43 ms·

Hacking Portable Air Conditioners

344 points by p1mrx 6y ago

Rebelgecko 6y ago
Hooking it up to the Nest was really clever. I've dabbled a bit with IR control of similar units, but that really takes it to the next level
- p1mrx 6y ago
  There's really nothing Nest-specific in the design. It just takes two components (AC input optocoupler and resistor) to sense the 24VAC output from any standard thermostat. Connecting to the Nest was probably easier than turning an ESP32 into a proper thermostat. The hardest part of the whole project was figuring out how to read a clean signal from a photodiode.
  - flak48 6y ago
    Just read your post and just wanted to say I'm in absolute awe!
leoedin 6y ago
This is interesting. We collectively spend _so much_ of our energy on heating and cooling buildings, and there's very little change happening. The problems identified in the article are such low hanging fruit. Everywhere you look in residential housing there's huge efficieny gains to be made, but very little effort is going in to making them. I'd love to find ways we can use technology to make housing more efficient. We need to - it's such a crucial pillar in dealing with climate change, and the vast majority of housing is so comically inefficient. The single tube air conditioners mentioned in the article are just the icing on the cake of all these massive energy wastes we accept because they're marginally more convenient. Does anyone know how to fix this?
- esaym 6y ago
  >and there's very little change happening. There's honestly a lot happening and changing. Obviously you won't see it by buying "HVAC" junk from a box store. What this person should have done is paid an actual HVAC tech to install a ductless mini-split [0]. It would have been a heck of a lot more efficient. He states his one unit is drawing 10 amps (110 volt I assume). Whereas my american standard 4 ton (48,000 btu) unit draws 10 amps as well (240 volt) and cools a 2200 square ft house in 100+ degree texas weather with an electric bill usually not higher than $120 per month (1200 - 1400 kwh or so). By comparison, at my old house (which was half the size, 1100 sq ft) with a much older 12 Seer unit, my electric bill was regularly over $200. I measured that unit at drawing 18 amps (at 240 volt) and it was only a 3 ton 36,000 btu out door unit. The latest and greatest 21/22 seer units are even more efficient than my current one mentioned above (which is probably only 17 seer). [0]: https://www.americanstandardair.com/products/heating-and-cooling/ductless/ https://www.americanstandardair.com/products/heating-and-coo...
  - rtlfe 6y ago
    > What this person should have done is You can't say what somebody "should have done" without knowing a lot more details about their life.
  - dhbanes 6y ago
    Yeah, he should have just spend a few grand on a mini split system to stay cool for one summer at home. Makes sense.
    - balfirevic 6y ago
      Why do they cost so much in the US? I can buy a decent split unit for $400-$500 + around $150 for installation. Installation will no doubt be more expensive in the US, but there is no reason for AC itself to be (if anything, most kinds of hardware seem to generally be cheaper in US than in Europe).
      - briHass 6y ago
        Largely because we have an HVAC cartel that charges insane hourly rates for even the simplest jobs. To be fair, a Mitsubishi mini split is going to run closer to $1200-$2000 for the unit itself, but you can expect to pay $2000+ to install on top of that, depending on how hard the job is. I suppose it's hard to complain too much. HVAC installers need to have some decent technical background, troubleshooting skills, and their bodies tend to get injured/broken by the time they're in their late 40s like most manual labor trades. A HVAC installer/tech can make $80K or more a year, which makes it one of the few jobs still out there where you can make a decent middle class income without tons of schooling.
- maxerickson 6y ago
  Regulation. Builders spend money on things that make them profit and home buyers don't particularly evaluate efficiency. After that you figure out how to spend public money on lower efficiency structures. Fraught, but spend money where it's likely to pay off and it probably works out okay.
- tgsovlerkhgsel 6y ago
  > The single tube air conditioners mentioned in the article are just the icing on the cake of all these massive energy wastes we accept because they're marginally more convenient. Does anyone know how to fix this? I'm using one of those portable units because I live in a rented apartment. There is nothing convenient about it compared to a much more efficient real (split) AC, but I have no other options. Even if the landlord was OK with allowing it, "green" laws intentionally make it incredibly tedious and expensive to get the permits to install an AC, so people swarm to the option they can get without paperwork.
lifeisstillgood 6y ago
Anyone else "back in the day" would buy portable air conditioners from the hardware store and sling them into your server broom cupboard in an attempt to keep things from overheating. It got so boring when we rebuilt with proper falso floors ceilings and real racks.
- walrus01 6y ago
  There's still a number of small ISP and telecom infrastructure sites cooled by setups like a pair of Haier consumer grade, ductless split 18000 to 24000btu/h units. Not an uncommon setup for places like small shelters at hilltop and mountaintop radio sites.
ajb 6y ago
This is really cool. Maybe there is a market opening for an open, hackable aircon unit? One thing I've long wanted to try with mine is use 'heating mode' as a quieter version of cooling mode. They work the same - the unit just runs backwards, with the cold air coming out of the tube instead of the vents - so in theory you can cool your bedroom without having the noisy aircon in the same room. But the thermostat doesn't work properly in this case, because it thinks it's trying to raise the temperature of whatever room you put it in, not cool the other end of the tube, so for this to work properly you need to hack the control board.
- userbinator 6y ago
  Maybe there is a market opening for an open, hackable aircon unit? In the US, I think the EPA would not let you... ...not that it stops people all that much, as a YouTube search for "DIY AC" will show.
  - derefr 6y ago
    > In the US, I think the EPA would not let you In Canada, you need to be a licensed something-or-other to purchase or own compressed CO2 canisters. This put SodaStream in an awkward position when entering the Canadian market, since their whole business model is built on selling people CO2. But they figured out a workaround: in Canada, you don't buy their CO2 canisters; instead, you "join a club" that allows you to borrow CO2 canisters (and/or refills the ones you have), and then charges servicing fees for "their" canister equipment. (Sort of like how a catering company would rent a helium tank.) I wonder if something similar could be done for refrigerant-supply licensing in the US.
    - xelan 6y ago
      Wait, what? I am in Canada and I have a couple of 5pound CO2 canister for home brewing and a modded sodastream to accept any CO2 canister. Where did you find this information? I even get it filled up at the corner store lol.
      - 6y ago
euroclydon 6y ago
That would be a great aftermarket product to hook up Nest to portable air conditioners.
- hinkley 6y ago
  I tried to look for something equivalent for those in-wall space heater units. They run on a different voltage, because of course they do. I think the boxes were like $40, but they looked like electrical junction boxes. Clearly meant to be buried in a wall cavity.
  - quickthrowman 6y ago
    Junction boxes are not meant to be buried in a wall. In fact, any junction box containing wire (not just connections/splices) is required to be accessible without removing any part of the building per the National Electrical Code.
starpilot 6y ago
The temp vs run duration doesn't seem that meaningful. It shows the first 3 minutes of runtime, and doesn't show if all configurations reach equilibrium performance after that. It looks like they might. These things are usually run for hours, is there a chance they'd have similar cooling performance at that length? The insulated hose is something I'm exploring myself. There's insulated ducting like this: https://www.homedepot.com/p/Speedi-Products-6-in-x-12-ft-Insulated-Flexible-Duct-with-Metalized-Jacket-R8-FD-12R8-06/203393272?MERCH=REC-_-pipsem-_-203393287-_-203393272-_-N https://www.homedepot.com/p/Speedi-Products-6-in-x-12-ft-Ins... but it looks terrible. I'm kind of worried about having fiberglass being in my living space like that, the PPE is significant https://homeguides.sfgate.com/safe-ways-handle-fiberglass-insulation-82010.html https://homeguides.sfgate.com/safe-ways-handle-fiberglass-in... and I'm pretty sure my cats would shred it up. I'm leaning toward adding reflectix sleeves with gaps so that the hose is flexible.
