I live in Japan and last year when we moved from an apartment to a house we installed a Mitsubishi EcoCute heat pump water heater which already has these features and is also a CO2 heat pump.
We have one of the "all-denka" electric plans, where we trade off cheap rates during solar hours for expensive rates during duck curve hours. By having the hot water only run during cheap hours, and having the aircon turned off/down during the expensive hours, we're paying less in energy for our all-electric house than we did in combined electric+gas in our 3x smaller apartment.
We pay approx (before fees, and the rates change slightly by season):
* 8 AM - 10 AM: 35 yen/kWh
* 10 AM - 4 PM: 13 yen/kWh
* 4 PM - 6 PM: 35 yen/kWh
* 6 PM - 8 AM: 19 yen/kWh
Our Mitsubishi has other nice features like it can recirculate the water in the bath through a heat exchanger after you already filled it and got in, so it will keep the water from cooling down to lukewarm, and you can even adjust the bath water temperature if you ended up with filling it with too warm or too cold water. Of course, there's also an app so you can start filling up the bathtub when you leave work for home so a hot bath is waiting for you. There's also an intercom to the kitchen "so mom can tell the kids to get out of the bath, dinner is ready".
> Our Mitsubishi has other nice features like it can recirculate the water in the bath through a heat exchanger after you already filled it and got in, so it will keep the water from cooling down to lukewarm, and you can even adjust the bath water temperature if you ended up with filling it with too warm or too cold water.
How long do you sit in a bath?
> Of course, there's also an app so you can start filling up the bathtub when you leave work for home so a hot bath is waiting for you.
My immediate reaction to this is, “there’s a way for my house to be remotely flooded”.
If I'm in the bath I'm either reading a good book, or talking with my wife (I have a tub big enough for two - takes a lot of water to fill) - either way I'm going to be in it for an hour or two. As the other poster said, if I want to get clean I'll take a quick shower. The tub is nice when my muscles get sore and tight from work.
Interesting that that's a feature of the water heater and not the tub. It has to travel through the plumbing all the way round-trip to the heater? You must have isolated recirculation plumbing to deal with the grey water, yeah?
> My immediate reaction to this is, “there’s a way for my house to be remotely flooded”.
I forgot to mention that it senses and automatically stops filling the bath at a select number of liters, even if you start a bath using the physical button when you're at home.
In the UK we've had off peak power overnight for decades. My current one is something like 1/3rd of the price of daytime power between 2300 and 0700.
However this is somewhat old fashioned, the most modern tarrifs vary on a 30 minute window, with prices set a day ahead. If there's a lot of solar and little demand on say a sunny sunday afternoon or windy february nighttime, then the prices may even go negative.
You want your consumption to be tied into there. You can do this with batteries -- for example on Tuesday I used 34kWh, 24kWh overnight (mainly to charge the car) and 10kWh in the day. If I had a battery I could have charged that battery overnight and saved a couple of quid, or about £600 a year (depends on what my daytime usage is)
However with a 30kWh battery I could have charged it on Sunday afternoon and been paid for that, and not used any power on Monday, Tuesday or Wednesday for the house. But then the agile rate last night was 25p/kWh. I did look at getting a battery and inverter installed but it wasn't cheap.
On top of that you've got my own generation. I have very little solar generation, but in theory I reckon I could have 8kWp on the roof -- I'd want to charge the car when the sun was shining then, which would be even cheaper than charging at night. Home Assistant will do that, but it feels a little fragile with my car charger (if the HA dies, the charger won't start, and then I can't go anywhere. It's not a great charger)
Holy crap that re-circulation feature is luxurious!
I'd love to have something like that!
Whenever I take a hot shower I fantasize about putting in a liquid-to-liquid heat exchanger so the hot water can heat up the cold water and you can run the hot water at a much lower temperature.
This application with the bath tub feels way more justified.
> Some Japanese utilities have introduced tariffs designed to encourage daytime water heating as growing volumes of solar generation enter the grid. [Emphasis added.]
I was quite confused at the use of "tariff" here, as it meant to me a "tax on a good crossing a political boundary." Turns out, 'tariff' has an older meaning: a published schedule of fees or taxes issued by some authority.
I've read that the word is borrowed from Arabic, meaning notification, and I think at first it was price notifications and then people started using it to mean that the prices were bound to some schedule or condition.
For example in Turkish, "tarife" means only that: Conditional / Schedule-based pricing, and according to Sevan Nişanyan (a language researcher), Turkish borrowed it from Italian, where it was being used similarly. Import tariffs are a completely different word.
It apparently came to English through Italian -> Spanish -> French.
So I'm not a native English speaker but as far as I understand, import tariffs are just one kind of tariff.
From French, tarif, a table showing the amounts of payable fees, or a list of prices set for certain goods or services (1572), via Spanish tarifa, from Arabic ta'arifa, meaning notification, coming from 'arrifa, to let know.
Big fan of Etymology as well, mostly because my brain seemingly needs to understand the origin/history of terms to feel like I've fully grasped concepts.
In the UK you can get agile tarrifs now where the price changes through the day according to demand and supply predictions. There's an API you can use to control chargers, heaters, bitcoin miners etc.
