[HN Gopher] DOE announces breakthrough in residential cold clima... ___________________________________________________________________ DOE announces breakthrough in residential cold climate heat pump technology Author : josephscott Score : 289 points Date : 2022-06-18 16:39 UTC (6 hours ago) (HTM) web link (www.energy.gov) (TXT) w3m dump (www.energy.gov) | jamisteven wrote: | "can save families as much as $500 a year on their utility | bills".... ehhh, people affected by an extra 500 per year arent | going to fork over 20k for a new system that will save only 500 | per year. | gehsty wrote: | Overall the cost may not be that much but the bigger shift is | to electrification of heating instead of a gas burning boiler, | as electrical systems can take advantage of power from offshore | wind / solar etc. another way of looking at it is most people | will replace their boilers in the next 20-30yrs, if they can | get a electrical heat pump system they should (and the | governments should make this economically advantageous to do | so). | hsbauauvhabzb wrote: | Is the cost on new homes comparable? Does the US subsidise this | at all? | disantlor wrote: | hmm as someone about to purchase a heat pump system for heat in a | northern climate I am not sure if I should wait... | | is this an announcement of a breakthrough or a challenge to find | a breakthrough? | zip1234 wrote: | There are already heat pumps that work at very low temps. | Mitsubishi has models that are still heating at -13f | boulos wrote: | FTA, they already measured it and will deploy in 2024: | | > The prototype delivers 100% heating at 5degF at double the | efficiency, and 70% to 80% heating at -5degF and -10degF. DOE's | Oak Ridge National Laboratory validated the performance and | efficiency of Lennox's prototype. | | > Lennox is one of nine manufacturers competing in the CCHP | Technology Challenge. Its product and others that meet the CCHP | Technology Challenge will undergo trials in cold climate | regions over the next two years to demonstrate performance, | efficiency, and comfort when applied in the field throughout a | winter. Deployment and commercialization are planned for 2024. | Jgrubb wrote: | I just bought a Mitsubishi mini split system to replace our oil | furnace and bring A/C to our house here in New Jersey for the | first time. Their high end outdoor units heat down to -13 F, | which is colder than I've ever seen here. It arrives in august. | | Gree has a system that claims to have full heat down to -31, so | I'd say just keep researching and you'll probably be fine. | throw0101a wrote: | > _Gree has a system that claims to have full heat down to | -31, so I 'd say just keep researching and you'll probably be | fine._ | | Doing a quick search, they're using 'standard' R410A | refrigerant (PDF): | | * https://www.greecomfort.com/assets/our-products/multi- | plus-u... | | the same as everyone else. It seems just that they though it | worth the engineering effort to push a little further than | most other companies. | | See anything with the label "For Extreme Conditions": | | * https://www.greecomfort.com/our-products/ | david422 wrote: | What is the plan for when it gets colder than -13? Do you do | a hybrid with your furnace? Some other solution? Thinking of | getting some heat pumps myself. | leviathant wrote: | In nearby Philadelphia, it rarely gets that cold, and not | for extended periods of time, but when it does, we bust out | blankets and space heaters to make up the difference. | Jgrubb wrote: | We usually switch to the wood stoves once winter sets in. | Our forced air furnace is incapable of making the house | warm and cozy because duct reasons that I can't really fix. | | I'm planning on getting rid of it altogether and doing the | heat pump(s) most of the year, the wood stoves in winter | and reclaiming a lot of headroom in the basement and an | entire utility room that the furnace currently takes up. | sokoloff wrote: | I've looked into heat pumps pretty extensively for my | upcoming boiler replacement (looking at an air-to-water in | my case, but very similar principles apply). | | In my case, the 99% design temperature is high single | digits Fahrenheit. For the 3.5 days/year colder than that, | the plan is to have the house "coast" on thermal mass. | | That's for cases where the ambient temp is below design | (where the heater can make heat but just no longer enough | to keep up with the building heat loss), not for when it's | below a cutoff (where the heater shuts off entirely). In my | case, that's so far below design temp that I'd expect to | never see it. (We hit -9degF in 2016 and would have to go | all the way back to 1943 to find a low of -14degF.) If it | happened, thermal mass would start to carry us with | electric space heating keeping the house from totally | freezing. | hamandcheese wrote: | I might invest in some backup propane heaters as well (a | buddy heater at Walmart is pretty affordable and is safe | for indoor use). I feel like in blizzard-like conditions | having electricity be your backup plan might not be too | wise. | newsclues wrote: | Go ahead as planned but perhaps have the installer plan for a | future upgrade when the current device fails | mjmahone17 wrote: | You probably should not wait: it will be 2 years of testing | according to the announcement, and if you're doing a retrofit | most the cost of installation will be installing the transfer | lines inside, mounting the unit, etc (opening walls and closing | them back up). Transferring from an old outdoor unit to a new | one should be a fraction of the original install cost | (basically just the new unit cost plus the cost of hooking it | up). | | But, if you're willing to wait or pay extra for the efficiency | gains, you might be even better off getting set up with a | ground source heat pump now. The install cost is more up front, | but because ground temperature is higher than air temperature | in winter and lower than air temperature in summer, the | differential you need to pump in or out is a lot less, and | therefore much more efficient. I don't think any air to air | heat pump in the next 20 years will be as efficient as a ground | to air system you could install now. The air to air systems | just have lower up front install costs. | selimnairb wrote: | This doesn't sound any better than the efficiency of | Mitsubishi/Trane "hyper heat" heat pumps, which are already on | the market. | tzs wrote: | It depends on what they mean by this: | | > The prototype delivers 100% heating at 5degF at double the | efficiency, and 70% to 80% heating at -5degF and -10degF. DOE's | Oak Ridge National Laboratory validated the performance and | efficiency of Lennox's prototype. | | Usually when people talk about efficiency of heat pumps they | are comparing to electrical resistance heating (which is 100% | efficient). If that's what they mean then they are saying 200% | efficient at 5, which is not as good as Mitsubishi, which is | better than 200% at 0. | | But in the first paragraph they say: | | > The U.S. Department of Energy (DOE) today announced that | American heat pump manufacturer Lennox International became the | first partner in the U.S. Department of Energy's (DOE's) | Residential Cold Climate Heat Pump Technology Challenge to | develop a next-generation electric heat pump that can more | effectively heat homes in northern climates relative to today's | models. | | It could be that they are stating efficiency compared to | current heat pumps, not compared to resistance heating, in | which case they would be claiming quite a bit higher efficiency | than Mitsubishi, which would certainly justify calling it a | breakthrough. | | Another possibility is that what they could be claiming as the | breakthrough is the 100% heating at 5 part. The Mitsubishi cold | weather heat pumps start losing capacity below 23, falling from | 100% at 23 to 76% at -13. | | I don't think that would be as big a breakthrough as double the | efficiency of current heat pumps, because it wouldn't make it | so heat pumps are feasible in climates too cold for Mitsubishi. | But it would make it so that in places you can use a heat pump | you might not need as big of a heat pump with the new | technology as you would need with a Mitsubishi. That could | lower up front cost making converting from something else to a | heat pump more feasible for many. | joenathanone wrote: | Domestic is the key here. | adrianmonk wrote: | Mitsubishi's products seem to be mini-split systems[1]. | | _-- > EDIT: Or maybe not... they seem to offer forced-air too. | <--_ | | The DOE challenge is for ducted systems. Their site[2] says: | | > _The Challenge is currently focused on residential, centrally | ducted, electric-only HPs._ | | The DOE challenge also has other requirements[3] that I don't | know if the Mitsubishi systems satisfy. It requires certain | levels of efficiency