- Vendan 6y ago
  It seems to not be considering "can it reach a temperature", but "how much heat can it remove in 3 minutes", which, IMO, considering constant power usage, is more valuable for "how efficient is this"
  - sokoloff 6y ago
    For that short a period, it seems like the mass of the condenser would be relevant and disturb any extrapolation to efficiency from a run time which is not largely steady-state.
slig 6y ago
Very interesting video from Technology Connections <https://www.youtube.com/watch?v=_-mBeYC2KGc> https://www.youtube.com/watch?v=_-mBeYC2KGc> "Portable Air Conditioners - Why you shouldn't like them".
- starpilot 6y ago
  Ugh, clickbait title. TL;DW get a dual hose model. Mine was $260 from Craigslist. In the video he even says he uses two portable AC's. He backpedals further in his description: > Seriously, either we need to get more awareness of how dumb single-hose portable A/C units are, or we need to just use window units whenever possible. While I know that there are times a portable unit is the only option (remember, I’m in that boat), it seems that only very high capacity, premium machines have the facility to use two hoses. Which is frankly stupid but then again that’s what I’m trying to tell you now. Yes, you "shouldn't like them," unless it's you're only option, like in his case.
  - hinkley 6y ago
    TL;DW: get a window mount unit. The two hose models are still extremely inefficient.
    - starpilot 6y ago
      Portable AC's exist because window units don't fit in sliding windows and you can't move them from room to room. That's the point of being portable! Believe me I'd love to be able to buy a $50 used window AC like I did in college if it fit my window. In the video, the guy says he owns two portable AC's. So there's that.
      - crooked-v 6y ago
        > because window units don't fit in sliding windows Also, don't forget the ever-popular "apartment building doesn't allow anything protruding from the windows" rule.
mehrdadn 6y ago
Tangentially related, but how do you find portable ACs that work reasonably and reliably? I always found it so hard to search for them because it always seems like the reviews on these are difficult to trust. I've had at least one bad experience with one of them (single-hose) where it would just blow warm humid air sometimes, which was strictly worse than not running it at all. (At least something that might cool the air nearby consistently would be something useful, even if it can't cool the whole room.) I realize single-hose is probably a bad idea but somehow I don't have much faith in dual-hose either.
- starpilot 6y ago
  Wirecutter has never let me down: https://www.nytimes.com/wirecutter/reviews/the-best-portable-air-conditioner/ https://www.nytimes.com/wirecutter/reviews/the-best-portable... Interestingly, in their tests, they didn't find dual-hose models to work much better than single-hose, unless it's extremely hot.
  - mehrdadn 6y ago
    Thanks! I did look at Wirecutter actually, but for example the Amazon reviews for LG LP1419IVSM appear a little scary -- average 3.5/5, with 20% of them being 1/5. Have you actually had good experience with portable ACs from Wirecutter recommendations, or did you just recommend them in general?
    - rtlfe 6y ago
      I don't know about portable, but FWIW the Wirecutter window AC reviews don't match my experience at all. They say that Friedrich is louder than LG, which I know to be false because I have one of each running in adjacent rooms.
      - TwoBit 6y ago
        Wirecutter reviewed the same models that you have?
    - 6y ago
gpm 6y ago
Could you use one of these units to many a diy fridge? Freezer? Or are they somewhat tied to reducing the air temperature to only room temperature?
- hinkley 6y ago
  Get a deep freeze. It costs very little energy to cool an insulated box that only opens at the top. Mechanically, they are simple as hell so not very expensive either.
  - gpm 6y ago
    Yes, we have one, it's great. Still curious about the diy potential here though... Edit: It occurs to me you might be suggesting that it would be better to rip out the guts of a freezer than to use an air-conditioner... which does make a certain amount of sense.
    - hinkley 6y ago
      Adam Savage did a video where he worked with a guy to build a cooling unit for a cosplay suit. They were using custom compressors that were actually pretty efficient, which makes a lot of sense if you're going to be battery powered. I think some manufacturer names were mentioned? There are units now with with variable compressors, so you run them constantly at low current instead of full blast. If you want to build your own fridge, just to build one, I'd maybe look at those. The efficiency of a heat pump is relative to the delta-T you're trying to push. If you are trying to hit 40° sitting in a 72° room? You could probably repurpose a portable unit for that, sure. If you're trying to bring ambient down to 40° for a cabin? I think you're right to be concerned if it's up for it. There's also the defrost functionality which you won't have.
      - derefr 6y ago
        Re: the cosplay suit — were they essentially trying to recreate the cooling system on EVA suits?
dencodev 6y ago
I have spent a LOT of time researching using a small window AC unit converted to work in a camper van without cutting a giant hole in a wall. There's a fellow on Youtube[1] that did this successfully, and he's the only known example of it that I've seen, and he was only able to because was he a professional HVAC technician and had several unique tools you'd never own if you weren't an HVAC tech. Essentially what I'm aiming for is this: https://www.cruisencomfortusa.com/hd-series https://www.cruisencomfortusa.com/hd-series which is a perfect product, except that it costs $4000 and still uses 20% more power than some of the smallest window units. It's ridiculous that the major difference between this $4000 unit and a $150 window AC is that the $4k version has a rubber hose connecting the compressor to the condenser coils instead of the typical thin copper pipe. I am sure there are other differences - it uses better components that are more suited to a moving vehicle with shocks and vibrations, has a strong compressor to deal with the longer hose length, and is already adapted to run off of 12V. But a $3850 price difference is ridiculous. As the fellow on Youtube has shown (it's been in his camper van for years without a problem) there's really no reason the components from a $150 window unit won't work. Whenever I finally do a camper van build I'm going to find an HVAC tech who can help me with a couple steps (mostly removing and then re-adding refrigerant) and convert the copper pipes to PTFE lined stainless braided hoses attached to SAE fittings. It may not work, and I've heard finding an HVAC tech to work on weird projects is very difficult, but I want to give it a try. [1] https://www.youtube.com/watch?v=AXgHIrFqm9o https://www.youtube.com/watch?v=AXgHIrFqm9o
- coderintherye 6y ago
  As a former HVAC tech assistant, I can say that you'll easily find a tech to help you out if you pay them enough. That said, refrigerant removal and reinsertion is regulated now and it's somewhat of a pain to do properly even with the right equipment.
  - dencodev 6y ago
    Good to hear, and I'm glad to leave the refrigerant stuff to the professionals.
wiremaus 6y ago
The magic product the writer is looking for does exist — somewhat. It's those Euro style mini-split heat pumps, that pump coolant through an external unit. Up front cost is higher, but the efficiency gains are huge, and they can cool/heat much faster.
- digianarchist 6y ago
  These are standard in Southeast Asia too.
  - masklinn 6y ago
    More than standard, they're basically universal. I'm surprised and shocked it's apparently a rarity in the US. Is it because HVAC is so common it usually makes sense to plug the AC in the HVAC, and the rest of the market is basically leftovers which get to have window units or crappy portable air conditioners?
    - deleted 6y ago
      [deleted]
    - sethhochberg 6y ago