US utilities also have Tariffs. It’s the statement of how the utility operates and charges users for service.
Anytime a utility needs to adjust costs/rates, they need to file a Rate Case with the public utility commissions, and resulting in changes to the Tariff.
My electricity contract in the Netherlands here is on a "Dynamisch tarief", with the most direct translation being "Dynamic tariff". It means I pay/get a different price for my power every 15 minutes.
"Tarief" just means price of mainly a service.
I think 'dynamic rate' is the proper translation for the US?
It's an arab loan word for ~"price list" (originally strongly suggesting an import-duty-like meaning).
The same word exists in e.g. German or Italian, but mostly just means "pricing scheme" there, like in the article ("import duty" using a different expression in those languages).
Might be a mostly/somewhat "false friend" for a German (pv magazine is german).
Tarif/Tarife means price list of anything. Your barber, restaurant, taxi service, hospital can have one. tariff as in the meaning of custom tax is a very narrow meaning considering the usage of the word in general (but that's OK).
Import duty is "gümrük vergisi", and the general list of this is "gümrük vergisi tarifesi" in broad sense. It also has a more technical name here but both I don't remember it, and it doesn't matter in this context.
In the Japan's context we would call it "elektrik fiyat tarifesi", or "elektrik tarifesi" for short, for example.
It’s confusingly super common in the US for that usage when talking about trucking and shipping. Where of course the other kind of tariffs are also common.
Some background info for context. (for those that may not be familiar).
Heat pump conjures up an image of an appliance, but it is a principle of physics. Heat can be created by burning fuel, or electric resistance. Cold can't be created, cold is the lack (or removal) of heat. Fridge keeps cool by moving heat from inside, dumping it outside. This movement of heat is called heat pump (pumping heat from one direction to another).
If we can do this for cold, we can also do this for heat. After all, we always have heat in the environment until we get to 0 degree kelvin. Which means we can have heat pump water heater in the garage. Or heat pump furnace.
Creating heat from fuel/resistance is at most 100% efficient (most likely a LOT less), but heat pumps are 400% - 500% efficient per unit of electricity, because the idea is just to move heat. In one direction, or another.
All of this is great, until we get to the refrigerant used to transfer the heat. These are very specific chemicals. Historically, these were Chlorofluorocarbons (CFCs). CFCs caused ozone depletion and have high GWP of 14,400.
What is GWP? CO2 is a warming gas that has Global Warming Potential (GWP) of 1 (the standard). Earth radiates heat back into the atmosphere (exactly the same as get from Sun) and CO2 acts as a barrier for the radiated heat from earth, retaining heat in the atmosphere and warming the planet. Why Greenhouse Gases Make the Planet Warmer: https://www.youtube.com/watch?v=AIBk0pGV_BQ
But, there are lots of other gases that have higher GWP. Fluorinated gases: Hydrofluorocarbons, perfluorocarbons, sulfur hexafluoride, and nitrogen trifluoride are synthetic gases used for refrigeration (maybe other applications). Fluorinated gases replaced CFCs, which were causing ozone depletion. But they have high GWP. HFCs: up to 12,400, PFCs: up to 11,100, NF3: 16,100, SF6: 23,500 (https://www.epa.gov/ghgemissions/fluorinated-gas-emissions)
So, we have to find better alternatives for refrigerants. Because, these leak. And everybody on the planet is going to buy ACs. CO2 is a terrific refrigerant because it has GWP 1 and leaking of CO2 is perfectly okay. With 40 - 60 billion tons of CO2 from fossil fuels, CO2 leaks from refrigerants are less than a rounding error.
Japan is so far ahead the rest of the world for quality and innovative heat pumps. Quiet, robust, high efficiency in cold climates. I wish they could bring the prices down though.
I worry in 15 years we will all have crapily made Chinese heat pumps for a fraction of the cost. Noisy, not robust, copying competitor designs not innovating, lower efficiency but easily replaceable. Theres probably an analogy here with software talent and AI but its too early to do that.
I'm a big fan of Chinese lenses. I reach for Japanese and German lenses when I want to take the highest quality photographs that look like the photographs all the other photographers take. When I want to take a picture like you've never seen before I reach for
It's true a $3000 lens from Sony has better optical quality than a $300 lens from China, like take a picture of a starry sky and you will see light rays bounce around a lot more inside the Chinese lens. But in terms of value and innovation Chinese lenses have a place, and many Chinese manufacturers are looking for this kind of opportunity for whatever they make.
China figured out how to make thermal imaging sensors as well. Why would you buy a $4,000 Flir with less resolution when you can get a $400 Topdon. What's funny is now it appears Flir has cut their prices dramatically to compete.
I have Haier Arctic heat pumps that are made in China. They've been great so far. I've also worked with suppliers in Shenzhen for one-off custom electronic devices that would put western companies to shame in their communication, efficiency, turnaround time, cost, and engineering quality. The new transmission I just put in my truck was made in China too.
PRC's been white labelling / JV components for tier1 HVAC brands for 15 years now, they're fine quality/lifespan wise. Flagship PRC heatpump already caught up to JP in HSPF2 @ ~11 (GREE). Either way, more cheap commoditized heat pump = more installations = more aggregate global efficiency - every $ spend on JP premium is inefficient allocation of resources in terms of maximizing global energy savings.