and "grid interactivity" (meaning Energy | Star "demand response"[4] where your utility can temporarily | tweak your thermostat settings). | | --- | | [1] https://www.mitsubishicomfort.com/residential/new-products | | [2] https://www.energy.gov/eere/buildings/cchp-technology- | challe... | | [3] https://www.energy.gov/sites/default/files/2021-10/bto- | cchp-... | | [4] | https://www.energystar.gov/sites/default/files/ENERGY%20STAR... | R0b0t1 wrote: | Kind of a shame, ducted heating has a lot of issues, but is | the best for retrofit I guess. | oneplane wrote: | I wonder why ducted systems were part of the requirements, is | it because it's just aimed at the USA and then mostly at | adoptability for existing systems (which seems to be ducted | mostly)? I only have anecdotal experience and no numbers to | back that up, but it's the only reason I can come up with | that would put such a restriction in place. | | I'd say rip the ducts out and just use split systems but I | imagine other people have thought about that and figured it's | not the best way to go. (or at last not in the US) | pkulak wrote: | Yes, because nearly every house in cold climates is ducted, | and we're trying to get people off oil heating quickly, | easily, and cheaply. Popping a new heat exchanger in an | existing furnace is stupid simple compared to running | coolant lines to new, wall-mounted exchangers all over the | house. | sokoloff wrote: | Hydronic heat distribution (baseboard and radiators) is | quite common in New England. | Gibbon1 wrote: | I think that's true, if the ducts exist already that's | simplest and cheapest. If they don't mini-split type | systems are. But I suspect that long term those are going | to be a pain in the butt because you have a lot of | failure points. | gwittel wrote: | Many of the Mitsubishi heat pumps work with central ducted | systems just fine. I have one (replaced a central gas heat, | electric AC system). It's just a different air handler but | the heat pump was the same as would have been used in a mini- | split install. | | When cross shopping the Mitsubishi vs Trane, the Mitsubishi | was miles ahead. I didn't even get the most cold weather | efficient option (not needed for my climate). | adrianmonk wrote: | Oh, you must be right. I was finally able to find this on | Mitsubishi's site: | | https://www.mitsubishicomfort.com/residential/products/duct | e... | | And that says it's compatible with some "hyper-heat" | outdoor units. So apparently they do offer both. | pfdietz wrote: | I wonder if the ideas used here can make low temperature | geothermal systems more efficient. An example is the 760 kW | system at Chena Hot Springs, 50 miles east of Fairbanks, Alaska. | The system there uses hot water from said springs to generate | power using repurposed refrigeration technology. | fghorow wrote: | Chena Hot Springs geothermal _is_ a heat pump. It 's an | absorption chiller used partially (primarily?) to keep an ice | house chilled as a tourist attraction. It works for such | relatively low geothermal temperatures because the average | Carnot Delta T is pretty good (because Alaska). | | As to whether or not thermo-acoustic technology could work, | that's a good question. | markvdb wrote: | So much air in this statement, but almost zero raw numbers. | | In the mean time, there are good quality air/water heat pumps on | the market in Europe. Look at the Nibe F2120 for example. It | blows this thing out of the water. It has a COP of 2.5 at -25C... | gorbypark wrote: | Any sources of info on good heat pumps in the European market? | I just moved to Spain and am casually looking at options. | [deleted] | impostervt wrote: | That's great news. I have a heat pump in my house, but still need | to use the gas furnace when the temp drops below 40 degrees | Fahrenheit. | | A repair person goofed the settings last January, and I didn't | notice the furnace wasn't kicking in until the end of February. | My electric bill went from $150-ish for Feb 2021 to $450-ish for | Feb 2022. | dukeofdoom wrote: | So 10k+ outlay to save under $500/year. That would take only 20+ | years to pay off. The wall units are kind of flimsy. Expect at | least one to break. And that $500 in savings is probably | $300/year in reality. Its still a great option for some places, | just not really to switch over from a gas furnace. | prirun wrote: | Seems more reasonable to compare the typical initial cost vs | the increased initial cost for the higher efficiency unit that | saves $500/yr. | | My house was built in 2000 with a regular AC unit for the main | floor and heat pump for the 2nd floor, both Payne, a builder | grade of Carrier. The inside coil went first, at the 9-yr mark | with a 10-yr warranty, so I did get a new coil at no expense | but it cost $600 to install it. | | A couple years later, the outside heat pump went out, and | because of the system's age (about 11 years), they recommended | replacing the furnace and heat pump. | | A couple year later, the main floor furnace exhaust gas blower | mechanism went out, and again, the outside unit was replaced | because it was 14 years old. | | In contrast, my previous house had an American Standard AC and | furnace that was installed in 1970 when the house was built. I | had to replace the furnace blower motor one year - about $500 I | think - but the original AC and furnace were working like a | champ when I sold the house in 2003. | | In summary, you aren't getting 20 years out of any modern, | shitty system anymore. They're designed to fail after 10 years. | You might get lucky and have something fail after 9 years; then | you'll only have to pay for labor. But because there are 2 | major independent components, the outside compressor and inside | furnace, it's unlikely they'll both fail within the warranty. | | My AC guy told me the main reason they fail is because the new | coils are made of very thin aluminum and so fail sooner than | the old systems. If a coil fails, either in the furnace or the | outside condenser, you're screwed. They can sometimes fix them, | but good luck with that. Most HVAC dealers don't want to bother | doing that; they just want to sell a new system. | hgomersall wrote: | Which is always the problem when you ignore the negative | externalities. One would hope those externalities might start | to be internalised to the cost of burning fossil fuels for | heat, then heat pumps might become a better prospect. | | (Tbh, I recently did a high level analysis of a heat pump in a | temperate climate, and in light of climbing fuel bills and the | potential for low price electricity from renewables at low | demand plus batteries, heat pumps start to make a lot of sense. | You need to think about using them differently to gas though) | bialpio wrote: | I think it also ignores the fact that one of the big energy | suppliers entered a war of territorial expansion and it may | take a while until it's business as usual - I'd expect this | to also affect energy prices. | hgomersall wrote: | Is this a US thing? Please elaborate... | kmax12 wrote: | Interesting to see heat pumps come up more and more these days. | As a lot of comments here point out, heat pump technology is | already pretty good, even in cold climates. | | It seems to me a lot of the barriers to adoption in the US are | lack of awareness from consumers and widespread support from | installers. The equipment for a heat pump shouldn't be much more | expensive then an air conditioner since they share so many parts, | but that isn't the case in practice. | | I think government regulations that encourage heat pumps | manufacturing and installation are part of the solution. For | examples, Biden administration recently issued orders to use the | Defense Production Act to produce heat pumps [0] or NYC banning | new natural gas hook ups for heating [1]. | | The other part of heat pumps adoption is making them exciting for | consumers. It feels like if you get the right combo of all of | that, heat pumps could be the next electric vehicle. | | I only recently learned about heat pumps and found it difficult | to understand how they worked and potential benefits. Towards | that end, I started hacking on this tool for others to get that | info: https://www.heatpumpswork.com | | [0] https://www.whitehouse.gov/briefing-room/presidential- | action... | | [1] https://www.theverge.com/2021/12/15/22837799/new-york- | city-b... | rocqua wrote: | Reminds me of this company: https://www.blueheartenergy.com/ | | The claims are pretty amazing. High efficiency, efficient over a | wide range of temperature difference, high temperature | differences possible. | | The operating principle is totally different. It is based on | acoustic waves. Not using phase-changes but just the ideal gas | law (pressure and temperature are proportional). I tried to get | my head around it, and I got it with a standing sound wave. But | they