      Pretty much. Central AC is the default in regions of the US where you really need AC (which is most of the south and west, places that people didn’t really settle in large numbers until post WWII - among other reasons, because AC hadn’t been invented and the climate there is oppressive without it). In the northeast where buildings are generally the oldest in the country, window units are common - especially in rental units, because the tenant typically provides the AC themselves. One less thing for the landlord to maintain. The northwest, for the most part, doesn’t use AC much with their climate. Many homes don’t have AC at all. Mini-splits are becoming more and more common in big cities here now, but only if you’re lucky enough to own a place and you don’t have landmarked facade problems. I’d love to use one instead of my window units, but I rent a street-facing apartment in a landmarked building. Even if I could get my landlord to approve me paying for a mini-split to be installed, I couldn’t put anything outside. The commercial tenants in my building have mini-splits, but they have access to a side of the building which doesn’t front onto the public street, so no landmark concerns. (The fact that many landmarked facades have a random collection of window ACs hanging off the front seems much uglier to me than a bunch of professionally-installed identical mini-splits compressors would be, but, c'est la vie...)
TwoBit 6y ago
Dual hose units are increasingly hard to find. Hardly anybody makes them anymore. I've read in a couple places that they don't work great, despite that window units do.
- p1mrx 6y ago
  The thing is, dual-hose units could work great. The concept is theoretically sound, but nobody's trying to engineer them properly.
  - AshamedCaptain 6y ago
    I really doubt that. Most likely the vacuum efect is overrated as hell compared to the other various inefficiencies (e.g. not all the compressor's heat being vented outside) I paid extra for a dual hose unit and find myself almost never using the second hose at all. The effect is negligible and not worth the small effort of picking up the second duct from the closet. And on my unit (trotec) you _can_ close the intake vents with a simple switch if you install the 2nd hose, so its not like all manufacturers are idiots.
    - p1mrx 6y ago
      > The [vacuum] effect is negligible How did you determine that the effect is negligible? A single-hose A/C should actually blow colder air locally, because it's using cool interior air to cool its condenser. The problem is, it's also throwing cool interior air out the window, which is thermodynamically insane. Every unit of air it expels must be replaced by hot air somewhere else in the building. > e.g. not all the compressor's heat being vented outside This is an engineering problem; the compressor should be well-insulated from the room (thermally and acoustically), and cooled using outdoor air.
      - AshamedCaptain 6y ago
        By the power bill.
      - 6y ago
Zigurd 6y ago
If you have been getting Whole Foods deliveries, you may have quite a few insulated bags that could be repurposed, with some gaffer tape, to insulating cabinets and ducts.
refurb 6y ago
I'm impressed as hell that the customer service guy and engineers at the company were so willing to answer technical questions!
- jaggederest 6y ago
  It looks like Edgestar is a company that makes a pretty wide variety of HVAC equipment and prioritizes support. That makes a lot of sense for larger orders, especially for a design/build company. I love finding these kinds of companies, that focus on customer service. It's what made Amazon so special, at least back in the day. Anyone else know of other companies in this vein?
  - tgtweak 6y ago
    A few that I go out of my way to recommend: Logitech, Fellows, Dyson and Breville. Each has just straight up sent me a new unit or full replacement part when the previous one failed with no rma or warranty check - none of that nonsense just great service. Dyson support even sent me full factory service manual for the unit 5 years after it was discontinued (and 7+ out of warranty) since I wanted to troubleshoot a power supply issue which ended up working fine after resoldering the main power cord to the power board. These companies are increasingly rare.
    - vecinu 6y ago
      > Dyson Interesting! My AM11 fan started screeching and making a strange noise so I called in and my warranty had expired just a month ago and all they could do is replace my unit with a refurbished one. Sounded fine to me, especially because it was out of warranty, officially, but the unit that came was a different color and cosmetically in horrible condition, much worse than the one I sent in. At least it didn't squeak or screech and I suppose the fact they even helped out outside of the warranty period is nice.
      - deleted 6y ago
        [deleted]
BeetleB 6y ago
Years ago I bought a used (portable) evaporative cooler for $25. When the temperature is not higher than, say, 85F, it is very effective in the day. I do not live in a dry climate. During the day it's 20-50% humidity, and gets high at night. It's clearly a lot less effective at night, but it's usually cool anyway at night. Window air conditioners work great, but if you can't have that, consider an evaporative cooler if you can get one at a decent price. Do make sure you get one with a decent air flow as well as a decent sized tank (e.g. one where you can run it all night without the water running out in the middle). Probably won't work well in humid Midwest or South/East.
- axaxs 6y ago
  Yeah, swamp coolers are great in theory, but they do nothing at all in areas that most desperately need cooling.
  - grecy 6y ago
    They work brilliantly in places with low humidity by high temps - i.e. Arizona, California and my personal experience - towards the middle of Australia.
    - masklinn 6y ago
      Yeah they will work nicely in any "dry" desert. They do require access to significant amounts of water, though with the nice side-effect (for the context) that they also act as humidifiers,.
  - BeetleB 6y ago
    > Yeah, swamp coolers are great in theory For me, they're great in practice. And I don't live in a dry climate. I'll do anything to avoid living in a humid place, though. I can take very hot temperatures, but not hot and humid. At least when it's hot and dry I can still enjoy the outdoors.
    - axaxs 6y ago
mc32 6y ago
Author mentions Climax-Air as having decent units but out of stock. I think the Toyotomis are also pretty good in this class of A/C.
tgtweak 6y ago
Just get a mini split and save yourself a few hundred man hours - this being the engineering equivalent of polishing a turd. Even a poor mini split will outperform these in terms of efficiency and silence - and they can be wired directly to a nest or simple thermostat.
- spacedcowboy 6y ago
  Just installed a Carrier (40MAQB12B1 / 38MAQB12R1) mini-split in the shed, which I had spray-foam insulated (and then I installed drywall) beforehand. This for the work-at-home thing which we're doing for at least another 6 months... The difference between the loud portable unit and the blessed silence and efficiency of the mini-split is chalk and cheese. There really is no comparison. The mini-split cools the shed down to 72, where I have to increase the temperature to stay comfortable, in about 4 minutes. It's even silent outside, and these units will provide 12k BTU of heating or cooling, so it'll be useful in winter too.
  - tgtweak 6y ago
    Yep. Had a Fujitsu halcyon 18,000btu and you could not tell it was on. Prior to that I had a delonghi "penguino" 13,000btu portable AC (it cascades water over the hot side of the condenser and ejects it out of the exhaust line) which is light-years ahead of these models in terms of efficiency and quality and it struggled to cool 500sqft while the mini split can easily sustain temperatures in 1200sqft. This particular model can also heat with exterior temperatures as low as -26C (~ -15f) which cuts a ton of heating costs - heat pumps provide ~3x more heat per watt than baseboard heaters. Add to this the fact it's nearly inaudible inside or out and I can't imagine why someone would choose portable ACs over this - even high end ones. The installation is quite straightforward despite requiring a technician to do the refrigerant part and confirm the electrical setup.
saboot 6y ago
One thing with dual hose ACs that I would also like to see improved is an extension of the exhaust hose. For me often the hot air will heat up the window which then radiates heat back into the room. We do have 1980s aluminum framed windows, which really makes that problem worse. I did find a big improvement in getting duct insulation and wrapping the exhaust hose in that. For the window portion, I cut out an insulating foam board to mount the hoses, and taped the outside edge with reflecting tape. It's keeping my large bedroom around 76, unless it gets above 95 and will start creeping to low 80s.
dirtyid 6y ago
There's some pretty basic form factor changes that can go a long way to just eliminating portable units, i.e. these new U shaped designs. https://www.youtube.com/watch?v=0NELPBxrgsE https://www.youtube.com/watch?v=0NELPBxrgsE Wonder why there's no "n" designs for obstructive light. Regardless, there's no reason for portable AC, even duo hose ones due to length limitations on hose before inefficiencies. More effort into easy to install window / split units please.
anonu 6y ago
These things should be banned in my opinion. They're so inefficient and never get the room down to a decent temperature.