Arguably, PRC price / value engineer is their innovation and by far more MORE important than vs minute efficiency differences. Ultimately it's about TCO and global adoption, if JP can't bring their prices down, if they can't fractionalize cost, then they're doing more harm than good for net transition - there's better things to with that 30-50% premium.
This China craze won't last long. The Chinese PV export market crashed couple months ago(down 30% YoY), and it seems like their domestic auto market crashed too(down ~25% YoY since August).
It's just not as prevalent in the residential HVAC market (which this product serves?), and more in the commercial/industrial space (probably because of the higher pressures needed to get into a liquid state).
It's useful though, as I think (correct me if I'm wrong) that the gases generally used in HVAC tends to have much worse warming effect than co2 per volume.
We do need heat pumps deployed at large scale, but sometimes I worry we don't understand they need to be handled with care at the end of their life
That's true, old school refrigerants like R-12 are awful. The downside of modern replacement refrigerants are high operating pressure (>100 bar for R-744/CO2) or high flammability for natural refrigerants like R-290 (Propane) and R-600a (Isobutane).
But these are solely engineering problems, and I'm happy to know that my R-290 heat pumps at home (Panasonic L & Wolf FHS) and A/C (Midea Xtreme Save Blue) aren't awful to the environment, once they reach EOL.
The neat thing about propane as a refrigerant is that it's a really powerful one, actually rather better than R12 in practical applications.
If you replaced an R134a fill with R290 you'd need about half as much gas and if it got out, it's got a Global Warming Potential of 3, making it three times as bad as carbon dioxide and about 475 times better than the same amount of R134a.
Even in a very large air conditioning system like in my elderly Range Rover, the 500g or so of propane it would need is about the same as the engine sucks up in about four miles.
The effect of that escaping into the atmosphere is about as bad as the amount of petrol you spilled the last time you refilled your lawnmower.
If you're worried about the ZOMG IT IS GAS IT WILL MAKE A GINORMOUS EXPLODISHION aspect like a lot of people are, ask yourself this - how many aerosol cans are in your car right now? Tin of deicer, tin of magic tyre inflater, maybe a tin of air freshener or WD40 or something? You're already carrying more propane around with you, rattling around loose at your feet.
Because they're sensible heat machines, instead of latent heat machines. In a perfect frictionless vacuum, both of these can achieve the same theoretical efficiency. In practice, not so much. In particular, the isothermal heat exchange of the ideal Stirling cycle requires heat exchangers with no thermal resistance (and therefore no temperature difference). A latent heat pump has a much easier time to very closely approximate isothermal heat exchange because condensation/evaporation temperatures at a given pressure are essentially constant.
Yes, that dangerous effect is indexed as GWP - global warming potential.
CO2 has a GWP of 1 in this context, while other refrigerants are worse - for example, R32 has a GWP of 675 (so 675x worse if it escapes), not sure about R290 (Propane), which I believe is either about 40 or 14…
Regarding EoL: At least around here, household appliances such as fridges are brought to a recycling yard and are properly taken care of in that regard… and as for heatpumps - those are only to be installed by certified professionals, for this very reason.
The global warming potential of hydrocarbons as such is generally overblown, since they oxidize into CO₂ in the atmosphere with a half-life of a decade or two.
Yeah, ammonia can also be used, it's, IIRC, more efficient to use it and a bit safer because you don't high pressure, buuut enough ammonia in the air will suffocate you.
It's lighter than air so it will go away by itself if allowed to. For a purely exterior instalation it's much better than anything else.
I have a heat pump that uses R290 (propane) (as well as an CO2 one for hot water) and would take that any day of the week over ammonia! The charge of propane is pretty tiny and the safety standards extremely strict, so not really concerning in terms of flammability, ammonia I would consider far, far more dangerous.
If it is outside you can just use propane as refrigerant. Low warming value and it leaking to outside doesn't matter, not gonna catch on fire.
There are indoor devices using propane but they generally come with caveat "must be installed on room at least this m3", precisely so if it leaks it doesn't get to density that allows explosion
I believe there are propane using split AC systems where propane is used only in the outside unit. The outside unit has a heat exchanger transferring the heat to some glycol-water solution which is what then circulates through the inside unit.
I currently have R410a heat pumps with minisplits, when they're off warranty sometime in the future I might consider putting propane in them. The main question would be whether the oil used with R410a is compatible with propane as a refrigerant.
This is probably a little bit "dangerous" in the sense that I'll have high pressure propane in the line sets and minisplits inside the house, but it's a very small volume of propane and not really any more dangerous from a fire perspective than my propane fired condensing gas boiler.
I heard CO2 is a gas with a powerful green house effect. What happens at the end of life of these units I wonder? What if they leak and it gets into the atmosphere!
There are resident systems, and they're of exactly the type listed in the article (i.e. water heaters). Residential... area heating pumps, so to say, are moving towards propane (afaik). I've been looking into getting a propane monoblock air-to-water pump, with an antifreeze loop towards an indoors heat exchanger / water tank.