use a traveling wave, for which I could not find | explanations I understood. | | The general idea is "lower air pressure and move gas to cold side | so the gas heats up" followed by "raise air pressure and move gas | to warm side so the gas cools down". That means the low pressure | needs to be low enough that the gas gets colder than the cold | side, and the high pressure needs to be high enough that the gas | gets hotter than the hot side. Luckily that is 'just' a matter of | amplitude of the sound wave. I think this is how they achieve | their wide range of efficient temperature deltas. | | That wide range is the main difference with a phase-change based | unit. The phase change happens at a much more difficult to change | temperature. | [deleted] | lifty wrote: | Really curious what kind of COP this technique can achieve. | Cool tech if real, since it doesn't need any refrigerant. | Wondering if there are other downsides. | dr_dshiv wrote: | Fascinating. I wish my physics courses had focused more on | waves. | | https://en.wikipedia.org/wiki/Thermoacoustics | honksillet wrote: | When you get past freshman physics it is all waves! (Mostly) | WJW wrote: | All of it is also particles! (Mostly) | londons_explore wrote: | Non phase change systems are inherently more efficient because | every heat exchanger (air/air, air/coolant and coolant/water) | can be counterflow, allowing substantially greater efficiency. | | In phase change systems, the 'hot side' and 'cold side' are all | at the same temperature, which means any gradient in whatever | you are heating/cooling is lost energy. | jabl wrote: | Another non-phase change method is the reverse Brayton cycle. | Kind of like running a gas turbine in reverse. I think it is | somewhat widely used in cryocooling, and in jet airliner cabin | AC, but it seems to not have caught on for domestic heat pump | applications. Presumably the traditional phase change | approaches are more efficient in the relevant temperature | ranges. | rocqua wrote: | Does this have something to do with vortex tubes? | thinkingkong wrote: | This same mechanism is also how the james webb space telescope | stays cold! | babyshake wrote: | > The general idea is "lower air pressure and move gas to cold | side so the gas heats up" followed by "raise air pressure and | move gas to warm side so the gas cools down". | | This sounds like Maxwell's Demon, where the work required to | prevent the system from reaching thermodynamic equilibrium is | equal to or greater than the extra energy. How does this differ | from that? | chroem- wrote: | Energy input in the form of compressor work. It's not even | remotely similar to Maxwell's Demon. | huffmsa wrote: | Not at all. You use a compressor or some other means to | increase the pressure. That's what the electricity is for. | Dylan16807 wrote: | Can you explain in more detail how it sounds like Maxwell's | Demon? There's nothing that sounds like it sorts the air | particles, so I don't see the connection. | rocqua wrote: | Maxwell says that the effort you put in is more than the work | you can get out. So the heat difference you get, even if | converted perfectly to other kinetic energy, will always be | less than the electricity input. | | But we aren't after kinetic energy, or work. We are after | heat. | no-dr-onboard wrote: | DOE should probably be capitalized as it's unlikely that a doe (a | deer, a female deer. . .) came through with a technological | breakthrough ;) | RicoElectrico wrote: | The opaque HN automatic title mangler doing its job. I'd argue | it does more harm than good. | libria wrote: | We can't argue that until we have data on the true positives. | For all we know, HALF the titles had the submitters pet word | in all caps. | mh- wrote: | We could flag those. | RicoElectrico wrote: | How do we know? I did not notice such thing in original | submission titles (as in <title></title>). | dpcx wrote: | I thought it was Doe-Anderson (a local ad agency) first... I am | not a smart man without enough coffee. | im3w1l wrote: | This makes me idly wonder if we could use those rays of golden | sun for heating more efficiently than we are. Pitch black | panels facing the sun through which you pump some heat-transfer | fluid? Hooked up to a heatpump? | [deleted] | fortran77 wrote: | The Technology Connections guy is going to be vindicated! | pkulak wrote: | Someone Tweet this at him, pronto! | joemazerino wrote: | Big news for us NorthEasters. Propane and oil are going up. | endisneigh wrote: | Cheapest thing to do is remove all exterior drywall, spray foam | everything and call it a day. | mh- wrote: | Where do homes have "exterior drywall"? | jeffbee wrote: | I guess they meant demolish the interior finishes of exterior | walls, spray foam the wall cavities. | | That's certainly a way to retrofit an older building, but you | still need a heat pump. | endisneigh wrote: | You really don't. I've been in a house in Maine with spray | foam in 20 degrees with no heat turned on and interior temp | was around 65. It was pretty amazing actually. | | A heat pump isn't cost effective compared to Reno with | spray foam. An average heat pump probably takes a decade | minimum to pay off. | mh- wrote: | Ah, thanks. I get what they mean now. It doesn't sound like | a good idea, but I get what they mean. :) | t3rabytes wrote: | drywall on the interior of exterior-facing walls | [deleted] | amluto wrote: | Spray foam is expensive. It's considerably cheaper to install | mineral wool or blown cellulose or fiberglass. And you can blow | in insulation without removing the drywall. | endisneigh wrote: | Spray foam is expensive, but it pays for itself pretty | easily. You can diy drywall hanging simply enough so you're | really just paying for the foam and someone to plaster, you | can paint yourself. | | A cheaper option is rigid foam with canned spray foam around | the perimeter. | mh- wrote: | Aren't the tops of walls capped usually? How does one blow in | insulation without removing drywall? | | Serious question.. I'd have thought it not practical to | remove the cap on the wall (and that's assuming you can | access it from the attic). | | edit: "top plate" is the term I couldn't remember. substitute | for cap in my comment. | magicalhippo wrote: | > How does one blow in insulation without removing drywall? | | We got blown insulation in the floors (ie between roof and | floor), he drilled a 2 inch hole every two feet or so. We | added our parquet floor right on top, with just some thin | XPS sheets inbetween for noise. | | Not sure about drywall, but I'd imagine it's similar. | Easiest would be to just put some 6mm plasterboards on top | to cover the holes, saves you handling each one | individually. | amluto wrote: | You drill smallish holes in the drywall in each stud bay, | blow the insulation in through the holes, and patch them. | This is much less expensive and less messy than removing | and replacing drywall. It can be done with cellulose | insulation, with fiberglass (the loose fluffy kind, not | batts), and possibly some other products. | mh- wrote: | Ah ok that makes sense. Thanks! | beepy wrote: | "Lennox International... developed the first prototype that | achieved the Technology Challenge's standards about a year ahead | of schedule. The prototype delivers 100% heating at 5degF at | double the efficiency, and 70% to 80% heating at -5degF and | -10degF." | | The release goes on to say they expect commercialization and | deployment in 2024. | tempestn wrote: | Perhaps I missed it skimming the article, but my question is, | double the efficiency compared to what? To the current state of | the art cold climate hear pump? Or to a resistive heater? | pkulak wrote: | Yeah, and what is "100% heating"? Do they mean 100% of the | capacity? Why do people write things with important words | just left out? | | My new car can do 100% driving! | yason wrote: | What they probably meant is that at 5degF the pump can | supply 100% of the heat required to keep a house (of | certain size) warm, with no other form of heating required. | At -5 and -10, it can still extract enough heat from the | outside to supply 70-80% of what's needed but you will need | other means of heating such as resistive electric radiators | to complement the heat pump. | | Surely not engineering way of thinking but that's a common | heat pump metric for ordinary people. | joemazerino wrote: | To the current cold pump which can only be efficient at 0 or | above. Then you get diminshing returns for the electricity | expenditure | 2OEH8eoCRo0 wrote: | Heat pumps have efficiency > 100% | OJFord wrote: | No they don't. Just because you don't pay for an input | (outside air/the ground/a body of water) doesn't mean it | isn't an input. | lupire wrote: | Efficiency is a misleading word for heating, because the | units don't match; they are both energy, but different | "type". The denominator is