#60 设计不会回头困扰你的热泵系统，嘉宾：埃里克·菲茨

你可以更专业一点，直接量一量。

And you can get more sophisticated and just measure.

如果有松散的玻璃纤维或纤维素 insulation，就直接测一下厚度。

If you've got loose fiberglass or loose cellulose, just measure that depth.

对吧？

Right?

然后你就能判断出是什么类型的保温材料了。

And then you can figure out what the insulation is.

你继续说。

Go ahead.

在很多老房子里，尤其是我见过的那些，热成像仪很难准确判断，因为这些区域都已经被搅动过了。

So in many homes, I the older homes I've been into, it's really work blowing around the thermal camera because these cells have been worked up.

房子都翻新过。

They've been remodeled.

所以很可能里面

And so as a result, they very likely have

不同墙上的保温层厚度可能不一样。

different levels of insulation depending on which wall you're at.

没错。

Yeah.

所以刚才提到，尤其是对那些很老的房子，拿着红外热成像仪走一圈，看看各处温度差异，真的非常值得。

So the comment was that it can really be worth it, especially for really old homes, to walk around with that that infrared camera just to see the variation that's going on.

我确实见过一些现场案例，房子是新的，但不知什么原因，有一面墙完全忘了装保温材料。

There's certainly scenarios I've seen in the field where it's a newer home, and for whatever reason, someone just forgot to put insulation on an entire wall.

这种问题用这种临时方法很难发现，还是得靠红外热成像仪才能准确识别。

That's obviously harder to catch for using these, like, ad hoc methods versus an infrared camera to identify that issue.

你继续说。

Go ahead.

我不确定你后面会不会说到一天结束的事。

I I don't know if you're eventually gonna get to actually the end of day.

天然气、燃油、丙烷这些我都能理解，但热泵我就搞不太明白了。

I have a easy time with natural gas, oil, propane, but can't do a heat pump.

算不出来准确的数值。

Ain't gonna come out correctly.

我不明白是为什么。

I don't know why.

好的。

K.

我希望能最终有一个解决方案，

That's what I'm hoping that eventually one

好的。

K.

乔，因为我怎么都算不准BTU值，天然气的效率显示90%，燃油设备是80%，前端安装基本都能对上，可就是算不赢热泵。

Joe, because I I can't get the BTs to work out, right, and it shows me 90% efficiency for a natural gas, 80% efficiency, whatever a front end install, and you get it almost every time, but I can't get heat pump.

明白了。

Okay.

我刚才快速回应你的问题或看法是，你在为热泵、炉子和燃油锅炉的负荷计算头疼。

My quick response to the question or comment was that you're struggling trying to figure out load calculations for a heat pump versus a furnace versus an oil oil boiler.

我们待会儿再详细讲，但你要记住，负荷计算——也就是Manual J——跟设备本身其实没什么关系。

We'll get into this a bit more, but just remember that load calculations, Manual J, really has nothing to do with the equipment.

它关注的是房子本身。

It's about the home.

是关于围护结构的热传递。

It's about heat transfer through the envelope.

唯一跟设备有点关系的是风管系统，这个我们马上就会提到。

And the only piece where it kind of gets into the equipment is related to the duct system, which we'll touch on in a second.

不过我希望，当我们进入Manual S的时候，能帮大家理清一些困惑。

But I'm hoping as we get into Manual S, maybe that'll reveal some of the confusion around some of the stuff.

好的。

Alright.

你爬到阁楼的时候，也顺便四处看看。

While you're up in the attic, you should also be just looking around.

有没有通风口？

Do I have any venting?

如果阁楼有通风，那差别会很大。

If you have venting in an attic, that makes a big difference.

它能降低温度，特别是夏天，要是阁楼不通风，温度能升到160华氏度。

It reduces those temperatures, particularly in the summertime where, you know, if you have unvented attic, it can get up to a 160 degrees.

所以有通风的话，效果真的很明显。

So if you have venting, that makes a big difference.

在楼板和地下室里，通常都能方便地查看这些地方。

In floors, in basements, usually, have access to these places.

你只需要睁大眼睛，看看里面到底是什么情况。

Again, you just need to use your eyeballs, see what's going on in there.

地下室天花板的楼板龙骨里有没有保温层？

Do you have insulation in the floor joists in that ceiling of the basement or not?

门框周围有没有保温？还是像右边这种情形，地窖里根本啥都没做？

Is there insulation in the rim, or do you have a situation like this on the right here where it's a whole lot of nothing going on in this crawl space?

还有管道的保温。

And then duct insulation.

在Manual J里，这一点非常关键。

This is super, super sensitive in Manual J.

你上到阁楼、爬进地沟时，别忘了用眼睛仔细看看，那里可能有风管。

Again, while you're up in that attic, you're in that crawl space where that ductwork may be located, use your eyes.

如果安装的是比较新的设备，通常可以直接从这种柔性风管的保温层上读出R值。

Hopefully, if it's more modern equipment that's been installed, you can just read the r value right off of the insulation on this flex duct in this example.

你主要是想确认一下，保温情况是不是还不错。

And, again, you're just trying to verify, like, do you have something that looks pretty good?

是做了保温，还是像右边这种糟糕透顶的情况？

You got insulation or something really scary like this on the right?

你刚才说风管保温很关键，具体是指什么？

What do you mean when you said duct insulation is super sensitive?

对。

Yes.

意思是，你假设中的微小变化都会带来很大影响。

So it's super sensitive, meaning a small change in your assumption.

从R4提升到R6，对负荷计算的影响可不小，尤其是当管道在阁楼里，夏天温度极高，冬天又极低的时候。

So going from, like, r four to r six makes a big difference in terms of load calculations, especially if your ductwork is in an attic where you've got really high temperatures in the summertime and really low temperatures in the wintertime.

我就是这个意思。

That's what I mean.

这样理解清楚了吗？

That That make sense?

那这个也包括内层的管道板和管道吗？

And does that include also inner duct board and ducts?

管道板是另一个完全不同的话题了。

Duct board is like a whole other topic.

对。

Yes.

你需要评估的是设备送风侧和回风侧管道的平均保温性能，但管道板这东西普遍挺难搞的。

You're trying to figure out what is the insulating properties on average across that on the supply side and the return side of the equipment, but duct board is tricky stuff in general.

它是不是就像被忽视的那一个？

Is it considered, like, a redheaded stepchild or something?

所以问题是，‘红发继子’这个说法指的是什么？

So the question is, is redheaded stepchild?

埃德，我可要让你直接回答了。

Actually, Ed, I'm gonna put you on the spot.

关于 duct board 是不是算‘红发继子’，你有什么看法吗？

Do you have any comments about duct board that you'd like to make about it being or not being a redheaded stepchild?