Trends for new refrigerant depends on country... some to R-454B, and some to Propane, doesn't seem like C02 is very common which is a pity because I love the idea of a non-toxic non-flammable super cheap refrigerant.
This is for the Japanese market so perhaps the cons of the C02 systems are outweighed by the safety aspects.
CO2 does better with large temp deltas, like hot water tanks. Radiators don't produce large deltas - the inlet to outlet diff is typically under 10 degrees. But they run at higher pressures, making the manufacturing more expensive.
I live in Ohio in a 100 year old home with cast iron radiators and a natural gas boiler and a gas water heater. I’d love to move to electric but it feels like my only real option for keeping the cast iron is something like the Daikin Altherma 3 H HT. Does anyone more knowledgeable of this part of the industry know of any reasonable alternatives for electrifying old houses but keeping the radiators?
I'm actually in need of a new hot water tank and have been looking for a heat pump one. Wonder if these will be available in Australia, and how they compare to the current range.
The Australian electronics YouTuber Dave Jones (EEVBlog) had a heat pump water heater installed in his house, and while on the outside it was branded "Reclaim Energy", it had a Made in Japan sticker and was internally a Mitsubishi.
But having water leave the building envelope is a bit scary on very cold days. There are heat traces and freeze valves so it should be fine, but I do worry about power outages during cold snaps
“Hitachi has not yet disclosed full efficiency specifications for the two new models. Their predecessors, the BHP-FV37WD and BHP-FV46WD, have annual hot-water and heat-retention efficiency ratings under Japanese Industrial Standards (JIS) of 4.2 and 4.1, respectively.”
These tend to work fine down to -25° C or so ambient temperature (you lose some efficiency below -5° C or so), so should always be outside. Obviously you need an alternate source of water heating if you live somewhere where it routinely gets below that, but even in a lot of places like that you could set it up to use the heat pump 90-95% of the year and a cheap but far less efficient resistive heater for the very cold days, and still come out far ahead.
Technically your refrigerator heats up your kitchen in the same fashion adding extra work for your AC to compensate.
Unless you live in the artic where it's freezing year round, these things make sense. During the summer they reduce your cooling load and during the winter they are effectively heated by whatever your home heater is. Meaning if it's gas, then they are gas powered. If you have a heat pump outside then it's still pretty efficient. Even in the worst case of a resistive heater you are basically just running a slow resistive heater.
Most homes in Japan for decades have been designed for Tankless Gas Water Heaters stuck on the side of the building so there is no room indoors for a water tank.
The condenser unit for this literally just looks like the same one as for a regular mini split air conditioner, just a little bit larger.
which is why the bit thats sourcing the heat/cold is outside your house. it either has a massive radioator and fan, or pipes undergorund to source/sink the heat
Technology Connections has recently published an in-depth piece of the advantages and disadvantages of in-room heat-pump water heaters [1].
The tl;dw is that it is significantly slower than a resistive or gas-powered water heater, and lowers the temperature of the room by a few degrees, but nothing major. You have to over-provision them compared to your needs. And they are way bigger.
> significantly slower than a resistive or gas-powered water heater
This was TC being a weirdo. He bought a 120V hot water heater. Had he done a regular 240V water heater the recovery time would be comparable to pure resistive water heaters.
But the takeaway about cooling is important. These things barely chill the room they are in.
I believe that for every joule of electricity used, 4 or 4.1 joules are pumped from the environment into the water. This is contrast to conventional water heaters which are bounded by an efficiency of 1, where, for example, burning gas directly heats the water with some heat leaking into the environment instead of the water.
I live in Japan and last year when we moved from an apartment to a house we installed a Mitsubishi EcoCute heat pump water heater which already has these features and is also a CO2 heat pump.
We have one of the "all-denka" electric plans, where we trade off cheap rates during solar hours for expensive rates during duck curve hours. By having the hot water only run during cheap hours, and having the aircon turned off/down during the expensive hours, we're paying less in energy for our all-electric house than we did in combined electric+gas in our 3x smaller apartment.
We pay approx (before fees, and the rates change slightly by season):
* 8 AM - 10 AM: 35 yen/kWh
* 10 AM - 4 PM: 13 yen/kWh
* 4 PM - 6 PM: 35 yen/kWh
* 6 PM - 8 AM: 19 yen/kWh
Our Mitsubishi has other nice features like it can recirculate the water in the bath through a heat exchanger after you already filled it and got in, so it will keep the water from cooling down to lukewarm, and you can even adjust the bath water temperature if you ended up with filling it with too warm or too cold water. Of course, there's also an app so you can start filling up the bathtub when you leave work for home so a hot bath is waiting for you. There's also an intercom to the kitchen "so mom can tell the kids to get out of the bath, dinner is ready".
> Our Mitsubishi has other nice features like it can recirculate the water in the bath through a heat exchanger after you already filled it and got in, so it will keep the water from cooling down to lukewarm, and you can even adjust the bath water temperature if you ended up with filling it with too warm or too cold water.
How long do you sit in a bath?
> Of course, there's also an app so you can start filling up the bathtub when you leave work for home so a hot bath is waiting for you.
My immediate reaction to this is, “there’s a way for my house to be remotely flooded”.
