这个播客系列是摘自一个为期两天的类称为“建设科学基础”教乔Lstiburek博士和约翰·Straube构建科学的公司。

上周,乔博士提出了一种简单的方式看待建筑的空气质量:人,污染物,路径,压力。本周,他描述了他的室内空气品质诊断过程:相信你的直觉,按你的鼻子,惩罚青少年和ceo。__________________________________________________

常见的室内空气品质的噩梦:砖建筑了天花板

我们有了顶棚空气处理程序,对吧?你把两个或三个空气处理程序的吊顶;供应系统完全用管道输送,返回不是。你只是简单地把空气的天花板。所以整个吊顶负压。注入空气,空气被分成了天花板,上面的负压场和空气循环。但这个负压场屋顶/栏杆连接外部相交。你很少有室内石膏板连接到顶部。即使你做的,它不是封闭的。有人就推在矿棉。 So whatever is in that exterior wall or parapet is being sucked right out of that exterior wall, into the return system, and ejected out the supply system, into the breathing zone of the occupied space. You’ve actually coupled your building enclosure to the occupant. The parapets are often the fresh-air intake for most buildings. And if it’s hot and humid outside, what kind of air are you bringing in? Hot humid air. And if it hits a cold surface — say a chilled water line — what’s going to happen? It’s going to condense and it’s going to drip.

谨防潮湿的空气

机械工程师不占湿度载荷。这是一个隐藏的负载,一个潜在的负载,负载,他知道湿度。你知道,他就会知道它的存在。它不是计算,而是在现实世界中,但没人想到它。这是一个大问题。现在,如果你幸运的话(你很少)你会得到足够的凝结,它实际上滴,所以你可以看到一个污点。但是你通常得到足够的凝结导致湿度上升下降的天花板,但不够通过材料染色。当湿度上升,你注意到的是它开始发臭。有几个不同的气味。有多少人还记得吐闻起来像什么? Well, puke has a distinctive odor, and it’s actually called butyric acid, which comes from the fermentation of starch. Well, butyric acid is emitted from ceiling tiles that are made from cellulose and a starch binder. When the humidity goes above 80 or 85 percent, the butyric acid is emitted, and you have the odor of vomit. So one of the most common things you do when you lose control of the relative humidity because of the coupling of the negative pressure plenum to the outside wall is you get a whiff of vomit.

你的鼻子是一个伟大的诊断工具

现在,当我进入一个建筑和我——(吸入)——我不让客户知道,我用我的鼻子,我内置气相色谱仪,弄清楚这是怎么回事。但是如果我闻到丁酸,我知道我已经失去了控制相对湿度,我知道这是该死的天花板瓷砖。这就像,你知道,确凿的证据,如果你闻到它,你现在知道的连接,你知道发生了什么。所以这是第一个独特的气味。他们通常非常湿润的停留更长时间,因为有水分,没有人预期的存在。和你通常会得到一个红色的细菌生长在线圈,它散发的气味约翰的袜子。我们不叫它约翰的袜子综合症;我们叫它脏袜子综合症。有一种独特的气味,它就像一个更衣室。所以你进去(嗅)如果你闻到呕吐,或者你闻到脏袜子,你立即关注什么? Dropped ceiling return plenum negative pressures coupled to the exterior wall. So you smell mold, or musty odor, you smell vomit, or you smell a dirty sock, and those are distinctive. I mean they’re not there all of the time, but eight out of ten times — you’ve pretty much got it sourced out that you’ve basically coupled your return plenum to the exterior wall. Remember, I’m talking as an engineer; I’m not talking to you as a scientist or a physicist. I’m just telling you my experience has taught me when I walk into a building and I’m thinking what? People, pollutant, path, pressure, hot wet, UV, ozone — this relationship is true. This is so common I don’t go to the projects anymore. Or I don’t want to go. I’m bored, I’m tired. I send the youngsters in the office. But they don’t want to go either cause they’re bored too. And so, you know, the client gets all annoyed because John or I get the work, but we don’t go out there. They get all pissed off they say, “We hired the great Oz and they sent us Toto.” So sometimes I have to go and so I take a youngster with me to abuse them.

你的眼睛和肠道可以告诉你很多关于建筑

我们叫我们去,我不想在停车场下车。我不《停车场下车。我当时与Kohta,他说:“乔,你要下车,下车,下车。”“我不下车!我不需要离开这该死的车!这是愚蠢的!看!”你知道,Kohta,“什么,什么,什么?”“你不用下车!“我有砖,所以我有什么?储层包覆。我不需要把墙壁上的一个洞,知道我有什么?迫击炮的粪便。你知道它的钢钉导致他们都该死的钢钉。你知道他们Dens-Glass黄金导致所有该死的Dens-Glass黄金。 You know that they all have Tyvek and if they don’t they have tar paper. You know they’ve got friggin’ fiberglass in the wall cavity and it’s a fifty-fifty chance that I’ve got a plastic vapor barrier or vinyl wallpaper on the inside. Now, what kind of a mechanical system do I have? Nine times out of ten I’m going to have what? Dropped ceiling return plenum. So before I get out of the darn car, out of the parking lot, I have a nine out of ten certainty that whatever’s in that wall is not going to be good, and is in the breathing zone of the occupied space. But they’re paying me, and so I have to get my fat ass out of the car, and go in. So I’m not happy about it. So the first thing you do is you pop the ceiling tile, but you do it in the corner office to piss off the CEO who made you go there. And what do you see? There’s no connection between the gypsum board and the underside of the roof. You can actually see the exposed fiberglass, right? We knew that! And it’s dusty. Why is it dusty? You’re pulling the air through it. So we’re just actually sucking on it. You know? Because I knew it was a problem, because after it rains, three or four days later we always get this musty odor. You know? So, “Well, OK, we’ll send somebody out.” “We want you!!” “Well, OK.”