fuel energy lost, but the | numerator is thermal energy change within an area of | interest. A heat pump moves thermal energy from outside, | changing unimportant thermal energy into good thermal | energy. | | "Coefficient of performance" is a better term. | | https://en.m.wikipedia.org/wiki/Coefficient_of_performance | stormbrew wrote: | This just seems like unnecessary hair splitting to me. | Obviously the efficiency of something is subject to the | important inputs and outputs involved. | | If someone asks: "how efficient is this heat pump at | heating my house?" And you start digressing about how | that's the wrong question to ask you'll be giving them an | impression opposite reality, which is for most people: it | will use less electric energy than heat energy it puts | into your house, almost all the time. | ketzo wrote: | Huh, I've always heard the "heat pump efficiency > 100%" | but never really understood what that meant. Thanks for | the explanation. | | So the ">100%" comes from the fact that you're spending | less thermal energy than you are moving? | thedougd wrote: | Exactly. | Gibbon1 wrote: | Yeah take the energy you pump from Reservoir A to | Reservoir B divided by the energy requires to do that and | that's COP. Which you can think of as an efficiency. | PaulDavisThe1st wrote: | Slightly more precisely: you're using less energy (in the | form of electricity used to run the heat pump) than you | are moving into/out of the heated/cooled space. | martijnvds wrote: | Maybe they're trying to write around the term "Coefficient of | performance" (COP) for people who have never heard of heat | pumps. | | I think a COP of 2 at 5degF (-15degC) is pretty good. | tssva wrote: | Minimum COP for the competition is 2.1-2.4 at 5degF. No | idea what the actual COP for this unit are. | linsomniac wrote: | COP of 2 at 5F is good. But... Mitsubishi has one that is | 3.13 at 5F and LG has one at 2.65 at 5F, so this isn't | really the breakthrough that the press release claims, the | breakthrough is that a US company is doing it. | tssva wrote: | That depends on whether the Mitsubishi and LG units meet | the other requirements of the competition. | mikewarot wrote: | At some point, it would be great to use a natural gas powered | engine to run a heat pump. You could then use the exhaust gas as | a heat source for the heat pump, possibly eliminating the need | for a pre-heater. | | Cooling the output should increase the Carnot efficiency of the | motor. | | Heating the outside air intake with that heat should be | sufficient to avoid the need for an electrical resistance pre- | heater. | | This combination could also run on propane, ethanol, gasified | wood, etc. Anything that gets burned now could be used to create | far more heat output than straight up combustion. | | There's got to be a flaw in this idea, math/physics wise. | threeseed wrote: | > There's got to be a flaw in this idea | | The flaw is that we need to stop using fossil fuels now in | order to meet Paris targets. | | Natural gas in particular is an issue because demand is | increasing globally whilst large suppliers i.e. Russia, | Australia for many reasons are not able to meet it. Which is | pushing up prices and increasing unreliability over the short, | medium and long term. | | Now is the best time to bite the bullet and transition to a | decarbonised world. | [deleted] | lazide wrote: | I think you're basically describing a steam engine that | mechanically powers a heat pump, pumping it's own waste heat | and whatever environmental heat it needs. | | It's pretty complicated. Direct hearing via heat exchanger is | usually pretty good and much simpler, albeit less efficient. If | burning thermal sources, raw efficiency is rarely all that | necessary though. The heat output per unit mass is usually | pretty high. | speedgoose wrote: | > There's got to be a flaw in this idea | | Environmental impact or geopolitics issues aside, an | electricity grid is much more convenient and cheaper than a | propane/ethanol/gasified wood grid. Transporting gaz by trucks | and storing it in individual houses is not very convenient too. | cmarschner wrote: | Why would you create new technology with natural gas these | days. It seems such an energy source of the past. Europe is jus | suffering from the dependency on it and seeks to get away from | it as soon as possible. | finiteseries wrote: | Europe is resource poor and suffering from a dependency on | Russia. | | 55 billion cubic meters annually were set to be added to this | dependency as recently as February 21st of this year before | yet another land war erupted on the continent, forcing them | to _suspend_ certification. | | The pipeline is already built though. | Someone1234 wrote: | Agreed. Just electrify everything in the home, then while we | still have natural gas then just use it for electricity | generation. Natural gas's only benefit is that it is | currently cheap, when that stops being true, then it is just | worse than electricity across the board. | | The great thing about electricity is that it scales REALLY | well with new generation and distribution technologies. | petesergeant wrote: | I'd rather cook on a gas hob than an electric one at the | moment | threeseed wrote: | You may change your mind when it becomes orders of | magnitude more expensive. | coryrc wrote: | I use single dollars a month in gas cooking. | bonzini wrote: | Infrared absolutely, but induction cooktops are pretty | good and the only thing you can't do with them is stir | frying. | coryrc wrote: | So, you burn natural gas in a powerplant to create | electricity somewhere around 55% (hopefully) efficiency; in | most of the US, the heat output is wasted. You then lose 6% | to transmission, getting to 52% efficiency, to put it into | a 2x COP heat pump (which we mandate use gases with GWP in | the thousands) to get 104% of natural gas heating. | | Or, spend the same amount on air sealing reducing heating | needs by about 30%, pay workers instead of factories, and | get the same reduction in natural gas use, also without the | refrigerant bomb waiting to go off, and not needing more | power plants built. Mandate every rental have lower than 6 | ACH50, since misaligned incentives mean they're usually | worse than homeowner-occupied units. | seoaeu wrote: | Efficiency percentages are the wrong way to look at it. | If you instead frame it in terms of tons CO2 equivalent, | then locking in the emissions every year between now and | 2050 is going to be worse, compared to the alternative of | burning a bunch of natural gas for electricity now but | gradually phasing it out in favor of wind and solar. | coryrc wrote: | Most heat pumps aren't going to last 30 years. Passivhaus | only needs 1500W maximum of heating, so they usually | don't use heat pumps. | | Wind and solar also lock in natural gas usage, because | they don't provide inter-seasonal storage or even intra- | day storage. | [deleted] | 10u152 wrote: | These certainly exist and have some, rare use cases. | | Personally I've seen them use when there are large air | conditioning loads but insufficient electrical power | | https://www.yanmar.com/global/energy/ghp/ | starkd wrote: | Once again the headline does not match the claim in the article. | This is not a breakthrough in terms of technology. This is the | announcement of a partnership. There was no "breakthrough". This | is government advertising for a private sector company that | frankly is beginning to resemble corporate fascism. | dchichkov wrote: | There is plenty of opportunity in being more efficient. To give | an example, houses in the Bay Area has gray/black roofs. In the | summer such roof receives about 10kW of energy and readily | converts it into heat. Heat, which we are trying to evacuate from | the house with our super-efficient heat pumps in the air- | conditioning units. | | If only we'd painted these roofs with white reflective roof paint | (~92% reflection). We would have removed ~8kW of heating from | such roofs! And then, maybe, we wouldn't have to pump all that | energy into air-conditioning. So the surrounding air would be | cooler, less noise would be heard from air conditioning, less | energy would be spent. And the cost? 4 gallons of white | reflective paint and a couple of hours of work, painting the | roof... | drusepth wrote: | What happens to the "heat" energy that gets reflected by | white/reflective roofs? It seems like it'd stay in the relative | vicinity of the house, heating up the outside air further (even | by a small amount), right? If that's the case, are there | diminishing returns to worry about with effectively just moving | heat from one place to another, assuming the (hotter) outside | air will probably continue to warm up the house anyway? Do we | just bank on something else absorbing the energy instead? Does | it leave the area/atmosphere if nothing absorbs