If I'm in the bath I'm either reading a good book, or talking with my wife (I have a tub big enough for two - takes a lot of water to fill) - either way I'm going to be in it for an hour or two. As the other poster said, if I want to get clean I'll take a quick shower. The tub is nice when my muscles get sore and tight from work.
> How long do you sit in a bath?
The entire point of a bath is to relax and soak in it. Otherwise I'd just take a far more economical shower.
Interesting that that's a feature of the water heater and not the tub. It has to travel through the plumbing all the way round-trip to the heater? You must have isolated recirculation plumbing to deal with the grey water, yeah?
Most baths (in the UK at least) have overflows right so the primary risk is just wasting a lot of water?
> How long do you sit in a bath?
We love our baths here in Japan
> My immediate reaction to this is, “there’s a way for my house to be remotely flooded”.
I forgot to mention that it senses and automatically stops filling the bath at a select number of liters, even if you start a bath using the physical button when you're at home.
Omg the bath features, my dream!
In the UK we've had off peak power overnight for decades. My current one is something like 1/3rd of the price of daytime power between 2300 and 0700.
However this is somewhat old fashioned, the most modern tarrifs vary on a 30 minute window, with prices set a day ahead. If there's a lot of solar and little demand on say a sunny sunday afternoon or windy february nighttime, then the prices may even go negative.
You want your consumption to be tied into there. You can do this with batteries -- for example on Tuesday I used 34kWh, 24kWh overnight (mainly to charge the car) and 10kWh in the day. If I had a battery I could have charged that battery overnight and saved a couple of quid, or about £600 a year (depends on what my daytime usage is)
However with a 30kWh battery I could have charged it on Sunday afternoon and been paid for that, and not used any power on Monday, Tuesday or Wednesday for the house. But then the agile rate last night was 25p/kWh. I did look at getting a battery and inverter installed but it wasn't cheap.
On top of that you've got my own generation. I have very little solar generation, but in theory I reckon I could have 8kWp on the roof -- I'd want to charge the car when the sun was shining then, which would be even cheaper than charging at night. Home Assistant will do that, but it feels a little fragile with my car charger (if the HA dies, the charger won't start, and then I can't go anywhere. It's not a great charger)
Holy crap that re-circulation feature is luxurious!
I'd love to have something like that!
Whenever I take a hot shower I fantasize about putting in a liquid-to-liquid heat exchanger so the hot water can heat up the cold water and you can run the hot water at a much lower temperature.
This application with the bath tub feels way more justified.
And this is the builder-grade model we got from the house renovation company. There are higher grade ones with fancier stuff...
> Some Japanese utilities have introduced tariffs designed to encourage daytime water heating as growing volumes of solar generation enter the grid. [Emphasis added.]
I was quite confused at the use of "tariff" here, as it meant to me a "tax on a good crossing a political boundary." Turns out, 'tariff' has an older meaning: a published schedule of fees or taxes issued by some authority.
I've read that the word is borrowed from Arabic, meaning notification, and I think at first it was price notifications and then people started using it to mean that the prices were bound to some schedule or condition.
For example in Turkish, "tarife" means only that: Conditional / Schedule-based pricing, and according to Sevan Nişanyan (a language researcher), Turkish borrowed it from Italian, where it was being used similarly. Import tariffs are a completely different word.
It apparently came to English through Italian -> Spanish -> French.
So I'm not a native English speaker but as far as I understand, import tariffs are just one kind of tariff.
ps. I just f'ing love Etymology.
From French, tarif, a table showing the amounts of payable fees, or a list of prices set for certain goods or services (1572), via Spanish tarifa, from Arabic ta'arifa, meaning notification, coming from 'arrifa, to let know.
Big fan of Etymology as well, mostly because my brain seemingly needs to understand the origin/history of terms to feel like I've fully grasped concepts.
In the UK you can get agile tarrifs now where the price changes through the day according to demand and supply predictions. There's an API you can use to control chargers, heaters, bitcoin miners etc.
US utilities also have Tariffs. It’s the statement of how the utility operates and charges users for service. Anytime a utility needs to adjust costs/rates, they need to file a Rate Case with the public utility commissions, and resulting in changes to the Tariff.
My electricity contract in the Netherlands here is on a "Dynamisch tarief", with the most direct translation being "Dynamic tariff". It means I pay/get a different price for my power every 15 minutes.
"Tarief" just means price of mainly a service.
I think 'dynamic rate' is the proper translation for the US?
It's an arab loan word for ~"price list" (originally strongly suggesting an import-duty-like meaning).
The same word exists in e.g. German or Italian, but mostly just means "pricing scheme" there, like in the article ("import duty" using a different expression in those languages).
Might be a mostly/somewhat "false friend" for a German (pv magazine is german).
Tarif/Tarife means price list of anything. Your barber, restaurant, taxi service, hospital can have one. tariff as in the meaning of custom tax is a very narrow meaning considering the usage of the word in general (but that's OK).
Import duty is "gümrük vergisi", and the general list of this is "gümrük vergisi tarifesi" in broad sense. It also has a more technical name here but both I don't remember it, and it doesn't matter in this context.
In the Japan's context we would call it "elektrik fiyat tarifesi", or "elektrik tarifesi" for short, for example.