首先,密封间隙

于是我走到哪里,我下车,我在笑。那么我们如何解决呢?我们运行石膏板的底部,我们现在试图让一个积极的联系,喷洒PVA -聚醋酸乙烯酯和一些pookie。但我们希望pookie不燃烧。它不是容易找到pookie不燃烧。所以你要用什么东西,你知道的,喜欢的FireDam从3 m,因为它是一个pookie不燃烧。

然后,平衡压力

我们做了吗?不。那么我们该怎么做呢?我们添加一个叫做返回管空气处理程序。这是工程师不知道。它不是很大,很短。它只是附着在单位,直接穿过天花板瓷砖。你明白我的意思了吗?所以我不再吸哪里?我不吸的天花板,我吸的空间。 So then I take every fifteenth tile and I throw it away, and I put in a grille. And what’s the function of the grille? Well, to equalize the pressure. I don’t want to suck on the wall any more, so I’m bleeding the negative pressure field. I’m bleeding it two ways: One, I’m putting a return duct on it, and two, I’m perforating the ceiling. Well, why won’t the return duct itself work? Well, because you know the air duct, the air handler, and all of the pieces are going to leak no matter how good you are. And you don’t know where that leakage is going to be — on the return or the supply side. You just know what? It’s going to leak, and so by perforating it, it means you’re going to equalize the pressure regardless of what’s going on. Because what you’ve done is you’ve put that thing in the middle of the room. If you put it in the middle of the room, from a pressure-field perspective it’s doing only what we wanted it to do in the first place, which is to circulate the air without causing a pressure difference. So that’s it! So, you disconnect, you fill the hole, you bleed the pressure field, and you’re done.

如果你只密封的差距?

如果我刚刚运行的石膏板,使连接和其他我什么也没做,会有问题吗?答案是:它取决于良好的上限之间的一个连接我和石膏板。非常,非常困难的良好连接。所以我们仍会有东西被退出了墙。我们就不会有被退出了墙。好,现在它变成了一个稀释的问题。去除通风率,与我们吮吸它的速度吗?这是无法确定,除非你现在做什么呢?衡量。但测量并不容易。 What are you measuring for? See, do you measure the tiny particles? Or the medium-sized particles, or the big-sized particles? And are they viable, or non-viable? Well then, you have to plant them, and grow them, and nurture them like a farmer, you know? And depending on what relative temperature you incubate them at, is going to determine what you get. Anyway there’s about forty-two different combinations that you’d have to do for each sample. At that point it’s more difficult to figure out what’s going on with sampling than to just say, screw it! I should just take the ceiling tile out, and put in the return and bleed the pressure — because the cost of the diagnosis is going to be more expensive than the repair, you know? The big decision should be: is my wall getting wet and soggy, and should I intervene and fix that? And more often than not, we don’t get a shot at that. Why? Well, I’ll talk to you about the politics. Who called me into the space? It was usually the tenant, not the landlord. So I’m fixing what I can within the tenant’s control.

解决潮湿问题后,模具是一个问题吗?

背后的乙烯壁纸在潮湿的建筑就是我们经常发现可怕的黑霉菌。所以呢?所以什么?不是,在哪里?里面!我可以离开这里吗?是啊!嗯,离开它的后果是什么?嗯,取决于有多少水分。在某种程度上石膏板会-什么? Soft. And so you’re going to have to intervene in the places where you have an actual breakdown of the product. That’s not usually everywhere. It’s usually on the south and west exposures. You only rip it out if you have access to — what? OPM — other people’s money. And so if you have access to money, the conservative, safe bet is to do what? Rip it out, because the world is filled with stupid people that think it’s dangerous. If it’s not coming out of the wall, I don’t care. If I have access to money, I’m going to take it out because someone’s going to think it’s going to affect the real-estate value. You know what? That in itself is a justification to take it out. If you have access to what? Money. But if you don’t have access to money, leave it there. We get all kinds of people who have moldy crawl spaces . And they’re poor. They don’t have twenty thousand dollars to decontaminate a friggin’ crawl space. Which we scare them about — “you’re all gonna die!” Well, you friggin’ close the crawl space vents, put in a hundred-dollar exhaust fan, or radon fan, and suck on it and the air moves in the other direction. What have we done? We’ve left the mold in place. Big friggin’ deal. But that’s not a popular view, because there’s an awful lot of money available to do — what? Mold remediation, and scare people. Now, what do I do? Well, at the end of the day, you have to solve what? The mold problem. You solve it by solving the water problem that caused the mold problem. What you should probably do is take the vinyl wallpaper off. Now what happens is, when you take it off you have to be careful, because what’s going to be behind it? Mold. And one of the ways you should deal with mold is deal with it like you deal with drywall dust, right? Because if you rip it off, that’s when you trash the rest of the building! Right? So you ought not to have it spread around. So if you’re going to take it off, you may as well hire someone to take it off correctly. But you only do that if you have access to people who can actually pay for it. Otherwise you’re going to do what? Leave it alone. So, a pretty fundamental example of people, pollutant, path, pressure.