答复

1. Expert Member
   阿科斯|2022年4月12日下午10:17|#1

   https://ashp.neep.org/#!/product/51515/7/25000///0

   Turndown doesn't look all that good on those. but this data could be wrong. Daikin support is your best bet for accurate answers

   Generally with multi split, best is to avoid installing small heads on them as they can be running a good part of the time bellow the min output of the outdoor unit. When this happens the outdoor unit would be bypassing refrigerant through all the zones even if off which can create overheating or cooling of zones and efficiency is pretty low.

   Even with larger heads, you might only get a 2:1 turndown on the indoor unit. The overall turndown depends on the exact configuration which is surprisingly hard to find.

2. 
   Kyle Klouzal|Apr 12, 2022 10:58pm|#2

   Thank you for that website, it does give some insight into specific configurations. I was hoping to find the maximum supported turndown ratio of the particular heads regardless of whole system configuration, the 'theoretical turndown ratio' if you want to call it that.

   The RXTQ48TAVJUA for example supports a maximum of 8 indoor units. So if for instance I wanted to put 8 of the 7500btu heads on and 7 of them were running full blast but the 8th only needed to be on the lowest possible setting just shy of shutting itself off, what would that btu output be?

   I do understand that refrigerant will still run through the heads of a small system if the heads that are running don't equal at least the minimum turndown ratio of the outdoor unit, which for the RXTQ48TAVJUA is 14% or 6720btu.

   话虽这么说，在上面的理论配置中，只有一个7500btu的头部运行，室外单元只能将其自身降至6720btu。
   2个头，他们会在3360时运行吗？
   Could only 3 running heads turn themselves down to 2240?
   Can 4 heads get down to 1680?
   5点降至1344？
   6降至1120？
   7至960？
   所有8个头能否以最低的能力运行到840btu？

   我希望能够根据特定的房间安置和冷却需求计划边缘案例，并且必须为实现室内单位的转折比率计划。

1. Expert Member
   阿科斯|2022年4月13日上午09:34|#4

   通常，这不是它的工作方式。当每个人在线时，最小调制也会有所增加。

   正如您所建议的那样，您也有限时重叠的时间。更有可能的情况是同时呼吁加热的一个或两个头。这些将接近满足负载，因此它们将立即达到设定点。到其他区域要求加热的时候，它们将脱落，从而完全/完整的周期重复。

   To get a multi split setup working properly, each head must be matched to the zone it supplies. So a 9k head, needs a near 9k zone, you can't rely on modulation for matching.

   如果您想要更多的分区，则可以查看带有空气区设置的较大的管道​​单元，以喂养较小的房间。

1. 
   Kyle Klouzal|2022年4月13日下午10:44|#6

   I agree with you 100% you need to match the head to the room as close as possible 9/10 times.

   Say you have two rooms, one requires 5000btu and the other requires 4000btu peak cooling capacity. Now in this scenario I believe you have two choices, place a 9000btu head and duct it to both rooms OR place a 5800btu head in each room that has the capability to modulate down below peak requirement.

   现在，您必须担心短期循环。拥有单个头部的调制率可以帮助您做出更明智的决定，无论是否与一个较大的头或两个较小的头部相处。

   Maybe this system was also designed so that the connecting hallway, which requires 1500btu peak cooling capacity, be fed from these two rooms as well. This could further work to help offset short-cycling, or during the hottest days could even work against you and result in the two bedroom heads being slightly undersized.

   也许这座建筑物的设计也是通过单独的HRV/ERV系统从其所有房间中持续的50厘米fm的空气流通，这意味着可能有一些房间略微缩小，并且有些房间略微超大，基本上为您提供了一个小的BTU缓冲区，以缩小区域的尺寸。在这种情况下，每个房间都是其自己的单个区域，但是整个建筑物都是通过通风系统连接的，并不断有效地循环，使所有头部都可以在某种程度上协同工作。

   有太多的变量要计算，并且没有重要的变量，例如每个单独的头部上的扭转率，可以说是您的视力。Daikin为什么要扣留这些数据？这是他们的“秘密酱”，还是他们的比率太可怕了？恐怕我们可能永远不会知道。

   Sorry, I've been over analyzing, crunching numbers, peering through engineering datasheets, and chasing down what-ifs for what feels like an eternity now.

2. 
   詹姆斯·霍森|2022年4月14日上午09:09|#7

   有什么链接到空中案例研究吗？有人知道这些安装成本是多少吗？似乎不是在线价格。

   关于与VRF的TAMPER分区有关的文章，包括Airzone以及与多裂灾难的比较，对于GBA来说，这是一篇很棒的文章。

3. 
   Kyle Klouzal|2022年4月12日晚上11:19|#3

   Maybe the information I am looking for is actually with the branch provider box, each branch has it's own electronic expansion valve (I thought the indoor heads had EEVs too) so potentially the refrigerant is limited at the branch box and not the head.
   但是，我找不到分支盒的工程手册...多么方便。
   BPMKS049A3U

1. Expert Member
   阿科斯|Apr 13, 2022 09:35am|#5

   如果您确实找到了正确的信息，请在此处发布。这种信息几乎找不到。