
Home Office Projects Series: Air conditioner setup - gcds
https://www.techprowd.com/home-office-projects-series-air-conditioner-setup/
======
rsync
Having individual heating and cooling units ( _per unit gas heaters!_ ) is
stupendously inefficient.

I travel in Asia fairly regularly so this isn't new to me, but even after all
of these years I can't believe I continue to see shiny, brand new "high end"
condo buildings in Hong Kong, Shanghai, Tokyo, Seoul, etc., with individual AC
units hanging out the window.

Contrast this with a condo in Minneapolis that I own wherein heat and AC are
central in the building and individual units can set their temperature to
whatever they like - all run with tremendously higher efficiency.

It was explained to me once that there are Asian (specifically, Chinese)
attitudes towards thrift that make it inconceivable/impossible to pay for AC
that someone else might be using (or misusing). I don't know how true that is.

What I do know is, my building in MPLS looks very nice without several hundred
crappy boxes hanging out the windows.

~~~
ClumsyPilot
When I moved to UK I was shocked that each house amd apartment (!) has a
separate gas boiler, a device that need maintenance, takes up space, makes
noise and regularly kills people with carbon monoxide. I then met a person who
lost a loved one to that thing!

In Russia and Czech Republic we have district heating, you just get billed for
the amount of hot water consumed. Some of that heat comes from industrial
sources or nuclear power-plants.

Even where it's coming from a giant gas boiler, they can be efficient combined
heat and power units. Ofcourse, some of that infrastructure is old, but a rich
western country should be able to do even better.

We'd only have a boiler in rural areas, to have them in apartments is just
madness.

~~~
bserge
Yeah but there is no such infrastructure in most of the UK, so it would be a
big and expensive undertaking to build it.

Individual gas/electric boilers are a pretty good solution. Maintenance isn't
that hard, though legally you need a Gas Safe certified technician to do
everything, and they're smug, expensive, slow, and not all that smart tbh. But
because there's no competition you have to put up with that :D

That was the most frustrating thing for me - I could do everything myself, but
wasn't allowed to.

~~~
ClumsyPilot
For apartment blocks it's particularly silly because you can install a single
device in the basement at the time of construction. Some newer blocks have it.

UK housing stock is in desperate need of upgrades, most houses are literally
bleeding money through the walls because of poor insulation, and because
heatpumps are much more efficient that boilers.

Consider that they are more economical when supplying several houses, pay for
themselves over time and that interest rates are zero. It becomes obvious that
we need a large-scale program of energy efficiency upgrades, it would create
jobs during a recession and help address climate change.

~~~
martinald
My new build flat in London has district heating like you describe. It's a
complete nightmare and I wish I could get rid of it.

Firstly, it's incredibly expensive. There's no regulation on the price you can
charge for heat, and there's no competition for supply like gas and electric.
So the apartment freehold owners charge eye watering fees for it. I could save
probably 50-75% a month even paying for the cost on a new boiler, plus a
service package.

Secondly, there are a lot of outages. Much more than I've ever experienced
with standard boilers.

The outages are quite literally out of your control, unlike a gas/electric
boiler where you can get someone to fix it out of hours. One particularly bad
outage was nearly 48 hours in winter over a weekend, caused by incompetent
building management and a seeming inability to get highly specialised parts
from Germany to the UK to fix it on a weekend.

I've obviously had normal boilers break down but usually they can be fixed in
a couple of hours, at least temporarily enough to get a proper fix sorted.

------
bradlys
Someone said Japan used to be in the title - and now that it isn't - I think
it should go back. HN is mostly a US based website (with an emphasis on
Silicon Valley). This methodology is wildly uncommon in the US. There's very
little likelihood this kind of thing would happen in well over 90%+ of the
USA.

First off - if you're renting - you're not putting holes in the walls that go
to the exterior and there certainly aren't any already existing. I've never
seen or heard of that in the USA - particularly for apartments. Secondly -
you're not hanging air conditioning units off the exterior walls of the
apartment (rental or owned - you don't own/rent the exterior and ain't no
residential building consenting to that shit). If you had a balcony, that's
where it'd go, at best. Thirdly - where's your power coming from!? Most of
these units are 220V and usually there is only one or two 220V power outlets
in American homes these days and they're always dedicated to the washer+dryer.
Maybe you have a third for an electric oven/stove. (Or an electric water
heater) You'd have to run new power lines and that involves tearing up the
walls. You could try to find 110V mini-split AC units but they're pretty
uncommon in the USA (and much less powerful). As well, not having that AC on a
dedicated breaker means you'll be giving up all other outlets on that breaker
whenever the AC is on, which could be a lot of essential outlets in esoteric
places.