我特别推崇那些安装得当的产品。

I am a big fan any product eat proper.

凡是安装不到位的产品，我一概反对。

I am basically against any product that is not eat proper.

我觉得 duct board 或者任何类型的保温材料就是个绝佳的例子。

And I think duct fours or any kind of insulation is a perfect example.

没错。

Yeah.

你要控制好风速。

You keep your velocities in check.

它是一款非常不错的材料。

It is a perfectly fine prodigy.

但如果你不知道空气通过它时应有的流速，那就别用。

But you you don't know what the velocity of the air traveling through it should be, then don't use

对。

Yep.

没错。

Yeah.

按照制造商的规格来操作。

So follow the manufacturer's specs.

正确安装。

Install it correctly.

就没问题。

You'll be good.

好的。

Alright.

风管漏风。

Duct leakage.

这是Manual J中另一个非常关键的假设。

This is another really sensitive assumption in Manual J.

同样，有一种方法是通过目视检查来判断。

Again, there's a methodology that uses visual inspection.

它从完全未密封到极度密封，有一套评估标准。

It goes from this infiltration assumptions from totally unsealed to extremely sealed.

中间还有五个等级可选。

There's five options in between.

从一般密封到完全不密封，就拿我家来说，这会让风管系统的供暖负荷翻倍。

Going from average sealed to unsealed, that at least an example of my house, that that doubles the heating loads on that duct system.

所以这一点一定要重视。

So pay attention to this.

同样，你可以靠肉眼来判断。

Again, you can use your eyeballs.

对吧？

Right?

老房子，尤其是东北地区，地下室里通常布满风管。

Often in older homes, particularly in the Northeast, we've got a lot of ductwork that are in basements.

不知为什么，几十年前大家觉得没必要去密封这些风管。

And for whatever reason, people thought, hey.

那时候的人觉得，根本不用操心风管的密封问题。

We just fifty years ago, we don't really need to bother sealing that ductwork.

你一眼就能看出来。

And you can just tell.

看看各个接头处，有没有用密封胶的痕迹？

You just look at the various junctions, and do you see any signs of mastic?

有没有任何胶带封过的迹象？

Do you see any taping of any kind?

如果什么都没看到，我就按未密封来估算。

If you don't see anything, I'm gonna use an unsealed assumption.

更好的做法是，我会告诉房主这个问题。

Better yet, I'm gonna tell the homeowner about it.

我会提供一项服务，帮他们把风管彻底密封好。

I'm gonna offer a service to properly seal that ductwork.

理想情况下，你应该测量风管的漏气量。

And, ideally, you're measuring the duct leakage.

你得用风管气密性测试仪。

You're using a duct blaster.

你应该用压差法精准定位漏气点，而不是单靠目测来大概判断风管漏气有多严重。

You're using the difference method to really dial this in as opposed to using that visual inspection method to kind of figure out what is the leakiness of the ductwork.

现在我们已经是Manual J的行家了。

So now we are pros in Manual J.

再说一遍，

Again,

这个

this

我们其实可以花好几个小时继续聊Manual J的事。

is a we could spend hours talking more about Manual J.

对我来说，如果你用的是ACCA认证的软件，Manual J最关键的是输入数据。

For me, if you're using ACCA certified software, what Manual J like, what's most important are the inputs.

对吧？

Right?

重点在于这种目视检查。

It's about this visual inspection.

要靠这些工具来验证输入数据，这样你用大多数产品都能成功。

It's using these different tools to verify those inputs, and then you're gonna be successful with most products.

明白吗？

Alright?

所以要做认真细致的Manual J计算。

So do that thoughtful Manual J.

还有一个问题。

And one more question.

说吧。

Go ahead.

手动计算J需要花很长时间来准确收集所有数据，录入起来也不轻松。

So Manual J, it takes a long time to collect all that data accurately, and it takes a decent amount of time to enter it in.

最近很多人在讨论，能不能用电费账单数据来估算负荷。

Is there there's been a lot of talks about using utility billing data as a way to get the load counts.

你怎么看这个想法？

What are your thoughts on that?

是的。

Yeah.

每种方法都有它的利弊。

There's trade offs with every method.

目前在美国，还没有统一的标准来用能源消耗数据做负荷计算。

There is not a standardized methodology in The United States right now for using fuels for load calcs.

加拿大倒是在制定相关标准，我正关注着，看看这会不会对美国产生影响。

Canada is actually working on a standard, so I'm kind of watching that to see how that might end up impacting The US.

这两种方法各有优劣。

There's trade offs of both methodologies.

用燃料数据做负荷计算时，有些关键假设和误差是难免的。

There are key assumptions and errors that can happen with fuel based load calcs.

只要稍微练一练，我刚才说的那些 Manual J 里最常见、最关键的变量，核对起来十到十五分钟就够了。

And I would argue with a little bit of practice, most of the things that I just showed, the most common and most sensitive variables in Manual J, it takes ten to fifteen minutes to verify those details.

当然，如果要 setup 一个风机门测试，时间会更长一点。

Obviously, a bit more if you're setting up a blower door test.

但不管怎样，你本来就应该做风机门测试，因为还有其他很多用途，能帮你更了解房子的情况。

But you should be doing a blower door test anyways for all kinds of other purposes to understand at home.

所以只要有点经验，这些细节都能很快核对清楚，但两种方法的权衡还是很大。

So with some practice, you can verify these details, and there's big trade offs.

用燃料数据的方法，根本不适用于新建房屋。

Fuel based approaches, they don't work for new construction.

对吧？

Right?

你得用别的方法来做负荷计算。

You have to use some kind of other process for doing the load calculations.

但就我个人而言，我觉得Manual J这套方法和背后的思考过程，才是真正的黄金标准。

But for me, personally, I think the methodology and the thought that's gone into Manual J, it is the gold standard.

这里面凝聚了大量细致的考量和实践经验。

There's a lot of careful thought and practice that's gone into it.

如果你用的是经过认证的工具，保持一致性，核对这些细节，成功率会高很多。

And if you are using a certified product, you're being consistent, you're verifying those details, you're gonna have a lot of success.

我能简单补充一点吗？

Can I add something briefly to that?

它们其实是可以互相补充的，这样看更合适。

They can complement each other is a good way to look at it.

用燃料消耗数据来做分析，问题不少，尤其是像埃里克提到的新建房屋这种情况。

Using a a fuel usage basis to do something has a lot of folds in it simply from the perspective to Eric's point about new constructions.

我该怎么根据每个房间的BTU需求来设计风管系统？

How do I design a duct system based off of the BTU requirement per room?

那我该怎么根据燃料消耗来设计系统呢？

And it's a plaus do I design a system based off the fuel usage?

我可以为整个房子来做这个计算。

I can do it for the whole home.

