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 to be 40 degrees C, it can triple its "capacity" by heating it up to 90 degrees C and then mixing one part hot water with 2 parts cold water to give you three times as much hot water. Of course, this comes with a grave penalty to efficiency so you should only do it for "party mode".
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?
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.
Sounds like you're using a totally different type of water heater (tankless) and not a heat pump water heater (which has a tank, so even if the fuse pops, the water won't get cold instantly).
I was surprised at how cold "hot" water actually was. I thought it was 60-70, but apparently what feels "hot" is around 45-50. Especially for me, that finds anything beyond my shower's "middle" heat as uncomfortably hot, I must be showering with around 40 C water, which is basically "hot day" hot.
Going less than 55 °C tap temperature / 60 °C in the tank is bad though, at least in larger installations - otherwise, you risk legionella and other microbial infestations [1].
It's supposed to be HOT water, not lukewarm... I have my water heater set to 150F because it makes the hot water last longer, especially in the winter when the incoming supply is barely above freezing, but that doesn't make the tank bigger.
Why do you care what size it is though? It's only the capacity that matters. For example a tankless only has a few gallons inside, but that doesn't limit how long of a shower you can take.
These data mining companies really take us for chumps.
Pay EXTRA for a water heater that collects data on when you shower, how much water you use, and at what temperature, so that they can sell that that to someone who wants to serve you a towel ad on your smart fridge screen after you get dressed.
The pricing page does not make it clear how much the actual unit costs, just $6500 with installation. Never purchased a water heater, but going to Home Depot, I see traditional options priced $500-$2000.
Which says you are putting up a high upfront cost, hoping to recoup on increased efficiency. Which could be worthwhile, but you would have to run some simulations if the price is worthwhile. Seems potentially easier to get a dumb water heater to run extra hot using off-peak electricity.
I don't expect this unit to be much more efficient than a $1800 home depot heat pump water heater. On the other hand, installation seems to include a hot water return line and return pump (the pump itself would be another $300 on home depot), and I've been quoted around $1000-2000 in labor to install plumbing like that.
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 pressure before I do heating capacity.
If one breaks I just schedule a repair or replacement for weeks in advance and have to limit folks to 2 simultaneous showers at any given time. Hasn’t happened yet.
I will never go back to a tank based water heater unless outright forced into it. It’s one of those “TiVo like” upgrades to your lifestyle you never knew you needed until you have it.
Certainly not cheap, but also not prohibitively expensive if you can find a competent installer who doesn’t overcharge.
> If I’m gone on a trip for 2 weeks my hot water bill is zero
You mention other advantages, but money isn't one. You're limited to 100% efficiency with tankless.
Although an idle hot water tank can waste ~70W (~1.7kWh) of power, this is way more than made up for by using a heat pump. Plus tankless strains the grid a lot more than any system with a buffer built in.
Recirculating works fine with these, if I chose to do it. They both have a tiny hyper-heated insulated tank for the purpose so they can trickle a hot water loop to the furthest destination. They also have a recirc mode which would barely show up on your monthly energy bill.
If I was building new construction I’d do it, but the upgrade just isn’t worth it for me at the moment since it would require drywall repair and running another return line for relatively minimal benefit.
Note as others have pointed out: this setup is not to save money, it’s entirely quality of life as the primary metric under consideration.
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.
In my geographic area (coldest part of the lower 48 that isn’t an mountain) everyone heats water with natural gas which is cheap as hell anyways so we all have tank style water heaters.
A heat pump water heater seems like a no brainer way to improve efficiency.
They're not yet common, but there are many more options available over seas than in America.
This project seems emblematic of the challenges facing funding manufacturing initiatives in America.
What's funded are the projects that appeal to tech investors, more of a focus on flashy presentation, luxury design, AI, and cloud app features, than the baseline functionality.
We get innovation as a side effect of convincing investors that the idea will disrupt industries and create app ecosystems that lock in consumer attention.
Chasing the 100x unicorns and no longer training workhorses
Big problem in the US is that in many regions natural gas is cheaper than electricity, causing heat pump water heaters to be more expensive for the consumer. So everyone ends up burning more.
Maybe the problem is shared deeper than that, that both industry and individuals are not interested, incentivized, or capable of investing into improving on good enough.