- denysvitali 6y ago
  Unfortunately I guess they're the only solution when it comes to portable AC units. Not everyone is living in a house they own: otherwise I agree
danbr 6y ago
I attempted something similar, at least on the nest side of things. I quickly realized the nest wouldn’t recognize any attached equipment unless connected to a 24vac line. I always wondered how the nest derived DC power to charge its internal battery when a common line was not used. Maybe I’ll research this some more and try again.
- p1mrx 6y ago
  The Nest can sort of trickle charge itself through its relay outputs, but for reliability you really want to provide 24VAC between R<->C. To attach equipment, you can connect a 24VAC-friendly load between (e.g.) Y<->C or W<->C.
  - danbr 6y ago
    Didn’t know about the trickle charging, neat! Problem with attaching a load is that if you want to build a standalone unit with the nest, you’ll need some type of inverter when powered off DC, or perhaps a simple sine wave generator? I’m more of a digital, DC power guy.
    - p1mrx 6y ago
      Yeah, you need a sine inverter, either 24VAC, or 120VAC with a 24VAC transformer. There might be a way to trick the Nest into running on something closer to DC, but I could only guess.
curiousDog 6y ago
Whoa is this Paul Marks from Purdue? Haha, long time, I miss the Dtella days!
nullc 6y ago
There are inexpensive minisplits available, they're often a much better choice than two-hose portable ACs.
082349872349872 6y ago
With WFH widely accepted, I wonder if transhumance will regain popularity? (In my area, the herds would move between valley floor, mid-mountain, and alps. Most people would move between valley floor and mid-mountain. Peasant banking started here when everyone sent their cows up to the same alp, and the resulting cheese had to be divvied up between the owners and the alp crew.) https://en.wikipedia.org/wiki/Transhumance https://en.wikipedia.org/wiki/Transhumance
noipv4 6y ago
The minimum standards for a portable AC should be a dual-hose one. Single hose ACs make no sense; it is like throwing a lot of efficiency away, just to look a bit sleeker and a very slight increase in installability and mobility. Also who in their right minds in Europe decided to rate single hose AC at A+, or A efficiency levels; the same as a good split AC? Single hose portables should all start with an F to educate a potential customer as to how dumb this device design is. https://www.galaxus.ch/en/s2/producttype/air-conditioners-280?tagIds=40-62 https://www.galaxus.ch/en/s2/producttype/air-conditioners-28...
- Bombthecat 6y ago
  I want to buy dual hose, but no luck so far. They are just not sold...
  - pessimizer 6y ago
    I'm pretty sure the ones listed in the article are on Amazon. I bought my Whynter ARC-14S from Amazon. It's very loud, but it gets things cold. They're not cheap. edit: loud like air-whooshing loud, not like vibrating compressor loud.
    - Bombthecat 6y ago
      Not in germany :)
- lucb1e 6y ago
  100% agree. In summary, in my stupidity and ignorance I got one of those units for the office with my boss' money, whereas I could have had a passively cooled working place. If all of those units were labeled F for Friggin-retarded-noise-and-cooling-levels, it would have made me look into alternatives, because I did totally look at the energy label and noise level and the vast majority was very similar. I figured this was as good as it gets. Non-summary version: In the office, the sun bakes the roof to make our rooms a good bit hotter than outside, open windows or no. I was there for my interview on one of the hotter days that year and decided right then and there that either the company was going to buy an AC or I was. It ended up being the company, but I was fairly insistent about needing one so the money was kind of spent for me. If it had been my money, I'd have considered it a sunk cost and good lesson. It took about one day of using the device for me to start to wonder about its working principles. I mean, I roughly knew: I own a fridge after all. One side gets hot and you cool it with air that is then blown outside; the other side is cold and you use it to cool air that is then blown into the room. But I hadn't really thought about it until after we owned one: How can this thing have only one hose? What is the air that it blows out replaced by? I asked that question out loud in the office and, yeah, given that it only blows hot air out, it must be creating negative pressure in the room and basically sucking that hot outside air back into the room. It's nonsensical. I even sketched out for a friend how it should work instead because they didn't get my issue. Turns out I reinvented the dual host system (which I never heard of until today). To make matters worse, the ground floor apartment I moved into at the same time as starting to work there is amazing: it remains 22-24°C during the summer, also after 2 weeks of 35+°C outside (thick walls and shaded from the sun; no air conditioning involved at all). I didn't know that was possible. If I had known that it would be fine to work from home for a few weeks per year and that my apartment would be super cool (literally and figuratively), I would never have insisted on some kind of air conditioning to try and counteract 20kW of sunlight[1] hitting the office windows and roof. I could have saved a ton of power/CO2 and quite a bit of money. To make matters worse, we didn't use to be under the roof, we used to have only morning sun through the windows. It was only slightly cooler than the new place, but this unit could actually manage to cool the room down. But now we've chosen this course and I feel too guilty to say that we should just consider it a sunk cost, I'm not going to use it, it's so loud I can hardly concentrate, and I'll just work elsewhere during the hottest weeks. Can't do it. Recently, one of our smaller windows was replaced with some insulated plates with a hole cut out exactly for the AC hose in an attempt to make it work better. I think it does work better because it's less leaky than the flexible thing we had before to put in the window crack, but it's still a huge waste and we keep sinking money into this shitty "solution". I don't even get it. Like, how hard is it to put a horizontal piece of foam in the hose and have the dual hose system in one hose? Make sure the hot side is on top and put fins at the end of the top half to make the hot air be blown upwards. May not be as efficient as having them be in separate hoses, but wouldn't that be a lot better? It's also not as if you'd be putting cold air next to hot air: it's about the already-hot outside air that would be running alongside the slightly hotter waste-heat air. [1] https://hypertextbook.com/facts/1998/ManicaPiputbundit.shtml https://hypertextbook.com/facts/1998/ManicaPiputbundit.shtml 1.4kW/m² multiplied by an estimate of window and roof surface area of the single room that the AC is in.
fomine3 6y ago
Air conditioner's compressor without PWM inverter is less controllable so makes it inefficient. Here in Japan only mini-split type air conditioner features PWM inverter and it's dominant.
chx 6y ago
> The point of connecting portable A/Cs to a Nest is: > The usual "smart" stuff that Nest provides Reminder: https://michaelblume.tumblr.com/post/169525456166/tech-enthusiasts-everything-in-my-house-is-wired https://michaelblume.tumblr.com/post/169525456166/tech-enthu... > Tech Enthusiasts: Everything in my house is wired to the Internet of Things! I control it all from my smartphone! My smart-house is bluetooth enabled and I can give it voice commands via alexa! I love the future! > Programmers / Engineers: The most recent piece of technology I own is a printer from 2004 and I keep a loaded gun ready to shoot it if it ever makes an unexpected noise. > Security technicians: takes a deep swig of whiskey I wish I had been born in the neolithic.
arkanciscan 6y ago
It's not really a hack is it? More like a fix or an optimization. I was excited for a second cause I have a single hose portable AC and I've been thinking about "hacking" it with an intake hose. However, the more I use the thing the more I realize that there's nothing wrong with it. Since the rest of the house isn't air conditioned there are open windows and fans throughout. Air is more likely to be drawn in from the rest of the house than through the cracks to the outdoors. Might be an issue in a sealed studio apt, but in our leaky shoebox of a ranch style home, it's hardly the biggest inefficiency.
vilesolid 6y ago
https://vilesolid.com/how-to-make-10-dollars-a-day/ https://vilesolid.com/how-to-make-10-dollars-a-day/
sizzle 6y ago
What kind of toxic VOCs do these indoor units leak out?
dzhiurgis 6y ago
What I always wondered is why these units don't come with heat recovery ventilation system inside. Seems obvious.
oogetyboogety 6y ago
Love the "plant growing forum" reference