所以如果你想用它来对比整体负荷，这个方法是合理的。

So if you wanna compare it for a block load, that's a fair comparison.

但它可能无法准确满足每个房间的BTU需求，而这些需求最终会转化为每分钟的风量。

But may not j will be do the answer for your VTU requirement per room, which can be turned into how many CFM y e per week.

我觉得这两种方法可以很好地互补，但我不认为其中任何一个能完全取代另一个。

So I think they could complement each other nicely, but I don't think one is ever gonna replace the other.

没错。

Yep.

而且如果有人想精准定位那些起关键作用的因素的话。

And entirely, if somebody wants to pinpoint things that act.

很好。

Great.

这方面还有很多容易被忽略的问题。

And there's a bunch of other gotchas around this.

我们其实有一期播客专门讲过这个话题。

We actually have a podcast episode that goes into this topic.

推荐你去听听。

Check it out.

好的。

Alright.

气流和风管容量。

Airflow and duct capacity.

我们这里就不深入讲Manual D了。

So we're not gonna get into Manual D here.

我更想重点说的是，在改造项目中，通常你并不是要设计一套全新的风管系统。

What I really wanna focus on is in a retrofit application, typically, you're not designing an entirely new duct system.

你真正需要判断的是，现有的风管系统容量够不够。

You're trying to figure out, does the existing ductwork have sufficient capacity?

如果不够的话，有没有一些简单的办法可以提升风管的容量，而不需要完全按照 Manual D 的标准来改造？

And if it doesn't, are there simple things you can do to increase the duct capacity that doesn't necessarily require a full blown manual d.

Manual D 是另一套完整的体系。

D is a whole other protocol.

你们确实应该去了解它，但今天我不打算深入讲这个。

It's important you guys should learn about it, but I'm not gonna get into that today.

对。

Yeah.

请说。

Go ahead.

在改造项目中，你通常是在处理一个封闭空间。

So usually in a retrofit, you're working on an enclosure.

你会根据负荷来确定空调设备的制冷量大小。

You're using the load be the size of the BTU machine can be.

因此，通常情况下，你应该减少风管的容量。

So extensively, you should be reducing the duct capacity.

所以通常你会进入

So usually, you're going in the

那个需要减少过多负荷的方向。

direction where you apply over excess.

没错。

Yes.

非常好的观点。

So excellent comment.

如果你专注于建筑围护结构并降低建筑的负荷，就能减少你可能需要为那台热泵配置的容量。

If you're focusing on the enclosure and you're reducing the loads on the building, that reduces the capacity you may need for that heat pump that you're probably gonna put in.

所以专注于并改善围护结构是非常好的做法。

So excellent to work on the enclosure and improve the enclosure.

你这是在实现永久性的负荷降低。

You're doing permanent load reduction.

这太棒了。

That's fantastic.

这还能减少你可能遇到的问题，尤其是在那些原始设计就不合理的老旧住宅里，管道系统往往是个麻烦。

And that will reduce challenges that you may run into, especially in older homes where you've got ducts that are that were not designed properly in the original home.

所以在改造项目中，我们最需要弄清楚的基本问题是：现有的系统有没有足够的容量来支持我们打算安装的新设备？

So the key questions that we're trying to figure out in a retrofit application, you know, the most basic, do we have sufficient capacity to support this new equipment that we're thinking about putting in?

大概率是热泵。

Probably a heat pump.

我们得用多种方法来测试，确认这一点是否成立。

And we should be testing using different methods to figure out if that's the case or not.

你得先搞清楚最根本的问题到底是什么。

You need to figure out whether or not you're trying to understand the most basic question.

整体容量够不够？

Is there overall sufficient capacity?

但更往后的问题，可能是送风系统本身存在缺陷。

But maybe there's issues with the distribution system farther down the line.

所以你可以逐个风口测量，看看现有设备有没有气流不足的问题。

And so you can measure at each register and figure out, do I have airflow issues, again, with this existing equipment?

有没有哪里被压住了？

Has it been pinched off somewhere?

这一点我们需要核实一下。

And that's something we wanna verify.

就像我之前说的，如果风管漏风很严重，你得先检测并修复这些问题，再考虑其他更重大的改造，因为漏风问题影响很大。

And like I mentioned earlier, if you've got really bad duct leakage, you should test and fix those issues before you get into any of these other more significant modifications because duct leakage is a big deal.

测量风量的方法有很多。

There are a lot of different ways to directly measure airflow.

我来介绍一下最基础、最传统的方法：测量系统的总外部静压，然后参考风机的性能曲线。

I'm gonna talk through the most basic, oldest practice, which is to measure the total external static pressure and use a fan curve, the blower curve.

做这个只需要一些基本的工具。

You just need some basic tools to be able to do this.

现在市面上也有一些很好的新设备，比如TEC风量网格。

There are some great new products out there like the TEC flow grid.

它能让整个过程简单很多。

It really simplifies the process.

它会一步步带你操作。

It walks you through it.

这产品非常好，值得了解一下。

It's an excellent product, so it's worth checking out.

还有其他一些方法。

And there's some other methods.

有些智能控制系统可以直接从恒温器读取风量和静压数据，因为设备本身就在实时监测这些参数。

There's even some communicating controls that you can just directly read off of that thermostat what the airflow is, what the static pressure is because they're the equipment's measuring all those details.

但你得留心注意。

But you need to pay attention.

在盲目相信恒温器显示的数值之前，一定要确保蒸发器盘管和风管系统都是干净的。

Make sure the coil is clean, the duct system is clean before you just go look at that thermostat blindly and take whatever number it is off that thermostat.

真正厉害的是，如果你先确认了现有风管的实际容量，再按照Manual S流程，查一下设备的性能参数，算出设计风量，通常对于热泵来说，我们需要的风量会稍大一点。

So what's really amazing is if you verify what the existing duct capacity is and then you go through the Manual S procedure, you look up your equipment performance characteristics, you figure out what your design CFM is, often for heat pumps, we need a little bit more CFM.

比如，假设一套住宅目前需要约1000立方英尺每分钟的风量，静压在0.65英寸水柱左右，而你打算换的新设备标称是1400立方英尺每分钟，这时候你就可以用风机定律直接算出未来系统的静压会变成多少。

So if we pretend in a home that we currently need about a thousand CFM at about point six five inches of water column and you think this new piece of equipment you're proposing is gonna be about 1,400 CFM, you can use fan law to just calculate what's your future static pressure gonna be.

所以我们在这儿算了一下，至少在这个案例里，静压会高得离谱。

And so we just do the math here, and it looks like, at least in this instance, our static pressure is gonna be way high.

这下问题来了。

So we got a problem.

明白吧？

Alright?

我们稍后再回过头来聊怎么确定设计风量。

We'll come back to how we figure out what that design CFM is in a moment.

