Hacking Portable Air Conditioners

by p1mrx • 6 years ago

344 241 6 years ago

Rebelgecko• 6 years 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

p1mrx8• 6 years 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• 6 years ago

Just read your post and just wanted to say I'm in absolute awe!

leoedin• 6 years 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• 6 years 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-coo...

rtlfe2• 6 years 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• 6 years 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.

p1mrx8• 6 years ago

Installing a mini-split would be a year-long project, including HOA negotiations, architectural design, electrical load calculations, city permits, and invasive construction. It's not the sort of thing you'd want to attempt at the beginning of a pandemic (or ever, for most people.)

Given the orders of magnitude less work required to find a product and click "Buy", it'd greatly benefit society for portable A/C manufacturers to compete on efficiency.

erik_seaberg• 6 years ago

Mini-split looks like a good design, but our landlord would not be happy about our leaving behind a 3" hole in an exterior wall.

eigenvector• 6 years ago

One of the biggest reasons portable air conditioners exist is for apartments. It's something anyone can buy without having to get permission from their landlord to make modifications to the property. So I would not compare them directly to anything that cannot be installed by a tenant without additional permission.

bradly• 6 years ago

Fwiw I was told I needed to get a permit and have a 220 line ran to install a mini-split in my house. That hassle put it out of contention for me and my not be an option for people renting.

maxerickson2• 6 years 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.

tgsovlerkhgsel4• 6 years 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• 6 years 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• 6 years 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• 6 years 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.

userbinator2• 6 years 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.

derefr3• 6 years 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.

euroclydon• 6 years ago

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

hinkley8• 6 years 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• 6 years 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.

starpilot4• 6 years 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-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-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• 6 years 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"

sokoloff3• 6 years 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• 6 years ago

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

starpilot4• 6 years 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.

hinkley8• 6 years ago

TL;DW: get a window mount unit. The two hose models are still extremely inefficient.

nwienert2• 6 years ago

If you live somewhere temperate the single hose will cool from low 70s to 62 in a bedroom for less money/eyesore.

gruez2• 6 years ago

Very interesting video

The content might be interesting, but it's way too long. The guy goes on way too many tangents and adds way too much filler. You probably can boil the whole video down to a few bullet points, yet it's 16 minutes long.

tdeck• 6 years ago

These TC videos are meant as a kind of entertainment. I enjoy them a lot but they're definitely not meant as a quick reference.

hombre_fatal• 6 years ago

On the other hand, I like his long-form video entertainment. I'll eat lunch while watching one maybe. Not everything needs to be optimized into bulletpoints.

hhh• 6 years ago

They're intended as entertainment and not condensed informational videos. They're meant to be an exploration into the topic.

rootsudo• 6 years ago

Youtube prefers long videos and it returns higher monetization rates because it's "user engagement."

princekolt• 6 years ago

Have you considered the possibility of not watching it?

interestica• 6 years ago

That's kind of the point though. It's a style and delivery method that makes the content enjoyable. A few bullet points could be broadcast via text+image alone, but that isn't the same thing.

Waterluvian• 6 years ago

His long format is very much the point. There’s countless quick format high quality channels out there for this stuff too!

Watching his videos reminds me of university and being in a really high quality lecture or lab session.

c3534l2• 6 years ago

I know I'm old because I immediately thought back to how in my day, my parents complained that kids got bored after 45 minutes or so. If you don't have the patience to watch a short YouTube video, then that's really a personality problem that lies with you, not the video.

johntfella2• 6 years ago

Living in a hoa that is loaded with some weird rules... I'm stuck with a portable as traditionals are not allowed. As per noise this was a happy find overtime. A dog of mine developed thunder and fireworks issues. The noise of the ac running helped filter out the thunder/fireworks. Eventually I gravitated towards something more powerful and a bit more expensive and did some self adjusting to the machine bypassing the temperature min so to have the a/c just run continously when I needed it to. This means a room that is typically 51-52ish.

