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Reservoir: Smart electric water heater

reservoirhome.com

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Re: Reservoir: Smart electric water heater

#41

Post by therapod12 »

porphyra wrote: post #3

Interesting but federal tax credits for heat pump water heaters is ending next month [1]. It looks nice though. For people wondering what's up with the "150 gal virtual" capacity, it's actually a 47 gal water heater but it heats water to a really high temperature (if needed) and mixes it with a thermostatic valve to output the desired temperature. For example if cold water was 15 degrees C and you want the hot water…

They must be doing something different to get that much capacity. There’s a bunch of water heaters with mixing valves but they don’t talk about that much capacity. What worries me is, doesn’t higher temperature make your tank rust faster?

Re: Reservoir: Smart electric water heater

#42

Post by thekraken57 »

swiftcoder wrote: post #11

... I may be out of touch with US water usage, but just how much hot water does the average household use? They quote $2,500 10-year savings vs oil. I have my hot water piggybacked on the oil-fired condensing boiler unit that's also used for my central heating, and I doubt I burn more than $250/year total on the hot water side of the equation (in a 4-bed, 4-bath house).

hot water is a huge piece of home energy. DOE had this study that showed more energy for water heating than electric car charging in a home with both. Just look at the total energy use on the energystar sticker of a standard water heater. https://www.energy.gov/eere/vehicles/articles/fotw-1307-sept...

Re: Reservoir: Smart electric water heater

#43

Post by maxerickson »

gmac wrote: post #25
phil21 wrote: post #23

The best investment in my comfort and upgrading my home was two redundantly configured Navien continuous water heaters. Never worry about running out of hot water ever again. If I’m gone on a trip for 2 weeks my hot water bill is zero. Due to having overcapacity, whenever I have guests staying with me no one ever has to worry about simultaneously using showers or any other hot water at all. I run out of water pressur…

Is this unusual in the US? I think almost everyone in the UK for years has been installing ‘combi’ boilers, which are ones that heat the water in radiators and also heat water on-demand.

A lot of US houses have forced air for heat (I guess because it combines well with cooling).

Re: Reservoir: Smart electric water heater

#44

Post by p1esk »

etrautmann wrote: post #39
p1esk wrote: post #31

Earlier quoted context omitted.

Two reasons I decided not to go with tankless: 1. Can’t have recirculation pump to supply hot water instantly throughout the whole house. 2. Significantly higher energy bill compared to heat pump. An additional bonus is the heat pump cools my garage in the summer.

1 sounds like a huge inefficiency?

Why?

Re: Reservoir: Smart electric water heater

#45

Post by swiftcoder »

thekraken57 wrote: post #42
swiftcoder wrote: post #11

... I may be out of touch with US water usage, but just how much hot water does the average household use? They quote $2,500 10-year savings vs oil. I have my hot water piggybacked on the oil-fired condensing boiler unit that's also used for my central heating, and I doubt I burn more than $250/year total on the hot water side of the equation (in a 4-bed, 4-bath house).

hot water is a huge piece of home energy. DOE had this study that showed more energy for water heating than electric car charging in a home with both. Just look at the total energy use on the energystar sticker of a standard water heater. https://www.energy.gov/eere/vehicles/articles/fotw-1307-sept...

I do not understand how this is possible in general. For example, I use ~3,600 litres of oil to heat through the winter, and the same boiler consumes less than 300 litres to produce domestic hot water for the other six months of the year.

That places my central heating on the order of 5-10x higher energy expenditure than my domestic hot water - this does not seem atypical in my area, and apparently data for the entire EU is similar (60% heating, 15% hot water): https://ec.europa.eu/eurostat/web/products-eurostat-news/w/d...

Re: Reservoir: Smart electric water heater

#46

Post by toledocavani »

bob1029 wrote: post #13

I don't think hot water should be this smart. The last "intelligent" systems that made sense to me in the home are variable speed HVAC and micro grid / solar / battery stuff. What is the value add to the customer of making hot water an app that can presumably stop working the next time AWS goes down?

It can misses some sensor readings, boil the water and scalds the user "automatically". Dumb heaters requires the user to "manually" do this, they never do though. P/S: I'd prefer your stop working scenario

Re: Reservoir: Smart electric water heater

#47

Post by Balgair »

porphyra wrote: post #3

Interesting but federal tax credits for heat pump water heaters is ending next month [1]. It looks nice though. For people wondering what's up with the "150 gal virtual" capacity, it's actually a 47 gal water heater but it heats water to a really high temperature (if needed) and mixes it with a thermostatic valve to output the desired temperature. For example if cold water was 15 degrees C and you want the hot water…

I had one of these types of water heaters in an old apartment. Thing worked kinda okay-ish? The main issue was that it was electric and if you used the hot water for really any time at all (bath, dishwasher) then it would pop the fuse from current draws and overheating. Likely this was some issue with the water heater and the electrical system of the apartment.

Still, really annoying when half way through your bath, the fuse would pop, colder water now coming out, and you'd have to completely dry yourself to reset it and wait for whatever got too hot to cool down enough to get the other half of the bath going again.

Re: Reservoir: Smart electric water heater

#48

Post by maxerickson »

swiftcoder wrote: post #45
thekraken57 wrote: post #42

Earlier quoted context omitted.

hot water is a huge piece of home energy. DOE had this study that showed more energy for water heating than electric car charging in a home with both. Just look at the total energy use on the energystar sticker of a standard water heater. https://www.energy.gov/eere/vehicles/articles/fotw-1307-sept...

I do not understand how this is possible in general. For example, I use ~3,600 litres of oil to heat through the winter, and the same boiler consumes less than 300 litres to produce domestic hot water for the other six months of the year. That places my central heating on the order of 5-10x higher energy expenditure than my domestic hot water - this does not seem atypical in my area, and apparently data for the entir…

It's comparing it to EV charging. I expect part of the point of the linked study is to examine readiness as more people adopt EVs.

With the heavy use of direct combustion for home heating in the US, heating wouldn't be hugely interesting in that context. I consume more natural gas for heating each month in the winter than I do for hot water annually.

Re: Reservoir: Smart electric water heater

#49

Post by swiftcoder »

maxerickson wrote: post #48
swiftcoder wrote: post #45

Earlier quoted context omitted.

I do not understand how this is possible in general. For example, I use ~3,600 litres of oil to heat through the winter, and the same boiler consumes less than 300 litres to produce domestic hot water for the other six months of the year. That places my central heating on the order of 5-10x higher energy expenditure than my domestic hot water - this does not seem atypical in my area, and apparently data for the entir…

It's comparing it to EV charging. I expect part of the point of the linked study is to examine readiness as more people adopt EVs. With the heavy use of direct combustion for home heating in the US, heating wouldn't be hugely interesting in that context. I consume more natural gas for heating each month in the winter than I do for hot water annually.

> It's comparing it to EV charging

"Space heating" is also on the same graph, and it's nearly 1-to-1 with water heating. Which seems odd

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