19 ms·

Heat Pumps – The Well-Tempered Future of A/Cs

195 points by mfiguiere 3y ago

digdugdirk 3y ago
Well this was an oddly terrifying introductory paragraph for an IEEE article: "... half of Phoenix residents are at risk of an emergency room visit or worse if their electricity fails during a future heat wave, according to a recent study. Air conditioning is what keeps people there comfortable—and alive—a growing fraction of the year. The extreme heat already kills hundreds of Phoenix-area residents every year, a number that went up by 25 percent from 2021 to 2022."
- silisili 3y ago
  Sure, but it can happen anywhere. I was just reading yesterday about a person who died in Portland of heat during the dome. Same with cold weather, if the gas/electric goes out during the winter. There's really only a few places one can live with moderate enough weather to avoid those scenarios.
  - tiahura 3y ago
    Half of Phoenix vs A person in Portland. It seems like there’s an important scale issue there. So the risk isn’t really the same everywhere.
    - RationPhantoms 3y ago
      Good point on the scale. However, Phoenix is also a retirement destination so you're looking at a larger portion of the population being susceptible to heat waves.
      - AlbertCory 3y ago
        > Phoenix is also a retirement destination People who retire there most likely go up to Flagstaff in the summer, or further north. Or they just have good A/C.
  - zht 3y ago
    what? do you really not see a difference between a place where the event is much more likely to happen for a much longer % of the time than another place where the same event is much less likely to occur?
  - ericd 3y ago
    And that's why you see fireplaces/stoves in a lot of houses in the northeast, even if they have gas/electric heat.
  - phpisthebest 3y ago
    >>Same with cold weather, I 100% disagree with this... Heat is made by everything, waste heat is a byproduct of all modern things, and there are TONS of easy low cost ways to make heat even it is just as simple as burning something. Also the body makes head naturally so adding layers to trap this heat does not require continual inputs from an outside resource Cooling on the other hand is MUCH harder, and electricity is really the only avenue to make cooling. Even if you say use ICE, well that Ice was made at some point by a freezer running on Electricity IMO hot climate is MUCH MUCH more dangerous than cold, which is why I choose to live in an area where there are only 1 or 2 months of even remotely hot climate. As I told my last HVAC... Heat I can make 100 ways... Cooling I need central air for...
    - silisili 3y ago
      For a young/healthy person, sure. But these aren't generally the at risk people in the first place. I grew up around the 38N parallel, gross enough to get too hot in the summer and too cold in the winter. Every winter people froze to death, just the same. It's not as bad as Phoenix percentage wise, but it's still a risk in the vast majority of places that people in the US live.
      - phpisthebest 3y ago
        Of course people can and do die from cold, that was never my claim My Claim is providing people with emergency heat is FAR FAR FAR FAR easier and cheaper than providing people with emergency cooling. Do "at risk" people die in the north from the cold, absolutely but I am not sure how that means the cold is worse As it stands right now, just from my daily activities my waste heat in my home makes my home about 10-15 degrees above ambient. Meaning in the winter if my target temp is 65deg, it would have to be 50 degrees or colder outside before I would even think about running my heat. In the winter time that means my AC is working hard to not only combat the outside temp but the internal waste heat from computers, cooking, TV's, humans, etc.
    - nerdbert 3y ago
      > Cooling on the other hand is MUCH harder, and electricity is really the only avenue to make cooling. Gas-powered fridges and coolers have existed for about two hundred years and are still a normal technology today - often used for camping and off-grid life. Here's a whole bunch of propane fridges for your viewing pleasure: https://bensdiscountsupply.com/collections/propane-refrigerator https://bensdiscountsupply.com/collections/propane-refrigera...
  - colechristensen 3y ago
    Eh, it is much much easier to keep warm when it's -40 outdoors than it is to keep cool when its 120+ outside. Unless you have a terribly insulated shelter, blankets, coats, and friends will keep you warm enough to the extent that unless you are not really capable of taking basic care of yourself, you're not dying of the cold when your heat goes out. You can always do more insulation, and you only need so much for your body to keep you warm. With heat though you run out of things to do. There is a difference between an impaired person or a person doing something unwise dies of the heat or cold... and there being an environment where there's nothing a healthy adult can do to survive without powered heating/cooling.
    - nerdbert 3y ago
      Part of this is because we build houses that are terribly suited for warm climates. I used to work in the Middle East, and their traditional structures with central pool and windcatcher/chimney design remained quite livable even when it was over 45°C outside, with zero active cooling.
- cmrdporcupine 3y ago
  I've read a few times that the population of the entire US south only really started to grow in earnest once AC was invented. Ah, here's an article: https://www.nytimes.com/2017/08/04/upshot/the-all-conquering-air-conditioner.html https://www.nytimes.com/2017/08/04/upshot/the-all-conquering... It's pretty crazy because growing up in central/northern Alberta, I never even really encountered air conditioning until I was into my early 20s and moved to southern Ontario (where living without it would be complete hell in the summer, hot humid disgusting "I feel like I'm being smothered in someone's armpit" summers). Our cars never had it and our houses certainly didn't need it; just an open window. Summers were mild and the heat when it came was a dry heat. But now when I go home to visit there, A/C is everywhere there, and it's frankly needed; the last summer I spent time out at my parents west of Edmonton there were multiple days in a row over 30C and it was frankly quite hellish and them having a ground source heat pump that cooled the house was a godsend. Just the 2-3C difference in peak temperatures from the 80s til now is enough to push it over the edge into new territory.
  - retrac 3y ago
    I've likewise read arguments that AC is linked to the substantial economic growth in the second half of the 20th century, in regions like southern France, southern Japan, and the southern United States. All regions that historically lagged economically behind their culturally and economically similar more northern counterpart regions. Hard to say how much of a factor, but there has to be some truth to it: just imagine productivity in a Texas factory at 40 °C and 90% humidity vs. 25 °C and 50% humidity.
    - kalleboo 3y ago
      The man credited with making Singapore the powerhouse it is today has also been adamant that without Air Conditioning, tropical countries couldn’t develop https://www.vox.com/2015/3/23/8278085/singapore-lee-kuan-yew-air-conditioning https://www.vox.com/2015/3/23/8278085/singapore-lee-kuan-yew...
- afavour 3y ago
  I've only ever visited Phoenix but when I did it was mid July and being outside genuinely did not feel hospitable to human life. That statement doesn't surprise me at all. Unless you're employed in, I dunno, the solar power industry I really feel like you shouldn't be living there. It should be like living on an oil rig.
  - melling 3y ago
    Can’t deal with a little extremes on earth? Sort of makes one wonder how we’re ever going to colonize Mars so we’re not a single planet species.
  - brabel 3y ago
    Do you think people shouldn't be living in Chicago (or most of Canada and the US midwest for that matter) because without heating it's just completely inhospitable to human life during the winter? Or pretty much all Australian cities in summer?
    - pkulak 3y ago
      Relying on a coat for survival is very different from relying on an HVAC system. One has no moving parts, requires no external inputs, and is routinely handed out for free to those who can’t afford them.
    - afavour 3y ago
