Not enough hot water
Please help my planning… hypothetical… but more that possible…
I am planning a 80 gallon heat pump water heater.. there is a strong chance that this will not meet the demand at times of a family of 5 who all shower in the morning… washing machine etc… and a soaker tub… Aside from the obvious (no soaker tub, spread out the showers, have less teenagers)
2个选项..
1. Install a marathon 50 gallon after the hpwh… I can then switch the heat pump water heater to heat pump only mode.. and the marathon would use its well insulated self to maintain the temp…
2. Install a stiebel eltron 36 plus to handle the load after the heat pump water heater starts delivering low temp…It may reduce the flow… but wont experience cold water… I guess part of the question is will this unit not use much electricity most of the time when the water temp from the hpwh is ok.
Which scenario makes the most sense, and uses the least amount of energy? best guess?
Thank you in advance
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Neither sounds like a very good option to me. With the Marathon after the heat pump, after a heavy draw you'd have 50 gallons of lukewarm water in the Marathon that you couldn't heat with the heat pump, unless you had a circulating pump to move water between the two tanks. With the electric tankless, you'd need high-current electric service, which could make it expensive to install and perhaps eventually expensive to run, if utilities start charging for peak load. The 36 requires 300 A service to your house, and then three 50 A circuits running to it! In principle that could work, but it seems a little crazy.
So what I recommend instead is a drainwater heat recover system such as the powerpipe system.http://www.renewability.com/general/index.html
你有重合时,效果最好or nearly coincident showers. It will make your tank go about twice as far, and will help your efficiency rather than hurting it (which the other two solutions would do).
Dean,
Stiebel Eltron Accelera 300的第一小时评级为76加仑。一种选择是与热泵热水器一起生活几个月，以查看它是否满足家人的需求。
两个建议：
1. Drain water heat recovery as suggested by Charlie - some upfront cost, but less than the options you mention - reduced operating cost. This works great for showers because the water drains at the same time as it is drawn.
2. Set the temperature higher so that your mixing valve mixes in more cold - no upfront cost but increased operating costs due to higher standby losses and lower COP. You can set the temperature back to around 120 whenever you don't have so many people at home.
我肯定会研究排水的恢复。.我只能将其用于主人，以及排水管的设置方式。我想我将按照马丁的建议安装Stiebel Accelera，看看是否足够……尽管我很确定洗澡后不会有一段时间...我只是希望它会装满浴缸...
I am just going to plumb ready for a marathon or a tempra after the accelara.. and plan for the electric as well.
If I did install the tempra... If It detects hot water coming in... will it not fire up? and then only use energy when the accelara empties out?
Here is a link to the marathon after a heat pump that Matt Risinger put in in one of his homes.https://youtu.be/oojkha_dqwa
Charlie, could you help me explain why I would need a recirc? I imagine that the hpwh would fill the marathon with hot water and it would heat its own water also... essentially i would have 130 gallons of first hour hot water available... Luke warm water would only fill the marathon after the 50 gallons from the marathon and the 80 gallons from the accelera are gone..
You would only need to circulate water between the two tanks if you wanted to heat both with a heat pump. If you don't mind finishing heating the 50 gallons with the electric element, that works fine. E.g. set point 140 F, and the temperature in the Marathon droops to 120 F after the big draw. You are then doing 50 gallons of heating the last 20 F with the electric element. If you circulated between the two tanks, you could do that heating with the heat pump.
I'm not recommending doing the circulation--to complex and expensive. I'm just saying that without it, you aren't doing all the heating with the heat pump.
是什么防止在其他排水管上使用排水恢复？如果有帮助，则使用不同的几何形状：
https://ecodrain.com/en/
You could use a geyser heat pump and a 200 gallon tank. Standard electric or solar storage tank, add the geyser and get the heat pump effect.
Ven,
You can buy 200-gallon stainless-steel tanks -- or larger ones -- but a 120-gallon tank is typically the maximum size that fits through conventional doors, or fits down conventional stairways.
@院长。我认为某些行为改变比试图满足最坏情况的情况更实用。您能说服您的青少年前一天晚上参加淋浴吗？当没有其他需求对油箱的需求时，您可以使用洗衣机和洗碗机使用吗？（并非有效的电器使用那么多水。）只是问。
排水热恢复（即使您必须购买倍数，才能提供所有淋浴）的生命周期成本也比以往任何时候都更低。
储能升高可以从水箱中获得更多的收益。它会稍微切入热泵水效率。
If you are heating the place with a hydronic boiler, an ~80,000 BTU/hr boiler can run a single shower 24/365 even in cold water country, and you would size the indirect tank for the monster-tub.
Is the master shower a super-luxe thing with six side sprays?
没有淋浴很大，但只有两个头……我真的无法证明洪水是合理的。
I am definitely going to do drainwater recover.. but only two of the showers are on the main level.. and one is a rarely used guest shower.. three showers in the daylight basement with drains in my "no mold, stay dry basement!" . So It realistically only makes sense for one drainwater recovery.
我在线看到“电源管”是我们正在接受的吗？
I wasn't planning on recirculating the water between the hpwh and the marathon.. hpwh on hp only mode... and marathon just does its thing.. but suppied 90 percent of the time with 140 degree water from the heat pump...
If i went with a geyser and a storage tank.. do they have elements to keep it at temp? If so then what is the difference in my plan..
我想我真正想知道的是...如果140个温度水流流过它，Tempra 36是否会使用几乎没有能量？而且只有在热泵无法跟上...出于某种原因时，我只是认为这是有道理的。
Although I do have natural gas, and am tempted by a condensing tank vented ... for some reason, I really want to stick with electric, partially because someday I might further explore pv.
达纳,现在的计划是一个传统的空气源heat pumps no furnaces, I am in NC... I started to go down the whole house mitsubishi plan.. went very far down that hole.. to the point of having mitsubishi designers out to the house.. The loads are low enough that tradional high seer, zoned system seems to make the most sense. That combined with the fact that no one in my area has enough experience with ducted and ductless mitsubishi. I have one quote still out on horizontal drilled ground source, but don't have that quote back yet... I am already struggling with the insane quotes I am already getting on the traditional air source route.
Fujitsu RLFCD series mini-ducted systems can be more straightforward and cheaper in low-load homes than multi-splits, if you can find a competent duct designer willing to deal with less-powerful-than-traditional air handlers. Among mini-duct cassettes they have some of the best blower specs.
Renewability's PowerPipe series are probably the biggest volume sellers, but they have competition. The biggest (both in diameter & length) that fits is the best choice, with the fastest payback. The unit costs more, but the installation labor is the same, and the higher return efficiency more than makes up for the marginally higher up front cost. There are others vendors as well. For apples-to-apples comparison purposes Natural Resources Canada developed a test protocol and maintains a list of models with third-party tested efficiency under standardized conditions. (see attached spreadsheet)
Dana,
I just went as far as I could with the low and high static ducted with mitsubishi... It just that I would need so many units, because of the size of the house. I just decided to simplify... I will have 3 variable speed high efficiency heat pumps zoned properly (leaning toward lennox xc25 which is pretty strong. I am putting in 2 one to one 30+ seer ducted fh09 for a couple of applications.