344 points by p1mrx 6y ago

Hooking it up to the Nest was really clever. I've dabbled a bit with IR control of similar units, but that really takes it to the next level

p1mrx 6y ago
There's really nothing Nest-specific in the design. It just takes two components (AC input optocoupler and resistor) to sense the 24VAC output from any standard thermostat. Connecting to the Nest was probably easier than turning an ESP32 into a proper thermostat. The hardest part of the whole project was figuring out how to read a clean signal from a photodiode.
- flak48 6y ago
  Just read your post and just wanted to say I'm in absolute awe!

leoedin 6y ago

This is interesting. We collectively spend _so much_ of our energy on heating and cooling buildings, and there's very little change happening. The problems identified in the article are such low hanging fruit. Everywhere you look in residential housing there's huge efficieny gains to be made, but very little effort is going in to making them. I'd love to find ways we can use technology to make housing more efficient. We need to - it's such a crucial pillar in dealing with climate change, and the vast majority of housing is so comically inefficient. The single tube air conditioners mentioned in the article are just the icing on the cake of all these massive energy wastes we accept because they're marginally more convenient. Does anyone know how to fix this?

esaym 6y ago
>and there's very little change happening. There's honestly a lot happening and changing. Obviously you won't see it by buying "HVAC" junk from a box store. What this person should have done is paid an actual HVAC tech to install a ductless mini-split [0]. It would have been a heck of a lot more efficient. He states his one unit is drawing 10 amps (110 volt I assume). Whereas my american standard 4 ton (48,000 btu) unit draws 10 amps as well (240 volt) and cools a 2200 square ft house in 100+ degree texas weather with an electric bill usually not higher than $120 per month (1200 - 1400 kwh or so). By comparison, at my old house (which was half the size, 1100 sq ft) with a much older 12 Seer unit, my electric bill was regularly over $200. I measured that unit at drawing 18 amps (at 240 volt) and it was only a 3 ton 36,000 btu out door unit. The latest and greatest 21/22 seer units are even more efficient than my current one mentioned above (which is probably only 17 seer). [0]: https://www.americanstandardair.com/products/heating-and-cooling/ductless/ https://www.americanstandardair.com/products/heating-and-coo...
- rtlfe 6y ago
  > What this person should have done is You can't say what somebody "should have done" without knowing a lot more details about their life.
- dhbanes 6y ago
  Yeah, he should have just spend a few grand on a mini split system to stay cool for one summer at home. Makes sense.
  - balfirevic 6y ago
    Why do they cost so much in the US? I can buy a decent split unit for $400-$500 + around $150 for installation. Installation will no doubt be more expensive in the US, but there is no reason for AC itself to be (if anything, most kinds of hardware seem to generally be cheaper in US than in Europe).
    - briHass 6y ago
      Largely because we have an HVAC cartel that charges insane hourly rates for even the simplest jobs. To be fair, a Mitsubishi mini split is going to run closer to $1200-$2000 for the unit itself, but you can expect to pay $2000+ to install on top of that, depending on how hard the job is. I suppose it's hard to complain too much. HVAC installers need to have some decent technical background, troubleshooting skills, and their bodies tend to get injured/broken by the time they're in their late 40s like most manual labor trades. A HVAC installer/tech can make $80K or more a year, which makes it one of the few jobs still out there where you can make a decent middle class income without tons of schooling.
maxerickson 6y ago
Regulation. Builders spend money on things that make them profit and home buyers don't particularly evaluate efficiency. After that you figure out how to spend public money on lower efficiency structures. Fraught, but spend money where it's likely to pay off and it probably works out okay.
tgsovlerkhgsel 6y ago
> The single tube air conditioners mentioned in the article are just the icing on the cake of all these massive energy wastes we accept because they're marginally more convenient. Does anyone know how to fix this? I'm using one of those portable units because I live in a rented apartment. There is nothing convenient about it compared to a much more efficient real (split) AC, but I have no other options. Even if the landlord was OK with allowing it, "green" laws intentionally make it incredibly tedious and expensive to get the permits to install an AC, so people swarm to the option they can get without paperwork.

lifeisstillgood 6y ago

Anyone else "back in the day" would buy portable air conditioners from the hardware store and sling them into your server broom cupboard in an attempt to keep things from overheating. It got so boring when we rebuilt with proper falso floors ceilings and real racks.

walrus01 6y ago
There's still a number of small ISP and telecom infrastructure sites cooled by setups like a pair of Haier consumer grade, ductless split 18000 to 24000btu/h units. Not an uncommon setup for places like small shelters at hilltop and mountaintop radio sites.

ajb 6y ago

This is really cool. Maybe there is a market opening for an open, hackable aircon unit? One thing I've long wanted to try with mine is use 'heating mode' as a quieter version of cooling mode. They work the same - the unit just runs backwards, with the cold air coming out of the tube instead of the vents - so in theory you can cool your bedroom without having the noisy aircon in the same room. But the thermostat doesn't work properly in this case, because it thinks it's trying to raise the temperature of whatever room you put it in, not cool the other end of the tube, so for this to work properly you need to hack the control board.

userbinator 6y ago
Maybe there is a market opening for an open, hackable aircon unit? In the US, I think the EPA would not let you... ...not that it stops people all that much, as a YouTube search for "DIY AC" will show.
- derefr 6y ago
  > In the US, I think the EPA would not let you In Canada, you need to be a licensed something-or-other to purchase or own compressed CO2 canisters. This put SodaStream in an awkward position when entering the Canadian market, since their whole business model is built on selling people CO2. But they figured out a workaround: in Canada, you don't buy their CO2 canisters; instead, you "join a club" that allows you to borrow CO2 canisters (and/or refills the ones you have), and then charges servicing fees for "their" canister equipment. (Sort of like how a catering company would rent a helium tank.) I wonder if something similar could be done for refrigerant-supply licensing in the US.
  - xelan 6y ago
    Wait, what? I am in Canada and I have a couple of 5pound CO2 canister for home brewing and a modded sodastream to accept any CO2 canister. Where did you find this information? I even get it filled up at the corner store lol.
    - 6y ago

euroclydon 6y ago

That would be a great aftermarket product to hook up Nest to portable air conditioners.

hinkley 6y ago
I tried to look for something equivalent for those in-wall space heater units. They run on a different voltage, because of course they do. I think the boxes were like $40, but they looked like electrical junction boxes. Clearly meant to be buried in a wall cavity.
- quickthrowman 6y ago
  Junction boxes are not meant to be buried in a wall. In fact, any junction box containing wire (not just connections/splices) is required to be accessible without removing any part of the building per the National Electrical Code.

starpilot 6y ago

The temp vs run duration doesn't seem that meaningful. It shows the first 3 minutes of runtime, and doesn't show if all configurations reach equilibrium performance after that. It looks like they might. These things are usually run for hours, is there a chance they'd have similar cooling performance at that length? The insulated hose is something I'm exploring myself. There's insulated ducting like this: https://www.homedepot.com/p/Speedi-Products-6-in-x-12-ft-Insulated-Flexible-Duct-with-Metalized-Jacket-R8-FD-12R8-06/203393272?MERCH=REC-_-pipsem-_-203393287-_-203393272-_-N https://www.homedepot.com/p/Speedi-Products-6-in-x-12-ft-Ins... but it looks terrible. I'm kind of worried about having fiberglass being in my living space like that, the PPE is significant https://homeguides.sfgate.com/safe-ways-handle-fiberglass-insulation-82010.html https://homeguides.sfgate.com/safe-ways-handle-fiberglass-in... and I'm pretty sure my cats would shred it up. I'm leaning toward adding reflectix sleeves with gaps so that the hose is flexible.

