Decentralized ventilation shortcomings?
你好
I have read all of the articles here, and of the article comments and all of the Q&A posts and replies. So it’s safe to say I have all of the info. But, it might have been to much info to make a confident decision when choosing a ventilation system.
分散的系统对我来说似乎非常棒。
Pros
-much cheaper。For my planned 1900sqft house, a Zehnder/Paul central ventilation system is ~10000$ installed price. Lunos sytsem with 3 pairs of e2 and 2 egos installed price is ~4500$.
-粒度控制。I guess not as important and prone to human error, but nevertheless, I personaly see it as an advantage
-less spacetaken. Central ventilation with flexible plastic ducting would take an additional 3 inches vertically, and a couple of m2 in the utility room.
-更容易安装。至少在我的情况下。我们可以自己做的一些工作，因为我们不能，它更容易找到。
Cons
-not as quiet（？）。看着数据表，Lunos e。在最低设置中仅生产16.5dB，最高设置仅为26dB。我的笔记本电脑在装载时产生35dB，我没有发现它响亮的令人讨厌，甚至在晚上都不会讨厌。
-粒度控制。我可以看到它是如何骗局。这不是吻。例如，如果外面有烟雾，我想转向通风，我必须在2-4个地方做，而不是一个。我没有看到经常会这样做。
中性的
- 效率对我来说并不担心。它类似于不带来差异。
- 成本效益is likewise not important to me. It’s simlar enough in both cases (neither is probably cost effective in a reasonable timeframe)
Are there any more important reasons to go with the much more expensive central ventilation solution, even when dealing with a new build (clay brick)?
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答复
I did read the following complaints in 1 review by the company that has a steak in CENTRAL HRV ventilation, so not sure how much of it might be true.
-energy efficiency and CFM rate is fake and is at least half of claimed
因为它是由EN308而不是PHI测量，所以它没有足够的证据。此外，这确实有一些意义：如果一对伦敦E2球迷保持切换方向，我们已经将它们交叉发动机更大的房间，他们将50％的时间从一侧移动内部污染空气。其他，而不是将索赔的CFM带到房子里面的新鲜空气。因此，实际的CFM平均由LunoS声称的一半。
——大多数情况下,很难实现良好的通风ilation, because of similar issues in previous point. Basically, they say it's hard to actually extract used polluted interior air, and that through-wall ventilators like the Lunos at least half of the time just move stale air around.
- price is similar to central.
我知道的这个不是真的，因为我都有在两者上提供。正如我在我的OP中所说的那样，Lunos系统，便宜至少50％。这是一个很大的不同。而这篇文章由公司的所有者制定，我从中获得了中央通风报价。所以他在类似的地理位置，价格相似。如果他在美国，我可以理解
一对伦索斯〜650美元+ Compisioning是〜70 $每对。钻孔和电力，我不确定，但我可以做到自己。
随着中央，我需要很多额外的eps，我也需要大量的孔，在内墙和混凝土中。
过滤器维护：清洁/更换一个中央滤波器比通过家庭展开的几个更容易。
Thanks.
是的，忘了提到这一点。
Though, how often does one does that? Once or twice a year? It's definitely something to think about for someone who really wants minimize all distractions, but this is not something I personally would mind much. Because currently, ventilating using windows is a much, much greater undertaking, so even having to mind 8 filters is a vast improvement in comparison :)
I keep hearing that decentralized systems, like Lunos or ComfoAir 70 or other similar systems, are only ever used in remodeling. So there has got to be a bigger reason I am missing. After all, mechanical ventilation is only a recent development, it's not like there is a tradition of centralized ventilation systems. I am currently looking for new builds that have it and people who are willing to share subjective experiences. Those would be valuable.
