国内热水需求不再是一个问题吗？
传统上，加热和冷却要求是房屋中最大的能量绘制。现在可以通过更好的建筑技术（例如pH）来重复在家用能拉伸层级中的加热和冷却到2ND甚至第3位的能力。普遍认为，绘制的新王是DHW。但是，我想知道现在是HPHW系统是否仍然是这种情况。我住在一个暖气的气候中。每phi允许的最大加热需求为4.75 kbtu / sf或5.2kbtu / sf，每个phius +为我的气候区。如果我要建造1,500个SF家，这意味着我PHI中的最大允许的年度加热需求为KWH 2,088（（4.75 / 3.412）* 1500）。我应该预期我的年度DHW需求的需求以及它如何比较。我看着DWH的一个室内和分裂系统ASHP。当我在Wufi中的室内建模时，由于来自冷凝器的冷空气引起的寄生热损失，我无法遵守年度供暖要求。 When I used the Sanden inputs provided by PHIUS, I easily beat the heat demand numbers. However, that did not tell me anything about my DHW demand. All I had to go on was that it was more efficient than using ER or indoor only ASHP. I have been following Matt Bower’s blog for his to be certified PH in Rochester, NY, a colder climate than mine. He recently posted a picture of his Sanden and according to the Energy Guide sticker on the tank, the projected annual consumption in KWH is 1,250! Huh? Less than PH heating demand. Too good to be true. I checked Sanden’s website and found this presentation given by WSU at the the 2015 NAPH Conference.
http://www.sandenwaterheater.com/sanden/assets/File/Advanced_HPWH_Research_Fall2015_NAPHN2015.pdf
根据他们的分析，桑德使用约5kWh / 100加仑。除非每个人都在洗澡，否则100加仑可能超过一家4家使用。它似乎也与能源指南一起。这不包括排水水热量回收，Matt用他的单位安装。一般来说，热回收制造商仍可储蓄另外30％。所以，我们可以看出3.5kWh / 100加仑的下方。我错过了一些东西，或者这是寒冷气候的新现实吗？这是否意味着室内只能提供类似的益处是暖气的温暖气候占主导地位？
It will be interesting to see what Matt’s usage looks like after his first winter and I hope he posts it.
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Replies
热回收厂家总HW的估计energy savings are not to be trusted. It depends a LOT on the actual hot water use profile, and the flow rate for continuous flow applications such as showers. NRCAN testing standards are at 2.5gpm at a fairly substantial delta-T between incoming water and drain outflow. Lower flow such as a low flow shower head increases recovery efficiency, but also reduces the total hot water used for showering, making it a lower fraction of the total hot water use. Warmer than tested incoming water temps reduces the heat transfer effectiveness,, but also reduces the total amount of energy needed to heat that water to useful temperatures.
Bottom line- 30% is likely to be a significant exaggeration, though it's conceivable that fanatic "endless shower" hot water hogs could beat that, if showering represented 3/4 or more of their total hot water use. For most families I suspect 15-20% net energy savings is more realistic.
Dana,
我怀疑你是正确的，实际上节省了非常依赖于行为/用法，并且可能少于预期。我的原始计划是在净水器下游安装排水水热回收管，并根据制造商推荐给冷水供应。我要保持设计，但坚持购买和安装一个，看看我的实际使用情况是什么。