Vendan 6y ago
It seems to not be considering "can it reach a temperature", but "how much heat can it remove in 3 minutes", which, IMO, considering constant power usage, is more valuable for "how efficient is this"
- sokoloff 6y ago
  For that short a period, it seems like the mass of the condenser would be relevant and disturb any extrapolation to efficiency from a run time which is not largely steady-state.

slig 6y ago

Very interesting video from Technology Connections <https://www.youtube.com/watch?v=_-mBeYC2KGc> https://www.youtube.com/watch?v=_-mBeYC2KGc> "Portable Air Conditioners - Why you shouldn't like them".

starpilot 6y ago
Ugh, clickbait title. TL;DW get a dual hose model. Mine was $260 from Craigslist. In the video he even says he uses two portable AC's. He backpedals further in his description: > Seriously, either we need to get more awareness of how dumb single-hose portable A/C units are, or we need to just use window units whenever possible. While I know that there are times a portable unit is the only option (remember, I’m in that boat), it seems that only very high capacity, premium machines have the facility to use two hoses. Which is frankly stupid but then again that’s what I’m trying to tell you now. Yes, you "shouldn't like them," unless it's you're only option, like in his case.
- hinkley 6y ago
  TL;DW: get a window mount unit. The two hose models are still extremely inefficient.
  - starpilot 6y ago
    Portable AC's exist because window units don't fit in sliding windows and you can't move them from room to room. That's the point of being portable! Believe me I'd love to be able to buy a $50 used window AC like I did in college if it fit my window. In the video, the guy says he owns two portable AC's. So there's that.
    - crooked-v 6y ago
      > because window units don't fit in sliding windows Also, don't forget the ever-popular "apartment building doesn't allow anything protruding from the windows" rule.

mehrdadn 6y ago

Tangentially related, but how do you find portable ACs that work reasonably and reliably? I always found it so hard to search for them because it always seems like the reviews on these are difficult to trust. I've had at least one bad experience with one of them (single-hose) where it would just blow warm humid air sometimes, which was strictly worse than not running it at all. (At least something that might cool the air nearby consistently would be something useful, even if it can't cool the whole room.) I realize single-hose is probably a bad idea but somehow I don't have much faith in dual-hose either.

starpilot 6y ago
Wirecutter has never let me down: https://www.nytimes.com/wirecutter/reviews/the-best-portable-air-conditioner/ https://www.nytimes.com/wirecutter/reviews/the-best-portable... Interestingly, in their tests, they didn't find dual-hose models to work much better than single-hose, unless it's extremely hot.
- mehrdadn 6y ago
  Thanks! I did look at Wirecutter actually, but for example the Amazon reviews for LG LP1419IVSM appear a little scary -- average 3.5/5, with 20% of them being 1/5. Have you actually had good experience with portable ACs from Wirecutter recommendations, or did you just recommend them in general?
  - rtlfe 6y ago
    I don't know about portable, but FWIW the Wirecutter window AC reviews don't match my experience at all. They say that Friedrich is louder than LG, which I know to be false because I have one of each running in adjacent rooms.
    - TwoBit 6y ago
      Wirecutter reviewed the same models that you have?
  - 6y ago

gpm 6y ago

Could you use one of these units to many a diy fridge? Freezer? Or are they somewhat tied to reducing the air temperature to only room temperature?

hinkley 6y ago
Get a deep freeze. It costs very little energy to cool an insulated box that only opens at the top. Mechanically, they are simple as hell so not very expensive either.
- gpm 6y ago
  Yes, we have one, it's great. Still curious about the diy potential here though... Edit: It occurs to me you might be suggesting that it would be better to rip out the guts of a freezer than to use an air-conditioner... which does make a certain amount of sense.
  - hinkley 6y ago
    Adam Savage did a video where he worked with a guy to build a cooling unit for a cosplay suit. They were using custom compressors that were actually pretty efficient, which makes a lot of sense if you're going to be battery powered. I think some manufacturer names were mentioned? There are units now with with variable compressors, so you run them constantly at low current instead of full blast. If you want to build your own fridge, just to build one, I'd maybe look at those. The efficiency of a heat pump is relative to the delta-T you're trying to push. If you are trying to hit 40° sitting in a 72° room? You could probably repurpose a portable unit for that, sure. If you're trying to bring ambient down to 40° for a cabin? I think you're right to be concerned if it's up for it. There's also the defrost functionality which you won't have.
    - derefr 6y ago
      Re: the cosplay suit — were they essentially trying to recreate the cooling system on EVA suits?

dencodev 6y ago

I have spent a LOT of time researching using a small window AC unit converted to work in a camper van without cutting a giant hole in a wall. There's a fellow on Youtube[1] that did this successfully, and he's the only known example of it that I've seen, and he was only able to because was he a professional HVAC technician and had several unique tools you'd never own if you weren't an HVAC tech. Essentially what I'm aiming for is this: https://www.cruisencomfortusa.com/hd-series https://www.cruisencomfortusa.com/hd-series which is a perfect product, except that it costs $4000 and still uses 20% more power than some of the smallest window units. It's ridiculous that the major difference between this $4000 unit and a $150 window AC is that the $4k version has a rubber hose connecting the compressor to the condenser coils instead of the typical thin copper pipe. I am sure there are other differences - it uses better components that are more suited to a moving vehicle with shocks and vibrations, has a strong compressor to deal with the longer hose length, and is already adapted to run off of 12V. But a $3850 price difference is ridiculous. As the fellow on Youtube has shown (it's been in his camper van for years without a problem) there's really no reason the components from a $150 window unit won't work. Whenever I finally do a camper van build I'm going to find an HVAC tech who can help me with a couple steps (mostly removing and then re-adding refrigerant) and convert the copper pipes to PTFE lined stainless braided hoses attached to SAE fittings. It may not work, and I've heard finding an HVAC tech to work on weird projects is very difficult, but I want to give it a try. [1] https://www.youtube.com/watch?v=AXgHIrFqm9o https://www.youtube.com/watch?v=AXgHIrFqm9o

coderintherye 6y ago
As a former HVAC tech assistant, I can say that you'll easily find a tech to help you out if you pay them enough. That said, refrigerant removal and reinsertion is regulated now and it's somewhat of a pain to do properly even with the right equipment.
- dencodev 6y ago
  Good to hear, and I'm glad to leave the refrigerant stuff to the professionals.

wiremaus 6y ago

The magic product the writer is looking for does exist — somewhat. It's those Euro style mini-split heat pumps, that pump coolant through an external unit. Up front cost is higher, but the efficiency gains are huge, and they can cool/heat much faster.

digianarchist 6y ago
These are standard in Southeast Asia too.
- masklinn 6y ago
  More than standard, they're basically universal. I'm surprised and shocked it's apparently a rarity in the US. Is it because HVAC is so common it usually makes sense to plug the AC in the HVAC, and the rest of the market is basically leftovers which get to have window units or crappy portable air conditioners?
  - deleted 6y ago
    [deleted]
  - sethhochberg 6y ago
    Pretty much. Central AC is the default in regions of the US where you really need AC (which is most of the south and west, places that people didn’t really settle in large numbers until post WWII - among other reasons, because AC hadn’t been invented and the climate there is oppressive without it). In the northeast where buildings are generally the oldest in the country, window units are common - especially in rental units, because the tenant typically provides the AC themselves. One less thing for the landlord to maintain. The northwest, for the most part, doesn’t use AC much with their climate. Many homes don’t have AC at all. Mini-splits are becoming more and more common in big cities here now, but only if you’re lucky enough to own a place and you don’t have landmarked facade problems. I’d love to use one instead of my window units, but I rent a street-facing apartment in a landmarked building. Even if I could get my landlord to approve me paying for a mini-split to be installed, I couldn’t put anything outside. The commercial tenants in my building have mini-splits, but they have access to a side of the building which doesn’t front onto the public street, so no landmark concerns. (The fact that many landmarked facades have a random collection of window ACs hanging off the front seems much uglier to me than a bunch of professionally-installed identical mini-splits compressors would be, but, c'est la vie...)