但这其实只是简单的计算。

But this is just simple math.

我们能提前预估出来。

We can make a forecast.

再提一次TEC，他们的产品现在内置了这个预测功能。

One more plug for TEC.

你可以用他们的真风量网格测量，再配合他们的小App，完成整个预测流程。

They have this forecasting capability built into their product now so you can measure with their true flow grid and use their little app to do this forecasting workflow.

所以这能大大减少你手动计算的麻烦。

So it really helps instead of having to do your own little hand calcs.

明白了。

Alright.

接下来我们聊聊传统的做法：直接测量全外静压，再对照风机曲线。

So let's talk about the good old fashioned way of just measuring total external static pressure and using fan curves.

你需要一个性能不错的双通道微压计，能精确测量到单帕级别的压力。

You just need a decent dual port manometer that can measure down to, like, single Pascal level.

必须达到这种灵敏度才行。

It needs to be that level of sensitivity.

这类设备通常贵一点，几百美元，但你本来就该备一个。

Those tend to be a little bit more expensive, a couple $100, but you should have one of these anyways.

如果你有风机密闭测试装置，那你的压差计很可能已经够灵敏了。

If you've got a blower door rig, you've already got manometer that's probably sensitive enough.

然后你测出全外静压，再对照风机曲线查一下。

And so you measure that total external static pressure, and you then look up the fan curve.

从我的角度看，这部分特别麻烦，尤其是对老设备来说。

So this is a hard part from my perspective, particularly for older equipment.

有时候，要找到这些数据还真不容易。

It can be hard to track down this data in some cases.

有时候数据就贴在设备上的一张标签里。

Sometimes it's a sticker that's on the piece of equipment.

有时候你真得翻来覆去才能找到这些信息。

Sometimes you really gotta dig around to find this information.

这张幻灯片上看不太清，但我们这里看的是一个表格，先确认了设备上的拨码开关设置，这决定了不同风速对应的参数。

It's hard to see in this slide, but we're looking at a table here where we have first verified the dip switches that are on the piece of equipment, which specifies what the, you know, different fan speeds might be.

右边列出了不同的静压数值。

And then across the right there are different static pressure numbers.

然后我们根据实际设置的拨码开关状态来查对应的数据。

And then we can just grab from our DIP switches, however they're set.

这样我们就能确定，这台设备的风量是1255立方英尺每分钟。

We can then figure out, in this particular instance, that we've got 1,255 CFM for this piece of equipment.

所以，这其实挺简单的。

So, again, it's pretty straightforward.

你先测一下静压。

You do the static pressure measurement.

然后查一下表格，就能得出结果了。

You look up in the table, and you can figure it out.

那到底什么是总外部静压呢？

So what the heck is total external static pressure?

这话题其实可以展开讲很久。

This could, again, be a much longer conversation.

但简单来说，它就是衡量风管系统对气流的阻力大小。

But at a very high level, it's essentially the measure of resistance to airflow in that duct system.

我们关心这个是因为大多数风机盘管的设计静压是半英寸水柱，风扇最多能承受大约零点八英寸。

And why we care about it is that most air handlers are rated to about half an inch of water column, and fans maybe can handle up to about point eight.

一般超过零点八，问题就来了，风扇电机很可能会比预期早很多就出故障。

Generally, over point eight, you run into trouble, and you're gonna have fan motor failures much earlier than expected.

如果这些压力过高，本质上就是系统内摩擦和阻力的体现。

And if these pressures are too high, it's basically it's a measure of friction of resistance that's in this system.

如果风机遇到过高的压力，就根本没法提供足够的风量。

And if your fan sees pressures that are too high, it just can't actually deliver the airflow.

明白了。

Alright.

测量静压的另一个难点在于，必须在设备的正确位置进行测量。

So the other tricky part about measuring a static pressure is you've got to measure in the right places in the equipment.

以燃气炉为例，假设我们要把它换成热泵，就需要在过滤器之后、线圈之前（如果有线圈的话）进行测量。

So for a furnace, so we're assuming we're we're swapping out a gas furnace for a heat pump, we need to measure just after the filter and right before a coil if you've got one.

把这两个数值都测出来。

You take these two measurements.

然后做一点简单的减法，就能算出总的外部静压是多少。

We do a little little subtraction, and you can measure what that total external static pressure is.

如果你用的是空气处理机组，那就不是燃气炉了。

If you've got an air handler, it's not a furnace.

如果是空气处理机组，钻孔位置会稍有不同，同样在空气过滤器之后，但在盘管之后。

You got drill ports at a slightly different spot, again, after the air filter, but then after the coil if you've got an air handler.

好的。

Alright.

举个简单的例子。

So quick example.

这些测量值真正厉害的地方在于，它们能直接帮你判断问题所在。

What's really great about these measurements is it can actually guide you.

当你看过滤器后的读数，再对比 furnace 或空气处理机组盘管后的读数，对比这两个数值，就能知道问题是出在设备的哪一侧。

So when you look at the measurement just after the filter, you look at the measurement just after the for furnace or for air handler just after the coil, looking at those numbers, you can tell which side of the equipment do you have an issue.

是送风侧的问题，还是回风侧的问题？

Is it more driven on the supply side or the return side?

在这个例子中，回风侧的读数大约是 0.7。

So in this example, we're actually seeing about point seven of measurement on the return side.

这说明，相对于送风侧的读数，回风侧很可能存在更大的阻力。

So that indicates I probably, relative to my supply side measurement here, I've most likely got a, you know, more restriction on the return side.

所以我还可以再做些测量。

And so I can do a little bit more measurement.

我可以把探头放在过滤器上游测一下，这样就能发现，大部分压降其实都来自这个过滤器。

I can take a probe and measure just upstream of that filter, and now I can figure out that I've actually got almost all that restriction on the return side is coming from the filter.

对于那些测出外部静压偏高的住宅来说，这往往是最容易解决的问题之一。

And this is actually one of the most common areas of low hanging fruit for a home that you measure a high external static pressure.

问题往往出在过滤器盒和过滤器本身太 restrictive 了。

It's you've got a filter box and a filter that's just too restrictive.

你用的是一英寸的 MERV 13 过滤器，简直把整个系统都堵住了。

You've got a a one inch, you know, MERV 13 filter that's just choking that whole system.

如果换成一个四英寸的过滤器，对设备的性能会有很大改善。

And if you can put in a nice four inch filter, that's gonna make a huge difference for that equipment.

对。

Yeah.

关于过滤器尺寸，艾莉森·韦尔斯写过一篇文章，提到了一个经验法则。

So on the filters, Allison Vails had an article about a rule of thumb for the filter size.

他说每平方英尺的过滤器迎风面积对应两平方英尺的过滤介质面积

He said two square feet of face area per not surface area

没错。

Yep.