it? | | (Please don't take this as a rhetorical "this is why X solution | doesn't work" -- I'm no expert here and am just curious where | all that reflected heat/energy goes!) | jliptzin wrote: | I would assume those light rays reflect off the roof instead | of getting absorbed...in that case the heat is absorbed into | the atmosphere, I have a hard time believing it sits around | the house and lingers there for any significant amount of | time (doesn't heat rise?) | oneoff786 wrote: | Heat rises is short for hot air rises. The light would not | be completely absorbed by the atmosphere more than it did | on the way down. | extra88 wrote: | With a light or reflective surface, a lot of the energy is | reflected as light so it's not converted to heat. Relatively | little will be absorbed by the air near ground level, heating | the air only a little. | dexwiz wrote: | "Heat" from the sun that we feel is mostly IR/Visible light. | Mix of stuff happens if we reflect it with white surfaces. | Some of it does go back into space. Some of it will get | reflected by the atmosphere back towards the ground. IR light | is also directly absorbed by the air molecules, but very | little. Air is mostly transparent at visible wavelengths so | it absorbs very little energy. Solids are much better at | converting IR to thermal energy. Realistically air | conditioning is just moving heat from one side of a wall to | another. Overall painting buildings white won't change the | temperature of Earth, but it does help the building in | question, which is all air conditioning cares about anyways. | rayiner wrote: | Would that work in terms of all the other stuff? Rain snow etc. | recuter wrote: | Imagine instead of paint if we could come up with some sort of | material that generates electricity. | | P.S. - If you look into the white paint thing more carefully | you'll be rather disappointed. | highwaylights wrote: | Wouldn't a reflective coating work better? | | Given it's a once off cost it seems like this should be | doable. | throwaway3334 wrote: | Actually, I was looking into installing solar, to offset | $400/month of air-conditioning costs, during the summer. I | could have had around 1.5kW of solar. But the cost of this is | north of $25k, plus all the hassle to get the permits, plus | all the extra complexity. While the cost of painting the roof | is $100 + work. And now it is very rare that I have to run | the AC. | sxates wrote: | Do you mean 15kw? 1.5 is only like 4 panels, it wouldn't | make $400 per month and wouldn't cost anywhere near $25k. | throwaway3334 wrote: | I was looking at installing a very small solar array, | just to offset the AC costs. The quote for the solar kit | that could produce ~1.5kW (2170W Solar Kit: 7xURE NSP | 310W - Mono 60 Cell - All Black Panels + 7xEnphase IQ7 | 60-Cell Microinverters w/QCables + 1x Enphase IQ Combiner | 3 + Wireless Monitoring) was $6.5k. | | But, I was also considering having a 10kW battery to | store that energy and to have a backup power, like Tesla | Powerwall - $10k. And then there was work to install, | permits, my time. Overall my estimate was, realistically | it'd be ~$25k. Maybe I was wrong. | | On my house I have two sections of roof that are | flat/horizontal. Roof is pretty thin there and although | there is insulation, on hot days ceiling was getting worm | in the 2 rooms under these sections. I also was hoping | that an extra layer of solar would insulate my roof a bit | more. So I wouldn't have to run AC that much. So the hope | was to stop wasting annoying $400 on AC in the hottest | months. But the cost of installing solar felt | prohibitive. So I've made a quick calculation and spent | $100 on the reflective roof paint instead... | 10u152 wrote: | 1.5 kW of solar for $25k ? Somethings way off, closer to $1 | per watt. | seltzered_ wrote: | Changing how roofs are approached (color, materials) may also | have a (possibly beneficial) hydrological effect, even better | would be some form of vegetation grown on roofs (likely called | 'green roofs' to some) to help with evapotranspiration for | facilitating a small water cycle (helping water vapor travel | inland) and reduce the 'urban heat dome' effect. | | (see Millan Millan's papers like | https://academic.oup.com/bioscience/article/69/2/143/5254231 , | can link to some other newer stuff if desired) | joshocar wrote: | This is one of the reasons metal roofs a nice, they reflect | heat and you don't need to paint them white, they make special | paints for metal roofs that help reflect the heat and also look | nice. | MobileVet wrote: | Black / dark tile roofs across the south are completely | ridiculous. I doubt people understood this when shingles were | first developed but we do now and we should adjust accordingly | hsbauauvhabzb wrote: | Pretty sure they were recently banned in Sydney, Australia. | amluto wrote: | If the roof assembly is decently insulated, then relatively | little of that 10kW heats the house. So, while improvement is | available, it's not nearly that large. | hn_throwaway_99 wrote: | Still, though, I have to wonder what the equivalent "CO2 | reduction" would be considering that a white roof is likely | to radiate most of the incoming sunlight back into space, | where if it is radiating in infrared then that heat is more | likely to be trapped on Earth. | throwaway3334 wrote: | For now, everyone is free to pump out kilowatts of heat | with their roofs, parking lots, air conditioners into the | surrounding air. It is not considered pollution, even when | it is already 100 degF outside. | | On the days when there is an inversion in the atmosphere, | the hot air stays trapped. People have to run ACs in their | houses, stores and offices. And that results in even more | heat routed to the place, with ACs units, literally pumping | energy from the solar arrays somewhere in the desert into | the city. | rocqua wrote: | My intuition says that the volume of inside vs outside | air is so big that it has little effect. | throwaway3334 wrote: | You can look at how much space roofs cover in the suburb | in the Bay Area. It'd be roughly 25% streets, 40% roofs, | 30% backyard, 5% front-yard. Adding white reflective | coating increases "Solar Reflectance" and decreases | "Thermal Emittance" and absorption. Most dark roof | materials reflect 5 to 20% of incoming sunlight, while | light-colored roof materials typically reflect 55 to 90%. | A white roof coating that you can purchase at your | regular home improvement store would do that 90%. | | So effectively, in the suburban area there is an | opportunity to change our average solar reflectance by | ~32% (90% - 10%) * 40%. If we just abandon the idea that | a good house should look like a house in Normandy and | have a black roof. | csomar wrote: | Yeah this was figured out in the Mediterranean probably a few | hundred years ago: https://www.santorini-view.com/white-houses- | of-santorini | | Unfortunately, we are losing some of this cumulative knowledge | due to it not being documented, and due to the looks of | alternatives (although the grey buildings in the US are as ugly | as it can get) | foobiekr wrote: | Hell most of the 1950s and 1960s Bay Area housing stock is | worse - it's tar and gravel roofs without any significant | insulation thereby turning houses into ovens. The right answer | to most of them is a new foam roof which both provides | insulation and reflectivity being white but people get quite | upset about the foam roof thing, especially with Eichlers. | epmatsw wrote: | There's actually a $500 tax credit to install reflective | shingles for this very reason. | https://www.energystar.gov/about/federal_tax_credits/roofs_m... | boardwaalk wrote: | > The prototype delivers 100% heating at 5degF at double the | efficiency, and 70% to 80% heating at -5degF and -10degF | | So, 2 EER (2x of resistive heat) at 5F, 1.8 at -5F and 1.6 at | -10F? Is that right? Seems awkwardly worded. | brtkdotse wrote: | That's uh, pretty terrible? My 15+ year old Nibe gets as much | hedora wrote: | It says "double" the efficiency, so I assume they mean 2x the | COP of the previous model at 5F, and 1.7-1.8x the old COP at -5 | and -10F. | | A COP of 2 @ 5F isn't a "breakthrough" vs. the first | commercially available model I could find numbers for, and a | COP of 1.5 at -10F seems implausible: | | https://www.nordicghp.com/2017/01/heat-pump-effective-temper... | | Honestly though, this press release is so poorly written, I | wouldn't trust the numbers match up to anything. | mlyle wrote: | > So, 2 EER (2x of resistive heat) at 5F | | Yes (or double of previous model as another commentator points | out-- hard to say). | | > 1.8 at -5F and 1.6 at -10F? | | They've not told us the efficiency-- just that it provides | 70-80% of nameplate amount of heating at those temperatures. | boardwaalk wrote: | Ah, I see. I figured they'd keep the input energy constant | because