TwoBit 6y ago

Dual hose units are increasingly hard to find. Hardly anybody makes them anymore. I've read in a couple places that they don't work great, despite that window units do.

p1mrx 6y ago
The thing is, dual-hose units could work great. The concept is theoretically sound, but nobody's trying to engineer them properly.
- AshamedCaptain 6y ago
  I really doubt that. Most likely the vacuum efect is overrated as hell compared to the other various inefficiencies (e.g. not all the compressor's heat being vented outside) I paid extra for a dual hose unit and find myself almost never using the second hose at all. The effect is negligible and not worth the small effort of picking up the second duct from the closet. And on my unit (trotec) you _can_ close the intake vents with a simple switch if you install the 2nd hose, so its not like all manufacturers are idiots.
  - p1mrx 6y ago
    > The [vacuum] effect is negligible How did you determine that the effect is negligible? A single-hose A/C should actually blow colder air locally, because it's using cool interior air to cool its condenser. The problem is, it's also throwing cool interior air out the window, which is thermodynamically insane. Every unit of air it expels must be replaced by hot air somewhere else in the building. > e.g. not all the compressor's heat being vented outside This is an engineering problem; the compressor should be well-insulated from the room (thermally and acoustically), and cooled using outdoor air.
    - AshamedCaptain 6y ago
      By the power bill.
    - 6y ago

Zigurd 6y ago

If you have been getting Whole Foods deliveries, you may have quite a few insulated bags that could be repurposed, with some gaffer tape, to insulating cabinets and ducts.

refurb 6y ago

I'm impressed as hell that the customer service guy and engineers at the company were so willing to answer technical questions!

jaggederest 6y ago
It looks like Edgestar is a company that makes a pretty wide variety of HVAC equipment and prioritizes support. That makes a lot of sense for larger orders, especially for a design/build company. I love finding these kinds of companies, that focus on customer service. It's what made Amazon so special, at least back in the day. Anyone else know of other companies in this vein?
- tgtweak 6y ago
  A few that I go out of my way to recommend: Logitech, Fellows, Dyson and Breville. Each has just straight up sent me a new unit or full replacement part when the previous one failed with no rma or warranty check - none of that nonsense just great service. Dyson support even sent me full factory service manual for the unit 5 years after it was discontinued (and 7+ out of warranty) since I wanted to troubleshoot a power supply issue which ended up working fine after resoldering the main power cord to the power board. These companies are increasingly rare.
  - vecinu 6y ago
    > Dyson Interesting! My AM11 fan started screeching and making a strange noise so I called in and my warranty had expired just a month ago and all they could do is replace my unit with a refurbished one. Sounded fine to me, especially because it was out of warranty, officially, but the unit that came was a different color and cosmetically in horrible condition, much worse than the one I sent in. At least it didn't squeak or screech and I suppose the fact they even helped out outside of the warranty period is nice.
    - deleted 6y ago
      [deleted]

BeetleB 6y ago

Years ago I bought a used (portable) evaporative cooler for $25. When the temperature is not higher than, say, 85F, it is very effective in the day. I do not live in a dry climate. During the day it's 20-50% humidity, and gets high at night. It's clearly a lot less effective at night, but it's usually cool anyway at night. Window air conditioners work great, but if you can't have that, consider an evaporative cooler if you can get one at a decent price. Do make sure you get one with a decent air flow as well as a decent sized tank (e.g. one where you can run it all night without the water running out in the middle). Probably won't work well in humid Midwest or South/East.

axaxs 6y ago
Yeah, swamp coolers are great in theory, but they do nothing at all in areas that most desperately need cooling.
- grecy 6y ago
  They work brilliantly in places with low humidity by high temps - i.e. Arizona, California and my personal experience - towards the middle of Australia.
  - masklinn 6y ago
    Yeah they will work nicely in any "dry" desert. They do require access to significant amounts of water, though with the nice side-effect (for the context) that they also act as humidifiers,.
- BeetleB 6y ago
  > Yeah, swamp coolers are great in theory For me, they're great in practice. And I don't live in a dry climate. I'll do anything to avoid living in a humid place, though. I can take very hot temperatures, but not hot and humid. At least when it's hot and dry I can still enjoy the outdoors.
  - axaxs 6y ago

mc32 6y ago

Author mentions Climax-Air as having decent units but out of stock. I think the Toyotomis are also pretty good in this class of A/C.

tgtweak 6y ago

Just get a mini split and save yourself a few hundred man hours - this being the engineering equivalent of polishing a turd. Even a poor mini split will outperform these in terms of efficiency and silence - and they can be wired directly to a nest or simple thermostat.

spacedcowboy 6y ago
Just installed a Carrier (40MAQB12B1 / 38MAQB12R1) mini-split in the shed, which I had spray-foam insulated (and then I installed drywall) beforehand. This for the work-at-home thing which we're doing for at least another 6 months... The difference between the loud portable unit and the blessed silence and efficiency of the mini-split is chalk and cheese. There really is no comparison. The mini-split cools the shed down to 72, where I have to increase the temperature to stay comfortable, in about 4 minutes. It's even silent outside, and these units will provide 12k BTU of heating or cooling, so it'll be useful in winter too.
- tgtweak 6y ago
  Yep. Had a Fujitsu halcyon 18,000btu and you could not tell it was on. Prior to that I had a delonghi "penguino" 13,000btu portable AC (it cascades water over the hot side of the condenser and ejects it out of the exhaust line) which is light-years ahead of these models in terms of efficiency and quality and it struggled to cool 500sqft while the mini split can easily sustain temperatures in 1200sqft. This particular model can also heat with exterior temperatures as low as -26C (~ -15f) which cuts a ton of heating costs - heat pumps provide ~3x more heat per watt than baseboard heaters. Add to this the fact it's nearly inaudible inside or out and I can't imagine why someone would choose portable ACs over this - even high end ones. The installation is quite straightforward despite requiring a technician to do the refrigerant part and confirm the electrical setup.

saboot 6y ago

One thing with dual hose ACs that I would also like to see improved is an extension of the exhaust hose. For me often the hot air will heat up the window which then radiates heat back into the room. We do have 1980s aluminum framed windows, which really makes that problem worse. I did find a big improvement in getting duct insulation and wrapping the exhaust hose in that. For the window portion, I cut out an insulating foam board to mount the hoses, and taped the outside edge with reflecting tape. It's keeping my large bedroom around 76, unless it gets above 95 and will start creeping to low 80s.

dirtyid 6y ago

There's some pretty basic form factor changes that can go a long way to just eliminating portable units, i.e. these new U shaped designs. https://www.youtube.com/watch?v=0NELPBxrgsE https://www.youtube.com/watch?v=0NELPBxrgsE Wonder why there's no "n" designs for obstructive light. Regardless, there's no reason for portable AC, even duo hose ones due to length limitations on hose before inefficiencies. More effort into easy to install window / split units please.

anonu 6y ago

These things should be banned in my opinion. They're so inefficient and never get the room down to a decent temperature.