我们说的是迎风面积。

Filter media.

我们讨论的是过滤器的迎风面积。

We're talking face area.

很好。

Nice.

如果按照这个经验法则，你就会明白大多数回风过滤器有多小了。

So if you use that rule of thumb, you're gonna understand just how undersized most return

它们通常都偏小。

filters are.

它们通常都太小了。

They're usually undersized.

是的

Yeah.

对

Yep.

有个评论提到，艾莉森·贝尔斯写了一篇很棒的文章，讲了一个经验法则：你可以根据过滤器的迎风面积来估算，每制冷一吨大约需要两平方英尺的迎风面积。

So the comment was Allison Bales has a great article that talks about a rule of thumb where you can use the face surface area of the filter, it's and roughly you need about two square feet of face surface area per ton of cooling.

而且，当你用这个法则去衡量时，就会发现我们通常用的过滤面积实在太小，严重限制了设备的性能。

And, yeah, that you'll when you use that rule of thumb, you'll notice that often we've got way too little surface area really restricting that equipment.

过滤器的厚度有影响吗？

Does filter thickness matter?

这听起来有点反直觉，但一般来说，过滤器越厚，阻力反而越小，因为滤材没那么密集地堆叠在一起。

So it's somewhat counterintuitive, but typically the thicker the filter you have, the less restrictive it'll be because you're not as densely packing that filter medium.

所以厚度越大，过滤层就越深。

And so the thicker it is, the deeper it is.

阻力越小，静压降也就越低。

The less restriction you have, the less static pressure drop you will have.

所以这就是为什么我们更倾向于用厚一点的滤网，在其他条件不变的情况下，系统阻力会小很多。

So that's why we want to get to a thicker filter, and we'll actually have much less restriction on the system if you're keeping all other variables equal.

明白了。

Alright.

再举个类似的例子，这种情况下，问题往往出在盘管上。

So similar example, this is where we can see the restrictions really happening at the coil.

这可能是因为盘管太脏了。

This could be because the coil is filthy.

我自己还没遇到过这种情况，但我听不少客户提起过。

It could be I have not run into this myself, but I've talked to a number of our customers.

他们打开设备一看，发现安装说明书居然还塞在里面。

They have come across they've opened up a unit, and they found the install manual sitting inside the unit.

这导致了严重的静压损失。

And that was causing a lot of static pressure loss there.

所以一定要做一下视觉检查。

So just do visual inspection.

确保线圈是干净的。

Make sure that coil is clean.

这能解决很多问题。

That can solve a lot of problems.

好的。

Alright.

现在我们来验证一下。

So now here's, proved.

既然我们已经换上了合适的过滤器，

Now that we've addressed we've got a nice filter.

也搞清楚了线圈那边的问题，

We've figured out whatever was going on with the coil.

现在总的外部静压已经恢复正常了。

We're now in the green on the total external static pressure.

你继续说。

Go ahead.

还有一点，关于暖气加空调的线圈系统。

So another thing is on furnace plus AC coil system.

你不仅要考虑暖气线圈的静压，还得算上空调线圈的静压。

You have the static of both the furnace coil and you also have the static of the AC coil.

你本来就存在风管设计不佳的问题。

So you already have bad ducts.

这会让情况变得更糟。

Could make your life worse.

没错。

Yep.

对。

Yeah.

有两个线圈，意味着更大的阻力。

So having two coils, that's more restriction.

路上的障碍越多，气流就越受限制。

More stuff in the way of the airflow is gonna reduce.

这会增加静压，加大系统内的摩擦，让风机更难输送所需的风量。

That's gonna increase static pressure, increases friction in that system, and makes it harder for that fan to deliver those CFMs.

明白了。

Alright.

好的。

Okay.

接下来简单介绍一下Manual D的内容。

So one slide teaser on Manual D.

很多其他改善风管系统的方法，其实都跟‘等效长度’这个概念有关。

A lot of these these other opportunities to improve the duct system are just related to understanding this concept of equivalent length.

这张图我其实是从亚历克斯·米尼那里拿来的，特别棒。

This is a great slide I actually stole from Alex Meaney.

想象一下一个风管系统，这里只看一条送风支管。

So if you imagine a duct system, this is just a single supply run.

假设有一段10英尺的直管，接着是一个流畅的弯头，再连上一段差不多长的柔性风管。

We've got, let's say, 10 feet of just straight duct coming into this nice curved elbow and then a little flex duct roughly the same length of that this other straight duct.

当量长度考虑了由气流紊乱和方向改变引起的阻力损失，还有很多其他因素。

Equivalent length takes into account the losses, the friction that is caused by turbulence, by changing direction of the airflow, a bunch of different factors.

所以这个比较顺畅的90度弯头，其当量长度相当于30英尺的直管段。

And so the equivalent length of this relatively nice 90 degree elbow is equivalent to 30 feet of straight duct.

而这个很急的90度转弯根本没有导流叶片。

And this really hard 90 degree turn doesn't have any turning veins.

它的边角是尖的，没有圆滑过渡。

It's not rounded.

就这一个小小的接头，其阻力相当于80英尺的直管。

This one little junction, that's equivalent to 80 feet of straight ducts.

如果你已经处理过滤网箱，检查并清洁了线圈，但静压还是很高，

And so if you're already addressed the filter box, you've inspected and cleaned the coil, but you're still seeing high static.

那就可以看看设备附近有没有容易接触到的地方，也许只要换掉一两个管件，就能大幅降低静压。

You can look around for opportunities near the equipment that you can access where maybe you can just change a couple of these fittings, and you can reduce the static pressure dramatically just by swapping out even one fitting.

举个简单的例子，如果设备周围有点空余空间，你或许可以装一个带导流叶片的新回风管。

So simple example, if you've got a little extra space around that equipment, maybe you can put in a nice new return drop that's got turning vanes.

这能显著减少回风进入设备时的湍流。

It really helps reduce turbulence on that return coming into the equipment.

这样能大幅降低静压。

That will drop your static pressures dramatically.

明白吗？

Alright?

最后说说气流问题，这本身又是个很长的话题。

Last thing on airflow, again, it's a whole other long topic.

风管漏风是个大问题，尤其是在阁楼区域。

Duct leakage is really problematic, particularly in attic spaces.

这不仅导致风管本身大量能量损失，还会造成双重影响。

Not only does it cause significant energy loss through the ductwork itself, it actually creates like a double whammy.

这里说的是风管向室外泄漏的问题——如果风管漏到阁楼里，反而会让更多室外空气渗进建筑内部。

This is this topic of duct leakage to the outside, where if you have air that's leaking through the ductwork into the attic, it actually induces more infiltration into the building.