      Heating is considerably more energy efficient than having to run ACs all over the place. And if you need to go outside when it's cold you can: you add layers of clothing. In Arizona, in the middle of summer, you could be buck naked and you'd still overheat (and get burnt, to boot).
      - rcme 3y ago
        Until the widespread use of heat pumps, AC was much more energy efficient than heating.
      - triceratops 3y ago
- interestica 3y ago
  Time to start calling it Life Support Systems
- ashconnor 3y ago
  I would imagine solar panels would be a good investment in a climate like this.
  - genmud 3y ago
    There is actually efficiency issues with the high heat... but they do help offset the AC requirements, so overall even if the efficiency is down 20-40% because of heat, you require potentially 20-50% less A/C because it shades the roof.
  - willis936 3y ago
    Or a solar boiler connected a refrigerant compressor. The hotter it gets the more cooling power you have. Steam punk for the 21st century.
- genmud 3y ago
  Luckily, the local grid here in AZ is fairly robust, probably one of the best in the US. During the 3 years I lived in DC area, I probably had 3 or 4 power outages due to weather (ranging from a couple hours to multiple days). In the 30+ years I have lived in Arizona, I have experienced probably 2 outages, lasting a total of a few hours (one was when a car hit a transformer, the other was when a microburst knocked a bunch of aging poles down). The last outage I had was like 6-8 years ago.
- londons_explore 3y ago
  It raises the question of if we should deploy 'emergency coolers' - perhaps single-use barrels of some chemical that gets cold when a pull-tab is pulled. To be a workable solution, it needs to be more reliable/cheaper/more effective than just a regular gasoline generator powering a regular aircon unit. After a flood/hurricane/nuclear strike, they would provide enough coolness to keep people alive for a few days.
  - sigilis 3y ago
    Water can be used for this purpose, and swamp coolers are something that can be pretty trivially implemented by people in relatively dry areas. For very humid places you generally need energy input for cooling.
  - mindslight 3y ago
    I believe the straightforward answer is to dig a hole. But it would certainly be interesting to calculate exactly how much cooling capacity you could get out of one or two 55 gallon drums of some endothermic precursors. Bonus points for being easily reversible when the electricity comes back on (like those sodium acetate heating packs).
nottorp 3y ago
Isnt any a/c a heat pump though?
- cornstalks 3y ago
  Yes, but typically “heat pump” is used to mean it can provide heating too, whereas standard “A/C” is a “one-way” heat pump that only provides cooling.
  - LUmBULtERA 3y ago
    I always went with this description too, though oddly a "heat pump water heater" only works one direction, yet "heat pump" is still in its name.
    - sidewndr46 3y ago
      all heat pumps work in one direction. You can't move cold around with any mechanism. Only heat can be moved. The difference is residential "heat pumps" just have a set of reversing valves so you can move heat from outdoors to indoors.
      - anamexis 3y ago
        > The difference is residential "heat pumps" just have a set of reversing valves so you can move heat from outdoors to indoors. So.. they work in two directions.
        TheSpiceIsLife 3y ago
        It depends on your frame of reference.
    - wcfields 3y ago
      Have to imagine that the niche market for making 40F/4C "cold" water from luke-warm tap water (if you live in an area that is so hot the tap water is warm) is fairly small.
__MatrixMan__ 3y ago
I live in a colder climate where heat pumps are not popular. After talking with a number of HVAC people about this I was surprised to learn that despite being very similar to an AC system in principle, in practice converting an AC system into a heat pump system doesn't make economic sense--you end up just ripping one out and installing the other. I don't fully understand why this is the case, but I hope that there's something that can be done to improve it. I'd love it if I could drive my AC unit as a heater for 95% of the winter, resorting to natural gas only during in the extreme cases.
- deleted 3y ago
  [deleted]
- nightski 3y ago
  The thing is (especially where I live) I'd still need a gas furnace. We regularly see -20F to -40F in the winter. While the 95% scenario sounds great, in practice still needing gas means we still need all the gas infrastructure. From my understanding natural gas burns pretty clean. The problem is leaks in infrastructure and drilling, which isn't going away because I buy a heat pump.
  - GlickWick 3y ago
    They make heat pumps with backup gas systems now.
  - elil17 3y ago
    Although natural gas is "clean" compared to, say, coal, the advantage of a heat pump is that it uses less total energy than natural gas. That means it would be more efficient to run a heat pump off a natural gas power plant than to burn natural gas to heat your home directly.
    - __MatrixMan__ 3y ago
      Where I live, you can bank solar credits. If you cash them out you get the "wholesale" energy price for them (much lower), but if you spend them on electricity then you've avoided paying full price for that electricity. So if your system produces more than you consume, you've got this free energy budget to spend--a budget that applies to heat pumps and not to gas furnaces.
nemo44x 3y ago
I have both HVAC and a ducted heatpump for one part of the home. The biggest issue with the heatpump is that in the climate I live in there are times of year where you may have the heat on in the morning and the AC in the afternoon. Or you may leave and when you return you want to change the temperature. A furnace and an AC can do this rapidly. A heatpump takes time. It's more of a trickle of climatized air than a blast of it. Also, I'd never want a ductless system as they look awful in a room. They are the future though. Especially as new regulations go into effect by 2035. Sadly, many American manufactures haven't taken it seriously and are far behind the Asian companies like Daikin.
- adgjlsfhk1 3y ago
  If you have the heat on in the morning and AC in the afternoon, your home is horribly under-insulated (or you are trying to keep in way too small a temperature range).
  - nemo44x 3y ago
    Old homes tend to not have any insulation. Parts of my house have modern insulation due to renovations/additions but other parts not so much. I wouldn't swap out the original windows and glass on the facade, for instance. And insulating it would probably be a destructive action as you need proper vapor barriers for insulation to not rot your home.
- davidmurdoch 3y ago
  Mine take maybe 2 minutes to switch from heating to cooling, or cooling to heating.
  - nemo44x 3y ago
    I’m saying the time it takes to change the temperature in the home, not the time to switch function.
    - davidmurdoch 3y ago
post_break 3y ago
When my AC finally needs replacing I'm going heat pump, and then also ditching my gas water heater. The constant fees of a gas line are ridiculous at this point and any more electricity usage will be offset by the 9 months of the year I'd never turn on the heat.
- punkybr3wster 3y ago
  Now you can even get water heaters with heat pumps and combo units that dump your waste heat from your hvac heat pump into the water heater. It’s wild.
  - crazygringo 3y ago
    Your AC powering your hot water heater at the same time... that's genius.
  - jay_kyburz 3y ago
    When we put the solar on the roof we bundled in heat pump hot water system as well. It's timed to only use power right in the middle of the day when the sun is shining, and in the middle of the night when power is cheap. (needs both because the tank is fairly small and my kids like long showers)
- deleted 3y ago
  [deleted]
ramesh31 3y ago
Swamp coolers are massively underutilized as well. The vast majority of residential cooling in all but the most humid climates can be done with nothing but a fan and some cold water; no compressed gases necessary.
- metiscus 3y ago
  The issue with swamp coolers (evaporative cooling) is that you need relatively low humidity for them to work and they increase the humidity of the interior cooled environment. If you use them in combination with an air conditioner, they will very likely reduce the efficiency of the air conditioner by increasing the dehumidification load of the air conditioner.
- elil17 3y ago