7thaccount2• 6 years ago

Celsius? My perfect temp is ~70 farenheit

derekp7• 6 years ago

I knew someone that had an HOA rule against window air conditioners. His solution was to keep the window-mount unit inside his bedroom, with the back end (that normally sticks outside the house) enclosed in a box. That box had an intake and exhaust fan, with flexible duct work that routed to a piece of plywood stuck up in the window. From the outside, you just see the screen with the plywood on the other side. But it worked about as effectively as if the whole unit was mounted in the window.

c3534l2• 6 years ago

I watched that immediately after buying a portable air conditioner. Thankfully, too, because I think he oversells the inefficiency and effectiveness of portable air conditioners. It's very easy to leave that video thinking you shouldn't bother with one, but the reality is that they're actually pretty damned good machines. Window-mounted units are marginally better, sure, but if that's not an option or you live a place that doesn't stay hot for very long, then they're fine, your electric bill is just a little higher. Which is fine for me because there's two months out of the year I need A/C and the alternative is a fan.

Retric2• 6 years ago

I think you’re talking about a different device. Portable swamp coolers provide zero value in high humidity areas.

amelius2• 6 years ago

but the reality is that they're actually pretty damned good machines

... if you ignore the energy consumption, which is the whole point of the video.

chiph• 6 years ago

The A/C in an apartment I was living in in Texas failed one summer, and the management firm put one like that in my bedroom temporarily.

Noisy and inefficient is a good description. Granted, it had to run off a regular 15A outlet so it was never going to be as powerful as the one in the attic. But it made sleeping possible by getting the temperature below 85F (30C).

simonebrunozzi• 6 years ago

It's a fantastic video, and the guy explaining it all has a natural talent for teaching and dissecting things. Thanks for sharing it!

karimmaassen• 6 years ago

After watching that video, I decided to relocate my portable air conditioner. The exhaust tube is now super short, directly mounted to a hole in the wall, and insulated to compensate for the inefficiency of these type of devices. It made all the difference.

mehrdadn2• 6 years 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.

starpilot4• 6 years ago

Wirecutter has never let me down: 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.

mehrdadn2• 6 years 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?

phendrenad2• 6 years ago

It seems to me that portable units are all kind of equally meh. Seem to be about 50% as good as a window unit (which is about 50% as good as a mini-split or whole-home AC in my opinion). The dual-hose units don't seem to be a whole lot better than the single-hose units, honestly. Considering getting someone to professionally install a mini-split in my apartment to replace two portable units (1hose and 2hose).

dehrmann• 6 years ago

I have a dual-hose version that looks very similar to OP's. I use it on-and-off when it gets hots. It can keep a poorly insulated bedroom cool, or two rooms bearable. It's loud to the point that I worry slightly about hearing damage if I sleep with it running, but as an AC, it's worked for several years.

gpm3• 6 years 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?

hinkley8• 6 years 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.

gpm3• 6 years 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.

p1mrx8• 6 years ago

This particular model will not cool below 60F/16C. Even if it could, the point of a portable A/C is to avoid cutting holes in the wall, which is not relevant if you're building a custom enclosure.

In theory, you could build an insulated box with a mini-split or window/wall unit, but they're probably all optimized for cooling a large space, not freezing a small space.

Tech Ingredients made a DIY fridge (and a freezer in later videos) using peltier coolers: https://www.youtube.com/watch?v=YWUhwmmZa7A

gpm3• 6 years ago

That was a super interesting video, thanks!

bserge3• 6 years ago

That's just the thermostat, though. If you powered and ran the compressor directly, it would pump heat until the heat exchanger goes well into negative temperature.

People used to turn portable A/Cs into PC coolers, which was pretty... cool.

lucb1e4• 6 years ago

The one we have in the office blows out 5-8°C air but indeed refuses to cool below a certain temperature. The unit isn't incapable of fridge temperatures, its software just doesn't want it to.

bserge3• 6 years ago

Youd have to build the whole enclosure yourself, but otherwise yeah you could do that. It's just a phase change heat pump, after all.

dencodev5• 6 years 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

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

coderintherye• 6 years 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.

dencodev5• 6 years ago

Good to hear, and I'm glad to leave the refrigerant stuff to the professionals.

elliekelly• 6 years ago

What about the mayor bloomberg route? https://m.youtube.com/watch?v=P5vJWHMlHHg

dencodev5• 6 years ago

A lot of camper vans do this - it just looks awful, destroys any stealth value, has to be moved in and out of the opening any time you start driving, and takes up a ton of internal room when not deployed.