所以，你不仅损失了本该送入室内的风量，还因为风管向室外泄漏，给建筑增加了额外负荷。

So not only are you losing CFMs you can deliver to the home, you're actually adding loads to the building through that duct leakage to the outside.

这会严重影响室内空气质量。

It really leads to poor indoor air quality.

如果送风或回风的某段出现泄漏，房间就会出现冷热不均的情况。

You get all these different cold and hot spots if, like, a certain part of the supply or certain part of the return is leaking.

还可能带来安全隐患，以及各种湿度问题。

There can be safety hazards, all kinds of humidity issues.

所以一定要注意防止风管泄漏。

So just be careful with duct leakage.

特别是阁楼区域，一定要及时处理风管泄漏问题。

Address duct leakage, especially in attics.

不好意思，我问得有点基础。

Sorry to be asking.

对。

Yeah.

这些问题都是基本的。

These are basic questions.

不好意思。

I'm sorry.

不过你们在阁楼里会单独做一次Manual J计算吗？

But do you do a Manual J separately perhaps in an attic?

这种情况真的会做吗？

Is that ever done?

Manual J会考虑阁楼的各种具体情况，比如阁楼里发生了什么，以及这如何影响风管或天花板的热传递。

Manual J takes into account these different attic details for, yeah, what's going on the attic, how that affects whether that's the ductwork or heat transfer through the ceiling.

没错。

Yep.

问得好。

Good question.

好的。

Alright.

所以我们对Manual J很在行。

So we're pros on Manual J.

我们在测量风管容量方面已经是行家了。

We're pros on measuring duct capacity.

现在我们可以开始选设备了。

Now we can get into equipment selection.

提醒一下，Manual S 有个典型的垃圾进、垃圾出的问题。

So just a reminder, Manual S, we got this garbage in, garbage out problem.

如果我们没认真做 Manual J，也没测过风管容量，那可能根本没必要急着选设备。

If we haven't done a thoughtful Manual J, if we haven't measured the duct capacity, it may be even we shouldn't even bother with selecting equipment.

对吧？

Right?

你根本不知道风管容量是多少，或者你已经测过了。

You have no idea what the duct capacity is, Or you've measured the duct capacity.

结果发现，天哪，问题一大堆。

You've discovered, holy cow, we've got all kinds of different issues.

在进一步推荐整个系统更换之前，你得先跟客户好好聊聊——也许先改善建筑围护结构，降低冷热负荷，这样风管系统才有可能正常运行。

You need to have a conversation with your customer before you even go further and start recommending, like, a whole system change out because maybe you need to improve the envelope so you can reduce the loads and then actually make this duct system workable.

或者你可能需要先花一笔不小的费用，把风管的密封问题彻底解决，处理好各种接头，之后才值得去考虑更换设备。

Or maybe you need to spend a decent amount to air seal that ductwork to address a bunch of different fittings before it's even you need to have budget to consider equipment changes.

是的。

Yeah.

说吧。

Go

继续。

ahead.

Manual J 里头到底包不包括风管容量？

Manual J, does it or does it not include duct capacity?

还是说风管容量是另外一回事？

Or is duct capacity a separate thing?

风管容量是独立的一环，所以我才特意花时间讲这个，因为根本没被明确提出来。

Duct capacity is its own thing, which is why I actually I wanted to spend time on it because it's not really called out.

它不属于 Manual J 的内容。

It's not part of Manual J.

它也不属于 Manual S 的内容。

It's not part of Manual S specifically.

对吧？

Right?

Manual D 确实会详细讲这些，但流程很复杂，通常只在全新安装风管时才会用到。

Obviously, Manual D takes you through all of these details, but Manual D is it's a pretty intensive process and often is really only applied if you're doing brand new ductwork.

没错。

Yep.

好的。

Alright.

咱们来聊聊热泵吧。

So let's talk about heat pumps.

热泵有好几种性能指标，我们得搞清楚。

So there are a bunch of different performance characteristics of how we understand heat pumps in particular.

比如热性能，还有在不同室外温度下的制热能力。

We've got thermal performance characteristics, and we've got different heating capacity values at different outdoor temperatures.

我们有最小值和最大值，制冷方面也是一样。

We've got min and max values, same thing on the cooling side.

与显热比相对应的是显热因子。

The companion to the sensible heat ratio is the sensible heat factor.

也就是说，这是设备的显热制冷量除以设备的总制冷量。

So this is the sensible cooling capacity of the equipment divided by the total cooling capacity of the equipment.

这些性能特点都是为了提升舒适度。

And so these performance characteristics are all about comfort.

对吧？

Right?

这关系到系统如何转移能量，向室内输送或排出多少英热单位。

This is the ability of this system to move energy around and deliver BTUs or remove BTUs from the home.

这正是Manual S的核心内容。

This is what Manual S is all about.

另外还有一些能效方面的特性。

Now, there's some energy performance characteristics.

我相信你们都熟悉性能系数这个概念。

I'm sure you're familiar with the coefficient of performance.

这是用来计算夏季SEER（季节性能源效率比）和对应HSPF的基础指标。

This is the kind of foundational metric that's used for figuring out what SEER, the seasonal energy efficiency ratio, is for the summertime, what the corresponding HSPF is.

COP其实就是热输出除以电能输入的比值。

So COP, it's just simply the ratio of the thermal output divided by the electrical input.

热泵真的很厉害，每消耗一份电能，就能产生两到三、四，甚至五份的热能输出。

And heat pumps are pretty amazing that for every one unit of electrical input, we get two, three, four, maybe five units of thermal output.

这讲的是效率，但我特意把效率这边的字体调得很小，因为我们最关心的首先是舒适性。

So this is about efficiency, and I've intentionally made the font really small on the efficiency side here because we really wanna focus on comfort first.

一般来说，效率自然会跟着上来。

And generally speaking, efficiency will follow.

有意思的是，Manual S完全没提这些效率问题。

Now what's really interesting is Manual S is completely silent on these efficiency issues.

它只关注舒适性。

It's all about comfort.

好的。

Alright.

热泵的性能指标其实有很多种类。

So there are a lot of different performance metrics for heat pumps.

我们来看一下这张数据表。

Let's look at a table of data here.

我们列出了在两种不同室外温度下的制冷数据，以及在最多四种不同室外温度下的制热数据。

We've got cooling metrics at two different outdoor temperatures, and then we have heating information at up to four different outdoor temperatures.

麻烦的是，制造商并不强制要求报告最低温的那组数据，他们可以自行决定用哪个温度点。

The tricky part is that manufacturers are not required to report this fourth, like, most cold temperature, and they get to decide what temperature it is that they're using.

可能是零下五度。

So it could be at minus five.

也可能是零下十三度。

It could be at minus 13.

甚至可能是五度。

It could be at five degrees.