Cheers,
Your friendly Turkish HN user.
I've seen 'tariff' used a fair amount here in the UK on price lists (taxi etc)
Same in Portugal: a "tarifa" can mean a price charged for a rendered service or a tax on imported products.
It’s confusingly super common in the US for that usage when talking about trucking and shipping. Where of course the other kind of tariffs are also common.
The Japanese word used in the context of price lists would be something like 料金表 or 料金メニュー.
When I see "tariff", my mind only thinks of 関税 , and I was just as confused as you were. Turns out its just an item in a price schedule.
Some background info for context. (for those that may not be familiar).
Heat pump conjures up an image of an appliance, but it is a principle of physics. Heat can be created by burning fuel, or electric resistance. Cold can't be created, cold is the lack (or removal) of heat. Fridge keeps cool by moving heat from inside, dumping it outside. This movement of heat is called heat pump (pumping heat from one direction to another).
If we can do this for cold, we can also do this for heat. After all, we always have heat in the environment until we get to 0 degree kelvin. Which means we can have heat pump water heater in the garage. Or heat pump furnace.
Creating heat from fuel/resistance is at most 100% efficient (most likely a LOT less), but heat pumps are 400% - 500% efficient per unit of electricity, because the idea is just to move heat. In one direction, or another.
All of this is great, until we get to the refrigerant used to transfer the heat. These are very specific chemicals. Historically, these were Chlorofluorocarbons (CFCs). CFCs caused ozone depletion and have high GWP of 14,400.
What is GWP? CO2 is a warming gas that has Global Warming Potential (GWP) of 1 (the standard). Earth radiates heat back into the atmosphere (exactly the same as get from Sun) and CO2 acts as a barrier for the radiated heat from earth, retaining heat in the atmosphere and warming the planet. Why Greenhouse Gases Make the Planet Warmer: https://www.youtube.com/watch?v=AIBk0pGV_BQ
But, there are lots of other gases that have higher GWP. Fluorinated gases: Hydrofluorocarbons, perfluorocarbons, sulfur hexafluoride, and nitrogen trifluoride are synthetic gases used for refrigeration (maybe other applications). Fluorinated gases replaced CFCs, which were causing ozone depletion. But they have high GWP. HFCs: up to 12,400, PFCs: up to 11,100, NF3: 16,100, SF6: 23,500 (https://www.epa.gov/ghgemissions/fluorinated-gas-emissions)
So, we have to find better alternatives for refrigerants. Because, these leak. And everybody on the planet is going to buy ACs. CO2 is a terrific refrigerant because it has GWP 1 and leaking of CO2 is perfectly okay. With 40 - 60 billion tons of CO2 from fossil fuels, CO2 leaks from refrigerants are less than a rounding error.
Japan is so far ahead the rest of the world for quality and innovative heat pumps. Quiet, robust, high efficiency in cold climates. I wish they could bring the prices down though.
I worry in 15 years we will all have crapily made Chinese heat pumps for a fraction of the cost. Noisy, not robust, copying competitor designs not innovating, lower efficiency but easily replaceable. Theres probably an analogy here with software talent and AI but its too early to do that.
Not everything from China is crap.
I'm a big fan of Chinese lenses. I reach for Japanese and German lenses when I want to take the highest quality photographs that look like the photographs all the other photographers take. When I want to take a picture like you've never seen before I reach for
https://www.venuslens.net/product/laowa-9mm-f-5-6-ff-rl/?srs...
or
https://findingrange.com/2022/01/14/7artisans-photoelectric-...
It's true a $3000 lens from Sony has better optical quality than a $300 lens from China, like take a picture of a starry sky and you will see light rays bounce around a lot more inside the Chinese lens. But in terms of value and innovation Chinese lenses have a place, and many Chinese manufacturers are looking for this kind of opportunity for whatever they make.
China figured out how to make thermal imaging sensors as well. Why would you buy a $4,000 Flir with less resolution when you can get a $400 Topdon. What's funny is now it appears Flir has cut their prices dramatically to compete.
> But in terms of value and innovation Chinese lenses have a place
What's the innovation?
Making goods, cheap and accessible at scale is the innovation.
I have Haier Arctic heat pumps that are made in China. They've been great so far. I've also worked with suppliers in Shenzhen for one-off custom electronic devices that would put western companies to shame in their communication, efficiency, turnaround time, cost, and engineering quality. The new transmission I just put in my truck was made in China too.
PRC's been white labelling / JV components for tier1 HVAC brands for 15 years now, they're fine quality/lifespan wise. Flagship PRC heatpump already caught up to JP in HSPF2 @ ~11 (GREE). Either way, more cheap commoditized heat pump = more installations = more aggregate global efficiency - every $ spend on JP premium is inefficient allocation of resources in terms of maximizing global energy savings.
Arguably, PRC price / value engineer is their innovation and by far more MORE important than vs minute efficiency differences. Ultimately it's about TCO and global adoption, if JP can't bring their prices down, if they can't fractionalize cost, then they're doing more harm than good for net transition - there's better things to with that 30-50% premium.
This China craze won't last long. The Chinese PV export market crashed couple months ago(down 30% YoY), and it seems like their domestic auto market crashed too(down ~25% YoY since August).