  This sort of true? There are many hours per year in many climates where direct evaporative cooling alone could suffice to keep people comfortable. However, most climates also have a good number of hours where air conditioning is required for comfort. You can use this tool to visualize this: https://drajmarsh.bitbucket.io/psychro-chart2d.html https://drajmarsh.bitbucket.io/psychro-chart2d.html (Use the Givoni Bioclimatic Chart overlay and select a weather station using the globe icon.) That said, there are a number of more complex devices which could further reduce how often AC systems need to be used: dew-point (Maisotsenko Cycle) coolers, indirect evaporation cooling, and thermal energy storage to name a few.
- rimunroe 3y ago
  > The vast majority of residential cooling in all but the most humid climates can be done with nothing but a fan and some cold water Aren't swamp coolers only really useful when the humidity is under something like 50%? I guess I'm assuming you're talking about the US, but I don't think "vast majority" of people live in such areas. A quick search for average humidity of US states in July and August shows many of them have an average daily humidity of over 50%. It certainly rules out every place I've lived on the east coast (Richmond, Virginia, Long Island, and the Boston area), as the humidity in those places is usually at least 60% at the height of summer when most people actually use their AC. As a side note, I suspect most people overuse their air conditioning and don't let their bodies adapt to the warmer summer weather. It's weird how many people keep their houses under 75 °F when the heat index is only in the mid 80s.
davidmurdoch 3y ago
Being a Florida native, seeing an article titled "Heat Pumps [are] the Future of A/Cs" feels like it should have a ` [1973]` tacked on to the end of it. A heat pump is pretty much the only thing we use here, we just use them in reverse. Literally. Most residential units have a "reversing valve" that must be held open by a constant 24V in order to cool the air - the default mode is heating -- which is so smart to have a failure mode that causes your house to be heated in the summer to 95F while you sleep. Anyway, my heat pump just stopped working this weekend, and its getting very hot in here.
- chrsig 3y ago
  My electric furnace needed to be urgently replaced in the beginning of the winter, I'm quite happy that my new heat pump would default to heat...Half of the year :)
- MrRadar 3y ago
  A large part of it is that heat pumps only within the past decade became efficient enough to install in northern US climates, where temperatures are below freezing 4+ months of the year. It's relatively easy to design an air-source heat pump that will work efficiently down to freezing, it's much harder to design one that will work efficiently well below freezing, and frankly the A/C manufacturers who traditionally sold to the US market haven't really tried all that hard (they probably don't/didn't expect a large enough market to offset the development costs). It's newer market entrants from Asia that are really pushing the envelope of heat pump efficiency and making it feasible.
  - Maxion 3y ago
    Air source heat pumps have worked well at -20c for a few decades now over her ein Finland. Not sure what type of chinesium grade heatpumps you have over there in the US.
    - bob-09 3y ago
      Blame the building materials and shoddy aging homes, not just the pumps. -25c windchill whistled through cracks in my doors and windows at my last rental, and my feet would go numb if I forgot to wear slippers in the kitchen.
aurizon 3y ago
These gradient comfort guys want $5000 for an 8000 btu unit with a total weight of $150 pounds. Compressor and heat exhaust hand outside. Evaporator and fan/control hang inside, It has a SEER rating of 10. There are dozens of minisplits for $1000 that have a SEER from 19-24. I can see no reason why a close coupled mini split with a 1" armored electrical/freon joint could not be made. This is what a gradient comfort is WTF $5000 https://www.gradientcomfort.com/products/gradient-window-heat-pump?variant=43917461127423 https://www.gradientcomfort.com/products/gradient-window-hea...
- rapjr9 3y ago
  This seems to be a much more reasonable unit, 10,000 BTU, does both heating and cooling via a heat pump, and it costs $700, although there are a lot of negative reviews: https://www.amazon.com/dp/B09ZCZSSV8 https://www.amazon.com/dp/B09ZCZSSV8 $5000 is ridiculous for the Gradient Comfort 8000BTU window unit. The Soleus is the only other heat pump window unit I've seen for sale. Midea makes some A/C's that are more efficient because they use an inverter, but they don't do heating. There seems to be a market failure here, given that a bidirectional heat pump shouldn't cost much more than an air conditioner you'd think everyone would prefer a heat pump, especially since it would lower cooling costs and can do lower cost heating in the winter. But nobody is selling them at reasonable cost and quality. They could include a heat exchanger also to bring in fresh air without losing energy. But nobody makes such a thing. Maybe the barriers to entry in this market are high for some reason? Window air conditioners have always kind of sucked (too noisy, encourage mold, uneven distribution of cold, crummy temperature control). I wonder why. It seems wrong.
  - kelnos 3y ago
    It's that cheap because it's garbage. All the 1-star reviews (26% of all reviews) I looked at said various variations on the unit failing after some small number of months, and the return/replacement process is awful. Seems like the manufacturer just makes junk and hopes they can still keep the money by making it hard to return.
    - 3y ago
web3-is-a-scam 3y ago
My 20 year old air conditioner recently died and I was looking into replacements. In my climate the temperature ranges from 40C in the summer, and -40C in the winter. After doing some research, it seemed pretty clear that having a furnace+AC was the way to go for my climate. Hardly a magic bullet technology.
- nielsbot 3y ago
  -40C? That's an extreme situation. Heat pumps can be installed with backup heating as I understand it.
  - Alupis 3y ago
    > Heat pumps can be installed with backup heating as I understand it. Then, what's the point? If you still have to have gas lines and infra, just use the gas. It's vastly cheaper.
    - mason55 3y ago
      > Then, what's the point? If you still have to have gas lines and infra, just use the gas. It's vastly cheaper. A) Not everywhere B) Heat pumps can be powered with solar, reducing costs even if your gas would normally be cheaper C) Some people are willing to spend a little more if it helps push electrification forward, for environmental reasons
      - frumper 3y ago
        I tend to need heat when the sun isn't warming everything up.
      - Alupis 3y ago
        > Some people are willing to spend a little more if it helps push electrification forward, for environmental reasons It's not a little more though, that was the point. In my area, California, it's about 4x more. Gas here is so cheap, it's almost free. Anecdotally, I don't know anyone who's opted into the "green energy" plans offered by the area's utility providers - because they all cost a lot more than regular. People talk a lot - but their bank account dictates their actual decision making. Running a heatpump seems very expensive for a lot of the country, with negligible gains. Natural Gas isn't exactly what we would call "dirty"... seems like a min-max issue, with people forgetting there's still areas burning coil and oil for electricity production. > Heat pumps can be powered with solar Not in the dead of winter you can't... not everyone lives in big cities folks, and where it snows, it gets quite cold.
pdx_flyer 3y ago
I was looking for a whole home heat pump and got some quotes that started at $27,000 for a home that is 1800 square feet. That price is a bit hard to swallow. I really don't want to just cool one or two rooms in the house.
- zamalek 3y ago
  Are you sure you aren't getting quotes for a ground-sourced (AKA geo) heat pump? We just installed a 4.5 ton (overkill for your sqft) 20 seer unit for $18000.
  - cwkoss 3y ago
    I got a very similar quote ($27k for ~2000sqft home) in seattle a few months ago. Salesperson said there is excess demand for both labor and machinery for heat pump installations in the past few months. I wondered at the time to what extent this is a regional phenomenon (seattlites are nerds who like energy efficiency) vs. supply chain issues vs. a sales technique. Interestingly, I learned that it will be too cold for heat pumps <10 days out of the year, so most people either keep their gas furnace as backup, or install an electric furnace for these rare days.