Great insight for someone who lives in Japan and someone who wants to see what
it looks like to install AC in Japan. Put it back in the title!

~~~
outworlder
> Most of these units are 220V and usually there is only one or two 220V power
> outlets in American homes these days and they're always dedicated to the
> washer+dryer.

Meh. Only relevant if you need to pull more than 15A or so. There are plenty
of portable air conditioners for sale in the US and most are happy with 110V
and less than 15A.

> HN is mostly a US based website

This sounds like gatekeeping. There are lots of readers from all around the
world.

> Secondly - you're not hanging air conditioning units off the exterior walls
> of the apartment

In the US. This is not particular to Japan. In fact, I'd argue that this is
the most common air-conditioner setup worldwide, with building in many
countries providing supports for either split systems or, more commonly,
'window' units.

~~~
brendawalsh
These minisplit units are typically, at least 9k to 12k BTUs, and if it a
multi-zone unit it can be 24k or more.

I have yet to see a portable AC in the US that is more than 12k btus and as
quiet as a mini-split.

Mini-splits are more popular now in the US, but, for whatever reason, the US
is really into ducted systems.

I never understood why putting an air duct in a hot attic and an air handler
in a hot garage made any sense.

You do have me curious on traffic stats for HN by country, though.

~~~
twblalock
A lot of central AC installations in the USA were added to the house some time
after it was built, and the heating ducts were already there, so now they are
used as the AC ducts too.

~~~
brendawalsh
Do you have any more info about this?

I am curious about the history of residential HVAC in the US.

~~~
twblalock
I only really know about it in the area where I live. AC was not generally
included in new construction in the San Francisco Bay Area until the 1980s or
1990s. I wouldn't be surprised if a majority of apartments in the area still
didn't have AC, based on the amount of window AC units I see.

However, most homes built in this area were built central ducted heating
systems since the 1950s-1960s, when there was a massive building boom. Most
older homes have had central heating added as a retrofit decades ago -- even
old Victorian homes. So when people upgrade to AC today, it's very common to
just use the same ducts.

It's not easy to find a house with a ductless mini split AC system around
here. Most homes have a single-zone central system that cools the entire
house.

------
calvinmorrison
I like that the schematics are included on the air conditioner. I have a few
older appliances like this that have it, and it has helped me a few times
replacing/diagnosing parts.

I laughed a bit where he explains about "Humidity" and the temperature. I know
Americans are fat and lazy and love our AC's, but if you spend any time on the
east coast, it's a giant swamp. Life is pretty insufferable without an AC when
you are sitting inside all day working - and newer buildings are not designed
with passive cooling in mind. I'd like to thank my forerunners for sucking it
up but I basically keep my 3 window unit AC's on from June-Sept in
Philadelphia.

~~~
7thaccount
In Louisiana and Arkansas (probably several other states), the temperature can
get over 100 Farenheit with super high humidity. This leads to "swamp @$$"
without copious amounts of AC. Being comfortable requires AC in the home, car,
and at work.

In highschool gym class we would just sit in the shade under the bleachers
during the summer (too hot to do anything) and be dripping sweat everywhere
back in class. It was miserable.

It's just so miserable during the summer. The downside is that I'm only used
to temperatures between 69 and 74 Farenheit, so I would be miserable in some
place like Germany where they just live with the heat for a few weeks each
year. I rented a house in Portland once without AC and it was during a heat
wave. I'd douse myself in cold water, sit under the fan, and get very little
sleep.

A hurricane just hit Louisiana and the grid damage has been extensive (worst
on record) so no power or AC. My mother's house is 85 degrees inside at night
so she's sleeping in her office which is in a nearby town with power. I
haven't seen the numbers yet, but typically a lot of elderly people die in
these conditions without AC.

The hurricane hit last Thursday I think and these are the current outages
still in effect. Normally we would have power again in a couple of days in
most non rural areas. The fact that it's been a full week and could be out for
two more weeks is just unheard of.

[https://poweroutage.us/area/state/louisiana](https://poweroutage.us/area/state/louisiana)

~~~
kijin
We love to romanticize the past, when people supposedly did fine without
energy-wasting gadgets.

The oft-forgotten truth is that people in the past just died more. And still
do, in many parts of the world that are surprisingly close to us.