You can't be the worlds premier manufacturer for 30 years and not get really damn good at making stuff
> crapily made Chinese heat pumps for a fraction of the cost
China is now at a stage of economic development where it can manufacture products across the entire quality spectrum.
Japan went through a somewhat similar transition: in the 1960s and 70s.
CO2 as a refrigerant isn't new:
* https://en.wikipedia.org/wiki/R-744
It's just not as prevalent in the residential HVAC market (which this product serves?), and more in the commercial/industrial space (probably because of the higher pressures needed to get into a liquid state).
It's useful though, as I think (correct me if I'm wrong) that the gases generally used in HVAC tends to have much worse warming effect than co2 per volume.
We do need heat pumps deployed at large scale, but sometimes I worry we don't understand they need to be handled with care at the end of their life
That's true, old school refrigerants like R-12 are awful. The downside of modern replacement refrigerants are high operating pressure (>100 bar for R-744/CO2) or high flammability for natural refrigerants like R-290 (Propane) and R-600a (Isobutane). But these are solely engineering problems, and I'm happy to know that my R-290 heat pumps at home (Panasonic L & Wolf FHS) and A/C (Midea Xtreme Save Blue) aren't awful to the environment, once they reach EOL.
The neat thing about propane as a refrigerant is that it's a really powerful one, actually rather better than R12 in practical applications.
If you replaced an R134a fill with R290 you'd need about half as much gas and if it got out, it's got a Global Warming Potential of 3, making it three times as bad as carbon dioxide and about 475 times better than the same amount of R134a.
Even in a very large air conditioning system like in my elderly Range Rover, the 500g or so of propane it would need is about the same as the engine sucks up in about four miles.
The effect of that escaping into the atmosphere is about as bad as the amount of petrol you spilled the last time you refilled your lawnmower.
If you're worried about the ZOMG IT IS GAS IT WILL MAKE A GINORMOUS EXPLODISHION aspect like a lot of people are, ask yourself this - how many aerosol cans are in your car right now? Tin of deicer, tin of magic tyre inflater, maybe a tin of air freshener or WD40 or something? You're already carrying more propane around with you, rattling around loose at your feet.
I always wondered why we don't see more Sterling Engine based heat pumps. IIUC they can use almost any gas including air.
Because they're sensible heat machines, instead of latent heat machines. In a perfect frictionless vacuum, both of these can achieve the same theoretical efficiency. In practice, not so much. In particular, the isothermal heat exchange of the ideal Stirling cycle requires heat exchangers with no thermal resistance (and therefore no temperature difference). A latent heat pump has a much easier time to very closely approximate isothermal heat exchange because condensation/evaporation temperatures at a given pressure are essentially constant.
What is the back of the envelope efficiency penalty we're talking about here?
https://www.sciencedirect.com/science/article/abs/pii/S01407...
Looks like 30-50% less efficiency.
Thank you!
Yes, that dangerous effect is indexed as GWP - global warming potential.
CO2 has a GWP of 1 in this context, while other refrigerants are worse - for example, R32 has a GWP of 675 (so 675x worse if it escapes), not sure about R290 (Propane), which I believe is either about 40 or 14…
Regarding EoL: At least around here, household appliances such as fridges are brought to a recycling yard and are properly taken care of in that regard… and as for heatpumps - those are only to be installed by certified professionals, for this very reason.
Per the latest IPCC report, GWP of propane is estimated to be 0.02, previously it was estimated to be around 3.
R32 also got rated higher: GWP went from 675 -> 771
The global warming potential of hydrocarbons as such is generally overblown, since they oxidize into CO₂ in the atmosphere with a half-life of a decade or two.
R32 is on the safe side of common refrigerants. R410 just started its phase out in the US and carries a GWP of >2000.
Yeah, ammonia can also be used, it's, IIRC, more efficient to use it and a bit safer because you don't high pressure, buuut enough ammonia in the air will suffocate you.
It's lighter than air so it will go away by itself if allowed to. For a purely exterior instalation it's much better than anything else.
I have a heat pump that uses R290 (propane) (as well as an CO2 one for hot water) and would take that any day of the week over ammonia! The charge of propane is pretty tiny and the safety standards extremely strict, so not really concerning in terms of flammability, ammonia I would consider far, far more dangerous.
I feel like potential suffocation is not what I'd be most concerned about if I were in an atmosphere with high concentrations of gaseous ammonia.
If it is outside you can just use propane as refrigerant. Low warming value and it leaking to outside doesn't matter, not gonna catch on fire.
There are indoor devices using propane but they generally come with caveat "must be installed on room at least this m3", precisely so if it leaks it doesn't get to density that allows explosion
I believe there are propane using split AC systems where propane is used only in the outside unit. The outside unit has a heat exchanger transferring the heat to some glycol-water solution which is what then circulates through the inside unit.
I currently have R410a heat pumps with minisplits, when they're off warranty sometime in the future I might consider putting propane in them. The main question would be whether the oil used with R410a is compatible with propane as a refrigerant.
This is probably a little bit "dangerous" in the sense that I'll have high pressure propane in the line sets and minisplits inside the house, but it's a very small volume of propane and not really any more dangerous from a fire perspective than my propane fired condensing gas boiler.