    - hedgehog 3y ago
      Getting anything at all done in the Seattle area is super expensive. Not sure why. The rep is wrong about the too cold bit though, even just what's in stock at Lowe's is rated to well below record lows for the region.
      - notyourwork 3y ago
        Price gouging. I've gotten quotes for fence replacements, heat pumps, roofs, window restoration. There is nothing that isn't ridiculous price in my experience. Every company has the same, supply/demand and reference to pandemic statements to substantiate their costs. It's also the case that demand is huge.
    - 3y ago
deleted 3y ago
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Kye 3y ago
It's interesting how a sufficiently large local norm can affect perspective. I thought everyone had heat pumps for the longest time. I've rarely seen a building without them. I also live in the southeast where they're at their best. Then this recent rise in popularity elsewhere dispelled that notion.
- nonethewiser 3y ago
  I have only heard of them on hacker news. Never heard of them im the wild.
nsxwolf 3y ago
When I needed a new air conditioner a couple years ago I was quoted $17,000 for a heat pump. I can only guess at that point whatever energy cost savings it would bring would never be realized within the service life of the system. I went with a $6000 standard replacement AC unit.
- SECProto 3y ago
  What kind of a system were you installing? We had a heat pump installed three years ago for less than $5k Canadian. Can't remember if we got a rebate on top of that or not.
  - chongli 3y ago
    We got a system for around $10,000 Canadian. But then there was a $5000 rebate. These things are quite expensive. I think the HVAC installers are making a large commission though. The actual equipment costs much less than that.
    - xattt 3y ago
      I have a sneaking suspicion that green rebates are being exploited by historically shady businesses (contractors and car dealers) by baking in the cost of the rebate into the final price. There’s a local lot with a used 2021 Ioniq with the usual “used car dealer” hand-lettered sign proclaiming the $5,750 provincial rebate. I’m also fairly certain the car had its price inflated by that much by the dealer, or will climb by that as soon as negotiations start. (1) https://www.apexautogroup.ca/inventory/2021-hyundai-ioniq-electric-preferred-qBfbefEKQU2gTj1W90yUyQvdp/ https://www.apexautogroup.ca/inventory/2021-hyundai-ioniq-el...
      - JumpCrisscross 3y ago
        It’s naïve to assume 100% of a subsidy will fall on a consumer, though delays between purchase and subsidy help in that respect.
  - eclarkso 3y ago
johnea 3y ago
Wow, I never cease to be amazed at how few of the HN comments have anything to do with the original post. I guess I'll jump on the bandwagon, while my comment is tangential, it does have to do with the article's focus on reducing greenhouse gases and fuel consumption. Switching to a heat pump should be done in all cases where a traditional A/C is being replaced, but the biggest bang for the buck is in how the house is constructed in the first place. "Passive solar" orientation and insulation can prevent a HUGE amount of energy consumption. To point to another HN post article: https://thebaffler.com/salvos/construction-time-again-sisson https://thebaffler.com/salvos/construction-time-again-sisson I've been saying for 20 years here in San Diego county, that if developers built track housing with passive solar orientation, and covered them with photovoltaic, the neighborhoods would be power plants. They could offer free HOAs and free electricity for the life of the house. Instead, we orient, organize and build for the maximum efficiency of a group of people who are only onsite for about 1 year (the developers) and then leave the people who live there for decades holding the bag.
- nonethewiser 3y ago
  > Passive solar" orientation and insulation can prevent a HUGE amount of energy consumption. In San Diego
- Terretta 3y ago
  > if developers built track housing with passive solar orientation https://en.wikipedia.org/wiki/Tract_housing https://en.wikipedia.org/wiki/Tract_housing https://brians.wsu.edu/2016/05/25/track-home/ https://brians.wsu.edu/2016/05/25/track-home/
ashayh 3y ago
The article mentions the most important point towards the end: “The better you insulate, the less heat you need in the first place,” No heat pump will help if your house is leaky or under insulated.
- anonporridge 3y ago
  Insulation also matters for keeping your house cool and improving AC efficiency.
- northwest65 3y ago
  Sure they can, you can absolutely use heat pumps to brute force it, been there done that.
  - danans 3y ago
    Not only that, but since a heat pump is at least 3x as energy efficient as the most efficient gas furnace, using one results in about 1/2 the E2E CO2 emissions as the gas furnace when the grid electricity being consumed is natural gas based. If you live in an area with abundant zero emissions electricity, then you are heating without any C02 emissions at all. That said, we should do both heat pumps and insulate better.
    - ori_prior 3y ago
      Your numbers are off. Thermal power plants typically do have a thermal-to-electric efficiency of around 30% (40% max), so with your heatpump having an electric-to-thermal efficiency of an assumed 300%, you end up with basically no difference in CO₂ emissions. Note that there are some misleading efficiency claims for gas plants around 60%, but those are not for thermal-to-electric efficiency but for generating electricity plus district heating from waste heat.
      - coderenegade 3y ago
        60% would be terrible thermodynamic efficiency for a cogeneration plant. Modern CCGT systems crack 60% thermodynamic efficiency for just the electricity generation. With cogeneration, system efficiencies are typically in the 70-80% range.
senectus1 3y ago
In Australia we call these "Reverse Cycle" Air-conditioners.
gooseyman 3y ago
Heat pumps are great, but it’s the dc inverter and advances in compressor efficiency that is really the biggy on energy usage here. Every one of these “heat pumps are the future” articles is so soft on data, and they often fail to explain the basics or a simple “why.” Once we get past the clickbait heat pump articles, we can actually make an impact.
- glogla 3y ago
  I think the consensus on why heat pumps _should_ be the future is that you can power them with low carbon electricity, as opposed to literally world destroying natural gas.
  - gizmo686 3y ago
    A quick Google search says that natural gas -> electricity has an efficiency of about 44%, with an additional 5% loss during transmission. Lets call this about 40% efficiency for getting energy from natural gas to your electric heat pump. A heat pump operating at 250% efficiency will use just as much natural gas as a furnace operating at 100% efficiency. Modern heat pumps can often exceed 250% efficiency, making them use less natural gas, even if they are ultimately powered by a natural gas burning power plant.
    - gooseyman 3y ago
      I made a note for myself to go do this math. You beat me to it and answered the question. Thank you :) I vaguely recall I did some back of envelope math a couple years back and determined that a natural gas powered heat pump was actually more efficient (in terms of emissions) based on my grid power source mix. Solar breaks that equation obviously.
- brnt 3y ago
  I think many people suddenly realized that moving heat translates to efficiencies far north of 100%, also for heating. Moving in opposition to creating heat, which tops out at 100% in the best case. Plus, they can run on any power source, including green and/or decarbonized.
vinay_ys 3y ago
In India, we have been using "Ductless Air-Source Heat Pumps" aka split AC units with 3,4,5 star energy ratings for decades. The more efficient ones come with dual inverter compressor which allows them to operate at lesser power (for lesser cooling) during long continuous operation periods (like sleeping at night).
- brnt 3y ago
  Their application is however limited by climate: I've heated a room with a split AC last winter, but around here that is quite a bit of noise for quite a lot of time in the day/year. Having a heat pump warm up central heating water and use appropriate radiators or floor heating allows you to move the noisy bits outside the rooms you're in.