这由他们说了算。

It's up to them.

但希望你能看到四个不同的室外温度数据，尤其是在特别寒冷的地区。

But, hopefully, you've got four different outdoor temperatures, especially if you're in a much colder climate.

这些不同温度下，我们都有最小和最大制热能力的数据。

And we have min and max capacity values for all of these different temperatures.

举个例子，当室外温度是47华氏度时，这台设备——确实是真实设备——在最低运行模式下制热能力约为11,000英热单位，对应的能效比大约是3.23。

So just using an example here with the heating data at 47 degrees outdoor temperature, This particular piece of equipment, this is a real piece of equipment, has about 11,000 BTUs of capacity on its minimum operating mode and a corresponding COP of about 3.23 at 47 degrees.

而在最大输出时，制热能力大约是45,000英热单位，对应的能效比也更高。

And then it's got a corresponding max capacity at of about 45,000 BTUs and a corresponding COP.

实际上，这个最大能效比比最低能力时高得多。

It's actually much higher than the VIN capacity.

这在大多数热泵设备上都很常见。

And this is actually something that's pretty common with most heat pump equipment.

当设备接近最大输出时，我们反而会看到最高的能效比。

As you approach the getting closer and closer to maximum capacities, we actually see the highest COP's.

所以这也是为什么正确选择热泵的容量特别重要——如果设备选得太大，它大部分时间都会在接近最低输出的状态运行，而这时候效率是最低的。

So this is another reason why it's really important to size heat pumps correctly because if you massively oversize equipment, it's gonna spend most of its time closer to its minimum levels, which is the lowest efficiency for that equipment.

明白了。

Alright.

潜热容量的数据就复杂多了，不同厂家提供的数据格式差别很大。

Latent capacity values, these are much trickier, and it really depends on the manufacturer what this data is gonna look like.

通常你会看到类似这样的表格。

So often you'll see a table that looks something like this.

我知道后排的人可能看不太清楚。

I know it's hard to see in the back of the room.

表格竖着列的是室外温度，横着是室内机盘管的温度。

And what we've got vertically are different outdoor temperatures, and across the top are different coil temperatures in the indoor unit.

我们可以查到设备的总制冷量。

And we can look up what's the total cooling capacity of that equipment.

但厂家通常不会直接给出潜热容量的数据。

But often the manufacturers will not include the latent capacity directly.

他们只会提供总制冷量和显热制冷量。

They'll instead just give you the total cooling capacity and then the sensible capacity.

所以我们得自己算一下，latent capacity就是总制冷量减去显热制冷量。

So we have to do a little bit of math ourselves to figure out what is the latent capacity, which is just that total minus the sensible.

现在我们有了latent值。

We now have latent.

挺简单的。

Pretty straightforward.

我不明白为什么，很多风管机厂商偏偏用每小时品脱来标示潜热容量。

I don't know why, but a lot of ductless manufacturers decide to report latent capacity data in terms of pints per hour.

好消息是，换算很简单。

Good news is there's a simple conversion.

每小时一品脱的潜热容量大约相当于一千BTU。

There's about a thousand BTUs of latent per pint per hour of capacity.

所以在这个例子中，每小时3.8品脱，大概就是4000BTU的潜热容量。

So in this example, 3.8 pints per hour, that's roughly equivalent to about 4,000 BTUs of latent.

有时候，制造商还会用第三种方式来呈现数据。

And then sometimes there can be a third kind of variation that manufacturer will report the data in.

看起来像表格A，但不是给出总制冷量和显热容量，而是给出总制冷量和我们之前提到的显热比。

It'll look like table a, but instead of having the total cooling capacity and the sensible, they'll have that total cooling capacity and then the sensible heat factor that we talked about earlier.

这样我们就可以通过一点计算，推算出潜热容量是多少。

And so we can do a little bit of math, and we can figure out what that latent capacity is.

明白了。

Alright.

所以数据量真不小。

So it's a ton of data.

热泵涉及的东西真多。

Heat pumps got a lot going on.

各种数值都挺复杂的。

There's lot of different numbers.

请讲。

Go ahead.

你能回一下上一张幻灯片吗？

Can you go back to the last slide?

可以。

Sure.

好的。

Okay.

他说在最小容量时，能效比通常会低一些。

So he said at min capacity, the COP is typically lower.

这并不总是对的。

That is not always true.

是这样的吗？

That's that's right?

对。

Yep.

不总是这样。

Not always true.

大多数情况下是这样，但绝对不是总是如此。

Most of the time it is, but it's definitely not always true.

甚至大多数时候都不是。

Not even most of the time.

有时候才是。

Is sometimes.

所以变频热泵在中等负荷下的能效比通常很高，这点很有帮助。

So inverter heat pumps frequently have mid capacity COP's are very helpful.

不过要注意的是，你展示的这张表来自NEAT数据库，而这个数据库里的数据并没有经过实际测试或验证。

Now the caveat is you're showing that table and that table returned from the neat database and the neat database is not data that is been tested or proven.

只有少数几组数据

There's only certain numbers

是经过测试和验证过的。

out there that have been tested and proven.

对。

Yes.

制造商的数据就是这种情况。

So this is the case with manufacturer data.

大多数时候，他们用的是实验室里的测试数据点，但会往外推算。

Most of the time, they're using test data points they do in a laboratory, but they're extrapolating Extrapolate.

所以NEEP的数据，都是直接从制造商那里拿来的。

And so the NEEP data, it's all NEEP gets it directly from the manufacturers.

制造商把数据报给NEEP。

So the manufacturers are reporting to NEEP.

NEEP只是把数据展示出来。

NEEP is just displaying it.

你说得完全对。

But you're absolutely right.

这取决于设备本身，COP值是高是低，得看具体情况，后面我们会再详细讲。

It depends on the equipment of where those COP's, whether it's gonna be higher or lower, and we'll get into this a bit more.

这里最重要的是，你得了解自己的设备，但一般来说，高容量下COP值并不总是更高。

What's most important here is that you need to know your own equipment, but it's not generally always going to be higher COPs at higher capacities.

但很多时候确实如此。

But it's often it is.

这还是得看制造商。

Again, it depends on the manufacturer.

取决于具体的产品系列。

It depends on the particular product line.

好的。

Alright.

因为差异这么多，数据点又这么杂，想比较的时候特别容易让人头大。

So because there's all this different variation, there's so many different data points to look at, it gets overwhelming, especially when you're trying to compare.

我该选这个3.5吨的机组，还是4吨的呢？

Should I use this three and a half ton unit versus a four ton unit?

所以把信息可视化一下会很有帮助。

And so it can be helpful to visualize the information.

我一般会先从可视化家里的负荷开始。

So I like to start by visualizing the loads on the home first.