I heard CO2 is a gas with a powerful green house effect. What happens at the end of life of these units I wonder? What if they leak and it gets into the atmosphere!
CO2 has a surprisingly feeble greenhouse effect.
Almost anything else you could use as a refrigerant is worse.
Even water vapour is a worse greenhouse gas.
Edit: wait, have I been whooshed? Apologies if so... ;-)
There are resident systems, and they're of exactly the type listed in the article (i.e. water heaters). Residential... area heating pumps, so to say, are moving towards propane (afaik). I've been looking into getting a propane monoblock air-to-water pump, with an antifreeze loop towards an indoors heat exchanger / water tank.
Trends for new refrigerant depends on country... some to R-454B, and some to Propane, doesn't seem like C02 is very common which is a pity because I love the idea of a non-toxic non-flammable super cheap refrigerant.
This is for the Japanese market so perhaps the cons of the C02 systems are outweighed by the safety aspects.
CO2 does better with large temp deltas, like hot water tanks. Radiators don't produce large deltas - the inlet to outlet diff is typically under 10 degrees. But they run at higher pressures, making the manufacturing more expensive.
I live in Ohio in a 100 year old home with cast iron radiators and a natural gas boiler and a gas water heater. I’d love to move to electric but it feels like my only real option for keeping the cast iron is something like the Daikin Altherma 3 H HT. Does anyone more knowledgeable of this part of the industry know of any reasonable alternatives for electrifying old houses but keeping the radiators?
Underfloor heating works best with air source heat pumps, so just switch to that.
Then run a wee bit hot water through your cast iron rads for the look of the thing.
I'm actually in need of a new hot water tank and have been looking for a heat pump one. Wonder if these will be available in Australia, and how they compare to the current range.
The Australian electronics YouTuber Dave Jones (EEVBlog) had a heat pump water heater installed in his house, and while on the outside it was branded "Reclaim Energy", it had a Made in Japan sticker and was internally a Mitsubishi.
I have a heat pump hot water unit in Australia - Sanden: https://www.sanden-hot-water.com.au/
CO2 refrigerant as well.
I have this one in Canada. Works well!
But having water leave the building envelope is a bit scary on very cold days. There are heat traces and freeze valves so it should be fine, but I do worry about power outages during cold snaps
“Hitachi has not yet disclosed full efficiency specifications for the two new models. Their predecessors, the BHP-FV37WD and BHP-FV46WD, have annual hot-water and heat-retention efficiency ratings under Japanese Industrial Standards (JIS) of 4.2 and 4.1, respectively.”
What does this mean?
If I'm not mistaken, it means 1kWh of electricity moves 4.1kWh of heat into your hot water tank. Heat pumps are amazing.
well, in case of water heater it moves it from your room to the water.
Which means in winter that is extra work for your heating system to compensate for
But in climates where heating only really runs in winter it's great
These tend to work fine down to -25° C or so ambient temperature (you lose some efficiency below -5° C or so), so should always be outside. Obviously you need an alternate source of water heating if you live somewhere where it routinely gets below that, but even in a lot of places like that you could set it up to use the heat pump 90-95% of the year and a cheap but far less efficient resistive heater for the very cold days, and still come out far ahead.
Technically your refrigerator heats up your kitchen in the same fashion adding extra work for your AC to compensate.
Unless you live in the artic where it's freezing year round, these things make sense. During the summer they reduce your cooling load and during the winter they are effectively heated by whatever your home heater is. Meaning if it's gas, then they are gas powered. If you have a heat pump outside then it's still pretty efficient. Even in the worst case of a resistive heater you are basically just running a slow resistive heater.
The ones in Japan go outdoors.
Most homes in Japan for decades have been designed for Tankless Gas Water Heaters stuck on the side of the building so there is no room indoors for a water tank.
The condenser unit for this literally just looks like the same one as for a regular mini split air conditioner, just a little bit larger.
The one mentioned in the article has an outside unit.
And for the normal ones, at least they are leveraging outside temperature parts of the time while everything else stays at 1 in 1 out.
which is why the bit thats sourcing the heat/cold is outside your house. it either has a massive radioator and fan, or pipes undergorund to source/sink the heat
This specific model appears to be a split system that has an external unit to extract the heat from the outside air.
Technology Connections has recently published an in-depth piece of the advantages and disadvantages of in-room heat-pump water heaters [1].
The tl;dw is that it is significantly slower than a resistive or gas-powered water heater, and lowers the temperature of the room by a few degrees, but nothing major. You have to over-provision them compared to your needs. And they are way bigger.
[1]: https://youtu.be/F_7B2shTPPU
> significantly slower than a resistive or gas-powered water heater
This was TC being a weirdo. He bought a 120V hot water heater. Had he done a regular 240V water heater the recovery time would be comparable to pure resistive water heaters.
But the takeaway about cooling is important. These things barely chill the room they are in.
I believe that for every joule of electricity used, 4 or 4.1 joules are pumped from the environment into the water. This is contrast to conventional water heaters which are bounded by an efficiency of 1, where, for example, burning gas directly heats the water with some heat leaking into the environment instead of the water.