Dylan168072• 6 years ago

Wow, talk about having an axe to grind. That story simultaneously complains about it as a waste of money and says that he's rich so he can/should afford something sleeker.

dahfizz2• 6 years ago

This might be a stupid question: couldn't you just modify the AC unit already in your van to run off whatever power source you wanted to run your window unit off of?

Gibbon17• 6 years ago

Not stupid. The problem with most full sized vans is the ac compressor is run off a belt. Not totally insane would be add a second compressor and a three way valve. I've never heard of someone doing that. It's more common to use a RV rooftop AC unit.

Some newer passengers cars and maybe some vans use electric motors to drive the compressor. And EV's tend do that as well. In the EV case no mods are probably needed. Electric vans though are just becoming a thing and have low range and high price tag.

dencodev5• 6 years ago

Yes but the issue is power consumption. The idea is to run the AC off solar and batteries which is why the rooftop option doesn't work either - they use a buttload of energy. The AC systems in vehicles consume a ton of power to operate which is typically why they're belt driven by the engine directly. The all electric version in a Tesla uses around 3000 watts if I remember correctly, while a window unit use about 450.

moreati• 6 years ago

This might be of interest https://www.youtube.com/watch?v=woZH85EiHNY

dencodev5• 6 years ago

These unfortunately have absolutely awful reviews everywhere. It's impressive it's lasted as long as it had for him. I believe the manufacturer stopped making these because they suck so bad. They also aren't designed to be serviced and would still require a lot of hacking in the same way a window unit would be

yencabulator• 6 years ago

I know someone with a Home Depot residential style mini-split mounted on the back of their cargo trailer RV conversion. Probably too much for a van, but no huge hole in the wall.

wiremaus2• 6 years 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• 6 years ago

These are standard in Southeast Asia too.

masklinn11• 6 years 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?

neals• 6 years ago

Anybody got an example of these?

masklinn11• 6 years ago

Of a mini-split? https://www.fujitsugeneral.com/us/residential/what-is-a-mini...

It's the the large horizontal vents protruding from the wall you see in pretty much every low-rise (2-3 floors) residential buildings ("apaato"), or if you go to the back of the building you can see each flat's external unit, generally wall-mounted next to or below a window.

They're almost all reversible heat pumps, though their heating capacity tends to be lower than their cooling capacity.

Note that mini splits can also use a more discrete slim duct (as the link notes), but in my experience the wall mount is by far the most common, as that's way simpler and more convenient for multi-unit buildings.

peteretep• 6 years ago

Euro style

The only place in this wide world I’ve seen anything other than split units is North America, so “Euro style” seems an odd description.

wiremaus2• 6 years ago

That's accurate: they're the standard in much of the rest of the world due to their lower operating costs.

I was using "Euro" only to help people picture the things, it's a common way I've heard them described.

TwoBit2• 6 years 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.

p1mrx8• 6 years ago

The thing is, dual-hose units could work great. The concept is theoretically sound, but nobody's trying to engineer them properly.

AshamedCaptain4• 6 years 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.

Zigurd• 6 years 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• 6 years ago

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

jaggederest2• 6 years 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?

tgtweak5• 6 years 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.

jetrink• 6 years ago

I had a similar experience with a SunSaver solar charge controller. I was out in the field trying to fix a problem with a solar power supply and I called into their support line to ask about the error lights we were seeing. Within a few minutes, I was talking to an engineer and he spent 15-20 minutes helping us diagnose the problem. It turned out to be something dumb we had done triggering a fault mode in the controller. The controller itself cost less than $100, so we were definitely not worth his time.