otherwise you're not saying much at all (you could | figure that the efficiency plummets and you'd be better off | with a space heater). | mlyle wrote: | It's possible. Also possible it's barely outperforming the | space heater at the lower temperature and input power has | increased. They've not told us enough. | coryrc wrote: | The energy input goes down because it physically can't run | a differential high enough to get full heating output. | | They could choose the lowest temperature, find it's power | input, then fix it at that amount. But at low temperatures | the concern is usually less "efficiency" and more "am I | going to freeze to death", because in most of the cold | areas temperatures aren't usually that cold for that long | (though in others it definitely is, and if you're running | at 1.6 COP for a significant amount of time, you're better | off with more insulation than a heat pump). | ocdtrekkie wrote: | With natural gas hitting four times it's cost last year, couldn't | come at a better time. Next winter, heat will cost more than rent | in Chicago. | SV_BubbleTime wrote: | Don't worry, the rent will go up too. | formvoltron wrote: | Anyone know how this compares to a geothermal system? | thinkcontext wrote: | Heat pumps for geothermal applications don't need to be | optimized for less than 0C. | overeater wrote: | Does anyone know why there has never been any breakthroughs in | air conditioning for 50 years? Windows air conditioners have been | incredibly heavy, loud, expensive, and resource-intensive for so | long. Even a small room needs one that is back-breaking to | install. And pretty much everyone in the world (except those with | central air) needs a couple of air conditioners now. | | Sure the "efficiency" is improving but it's mainly tricks for | turning it on/off at better times. I know there are some U-shaped | ones now, but it's just a slightly different styling. | | Edit: two commenters pointed out examples of air conditioners | which are 77 lbs and 56 lbs. As a comparison, the OSHA | recommended lifting weight is 50 lbs. I would love to see someone | apply Apple's obsession with thinner, lighter, "revolutionary new | design" to ACs. | HPsquared wrote: | Most poetically answered by Flanders and Swann: | | The First Law of Thermodymamics. | | Heat is work and work is heat | | The Second Law of Thermodymamics: | | Heat cannot of itself pass from one body to a hotter body | | Heat won't pass from a cooler to a hotter | | You can try it if you like but you far better not-a | | 'Cos the cold in the cooler will get hotter as a rule-a | | 'Cos the hotter body's heat will pass to the cooler | | Heat is work and work is heat and work is heat and heat is work | | Heat will pass by conduction and | | Heat will pass by convection and | | Heat will pass by radiation | | And that's a physical law | kristiandupont wrote: | I have pondered this as well and studied it a bit. I feel that | there is room for new tech that can help with this increasingly | dire problem. | | Thermoacoustic refrigeration seems to be one of the more | promising technologies but I would love to hear about others. | vincnetas wrote: | Thermoacoustic... love to hear about others :) yes pun | intended. | rocqua wrote: | As I mentioned elsewhere: | https://news.ycombinator.com/item?id=31791936 there is a | company that claims to use thermoacoustics for general heat- | pump duty. I believe they are targeting European style | hydronic heating. Aiming to be efficient whilst still | producing the 80c water that many older hydronic systems here | in Europe still require. | | Interestingly, they aren't that loud because any sound lost | is energy lost, so they try very hard to 'keep it quiet'. | lock-the-spock wrote: | > And pretty much everyone in the world (except those with | central air) needs a couple of air conditioners now. | | Absolutely not. Where I live we had 34degCtoday but I would | still never buy an A/C unit, which will ruin your health | (heat/cold shock, bad air moisture levels, ...), waste immense | amounts of energy and makes leaving the house a pain as the | rest of the world becomes uncomfortable. Most of my friends | here earn very well but I can't think of anyone that would see | a reason to buy one. Live with the temperature and adjust - | like the famous Iberian or Mexican siesta, where you simply | accept that midday are low energy hours. | | But even beyond this, the reason for A/C use is just bad | architecture and city design. More trees in the streets can | lower the temperature in the street itself and nearby | residences easily by 1-2 degree. Less absorbing surfaces | (asphalt, stone sidewalks, ...) make another difference. | | And as regards the houses, there are plenty of ways for passive | and energy efficient buildings that keep cool. In the middle | east they have built self-cooling houses for centuries. | | And in all this, even if you are stuck with bad streets and | architecture, you can simply adapt, use efficient ways to keep | cool (a fan can work wonders) and drink warm rather than iced | drinks and your circulatory system will thank you as you don't | switch regularly get shocked with 10-15deg differences and you | will sweat much less. | hahamrfunnyguy wrote: | I'd been using a window unit for the bedroom but got sick of | taking it in an out and decided to see how long I could | manage without it. Now I prefer no air conditioning because | of the reasons you state above - it feels much more | comfortable being outside on hot days. I keep the windows and | doors closed during the heat of the day then open them up | when it's cooler outside than it is inside. | bonzini wrote: | Let me guess, where you leave there are "serious" blinds | outside the windows that help keeping sunshine out. I wonder | when Central Europe will start installing them. | adrianN wrote: | I also won't buy AC for myself anytime soon, but I'm still | young and healthy. Older people have a lot more serious | problems with heat waves. | sparsely wrote: | Mini splits are widely used and have become dramatically more | economical and popular over the last decade or so. They are | much quieter and more efficient than window units. | | Some areas ( _cough_ nyc _cough_ ) may need some regulatory | breakthroughs but the technology is there. | foobiekr wrote: | Can you expand on the regulatory issues or provide a pointer? | stormbrew wrote: | Window units really only exist at all because of buildings that | can't accommodate better designs for either practical or legal | reasons. There's just no amount of innovation that can make it | so that having the intake and the outtake right next to each | other without a nearly perfectly sealed box on one side (ie. a | fridge or a freezer) is gonna be anything but a big ugly noisy | energy gobbler. | | If you can't have central, you should have mini-split, and | that's where all your problems get solved. If you can't get | mini-split because your landlord won't let you drill conduit to | outside then you're just kinda stuck and the laws of | thermodynamics are your enemy, not a lack of innovation. | iancmceachern wrote: | "Lisa, in this house we obey the laws of thermodynamics!" | | It's physics and thermodynamics. It's basically the same as | with any heat engine, internal combustion engines included. | | There is a certain maximum theoretical efficiency that is not | 100%. When we build real machines (not theoretical ones) there | are real world losses like heat loss, fluid flow friction, | moving part friction, electrical inefficiencies, etc. Those | real world losses van be gradually worked on over time, | improved incrementally to yield small gains in efficiency. But | never large ones, and never more than the theoretical max | efficiency, which is not 100%. | | It's like hybrid cars (not plug in hybrids, but just gas | powered hybrids), they've doubled or trippled the mileage | compared to a comparable regular car, but they will always need | gas, they will never be 100% efficient. | | Same with this. There will always be some fundamental | electrical losses in the copper in the motor, air gap losses in | the motor, friction in the bearings and fluid, heat losses to | the environment, etc. It's the cost of doing the work. There is | no free lunch, so we can only incrementally improve the little | losses over time. | eloff wrote: | My understanding is that heat pumps can be over 100% | efficient because they're actually moving heat from A to B | where one side is the outside environment. It doesn't violate | thermodynamics if you view the Earth as a closed system. The | heat pump itself is not a closed system. | iancmceachern wrote: | Thanks for highlighting this because it's a common | misconception. | | "The coefficient of performance or COP (sometimes CP or | CoP) of a heat pump, refrigerator or air conditioning | system is a ratio of useful heating or cooling provided to | work (energy) required.