这是我在缅因州波特兰地区的家。

So you can take your this is actually my house in the Portland, Maine area.

在室外设计温度为五度的地方标一个点。

Just plot a point at five degree outdoor design temperature.

在那个温度下，我家的热负荷大约是四万两千英热单位。

I've got about 42,000 BTUs of load at that point.

然后我在华氏60度左右再标一个点，这时候我假设家里不需要供暖了。

And then I can draw another point at about 60 degrees Fahrenheit where I'm kind of assuming there's gonna be no heating loads on the home.

实际的温度会因气候区和建筑结构等因素略有不同，但60度对这种建模来说是个合理的参考值。

That actual temperature varies a bit depending on climate zone and architecture, bunch of other factors, but 60 is a reasonable place for this type of modeling.

这样我就能画出一条线，直观地看到房屋供暖负荷如何随室外温度变化。

And so I can draw a line, and now I can visualize how the heating loads of the home are varying with outdoor temperature.

制冷方面我也可以用同样的方法处理。

And I can do the same thing on the cooling side.

于是我就有了这两条线。

So I got these two lines.

我有一条供暖负荷线。

I've got a heating load line.

我有一条制冷负荷线。

I got a cooling load line.

现在我可以把这台热泵的性能数据叠加到同一张图上，从而更好地理解实际情况。

And now I can overlay that equipment performance data for this heat pump on top of the same graph and start to get some insight about what's going on here.

我们可以利用制造商提供的不同温度数据，绘制出最大供暖能力曲线。

And so we can use those different temperatures that are reported by the manufacturer, and we can generate this max heating capacity curve.

制冷侧也是同样的做法。

Same thing on the min side.

我们只是基于47华氏度的室外测试温度，或者 extrapolated 的数值来做的。

And we're doing that just using that that 47 degree outdoor test temperature or extrapolated value.

我们可以标出45,000 BTU这个点。

We can draw this point at 45,000 BTUs.

175的时候也一样，以此类推，然后画出这些曲线。

Same thing at seventeen five, so on and so forth, and we can draw these curves.

我们还可以叠加能效信息，看看它是怎么变化的。

And so we can also overlay some information about the energy efficiency and see how that's varying.

甚至可以用这些数据，来判断这户人家在特定温度下，用这套设备的制热性能系数是多少。

And we can even use this information to help us understand for this particular home with this particular equipment at a certain temperature, what's the COP gonna be.

所以我可以画一条线，连接最小和最大能力线，比如说在17度的时候，看看它和负荷线的交点在哪里，然后就能得出结果。

So I can actually look at where the line if I draw it between the min and the max line, let's say it's 17 degrees, I can look where it crosses my load line, and I can figure out, okay.

大致来说，这套设备在17度时为这户人家运行的制热性能系数大约是2.45。

Roughly speaking, this piece of equipment is gonna operate about a COP of 2.45 at 17 degrees for this home.

这工作量可不小，所以有聪明人就提出了HSPF这个指标。

That gets to be you know, it's a lot of work, which is why some smart people came up with HSPF.

SEER和HSPF这些评级，把各种温度和负荷变化都综合进去了，方便我们对不同设备做公平比较。

And SEER ratings encapsulate all of this variation for a a typical home load profile or or temperature profile and to be able to compare apples to apples between equipment.

好了。

Alright.

所以Manual S的核心，就是为设备选一个刚刚好的尺寸。

So Manual S, it is all about Goldilocks ing the equipment.

设备不能太大。

We don't wanna be too big.

也不能太小。

We don't wanna be too small.

ACCA刚刚发布了新版的Manual S。

ACCA released a brand new version of Manual S now.

大概是一年半以前发布的。

It's about eighteen months ago.

现在可以在ACCA官网上免费下载。

It is available for free on ACCA's website.

我强烈建议你们去了解一下。

I highly encourage you to check it out.

这是目前唯一完全免费的暖通设计手册，至少规范部分是免费的。

It's the only design manual that is available totally for free, at least the the normative section.

能让人免费获取，真是太好了。

Just excellent that it's available for everybody to take a look at with with no cost.

所以根据《Manual S》的核心理念，它特别强调尺寸限制，目的是为客户提供更舒适的体验。

So right from Manual S, it is really focuses on this concept of size limits to help deliver comfort for your customer.

我们试图在各种性能指标之间找到平衡点，比如供暖负荷、显热制冷和潜热制冷，就像找那个刚刚好的金发姑娘一样。

And so we're trying to Goldilocks those different performance metrics that we were talking about, the heating loads, the sensible cooling, and the latent cooling.

这个新版《Manual S》特别棒的地方在于，它新增了很多专门针对热泵的调整内容。

What's really great about this new version of Manual S, there's a bunch of changes that are really specific to heat pumps.

现在有了新的选型容差范围。

So there's new sizing tolerances.

无论在潮湿还是干燥的气候下，选型都更灵活了，甚至为仅需供暖但配有独立除湿设备，或身处干燥地区的用户，专门设计了选型路径。

There's more flexibility both in wet and in dry climates, and there's even a a sizing pathway for heating only if you've got dedicated dehumidification or you're in a dry climate.

我们之所以如此重视这种‘刚刚好’的尺寸选择，背后有好多原因。

So we really care about this Goldilocks sizing for a bunch of different reasons.

所以我觉得有必要聊聊，设备选大了和选小了，分别会带来什么后果。

And so I think it's helpful to talk about, like, what happens when we oversize equipment versus when we undersize it.

设备选得太大，会导致频繁启停，室温波动剧烈，直接影响住户的舒适感。

So when we oversize equipment, we get a lot of short cycling, which leads to big temperature swings, has a big impact on comfort for that homeowner.

如果设备太小，就可能出现供暖能力不足的情况，冬天里客户家里可能会变得挺冷的。

When we undersize, we can obviously end up in situations where, let's say, heating, we just don't have enough capacity, it could get kinda cold, in the wintertime for that customer.

这显然让人不舒服。

That's obviously uncomfortable.

还可能导致风机转速过高，带来其他类型的噪音问题。

It can also lead to higher fan speeds, so other kind of noise discomfort.

这对室内空气质量也会产生一些有意思的影响。

There's some interesting impacts on the indoor air quality side.

特别是在潮湿地区，比如路易斯安那州，如果设备严重选大了，可能会出现严重的霉菌问题。

Dramatically oversizing, particularly in a humid climate, let's say, a place like Louisiana, you can get some really scary issues with mold growth.

对吧？

Right?

如果设备频繁启停或者短时间循环，它其实根本没在持续运行。

If that equipment is constantly cycling on and off or if it's short cycling, that equipment's not running.

要是设备不运行，空气没法流过换热盘管，我们就没法有效除湿。

If the equipment's not running to actually move the air across the coil, we're not gonna be extracting any moisture.