That doesn't make a lot of sense. A modern gas-fired plant is ~50% efficient and heat pumps typically have a COP of ~3 for hot water, so if you take natural gas, burn it to convert it to electricity, then feed that electricity to a heat pump, you'll get ~1.5x the energy you'd get if you just burned the natural gas.
How does the electricity get from the generating unit to the heat pump? What are the environmental conditions during heat pump operation?
These things sound so obvious when you don't factor in the annoying little details like transmission of energy. System complexity also matters. There's this thing called "total cost of ownership" that paints a more honest picture regarding how these economics interact.
Using heat pumps to solve a problem looks fantastic in operational efficiency terms, but what happens if the control board breaks and the vendor decided to move on? Dumb, slightly less efficient appliances might actually be cheaper and better for the environment in total. If I have to create a pile of e-waste every 3 years just to save 10% on my energy bill for something that is already incredibly cheap in absolute terms, I think it could be argued I've made everything worse.
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
Technology Connections have a video about how water heaters work in detail and how much power can be saved by strategically turning them off when not needed.
There's several layers of humor in TC videos, the cringe joke, the acknowledgement that "I'm making a cringe joke", the acknowledgement that the joke is still lame with the meta-joke, the "well I put it in the video anyway, aren't I funny?".
But the end result makes me cringe after all.
Edit: oh, you're talking about this product website...
One thing I learned from the video was how do water heaters get away with giving higher capacity numbers than they actually have. Well, apparently, kind of like air, hot water also rises and the heater keeps working while in use and it also has secondary heater element it can switch to, so it can follow the cold-hot water separation line.
There are systems (like the sanco2) that use an indoor/outdoor pump.
> This sounds terrible for efficiency in winter, as you will need to reheat the room
Sure, but lots of people have some point of the year they want cooling.
Even during the heating season it's only worse if you're heating the living space with something _worse_ than what you're using to heat the hot water. If you have a heat pump for room heat then you're moving heat from outside, to in the house, to in the water heater.
If you're heating the room with electric then in the winter it's no different than using an electric water heater (100% efficient).
Where does it day that? Would be great if it chose inside or outside based on target inside temp (e.g. cools indoor air in summer to heat water for washing and showers)
Looking at pictures it must pull heat from ambient air or from electricity. There is not enough tubes to have interior and external heat exchanging units.
$6.5k for a water heater? Does it make coffee and give back massages?But seriously, is it going to recoup the extra 4.5$ in 10 years or so or however often people replace water heaters.
And hopefully the smart part is not relying on external connections or services. Otherwise next time the cloud service goes down you end up taking cold showers, both figuratively and literally.
Pretty cool. Reminds me of Impulse. I think there's a big market for home appliances that have more care and attention to detail than we're accustomed to. No one I know is overly satisfied with their water heater.
... 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...
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.
You are thinking too simple. Isn't more obvious option to tie ad-views to hot water flow? So it might stop hot water when you are in shower until you have watched enough ads. Just think of monetization opportunities!
Color me skeptical but the lack of mention about data privacy on that website screams this to me:
Pay EXTRA for an over engineered water heater whose company sells your data about how much water you use, when you use it, and at what temperature, so that costco or someone can serve you a towel ad on your smart fridge screen after you get dressed or do the dishes.
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 to be 40 degrees C, it can triple its "capacity" by heating it up to 90 degrees C and then mixing one part hot water with 2 parts cold water to give you three times as much hot water. Of course, this comes with a grave penalty to efficiency so you should only do it for "party mode".
[1] https://www.energystar.gov/about/federal-tax-credits
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?
> They must be doing something different to get that much capacity.
Yeah, they put the word 'virtual' in front.
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.
Sounds like you're using a totally different type of water heater (tankless) and not a heat pump water heater (which has a tank, so even if the fuse pops, the water won't get cold instantly).
Nah, same type. The tank was about half the size of a normal one. The water didn't get cold, just not as hot as I'd liked it to be.
Yeah this sounds disingenuous. I can also see my heater to 70C if I want, that does not increase its size...
It is a scalding hazard though. At 70°C skin burns occur in about a second or so.
The thermostatic valve makes it so that the water that comes out of the water heater is at a more reasonable temperature.