denysvitali 6y ago
Unfortunately I guess they're the only solution when it comes to portable AC units. Not everyone is living in a house they own: otherwise I agree

danbr 6y ago

I attempted something similar, at least on the nest side of things. I quickly realized the nest wouldn’t recognize any attached equipment unless connected to a 24vac line. I always wondered how the nest derived DC power to charge its internal battery when a common line was not used. Maybe I’ll research this some more and try again.

p1mrx 6y ago
The Nest can sort of trickle charge itself through its relay outputs, but for reliability you really want to provide 24VAC between R<->C. To attach equipment, you can connect a 24VAC-friendly load between (e.g.) Y<->C or W<->C.
- danbr 6y ago
  Didn’t know about the trickle charging, neat! Problem with attaching a load is that if you want to build a standalone unit with the nest, you’ll need some type of inverter when powered off DC, or perhaps a simple sine wave generator? I’m more of a digital, DC power guy.
  - p1mrx 6y ago
    Yeah, you need a sine inverter, either 24VAC, or 120VAC with a 24VAC transformer. There might be a way to trick the Nest into running on something closer to DC, but I could only guess.

curiousDog 6y ago

Whoa is this Paul Marks from Purdue? Haha, long time, I miss the Dtella days!

nullc 6y ago

There are inexpensive minisplits available, they're often a much better choice than two-hose portable ACs.

082349872349872 6y ago

With WFH widely accepted, I wonder if transhumance will regain popularity? (In my area, the herds would move between valley floor, mid-mountain, and alps. Most people would move between valley floor and mid-mountain. Peasant banking started here when everyone sent their cows up to the same alp, and the resulting cheese had to be divvied up between the owners and the alp crew.) https://en.wikipedia.org/wiki/Transhumance https://en.wikipedia.org/wiki/Transhumance

noipv4 6y ago

The minimum standards for a portable AC should be a dual-hose one. Single hose ACs make no sense; it is like throwing a lot of efficiency away, just to look a bit sleeker and a very slight increase in installability and mobility. Also who in their right minds in Europe decided to rate single hose AC at A+, or A efficiency levels; the same as a good split AC? Single hose portables should all start with an F to educate a potential customer as to how dumb this device design is. https://www.galaxus.ch/en/s2/producttype/air-conditioners-280?tagIds=40-62 https://www.galaxus.ch/en/s2/producttype/air-conditioners-28...

Bombthecat 6y ago
I want to buy dual hose, but no luck so far. They are just not sold...
- pessimizer 6y ago
  I'm pretty sure the ones listed in the article are on Amazon. I bought my Whynter ARC-14S from Amazon. It's very loud, but it gets things cold. They're not cheap. edit: loud like air-whooshing loud, not like vibrating compressor loud.
  - Bombthecat 6y ago
    Not in germany :)
lucb1e 6y ago
100% agree. In summary, in my stupidity and ignorance I got one of those units for the office with my boss' money, whereas I could have had a passively cooled working place. If all of those units were labeled F for Friggin-retarded-noise-and-cooling-levels, it would have made me look into alternatives, because I did totally look at the energy label and noise level and the vast majority was very similar. I figured this was as good as it gets. Non-summary version: In the office, the sun bakes the roof to make our rooms a good bit hotter than outside, open windows or no. I was there for my interview on one of the hotter days that year and decided right then and there that either the company was going to buy an AC or I was. It ended up being the company, but I was fairly insistent about needing one so the money was kind of spent for me. If it had been my money, I'd have considered it a sunk cost and good lesson. It took about one day of using the device for me to start to wonder about its working principles. I mean, I roughly knew: I own a fridge after all. One side gets hot and you cool it with air that is then blown outside; the other side is cold and you use it to cool air that is then blown into the room. But I hadn't really thought about it until after we owned one: How can this thing have only one hose? What is the air that it blows out replaced by? I asked that question out loud in the office and, yeah, given that it only blows hot air out, it must be creating negative pressure in the room and basically sucking that hot outside air back into the room. It's nonsensical. I even sketched out for a friend how it should work instead because they didn't get my issue. Turns out I reinvented the dual host system (which I never heard of until today). To make matters worse, the ground floor apartment I moved into at the same time as starting to work there is amazing: it remains 22-24°C during the summer, also after 2 weeks of 35+°C outside (thick walls and shaded from the sun; no air conditioning involved at all). I didn't know that was possible. If I had known that it would be fine to work from home for a few weeks per year and that my apartment would be super cool (literally and figuratively), I would never have insisted on some kind of air conditioning to try and counteract 20kW of sunlight[1] hitting the office windows and roof. I could have saved a ton of power/CO2 and quite a bit of money. To make matters worse, we didn't use to be under the roof, we used to have only morning sun through the windows. It was only slightly cooler than the new place, but this unit could actually manage to cool the room down. But now we've chosen this course and I feel too guilty to say that we should just consider it a sunk cost, I'm not going to use it, it's so loud I can hardly concentrate, and I'll just work elsewhere during the hottest weeks. Can't do it. Recently, one of our smaller windows was replaced with some insulated plates with a hole cut out exactly for the AC hose in an attempt to make it work better. I think it does work better because it's less leaky than the flexible thing we had before to put in the window crack, but it's still a huge waste and we keep sinking money into this shitty "solution". I don't even get it. Like, how hard is it to put a horizontal piece of foam in the hose and have the dual hose system in one hose? Make sure the hot side is on top and put fins at the end of the top half to make the hot air be blown upwards. May not be as efficient as having them be in separate hoses, but wouldn't that be a lot better? It's also not as if you'd be putting cold air next to hot air: it's about the already-hot outside air that would be running alongside the slightly hotter waste-heat air. [1] https://hypertextbook.com/facts/1998/ManicaPiputbundit.shtml https://hypertextbook.com/facts/1998/ManicaPiputbundit.shtml 1.4kW/m² multiplied by an estimate of window and roof surface area of the single room that the AC is in.

fomine3 6y ago

Air conditioner's compressor without PWM inverter is less controllable so makes it inefficient. Here in Japan only mini-split type air conditioner features PWM inverter and it's dominant.

chx 6y ago

> The point of connecting portable A/Cs to a Nest is: > The usual "smart" stuff that Nest provides Reminder: https://michaelblume.tumblr.com/post/169525456166/tech-enthusiasts-everything-in-my-house-is-wired https://michaelblume.tumblr.com/post/169525456166/tech-enthu... > Tech Enthusiasts: Everything in my house is wired to the Internet of Things! I control it all from my smartphone! My smart-house is bluetooth enabled and I can give it voice commands via alexa! I love the future! > Programmers / Engineers: The most recent piece of technology I own is a printer from 2004 and I keep a loaded gun ready to shoot it if it ever makes an unexpected noise. > Security technicians: takes a deep swig of whiskey I wish I had been born in the neolithic.

arkanciscan 6y ago

It's not really a hack is it? More like a fix or an optimization. I was excited for a second cause I have a single hose portable AC and I've been thinking about "hacking" it with an intake hose. However, the more I use the thing the more I realize that there's nothing wrong with it. Since the rest of the house isn't air conditioned there are open windows and fans throughout. Air is more likely to be drawn in from the rest of the house than through the cracks to the outdoors. Might be an issue in a sealed studio apt, but in our leaky shoebox of a ranch style home, it's hardly the biggest inefficiency.

vilesolid 6y ago

https://vilesolid.com/how-to-make-10-dollars-a-day/ https://vilesolid.com/how-to-make-10-dollars-a-day/

sizzle 6y ago

What kind of toxic VOCs do these indoor units leak out?

dzhiurgis 6y ago

What I always wondered is why these units don't come with heat recovery ventilation system inside. Seems obvious.

oogetyboogety 6y ago

Love the "plant growing forum" reference