[1][2] Higher COPs equate to higher | efficiency, lower energy (power) consumption and thus lower | operating costs. The COP usually exceeds 1, especially in | heat pumps, because, instead of just converting work to | heat (which, if 100% efficient, would be a COP of 1), it | pumps additional heat from a heat source to where the heat | is required. Most air conditioners have a COP of 2.3 to | 3.5. Less work is required to move heat than for conversion | into heat, and because of this, heat pumps, air | conditioners and refrigeration systems can have a | coefficient of performance greater than one. However, this | does not mean that they are more than 100% efficient, in | other words, no heat engine can have a thermal efficiency | of 100% or greater. For complete systems, COP calculations | should include energy consumption of all power consuming | auxiliaries. The COP is highly dependent on operating | conditions, especially absolute temperature and relative | temperature between sink and system, and is often graphed | or averaged against expected conditions." | | https://en.m.wikipedia.org/wiki/Coefficient_of_performance# | :.... | | More detail here: | | https://physics.stackexchange.com/questions/489467/can-a- | hea... | | In short, a heat pump is more efficient when compared to | using the energy to directly generate heat because it's | more efficient to move heat than generate it. | Dylan16807 wrote: | They're not talking about that 100. | mensetmanusman wrote: | That means you need somewhere to move the heat to, and the | thermoynamics of heat capacity are not forgiving if you are | trying to make something lightweight. You need atoms and | lots of entropic states to store heat :) | bushbaba wrote: | Idk this "toshiba" AC has a built in heat pump and operates at | super quiet levels. Would I call it a "breakthrough", likely | not. But it is a meaningful improvement over an AC released | decades ago. | | https://www.homedepot.com/p/Toshiba-14-000-BTU-12-000-BTU-DO... | JaimeThompson wrote: | Check out the inverter type ones such as this one [1] It isn't | light but it is quiet and adjusts the amount of power it uses | depending on cooling needs much better than a typical window | unit making it more efficient. | | [1] https://www.midea.com/us/air-conditioners/window-air- | conditi... | devwastaken wrote: | Patents, intellectual property, etc. It's why every appliance | is trash nowadays. Big corps are IP holders, and there's only | so many ways to engineer certain actions. Regardless even if | you try to startup a company you'll be pushed out by the | control big corps have over manufacturing. | | We need to start nullifying IP if we ever hope to see | innovation. | mensetmanusman wrote: | Probably not this, most IP can be worked around, and | especially in the area of AC operations and thermodynamics, | that hasn't changed in almost a century. | jeffbee wrote: | Talk about moving the goalposts. You asked, people answered. | The revolution is that you can now buy an 8000 BTU unit that | weighs little, costs almost nothing, and can be installed | anywhere in a few minutes. | [deleted] | Ekaros wrote: | Thermodynamics are harsh mistress... Add that to limitations on | what can be used as refrigerants. The reality that these | systems need to operate with rather long duty cycles for | decade+ at minimum. And the reality is that there isn't much | magic in how they operate. Compression and expansion of gas. | | Computers are actually a very special case. They don't really | do any physical work in sense other stuff does, thus | miniaturization gives lot of gains there. I have long said that | small drones are answer to flying cars. We have them and they | are small, but lifting people is hard work. | vanderZwan wrote: | AFAIK the physics of heat pumps is considered to have been | fully figured out for ages and all that's left is the | engineering. Maybe it wasn't considered a "sexy" enough topic | to nerd out over and hyper-optimize? | | Edit: it might also be an issue of diminishing returns of | better efficiency compared to how difficult it is to produce | and maintain a better unit. Thermodynamics can be a pain like | that. | mikepurvis wrote: | We got a U-shaped one for a big open attic space and I'm a fan | of it. It cost more and was a little bit more drama to install | (came with a big support bracket thing), but it's very | effective and quiet. We meant it as a stepping stone to | eventually putting a mini-split setup on that side of the | house, but it might end up just being the long-term solution. | | EDIT: Oh lol, the unit we got was actually one of those Midea | ones linked in a sibling comment. | pengaru wrote: | What a misleading clickbait headline. | | This isn't a technology breakthrough, this is a DOE | policy/partnership/funding "breakthrough". | asdfman123 wrote: | "Tapping into the emerging clean energy market is a huge economic | opportunity that will bring a bolstered manufacturing sector, | good paying jobs, and a brighter, cleaner future to _Texas_ and | communities across America." | | If anyone else is confused by this, it's because Lennox is | headquartered in Texas. | davidro80 wrote: | You are confused by this? It's a straightforward statement. | InsomniacL wrote: | what's not straight forward is understanding why the | statement lists a single state and everyone else falls under | 'communities across America' which the comment above clears | up. | mrfusion wrote: | What's the breakthrough on the tech old level? What did they | discover? | tootie wrote: | It can operate efficiently at lower temps. Current air source | heat pumps see degraded performance and below freezing temps | and will not be able to effectively heat a home at the lowest | temps that can occur in the northern hemisphere. | mrfusion wrote: | Thanks. But I'm trying to figure out how they do that. | margalabargala wrote: | The "secret sauce" of the increased efficiency is that | they're using thermoacoustics, which previously had been a | technology used in one-off applications with a large budget | (e.g. the James Webb telescope uses it to stay cool). Prior | to now there were no manufacturers providing the technology | to be widely available at scale. | PaulDavisThe1st wrote: | No idea how the Lennox units in TFA do it, but the Mitsubishi | "hyper-heat" units do it by diverting a small amount of their | output back into heating up the refrigerant at very cold | temperatures. It starts to get a bit "slushy" at the low end of | the performance range, which impacts the ability to move heat. | By warming it back up to the bottom of its ideal operating | range, the whole system functions more efficiently. | londons_explore wrote: | Lab vs typical observed performance differs quite widely for many | home heating systems. | | Thats because typically each appliance is tested at optimal | conditions (eg. water flow rates). Then, in a real deployment, | every parameter differs a little from optimal (eg. the water may | circulate slower than expected because you have longer pipes | around your home than the lab ones, and your hot water tank is | hotter than expected because you like it set hot, and your | airflow is less than expected because the filter is a bit | blocked, etc.). Each knocks a few percentage points off the | efficiency, but the overall impact can be dramatic. | | We really need 'smarter' heating systems which can detect and | correct for such things. For example, water and air pumps which | measure temperatures and flow rates of air/water, and adjust | speeds up and down to maintain the optimal efficiency point. | mrfusion wrote: | Could this be useful in electric cars? I know they spend a lot on | heating the cabin. | hedora wrote: | Yes; many EVs already use heat pumps, so if this has a higher | coefficient of power (and is not much heavier), and it can be | scaled down to automobiles, then it will be a win. | | (None of those details can be inferred from the press release.) | borner791 wrote: | Clever Deers.. | lucb1e wrote: | For anyone else confused, this refers to a previous title | version as per https://news.ycombinator.com/item?id=31791942 | and https://news.ycombinator.com/item?id=31792348 (the comment | I'm replying to was far above those others for me, so I was | quite confused) | visviva wrote: | Since DOE is an initialism and not an acronym, the capitalization | in the title is incorrect. It should be "DOE". | dang wrote: | Fixed now. Thanks! | euroderf wrote: | P.R. with zero tech details is indistinguishable from 100% | balonie. | hedora wrote: | But it delivers 100% words at 5degF at double the efficiency, | and 70% to 80% words at -5degF and -10degF. DOE validated the | performance and efficiency of the press release. | [deleted] | kennywinker wrote: | Great, now if someone can crack the engineering challenge of | installing a name-brand heat pump for less than $18,000 (CAD) | that'd be great. | com2kid wrote: | Lots of do it yourself videos on YouTube showing installs for | well under 5k. | | Labor is expensive right now. :( | bbarnett wrote: | Name brands tend to be unbuyable by the consumer in Canada, | and if you import one, or buy via grey market, the threat is | that you have no warranty. | kennywinker wrote: | All the quotes I got were for a day of install. I assume it'd | be one tech, but let's be generous... 