195 points by mfiguiere 3y ago

Well this was an oddly terrifying introductory paragraph for an IEEE article: "... half of Phoenix residents are at risk of an emergency room visit or worse if their electricity fails during a future heat wave, according to a recent study. Air conditioning is what keeps people there comfortable—and alive—a growing fraction of the year. The extreme heat already kills hundreds of Phoenix-area residents every year, a number that went up by 25 percent from 2021 to 2022."

silisili 3y ago
Sure, but it can happen anywhere. I was just reading yesterday about a person who died in Portland of heat during the dome. Same with cold weather, if the gas/electric goes out during the winter. There's really only a few places one can live with moderate enough weather to avoid those scenarios.
- tiahura 3y ago
  Half of Phoenix vs A person in Portland. It seems like there’s an important scale issue there. So the risk isn’t really the same everywhere.
  - RationPhantoms 3y ago
    Good point on the scale. However, Phoenix is also a retirement destination so you're looking at a larger portion of the population being susceptible to heat waves.
    - AlbertCory 3y ago
      > Phoenix is also a retirement destination People who retire there most likely go up to Flagstaff in the summer, or further north. Or they just have good A/C.
- zht 3y ago
  what? do you really not see a difference between a place where the event is much more likely to happen for a much longer % of the time than another place where the same event is much less likely to occur?
- ericd 3y ago
  And that's why you see fireplaces/stoves in a lot of houses in the northeast, even if they have gas/electric heat.
- phpisthebest 3y ago
  >>Same with cold weather, I 100% disagree with this... Heat is made by everything, waste heat is a byproduct of all modern things, and there are TONS of easy low cost ways to make heat even it is just as simple as burning something. Also the body makes head naturally so adding layers to trap this heat does not require continual inputs from an outside resource Cooling on the other hand is MUCH harder, and electricity is really the only avenue to make cooling. Even if you say use ICE, well that Ice was made at some point by a freezer running on Electricity IMO hot climate is MUCH MUCH more dangerous than cold, which is why I choose to live in an area where there are only 1 or 2 months of even remotely hot climate. As I told my last HVAC... Heat I can make 100 ways... Cooling I need central air for...
  - silisili 3y ago
    For a young/healthy person, sure. But these aren't generally the at risk people in the first place. I grew up around the 38N parallel, gross enough to get too hot in the summer and too cold in the winter. Every winter people froze to death, just the same. It's not as bad as Phoenix percentage wise, but it's still a risk in the vast majority of places that people in the US live.
    - phpisthebest 3y ago
      Of course people can and do die from cold, that was never my claim My Claim is providing people with emergency heat is FAR FAR FAR FAR easier and cheaper than providing people with emergency cooling. Do "at risk" people die in the north from the cold, absolutely but I am not sure how that means the cold is worse As it stands right now, just from my daily activities my waste heat in my home makes my home about 10-15 degrees above ambient. Meaning in the winter if my target temp is 65deg, it would have to be 50 degrees or colder outside before I would even think about running my heat. In the winter time that means my AC is working hard to not only combat the outside temp but the internal waste heat from computers, cooking, TV's, humans, etc.
  - nerdbert 3y ago
    > Cooling on the other hand is MUCH harder, and electricity is really the only avenue to make cooling. Gas-powered fridges and coolers have existed for about two hundred years and are still a normal technology today - often used for camping and off-grid life. Here's a whole bunch of propane fridges for your viewing pleasure: https://bensdiscountsupply.com/collections/propane-refrigerator https://bensdiscountsupply.com/collections/propane-refrigera...
- colechristensen 3y ago
  Eh, it is much much easier to keep warm when it's -40 outdoors than it is to keep cool when its 120+ outside. Unless you have a terribly insulated shelter, blankets, coats, and friends will keep you warm enough to the extent that unless you are not really capable of taking basic care of yourself, you're not dying of the cold when your heat goes out. You can always do more insulation, and you only need so much for your body to keep you warm. With heat though you run out of things to do. There is a difference between an impaired person or a person doing something unwise dies of the heat or cold... and there being an environment where there's nothing a healthy adult can do to survive without powered heating/cooling.
  - nerdbert 3y ago
    Part of this is because we build houses that are terribly suited for warm climates. I used to work in the Middle East, and their traditional structures with central pool and windcatcher/chimney design remained quite livable even when it was over 45°C outside, with zero active cooling.
cmrdporcupine 3y ago
I've read a few times that the population of the entire US south only really started to grow in earnest once AC was invented. Ah, here's an article: https://www.nytimes.com/2017/08/04/upshot/the-all-conquering-air-conditioner.html https://www.nytimes.com/2017/08/04/upshot/the-all-conquering... It's pretty crazy because growing up in central/northern Alberta, I never even really encountered air conditioning until I was into my early 20s and moved to southern Ontario (where living without it would be complete hell in the summer, hot humid disgusting "I feel like I'm being smothered in someone's armpit" summers). Our cars never had it and our houses certainly didn't need it; just an open window. Summers were mild and the heat when it came was a dry heat. But now when I go home to visit there, A/C is everywhere there, and it's frankly needed; the last summer I spent time out at my parents west of Edmonton there were multiple days in a row over 30C and it was frankly quite hellish and them having a ground source heat pump that cooled the house was a godsend. Just the 2-3C difference in peak temperatures from the 80s til now is enough to push it over the edge into new territory.
- retrac 3y ago
  I've likewise read arguments that AC is linked to the substantial economic growth in the second half of the 20th century, in regions like southern France, southern Japan, and the southern United States. All regions that historically lagged economically behind their culturally and economically similar more northern counterpart regions. Hard to say how much of a factor, but there has to be some truth to it: just imagine productivity in a Texas factory at 40 °C and 90% humidity vs. 25 °C and 50% humidity.
  - kalleboo 3y ago
    The man credited with making Singapore the powerhouse it is today has also been adamant that without Air Conditioning, tropical countries couldn’t develop https://www.vox.com/2015/3/23/8278085/singapore-lee-kuan-yew-air-conditioning https://www.vox.com/2015/3/23/8278085/singapore-lee-kuan-yew...
afavour 3y ago
I've only ever visited Phoenix but when I did it was mid July and being outside genuinely did not feel hospitable to human life. That statement doesn't surprise me at all. Unless you're employed in, I dunno, the solar power industry I really feel like you shouldn't be living there. It should be like living on an oil rig.
- melling 3y ago
  Can’t deal with a little extremes on earth? Sort of makes one wonder how we’re ever going to colonize Mars so we’re not a single planet species.
- brabel 3y ago
  Do you think people shouldn't be living in Chicago (or most of Canada and the US midwest for that matter) because without heating it's just completely inhospitable to human life during the winter? Or pretty much all Australian cities in summer?
  - pkulak 3y ago
    Relying on a coat for survival is very different from relying on an HVAC system. One has no moving parts, requires no external inputs, and is routinely handed out for free to those who can’t afford them.
  - afavour 3y ago
    Heating is considerably more energy efficient than having to run ACs all over the place. And if you need to go outside when it's cold you can: you add layers of clothing. In Arizona, in the middle of summer, you could be buck naked and you'd still overheat (and get burnt, to boot).
    - rcme 3y ago
      Until the widespread use of heat pumps, AC was much more energy efficient than heating.
    - triceratops 3y ago
interestica 3y ago
Time to start calling it Life Support Systems
ashconnor 3y ago
I would imagine solar panels would be a good investment in a climate like this.
- genmud 3y ago
  There is actually efficiency issues with the high heat... but they do help offset the AC requirements, so overall even if the efficiency is down 20-40% because of heat, you require potentially 20-50% less A/C because it shades the roof.
- willis936 3y ago
  Or a solar boiler connected a refrigerant compressor. The hotter it gets the more cooling power you have. Steam punk for the 21st century.
genmud 3y ago
Luckily, the local grid here in AZ is fairly robust, probably one of the best in the US. During the 3 years I lived in DC area, I probably had 3 or 4 power outages due to weather (ranging from a couple hours to multiple days). In the 30+ years I have lived in Arizona, I have experienced probably 2 outages, lasting a total of a few hours (one was when a car hit a transformer, the other was when a microburst knocked a bunch of aging poles down). The last outage I had was like 6-8 years ago.
londons_explore 3y ago
It raises the question of if we should deploy 'emergency coolers' - perhaps single-use barrels of some chemical that gets cold when a pull-tab is pulled. To be a workable solution, it needs to be more reliable/cheaper/more effective than just a regular gasoline generator powering a regular aircon unit. After a flood/hurricane/nuclear strike, they would provide enough coolness to keep people alive for a few days.
- sigilis 3y ago
  Water can be used for this purpose, and swamp coolers are something that can be pretty trivially implemented by people in relatively dry areas. For very humid places you generally need energy input for cooling.
- mindslight 3y ago
  I believe the straightforward answer is to dig a hole. But it would certainly be interesting to calculate exactly how much cooling capacity you could get out of one or two 55 gallon drums of some endothermic precursors. Bonus points for being easily reversible when the electricity comes back on (like those sodium acetate heating packs).

