yes, PLUS 5 would not be good) anyway.
并非总是那么整洁
I like the way that you have improved the analogy of jig saw and building science puzzles, Paul. Yeah, rarely if ever this tidy.
I did leave some "pieces" out: like the fact that the home inspector took a look at the attic and told the client that the mold was the result of too little attic ventilation, recommending a gable end exhaust fan to increase ventilation. And yes, that would have made the air leakage and mold WORSE! Or the unusual pattern of lichen and moss on the north side of the home, which I thought might correlate to the location of the attic mold blooms but turned out to be related to the leaching of zinc from the chimney flashing.
未来的难题不会那么“轻拍”。
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