每个区域的多层温度控制

Alok Khuntia|发布Mechanicals上2015年4月14日上午05:32

I am considering a multisplit heatpump system for our 3000 s.f. two-story renovation located in Chicago, Zone 5. I like the idea of a multisplit system for its high efficiency and zone control. I would like to provide 1 unit per bedroom using ducted interior units that supply conditioned air to each bedroom.

因为对于这150-200 S.F.，即使是最小的内部单元也会过度杀伤。卧室，我计划将每个单元的某些空气从一个公共空间中进行，同时将温度控制单元保存在卧室中。有人告诉我，在这样的高性能（近被动）房屋中，我无法真正控制每个卧室的温度。我发现这很难相信。如果该单元针对每个区域的一定温度，为什么我不能获得这种温度控制水平？

是否有人在这样的解决方案中拥有现实生活经验？

谢谢！

回答

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Replies

Expert Member

Dana Dorsett|2015年4月14日下午05:48|#1

If you are really at near-passivehouse levels there's no way you would ever need or want to have one unit per bedroom, dumping the excess heat into the common area, since that would overheat the common area. If you put the majority of the flow into the bedroom it will just cycle on/off, and never modulate.

Also, a multi-split that can handle 4-5 heads/cassettes has a minimum compressor load at which it will operate, and that min-load may even be comparable to your whole house design heat load. By having multiple heads it forces the compressor to be many times the size needed to heat the place, which cuts into both efficiency and comfort (not to mention, the installed cost.)

一个更好的解决方案是让一个基于计算的热载荷提供2-4间卧室的小型纸盒单元，并且与任何非调节管道的空气加热解决方案一样，设计和调整了用于温度平衡的流量。然后，单个乘员可以通过调整注册表来微调流程以适合其偏好。
Alok Khuntia|Apr 15, 2015 07:42am|#2

Thanks for that insight Dana. I will try to find a solution based on your suggestion. Am I correct to assume that I CAN get true zoning in a near-passivehouse as long as the total capacity of my indoor units is matched to the total load of the home? i think my initial layout would have provided about 30-50% more capacity from indoor units vs house load and result in excess cycling.
GBA Editor

马丁·霍拉迪（Martin Holladay）|Apr 15, 2015 07:53am|#3

Alok,
坦率地说，通过无管道系统（甚至是管道的迷你平台系统），很难对室内温度进行完美控制室内温度。不是不可能的，但是困难。

如果你需要完美的一致性thermostat temperature and your indoor air temperature in each room, you might be happier with electric resistance baseboard heat.
Charlie Sullivan|Apr 15, 2015 10:04am|#4

即使加热系统与负载完全匹配，它的肩部季节也超大，甚至是典型的一天。因此，当您说30-50％的超大号实际上比这听起来还差。
Expert Member

Dana Dorsett|2015年4月15日上午11:49|#5

超大的迷你切片与超大铸铁锅炉或2级燃气炉不同。它们调节，降低比率非常大。但是这些降低比率不是无限的。

The 3/4-ton Mitsubishi FH09NA can cut back to as little as 1600 BTU/hr. The 3/4 ton in that series can pull back to 2800 BTU/hr, and the 1.25 ton unit can drop to 5150 BTU/hr. But they can also deliver 10,900 BTU/hr, 13,600 BTU/hr, and 18,000 BTU/hr respectively. If the thing is 50% oversized for the load running at it's MAXIMUM capacity at 0F (the 99% outside design temp at Chicago's Midway Airport) it would still modulating MOST of the time. But if it's even 30% oversized for the 0F load at it's MINIMUM speed, it literally never modulates, only cycles on/off.

Fujitsu _ _ RLS3H系列都可以降至3100 BTU/HR，甚至1.25吨15RLS3H（还可以提供16,000 BTU/HR @ -15F。）3/4吨也可以提供近16,000 btu/hr @ 0f。借助该系列，它可以以最大容量为单位的负载100％超大，并且大多数时间仍会调节。

But even at mid-modulation at 0F any 9000' head is going to be oversized for the load of an individual bedroom, even in a code-min house, since it can deliver the full heat load at or near it's minimum modulation, and would be cycling on/off at the average winter temp. In a "...near passive..." house it's going to be INSANELY oversized. The heat load of a 200' bedroom in a code min house is tyically less than 2500BTU/hr @ 0F, and in a high-R house it's often in the 1000BTU/hr range or less, and it would be cycling on/off even during design conditions.