更不用说LunoS的“CopyCats”，像Marley HRV（http://www.marley-germany.com/en/products/ventilation/fresh_air_heat_recovery_unit/index.htm），价格仍然在一半。
我不会去这一特定的一个，因为它更响亮（在最低设置的3db是两倍的？甚至比那些19db更响亮。
3dB is double the sound pressure level, but human hearing is logarithmic. 10dB is a perceived doubling. 3dB is noticeable, but pretty modest. Given the different ways they can be testing it and reporting it, I wouldn't even count it representing any real difference. If it was the same manufacturer, sure.
As for price, you're comparing just about the most expensive option in Zehnder. I'm sure you can find options on distributed systems that are much closer to the Lunos price.
你会认为，但不是真的。至少在这里，我可以找到的中欧。
AFAIK,所有人(包括Zehnder) are using exchanger cores made by Paul, so prices are very similar.
Ducting and labor is the same.
Where I live, I only have Zehnder, Paul and Helios available, and they have very similar pricepoints.
I did hear that maybe I could find Mitsubishi Lossnay devices, but AFAICT, not officially.
对不起，我假设你在美国（因为大多数人在这里，你引用价格的价格，并引用了两个常见的品牌）。
我更震惊你没有更多的选择。Passivhaus学院列出了欧洲的几十个HRV / ERV制造商。Jablotron在捷克共和国，虽然如果他们的单位更便宜，但我会感到惊讶。
We're pleased with our Zehnder HRV. It's quiet, efficient, and was easy for our electrician to install. Mounted on the ceiling in the mechanical room, it doesn't take up much space. The boost switch is something we use a lot. The two MERV 13 filters are replaced in seconds. It was expensive, i.e. about $6,000 or so, installed about three years ago. We're glad we decided to spend the money.
We have 2 pairs of Lunos e2s, installed as part of a retrofit. We've been pretty satisfied with them, but one thing to realize about the sound level is that it is not constant. Rather, you will hear the fan slow down, stop, and then speed up every minute or so. We've become accustomed to it so don't notice it anymore, but we noticed it when first installed it, and any guests will notice it (this is especially true at night when trying to sleep in the bedrooms).
我记得读取许多人以最低速度保持他们的月经，以降低噪音水平。我们也这样做，所以我们只推动20个CFM，虽然这对20世纪60年代的牧场家园很好。但即使这20个CFM也不等同于20个CFM集中系统。分散的系统依靠空气混合，以便不能继续前后移动相同的空气，因此应该被认为比集中系统更少。
We went with Lunos because it was relatively cheap for our retrofit situation and wanted to avoid running ducts through the attic (we were considering cathedralizing). Now that we've decided not to cathedralize our attic, if we had to do over again, I might opt for a centralized system. We're satisfied with the Lunos, but would probably be happier with a centralized system.
Long story short, my recommendation to others is to only pursue a decentralized system if you're planning to move the target amount of air on lowest setting. Probably not ideal for a larger Passive House, but could be fine for a smaller Pretty Good House.
> Decentralized systems ... should be considered less effective than centralized systems.
让我们看看有关此索赔的数据。我希望门尺寸或更大的任何连接将对空气质量产生微不足道的影响。
> they will 50% of the time just be moving interior polluted air from one side to the other,
I don't understand where this claim comes from. Whenever the fan is running, it is exchanging air with the exterior.
是的，但如果有两个粉丝，一对，而且他们同步，就像其他人也表达出来一样，他们中只有其中一个将供应新鲜空气。所以，如果每个人设置为20cfm，你就不会得到40个CFM，只需20次CFM。或？
我的猜测是，与传统的ERV / HRV一样，CFM评级是整个系统的（即，一对风扇）。
The eGo model spec is clear "3/12 CFM with heat recovery / 27 CFM in exhuast mode".
Hm, yeah, but.. Systems like TwinFresh, they can also work each by itself. Meaning, they don't have to be balanced. And they are rated with similar CFM as Lunos. Syncing is optional with them, so I would reckon they would give the single fan CFM rating.
无论如何，这是我应该进一步调查的事情。