I was surprised at how cold "hot" water actually was. I thought it was 60-70, but apparently what feels "hot" is around 45-50. Especially for me, that finds anything beyond my shower's "middle" heat as uncomfortably hot, I must be showering with around 40 C water, which is basically "hot day" hot.
Going less than 55 °C tap temperature / 60 °C in the tank is bad though, at least in larger installations - otherwise, you risk legionella and other microbial infestations [1].
[1] https://www.verbraucherzentrale.sh/pressemeldungen/lebensmit...
Oh definitely, I'm purely talking about "feel".
It's supposed to be HOT water, not lukewarm... I have my water heater set to 150F because it makes the hot water last longer, especially in the winter when the incoming supply is barely above freezing, but that doesn't make the tank bigger.
I think what this "smart tank" does is mix the super-hot with cold.
If the automatic mixing feature malfunctions to super-hot, then it could be risky...
Why do you care what size it is though? It's only the capacity that matters. For example a tankless only has a few gallons inside, but that doesn't limit how long of a shower you can take.
These data mining companies really take us for chumps.
Pay EXTRA for a water heater that collects data on when you shower, how much water you use, and at what temperature, so that they can sell that that to someone who wants to serve you a towel ad on your smart fridge screen after you get dressed.
The pricing page does not make it clear how much the actual unit costs, just $6500 with installation. Never purchased a water heater, but going to Home Depot, I see traditional options priced $500-$2000.
Which says you are putting up a high upfront cost, hoping to recoup on increased efficiency. Which could be worthwhile, but you would have to run some simulations if the price is worthwhile. Seems potentially easier to get a dumb water heater to run extra hot using off-peak electricity.
I don't expect this unit to be much more efficient than a $1800 home depot heat pump water heater. On the other hand, installation seems to include a hot water return line and return pump (the pump itself would be another $300 on home depot), and I've been quoted around $1000-2000 in labor to install plumbing like that.
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 pressure before I do heating capacity.
If one breaks I just schedule a repair or replacement for weeks in advance and have to limit folks to 2 simultaneous showers at any given time. Hasn’t happened yet.
I will never go back to a tank based water heater unless outright forced into it. It’s one of those “TiVo like” upgrades to your lifestyle you never knew you needed until you have it.
Certainly not cheap, but also not prohibitively expensive if you can find a competent installer who doesn’t overcharge.
> If I’m gone on a trip for 2 weeks my hot water bill is zero
You mention other advantages, but money isn't one. You're limited to 100% efficiency with tankless.
Although an idle hot water tank can waste ~70W (~1.7kWh) of power, this is way more than made up for by using a heat pump. Plus tankless strains the grid a lot more than any system with a buffer built in.
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.
Recirculating works fine with these, if I chose to do it. They both have a tiny hyper-heated insulated tank for the purpose so they can trickle a hot water loop to the furthest destination. They also have a recirc mode which would barely show up on your monthly energy bill.
If I was building new construction I’d do it, but the upgrade just isn’t worth it for me at the moment since it would require drywall repair and running another return line for relatively minimal benefit.
Note as others have pointed out: this setup is not to save money, it’s entirely quality of life as the primary metric under consideration.
1 sounds like a huge inefficiency?
Why?
In SE Asia, tankless is generally placed closer to where it comes out.
Recirculation pump means that you're paying to keep your pipes from getting cold.
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).
In my geographic area (coldest part of the lower 48 that isn’t an mountain) everyone heats water with natural gas which is cheap as hell anyways so we all have tank style water heaters.
How often do your water boilers break? :O
A heat pump water heater seems like a no brainer way to improve efficiency. They're not yet common, but there are many more options available over seas than in America.
This project seems emblematic of the challenges facing funding manufacturing initiatives in America. What's funded are the projects that appeal to tech investors, more of a focus on flashy presentation, luxury design, AI, and cloud app features, than the baseline functionality.
We get innovation as a side effect of convincing investors that the idea will disrupt industries and create app ecosystems that lock in consumer attention. Chasing the 100x unicorns and no longer training workhorses
Big problem in the US is that in many regions natural gas is cheaper than electricity, causing heat pump water heaters to be more expensive for the consumer. So everyone ends up burning more.
Maybe the problem is shared deeper than that, that both industry and individuals are not interested, incentivized, or capable of investing into improving on good enough.