nottorp 3y ago

Isnt any a/c a heat pump though?

cornstalks 3y ago
Yes, but typically “heat pump” is used to mean it can provide heating too, whereas standard “A/C” is a “one-way” heat pump that only provides cooling.
- LUmBULtERA 3y ago
  I always went with this description too, though oddly a "heat pump water heater" only works one direction, yet "heat pump" is still in its name.
  - sidewndr46 3y ago
    all heat pumps work in one direction. You can't move cold around with any mechanism. Only heat can be moved. The difference is residential "heat pumps" just have a set of reversing valves so you can move heat from outdoors to indoors.
    - anamexis 3y ago
      > The difference is residential "heat pumps" just have a set of reversing valves so you can move heat from outdoors to indoors. So.. they work in two directions.
      - TheSpiceIsLife 3y ago
        It depends on your frame of reference.
  - wcfields 3y ago
    Have to imagine that the niche market for making 40F/4C "cold" water from luke-warm tap water (if you live in an area that is so hot the tap water is warm) is fairly small.

__MatrixMan__ 3y ago

I live in a colder climate where heat pumps are not popular. After talking with a number of HVAC people about this I was surprised to learn that despite being very similar to an AC system in principle, in practice converting an AC system into a heat pump system doesn't make economic sense--you end up just ripping one out and installing the other. I don't fully understand why this is the case, but I hope that there's something that can be done to improve it. I'd love it if I could drive my AC unit as a heater for 95% of the winter, resorting to natural gas only during in the extreme cases.

deleted 3y ago
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nightski 3y ago
The thing is (especially where I live) I'd still need a gas furnace. We regularly see -20F to -40F in the winter. While the 95% scenario sounds great, in practice still needing gas means we still need all the gas infrastructure. From my understanding natural gas burns pretty clean. The problem is leaks in infrastructure and drilling, which isn't going away because I buy a heat pump.
- GlickWick 3y ago
  They make heat pumps with backup gas systems now.
- elil17 3y ago
  Although natural gas is "clean" compared to, say, coal, the advantage of a heat pump is that it uses less total energy than natural gas. That means it would be more efficient to run a heat pump off a natural gas power plant than to burn natural gas to heat your home directly.
  - __MatrixMan__ 3y ago
    Where I live, you can bank solar credits. If you cash them out you get the "wholesale" energy price for them (much lower), but if you spend them on electricity then you've avoided paying full price for that electricity. So if your system produces more than you consume, you've got this free energy budget to spend--a budget that applies to heat pumps and not to gas furnaces.

nemo44x 3y ago

I have both HVAC and a ducted heatpump for one part of the home. The biggest issue with the heatpump is that in the climate I live in there are times of year where you may have the heat on in the morning and the AC in the afternoon. Or you may leave and when you return you want to change the temperature. A furnace and an AC can do this rapidly. A heatpump takes time. It's more of a trickle of climatized air than a blast of it. Also, I'd never want a ductless system as they look awful in a room. They are the future though. Especially as new regulations go into effect by 2035. Sadly, many American manufactures haven't taken it seriously and are far behind the Asian companies like Daikin.

adgjlsfhk1 3y ago
If you have the heat on in the morning and AC in the afternoon, your home is horribly under-insulated (or you are trying to keep in way too small a temperature range).
- nemo44x 3y ago
  Old homes tend to not have any insulation. Parts of my house have modern insulation due to renovations/additions but other parts not so much. I wouldn't swap out the original windows and glass on the facade, for instance. And insulating it would probably be a destructive action as you need proper vapor barriers for insulation to not rot your home.
davidmurdoch 3y ago
Mine take maybe 2 minutes to switch from heating to cooling, or cooling to heating.
- nemo44x 3y ago
  I’m saying the time it takes to change the temperature in the home, not the time to switch function.
  - davidmurdoch 3y ago

post_break 3y ago

When my AC finally needs replacing I'm going heat pump, and then also ditching my gas water heater. The constant fees of a gas line are ridiculous at this point and any more electricity usage will be offset by the 9 months of the year I'd never turn on the heat.

punkybr3wster 3y ago
Now you can even get water heaters with heat pumps and combo units that dump your waste heat from your hvac heat pump into the water heater. It’s wild.
- crazygringo 3y ago
  Your AC powering your hot water heater at the same time... that's genius.
- jay_kyburz 3y ago
  When we put the solar on the roof we bundled in heat pump hot water system as well. It's timed to only use power right in the middle of the day when the sun is shining, and in the middle of the night when power is cheap. (needs both because the tank is fairly small and my kids like long showers)
deleted 3y ago
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ramesh31 3y ago

Swamp coolers are massively underutilized as well. The vast majority of residential cooling in all but the most humid climates can be done with nothing but a fan and some cold water; no compressed gases necessary.