2 techs x 8 hours x | $150/hour = $2400 for labour. So that means either the pump | itself costs $15k, or somethings wrong in this market. | kennywinker wrote: | Or my alternate hot-take (or cold-take?): Great, now if someone | can crack the engineering challenge of an air-to-water heat | pump water heater that doesn't turn your basement into a walk- | in refrigerator, that'd be great. | ortusdux wrote: | Rheem, the brand HD carries, is easily ductable. Both the | inlet and outlet can take 100' of 8" ducting. | | I set mine up with T's, electric dampers and some simple | logic. | metadat wrote: | Add a server rack and things will warm up down there. | kennywinker wrote: | Make it a liquid-cooled server rack and we can cut out the | hot water heater entirely | thrill wrote: | Run it on solar power and pull the water out of the | atmosphere and we can save a bundle on running power and | water. | ulrikrasmussen wrote: | Why would it do that? The heat exchanger is placed outside. | thaeli wrote: | Heat pump water heaters mostly draw from room air. | jacobolus wrote: | Common heat pump water heaters (often called "hybrid") have | a heat exchanger on the top of the tank, and pull heat out | of the surrounding air. | kevstev wrote: | How cold does it really get? This could be great for a wine | cellar. | chrislund wrote: | Depending on your market, Sanden and Mitsubishi make air- | source DHW heat pumps where the evaporator/heat source source | is remote (i.e., outdoor) rather than integrated with the | tank. I can't speak to Mitsubishi's line but IIRC Sanden has | the DHW go straight to the outdoor unit, but then you may | need freeze protection, which I think Sanden provides via | heat trace. When my current water heater bites the dust, I | plan on getting a Sanden, and looking in to the feasibility | of making a glycol loop between the outdoor unit and an | indoor "indirect" tank to eliminate the need for freeze | protection. | kennywinker wrote: | Thanks for the tip! Where I am Mitsubishis seem to only be | available through big-name installers, and the only thing | they offered me when I talked to them was the all-in-one | style that cools your basement. Living in an old house with | not great insulation between floors, that was a hard no-go. | I'm now googling the Sanden ones and getting some promising | results I hadn't seen before. | Danieru wrote: | What you want is an "Ecocute". It is a air source heatoump | supercritical co2 tanked hot water system. Designed for the | Japanese market. Without install a 500l tank version costs | about 1.5k usd in Japan. So you should be able to get one | installed for about 20k usd in the US. If you beg the HVAC | guy of course. | nawitus wrote: | Why is it so expensive? It's like $1k in Finland. | kennywinker wrote: | I have no idea. | | You can definitely do it for cheaper. There are $1000-$3000 | single-head units available online for self-install, and you | could hire an HVAC person to come out and do the high | pressure line part of it (or all of it) for a similar range. | It just gets expensive with the name-brand ones. For some | reason that $2k-6k turns into 10k-20k when you switch to a | name brand (e.g. mitsubishi). They're only available through | specific installers, and using a non-authorized installer | means your warranty is void. | magicalhippo wrote: | Maybe we're talking about different things? I'm in Norway | and we got a Mitsubishi Kaiteki[1] for $1800 total, | including installation and 25% VAT. | | Of course, a multi-room install would probably get | expensive quickly here too. | | [1]: https://kaiteki.no/ | euroderf wrote: | Units are somewhere over a thou and (simple, not multiduct) | installation is somewhere under a thou. | [deleted] | stormbrew wrote: | I recently installed a (quite large) heat pump for less than | that, though it came close. A lot of the cost came from a few | things: | | - the Canada premium: these sorts of things are just more | expensive here. The base price was just higher than I could | find in the US, but obviously importing is too expensive. I | think the reason for this is there's almost no stock. | | - adapting my house: the house I live in was built to have | central air added to it, but even so the pipes going from the | furnace room to the outside had to be insulated both directions | instead of only one for an AC. Ripping up our basement ceiling | to do this added a lot to the cost. An unfinished basement | would help a lot here. | | - HVAC company confusion: I had to go through like five HVAC | companies before I found one that would believe me that I | really wanted it. The one I got is a commercial outfit, so | their prices were just higher. Even they were skeptical but | they were willing to work with us, and by the end they talked | about doing more installs so that was nice. | | I think the cost for the install and unit itself was $12k for a | top of line carrier unit capable of working down to pretty low | temperatures. But we already had a compatible carrier furnace | and exchanger. Was another couple thousand for ripping up the | basement, which we had other contractors do. | | This was also literally during the heat dome last year. They | had to ship the unit across the country. | bradleyjg wrote: | I don't believe in breakthroughs anymore until I see a shipping | product. I don't care if you are a scientist, company, government | agency, or NGO same thing applies. | | Tell me you've made an incremental improvement and I'll believe | you, tell me you've made a breakthrough and either you're lying | or something will prevent it from being realized before | commercial availability. This is what decades of press releases | and articles that might as well be press releases have taught me. | SV_BubbleTime wrote: | The "save up to $500" in the presser is just so obviously | fluff. $500 in what home? | | And I suspect the magic here is also an air tight new | construction home with a layout designed around this, not leaky | everything with an old water heater tucked under the stairs, a | 30 year old furnace, and R19 insulated walls. | WithinReason wrote: | > $500 in what home? | | The "up to" part means it's the absolutely largest home you | can possibly imagine | pbourke wrote: | Presumably the 30 year old furnace is replaced or | supplemented with a new heat pump. | | I have realized an approximately $500 yearly savings by | replacing an older electric tank water heater with a hybrid | electric (heat pump) water heater so I can believe that | claim. | [deleted] | linsomniac wrote: | You are right to be skeptical, but in this case the lie is not | in the performance but that it is a breakthrough. | | The announcement is basically: A US company (Lenox) has a | prototype heat pump that matches performance of Mitsubishi and | LG heat pumps. | | The DOE is running a competition to get US companies to improve | performance of their heat pumps. | nfin wrote: | it might work. | | But there exist sooo many prototyping breaktroughs. | | Those who follow press releases for many years know that just | a tiny fraction can transfer this in real world products that | actually work | | (so many more challenges to overcome compared to prototype | situations!! I don't even know where to begin... every ground | is different, average person doing the manual work is not as | skilled and has less support engineers, the guys | setting/defining the dimensions of various | recipients/pumps/conduits are often undeskilled and the | efficiency often lacks tremendously for that reason...) | linsomniac wrote: | My thinking on it is: It'd better work, they're just trying | to catch up to the state of the art. The bigger news would | be if Lennox _CAN 'T_ make a COP 2 at 5F heat pump. :- | otter-rock wrote: | I agree with the general sentiment, but the article explains | that this "breakthrough" is a product prototype that meets a | government spec. It's hyperbolic wording, but they're trying to | warm people up to the idea of eventually getting a heat pump to | alleviate some energy issues. | [deleted] | osigurdson wrote: | >> The prototype delivers 100% heating at 5degF at double the | efficiency, and 70% to 80% heating at -5degF and -10degF. | | Double the efficiency of what? All existing technology or | something else? Do they simply mean the COP is 2.0? ___________________________________________________________________ (page generated 2022-06-18 23:00 UTC)