Spooky232• 6 years ago

I was going to say the same thing. The idea that the customer service rep actually has the ability to talk to product engineering is pretty incredible.

sokoloff3• 6 years ago

In 2005, our customer care center was taken offline by a severe hurricane. Software developers, product people, and marketing staffed a temporary call center until the center could re-open. It was eye-opening for me to take customer calls and try to solve them with just the care tools. You can learn an incredible amount by letting/making engineers and product leads talk to customers.

ghostpepper• 6 years ago

I wish there was a site that allowed you to reviews products on things like this

BeetleB5• 6 years 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.

axaxs2• 6 years ago

Yeah, swamp coolers are great in theory, but they do nothing at all in areas that most desperately need cooling.

grecy• 6 years 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.

BeetleB5• 6 years 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.

exogen2• 6 years ago

I bought one for my space in Seattle and it's a game changer. I couldn't get A/C for several reasons, and was really nervous a swamp cooler would do nothing in this climate, but it works great!

Pros:

- You can (and are supposed to) keep the windows open for air flow. No worrying about closing everything off.

- They're rated for way more square footage than window or portable A/C units (although they are pretty directional). For example, mine is spec'd for 1600 sqft.

- Cost.

Cons:

- Requires cleaning. Not as much work as maintaining a fish tank, but it reminds me of that :)

BeetleB5• 6 years ago

I bought one for my space in Seattle and it's a game changer.

It's funny how when you search the Internet, everyone says "It's useless in Seattle because it rains so much and is never dry."

And yet...

I'm not sure I agree with all your pros, though. I think good brand new ones are quite pricey, and you can easily find used window A/Cs for much cheaper. In my experience, window A/C units work better at cooling, and handle more square footage, but perhaps you simply got a bigger/more powerful evaporative cooler than I have. No way would mine handle 1600 sqft. I assume yours is not portable...?

I grew up on window A/Cs[1] and I think they're the best, to be frank. They cool a room down much better than a central A/C. If you have a decent size house, a central A/C is probably more economical from an utility bill standpoint if you want to cool the whole house. But if I want it as cool as I'd like it, and only want to do 1-2 rooms, nothing beats a window A/C.

But if you want a portable unit, I think an evaporative cooler is much better than a portable A/C. The latter are crap.

[1] They were "window" A/Cs, but were installed in the walls. Unfortunately, few houses are designed with this in mind, and US society has a weird aversion to window A/C's (many HOAs ban them)

mc32• 6 years 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.

tgtweak5• 6 years 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• 6 years 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.

tgtweak5• 6 years 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• 6 years 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• 6 years 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

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• 6 years ago

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

denysvitali• 6 years 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

danbr2• 6 years 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.

p1mrx8• 6 years 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.

danbr2• 6 years 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.

curiousDog• 6 years ago

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

nullc• 6 years ago

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

082349872349872• 6 years 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

noipv4• 6 years 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-28...

Bombthecat2• 6 years ago

I want to buy dual hose, but no luck so far. They are just not sold...

pessimizer• 6 years 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.

lucb1e4• 6 years 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 1.4kW/m² multiplied by an estimate of window and roof surface area of the single room that the AC is in.

masklinn11• 6 years ago

Hell, even if it's a larger expense, for an office which regularly gets very warm for extended periods of time you bite the bullet and get a proper reversible heat pump. That way you have proper AC in the summer, and lower heating costs in winter (or if winters are so harsh the heat pump won't work you at least save some during spring and autumn when the heat pump suffices to keep the office warm).

AshamedCaptain4• 6 years ago

Perhaps they are giving the same ratings because, actually, the efficiency difference is not that significant? Or do you think they are handicapping the ratings in some way?

I keep it that I can find no difference between operating in with one or two hoses myself https://news.ycombinator.com/item?id=24025482 .

tgsovlerkhgsel4• 6 years ago

Split units and hose-based portables are rated on different scales afaik.

fomine3• 6 years 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• 6 years 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-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.

arkanciscan2• 6 years 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.

sizzle2• 6 years ago

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

dzhiurgis5• 6 years ago

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

oogetyboogety• 6 years ago

Love the "plant growing forum" reference

Hacking Portable Air Conditioners

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