metiscus 3y ago
The issue with swamp coolers (evaporative cooling) is that you need relatively low humidity for them to work and they increase the humidity of the interior cooled environment. If you use them in combination with an air conditioner, they will very likely reduce the efficiency of the air conditioner by increasing the dehumidification load of the air conditioner.
elil17 3y ago
This sort of true? There are many hours per year in many climates where direct evaporative cooling alone could suffice to keep people comfortable. However, most climates also have a good number of hours where air conditioning is required for comfort. You can use this tool to visualize this: https://drajmarsh.bitbucket.io/psychro-chart2d.html https://drajmarsh.bitbucket.io/psychro-chart2d.html (Use the Givoni Bioclimatic Chart overlay and select a weather station using the globe icon.) That said, there are a number of more complex devices which could further reduce how often AC systems need to be used: dew-point (Maisotsenko Cycle) coolers, indirect evaporation cooling, and thermal energy storage to name a few.
rimunroe 3y ago
> The vast majority of residential cooling in all but the most humid climates can be done with nothing but a fan and some cold water Aren't swamp coolers only really useful when the humidity is under something like 50%? I guess I'm assuming you're talking about the US, but I don't think "vast majority" of people live in such areas. A quick search for average humidity of US states in July and August shows many of them have an average daily humidity of over 50%. It certainly rules out every place I've lived on the east coast (Richmond, Virginia, Long Island, and the Boston area), as the humidity in those places is usually at least 60% at the height of summer when most people actually use their AC. As a side note, I suspect most people overuse their air conditioning and don't let their bodies adapt to the warmer summer weather. It's weird how many people keep their houses under 75 °F when the heat index is only in the mid 80s.

davidmurdoch 3y ago

Being a Florida native, seeing an article titled "Heat Pumps [are] the Future of A/Cs" feels like it should have a ` [1973]` tacked on to the end of it. A heat pump is pretty much the only thing we use here, we just use them in reverse. Literally. Most residential units have a "reversing valve" that must be held open by a constant 24V in order to cool the air - the default mode is heating -- which is so smart to have a failure mode that causes your house to be heated in the summer to 95F while you sleep. Anyway, my heat pump just stopped working this weekend, and its getting very hot in here.

chrsig 3y ago
My electric furnace needed to be urgently replaced in the beginning of the winter, I'm quite happy that my new heat pump would default to heat...Half of the year :)
MrRadar 3y ago
A large part of it is that heat pumps only within the past decade became efficient enough to install in northern US climates, where temperatures are below freezing 4+ months of the year. It's relatively easy to design an air-source heat pump that will work efficiently down to freezing, it's much harder to design one that will work efficiently well below freezing, and frankly the A/C manufacturers who traditionally sold to the US market haven't really tried all that hard (they probably don't/didn't expect a large enough market to offset the development costs). It's newer market entrants from Asia that are really pushing the envelope of heat pump efficiency and making it feasible.
- Maxion 3y ago
  Air source heat pumps have worked well at -20c for a few decades now over her ein Finland. Not sure what type of chinesium grade heatpumps you have over there in the US.
  - bob-09 3y ago
    Blame the building materials and shoddy aging homes, not just the pumps. -25c windchill whistled through cracks in my doors and windows at my last rental, and my feet would go numb if I forgot to wear slippers in the kitchen.

aurizon 3y ago

These gradient comfort guys want $5000 for an 8000 btu unit with a total weight of $150 pounds. Compressor and heat exhaust hand outside. Evaporator and fan/control hang inside, It has a SEER rating of 10. There are dozens of minisplits for $1000 that have a SEER from 19-24. I can see no reason why a close coupled mini split with a 1" armored electrical/freon joint could not be made. This is what a gradient comfort is WTF $5000 https://www.gradientcomfort.com/products/gradient-window-heat-pump?variant=43917461127423 https://www.gradientcomfort.com/products/gradient-window-hea...

rapjr9 3y ago
This seems to be a much more reasonable unit, 10,000 BTU, does both heating and cooling via a heat pump, and it costs $700, although there are a lot of negative reviews: https://www.amazon.com/dp/B09ZCZSSV8 https://www.amazon.com/dp/B09ZCZSSV8 $5000 is ridiculous for the Gradient Comfort 8000BTU window unit. The Soleus is the only other heat pump window unit I've seen for sale. Midea makes some A/C's that are more efficient because they use an inverter, but they don't do heating. There seems to be a market failure here, given that a bidirectional heat pump shouldn't cost much more than an air conditioner you'd think everyone would prefer a heat pump, especially since it would lower cooling costs and can do lower cost heating in the winter. But nobody is selling them at reasonable cost and quality. They could include a heat exchanger also to bring in fresh air without losing energy. But nobody makes such a thing. Maybe the barriers to entry in this market are high for some reason? Window air conditioners have always kind of sucked (too noisy, encourage mold, uneven distribution of cold, crummy temperature control). I wonder why. It seems wrong.
- kelnos 3y ago
  It's that cheap because it's garbage. All the 1-star reviews (26% of all reviews) I looked at said various variations on the unit failing after some small number of months, and the return/replacement process is awful. Seems like the manufacturer just makes junk and hopes they can still keep the money by making it hard to return.
  - 3y ago

web3-is-a-scam 3y ago

My 20 year old air conditioner recently died and I was looking into replacements. In my climate the temperature ranges from 40C in the summer, and -40C in the winter. After doing some research, it seemed pretty clear that having a furnace+AC was the way to go for my climate. Hardly a magic bullet technology.

nielsbot 3y ago
-40C? That's an extreme situation. Heat pumps can be installed with backup heating as I understand it.
- Alupis 3y ago
  > Heat pumps can be installed with backup heating as I understand it. Then, what's the point? If you still have to have gas lines and infra, just use the gas. It's vastly cheaper.
  - mason55 3y ago
    > Then, what's the point? If you still have to have gas lines and infra, just use the gas. It's vastly cheaper. A) Not everywhere B) Heat pumps can be powered with solar, reducing costs even if your gas would normally be cheaper C) Some people are willing to spend a little more if it helps push electrification forward, for environmental reasons
    - frumper 3y ago
      I tend to need heat when the sun isn't warming everything up.
    - Alupis 3y ago
      > Some people are willing to spend a little more if it helps push electrification forward, for environmental reasons It's not a little more though, that was the point. In my area, California, it's about 4x more. Gas here is so cheap, it's almost free. Anecdotally, I don't know anyone who's opted into the "green energy" plans offered by the area's utility providers - because they all cost a lot more than regular. People talk a lot - but their bank account dictates their actual decision making. Running a heatpump seems very expensive for a lot of the country, with negligible gains. Natural Gas isn't exactly what we would call "dirty"... seems like a min-max issue, with people forgetting there's still areas burning coil and oil for electricity production. > Heat pumps can be powered with solar Not in the dead of winter you can't... not everyone lives in big cities folks, and where it snows, it gets quite cold.

pdx_flyer 3y ago

I was looking for a whole home heat pump and got some quotes that started at $27,000 for a home that is 1800 square feet. That price is a bit hard to swallow. I really don't want to just cool one or two rooms in the house.