That doesn't make a lot of sense. A modern gas-fired plant is ~50% efficient and heat pumps typically have a COP of ~3 for hot water, so if you take natural gas, burn it to convert it to electricity, then feed that electricity to a heat pump, you'll get ~1.5x the energy you'd get if you just burned the natural gas.
How does the electricity get from the generating unit to the heat pump? What are the environmental conditions during heat pump operation?
These things sound so obvious when you don't factor in the annoying little details like transmission of energy. System complexity also matters. There's this thing called "total cost of ownership" that paints a more honest picture regarding how these economics interact.
Using heat pumps to solve a problem looks fantastic in operational efficiency terms, but what happens if the control board breaks and the vendor decided to move on? Dumb, slightly less efficient appliances might actually be cheaper and better for the environment in total. If I have to create a pile of e-waste every 3 years just to save 10% on my energy bill for something that is already incredibly cheap in absolute terms, I think it could be argued I've made everything worse.
What about heat pump and solar. Maybe just a financing issue then? Maybe installation issue for appartments and rentals.
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
Technology Connections have a video about how water heaters work in detail and how much power can be saved by strategically turning them off when not needed.
https://youtu.be/Bm7L-2J52GU
However, the website has some weird vibes as well, like why would you say something like below?
> And some just want Dad Mode for when your teenager needs to finish that shower.
There's several layers of humor in TC videos, the cringe joke, the acknowledgement that "I'm making a cringe joke", the acknowledgement that the joke is still lame with the meta-joke, the "well I put it in the video anyway, aren't I funny?".
But the end result makes me cringe after all.
Edit: oh, you're talking about this product website...
Yeah, that was a sneaky one on my part.
One thing I learned from the video was how do water heaters get away with giving higher capacity numbers than they actually have. Well, apparently, kind of like air, hot water also rises and the heater keeps working while in use and it also has secondary heater element it can switch to, so it can follow the cold-hot water separation line.
The heat pump will pull heat from inside the house? This sounds terrible for efficiency in winter, as you will need to reheat the room
There are systems (like the sanco2) that use an indoor/outdoor pump.
> This sounds terrible for efficiency in winter, as you will need to reheat the room
Sure, but lots of people have some point of the year they want cooling.
Even during the heating season it's only worse if you're heating the living space with something _worse_ than what you're using to heat the hot water. If you have a heat pump for room heat then you're moving heat from outside, to in the house, to in the water heater.
If you're heating the room with electric then in the winter it's no different than using an electric water heater (100% efficient).
Where does it day that? Would be great if it chose inside or outside based on target inside temp (e.g. cools indoor air in summer to heat water for washing and showers)
Looking at pictures it must pull heat from ambient air or from electricity. There is not enough tubes to have interior and external heat exchanging units.
The price is ridiculous. You can buy a premium heat pump water heater for ~$2000 and instantly save $4500.
lol. If only it were that easy. You have to get it installed too. Cheapest quote I got in Boston was $5k all in. And the work was…cheap.
$6.5k for a water heater? Does it make coffee and give back massages?But seriously, is it going to recoup the extra 4.5$ in 10 years or so or however often people replace water heaters.
And hopefully the smart part is not relying on external connections or services. Otherwise next time the cloud service goes down you end up taking cold showers, both figuratively and literally.
For the recirculation function to work do they install a cross connect under one of your sinks?
Pretty cool. Reminds me of Impulse. I think there's a big market for home appliances that have more care and attention to detail than we're accustomed to. No one I know is overly satisfied with their water heater.
we don't know one another, but we have one of these, and it kicks ass.
https://www.navieninc.com
it's a tankless natural gas heater in our case, heats endlessly so there's no sense of virtual tank capacity.
... 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...
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
Yeah, I expect that's small portable heaters rather than whole house.
Am I the only one who cringes now when I see "smart" attached to a device?
Long term support for these internet connected data miners is my first thought.
Gimmick is my second thought.
Not interested until it can also show ads.
You are thinking too simple. Isn't more obvious option to tie ad-views to hot water flow? So it might stop hot water when you are in shower until you have watched enough ads. Just think of monetization opportunities!
Color me skeptical but the lack of mention about data privacy on that website screams this to me:
Pay EXTRA for an over engineered water heater whose company sells your data about how much water you use, when you use it, and at what temperature, so that costco or someone can serve you a towel ad on your smart fridge screen after you get dressed or do the dishes.