zamalek 3y ago
Are you sure you aren't getting quotes for a ground-sourced (AKA geo) heat pump? We just installed a 4.5 ton (overkill for your sqft) 20 seer unit for $18000.
- cwkoss 3y ago
  I got a very similar quote ($27k for ~2000sqft home) in seattle a few months ago. Salesperson said there is excess demand for both labor and machinery for heat pump installations in the past few months. I wondered at the time to what extent this is a regional phenomenon (seattlites are nerds who like energy efficiency) vs. supply chain issues vs. a sales technique. Interestingly, I learned that it will be too cold for heat pumps <10 days out of the year, so most people either keep their gas furnace as backup, or install an electric furnace for these rare days.
  - hedgehog 3y ago
    Getting anything at all done in the Seattle area is super expensive. Not sure why. The rep is wrong about the too cold bit though, even just what's in stock at Lowe's is rated to well below record lows for the region.
    - notyourwork 3y ago
      Price gouging. I've gotten quotes for fence replacements, heat pumps, roofs, window restoration. There is nothing that isn't ridiculous price in my experience. Every company has the same, supply/demand and reference to pandemic statements to substantiate their costs. It's also the case that demand is huge.
  - 3y ago

deleted 3y ago

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Kye 3y ago

It's interesting how a sufficiently large local norm can affect perspective. I thought everyone had heat pumps for the longest time. I've rarely seen a building without them. I also live in the southeast where they're at their best. Then this recent rise in popularity elsewhere dispelled that notion.

nonethewiser 3y ago
I have only heard of them on hacker news. Never heard of them im the wild.

nsxwolf 3y ago

When I needed a new air conditioner a couple years ago I was quoted $17,000 for a heat pump. I can only guess at that point whatever energy cost savings it would bring would never be realized within the service life of the system. I went with a $6000 standard replacement AC unit.

SECProto 3y ago
What kind of a system were you installing? We had a heat pump installed three years ago for less than $5k Canadian. Can't remember if we got a rebate on top of that or not.
- chongli 3y ago
  We got a system for around $10,000 Canadian. But then there was a $5000 rebate. These things are quite expensive. I think the HVAC installers are making a large commission though. The actual equipment costs much less than that.
  - xattt 3y ago
    I have a sneaking suspicion that green rebates are being exploited by historically shady businesses (contractors and car dealers) by baking in the cost of the rebate into the final price. There’s a local lot with a used 2021 Ioniq with the usual “used car dealer” hand-lettered sign proclaiming the $5,750 provincial rebate. I’m also fairly certain the car had its price inflated by that much by the dealer, or will climb by that as soon as negotiations start. (1) https://www.apexautogroup.ca/inventory/2021-hyundai-ioniq-electric-preferred-qBfbefEKQU2gTj1W90yUyQvdp/ https://www.apexautogroup.ca/inventory/2021-hyundai-ioniq-el...
    - JumpCrisscross 3y ago
      It’s naïve to assume 100% of a subsidy will fall on a consumer, though delays between purchase and subsidy help in that respect.
- eclarkso 3y ago

johnea 3y ago

Wow, I never cease to be amazed at how few of the HN comments have anything to do with the original post. I guess I'll jump on the bandwagon, while my comment is tangential, it does have to do with the article's focus on reducing greenhouse gases and fuel consumption. Switching to a heat pump should be done in all cases where a traditional A/C is being replaced, but the biggest bang for the buck is in how the house is constructed in the first place. "Passive solar" orientation and insulation can prevent a HUGE amount of energy consumption. To point to another HN post article: https://thebaffler.com/salvos/construction-time-again-sisson https://thebaffler.com/salvos/construction-time-again-sisson I've been saying for 20 years here in San Diego county, that if developers built track housing with passive solar orientation, and covered them with photovoltaic, the neighborhoods would be power plants. They could offer free HOAs and free electricity for the life of the house. Instead, we orient, organize and build for the maximum efficiency of a group of people who are only onsite for about 1 year (the developers) and then leave the people who live there for decades holding the bag.

nonethewiser 3y ago
> Passive solar" orientation and insulation can prevent a HUGE amount of energy consumption. In San Diego
Terretta 3y ago
> if developers built track housing with passive solar orientation https://en.wikipedia.org/wiki/Tract_housing https://en.wikipedia.org/wiki/Tract_housing https://brians.wsu.edu/2016/05/25/track-home/ https://brians.wsu.edu/2016/05/25/track-home/

ashayh 3y ago

The article mentions the most important point towards the end: “The better you insulate, the less heat you need in the first place,” No heat pump will help if your house is leaky or under insulated.

anonporridge 3y ago
Insulation also matters for keeping your house cool and improving AC efficiency.
northwest65 3y ago
Sure they can, you can absolutely use heat pumps to brute force it, been there done that.
- danans 3y ago
  Not only that, but since a heat pump is at least 3x as energy efficient as the most efficient gas furnace, using one results in about 1/2 the E2E CO2 emissions as the gas furnace when the grid electricity being consumed is natural gas based. If you live in an area with abundant zero emissions electricity, then you are heating without any C02 emissions at all. That said, we should do both heat pumps and insulate better.
  - ori_prior 3y ago
    Your numbers are off. Thermal power plants typically do have a thermal-to-electric efficiency of around 30% (40% max), so with your heatpump having an electric-to-thermal efficiency of an assumed 300%, you end up with basically no difference in CO₂ emissions. Note that there are some misleading efficiency claims for gas plants around 60%, but those are not for thermal-to-electric efficiency but for generating electricity plus district heating from waste heat.
    - coderenegade 3y ago
      60% would be terrible thermodynamic efficiency for a cogeneration plant. Modern CCGT systems crack 60% thermodynamic efficiency for just the electricity generation. With cogeneration, system efficiencies are typically in the 70-80% range.

senectus1 3y ago

In Australia we call these "Reverse Cycle" Air-conditioners.

gooseyman 3y ago

Heat pumps are great, but it’s the dc inverter and advances in compressor efficiency that is really the biggy on energy usage here. Every one of these “heat pumps are the future” articles is so soft on data, and they often fail to explain the basics or a simple “why.” Once we get past the clickbait heat pump articles, we can actually make an impact.

glogla 3y ago
I think the consensus on why heat pumps _should_ be the future is that you can power them with low carbon electricity, as opposed to literally world destroying natural gas.
- gizmo686 3y ago
  A quick Google search says that natural gas -> electricity has an efficiency of about 44%, with an additional 5% loss during transmission. Lets call this about 40% efficiency for getting energy from natural gas to your electric heat pump. A heat pump operating at 250% efficiency will use just as much natural gas as a furnace operating at 100% efficiency. Modern heat pumps can often exceed 250% efficiency, making them use less natural gas, even if they are ultimately powered by a natural gas burning power plant.
  - gooseyman 3y ago
    I made a note for myself to go do this math. You beat me to it and answered the question. Thank you :) I vaguely recall I did some back of envelope math a couple years back and determined that a natural gas powered heat pump was actually more efficient (in terms of emissions) based on my grid power source mix. Solar breaks that equation obviously.
brnt 3y ago
I think many people suddenly realized that moving heat translates to efficiencies far north of 100%, also for heating. Moving in opposition to creating heat, which tops out at 100% in the best case. Plus, they can run on any power source, including green and/or decarbonized.

vinay_ys 3y ago

In India, we have been using "Ductless Air-Source Heat Pumps" aka split AC units with 3,4,5 star energy ratings for decades. The more efficient ones come with dual inverter compressor which allows them to operate at lesser power (for lesser cooling) during long continuous operation periods (like sleeping at night).

brnt 3y ago
Their application is however limited by climate: I've heated a room with a split AC last winter, but around here that is quite a bit of noise for quite a lot of time in the day/year. Having a heat pump warm up central heating water and use appropriate radiators or floor heating allows you to move the noisy bits outside the rooms you're in.