~~~
Scoundreller
And are/were substantially less productive.

When Singapore developed, the first thing the PM did was install A/C in all
government buildings.

[https://www.vox.com/2015/3/23/8278085/singapore-lee-kuan-
yew...](https://www.vox.com/2015/3/23/8278085/singapore-lee-kuan-yew-air-
conditioning)

------
bemmu
I also live in Japan, and recently bought 3 new air conditioners, but my
instinct was the opposite: forego anything "smart".

For tech like that I want it to be as dumb as possible so that there are less
things that can go wrong with it. As a bonus the dumb ones are much cheaper as
well.

~~~
gcds
Those 2 AC's there almost the cheapest models you can buy for 6 tatami size
and iirc they were 39k/ea. I needed to buy those modules extra to make it
"smart"

~~~
bemmu
Nice, your now smartened ones are actually cheaper than our dumb ones then. I
was looking at CS-220DFR, also for 6 tatami, for which the best price on
Kakaku is 49k (tax inclusive).

But in the end we got three Daikin ones from our moving company, because their
prices were similar (actually almost felt like we get the moving service as a
bonus), and it seems very convenient to have one company do everything.

Curious to see if they try to sneak in some extra fees at the last moment,
because as it is I wonder if they're actually making a profit with us.

~~~
gcds
Exacatly my 30k install cost for 2 ACs were high already after all works they
like so it will be 15k extra I am like WHUT but oh well it's japan next time
going to rent tools for 5k and materials for like 10k max.

My unit CS-229CFR with tax I think was 42k or similar and model to make it
smart was +5k so it was still cheaper than cheapest smart model

------
sergers
Is this really specific to Japanese air conditioners? Or is this really about
mini-split ac that are manufactured around the world under many companies.

I don't see whats specifically Japanese outside of the person using Panasonic
and is in Japan.

The person could be in the USA with Mrcool mini split, it would be a similar
article.

Edit: title has been changed to remove mention of Japan, so my nitpick may no
longer valid:)

~~~
agwa
I've never seen an apartment building in the US with special pipes for running
the refrigerant lines. It's just not feasible to install a mini split in the
US if you're renting, but it appears Japan is totally set up for it.

~~~
gcds
Impossible to live without AC in Japan. Also almost every move company can
remove/install AC's pretty easily so it's kinda convient.

Also if all rooms already have installed AC's then apartment rent price is
much higher than similar without it so it's 50/50 what you want.

~~~
driverdan
> Impossible to live without AC in Japan

Come on. People lived there for thousands of years before AC.

~~~
sandworm101
Not in highrises. Not in megacities.

~~~
fomine3
Even in rural area, temperatures in this August is sometime 36-40C (or even
high) so cooler is mandatory.

------
mc32
What I’d like to know is how they safely pipe gas to all apartments given the
occurrence of earthquakes. Does the main valve auto shut off in the event of
tremors above M3 of something?

~~~
gcds
There is heavy measures regarding that topic. One is Gas Meter turns off all
the gas when earthquake happens. Second I think all pipes are flexible so it
wouldn't break from earthquakes

------
dvcrn
I did a much easier solution for my airconditioner (also in Tokyo so
everything OP said applies): I bought a broadlink rm mini3 (IR emitter) for
<$30 and hooked it up to homebridge using homebridge-broadlink-rm [0]. Then
went ahead and recorded all signals my aircon remote could send and put it in
an excel sheet for safe-keeping. Next, plugged the IR codes into the
homebridge plugin, put the small device in line-of-sight with the aircon and
tadaaa, my old ghetto aircon is now smart.

For getting the temperature of the room, I use other devices (a netatmo
weather station) and used their API to pull the current degrees into a
textfile on the server that is getting fed into the airconditioner plugin.

Bonuspoint: I use the same IR emitter to control my TV. I just have to make
sure it's in a place that is in line-of-sight with both my TV and aircon, but
given how small apartments here are - that was not a problem. The plugin has a
functionality to frequently ping an IP for checking if something is turned on,
so I use that to determine whether my TV is on/off.

[0]: [https://www.npmjs.com/package/homebridge-broadlink-
rm](https://www.npmjs.com/package/homebridge-broadlink-rm)

~~~
wlesieutre
You may not even need direct line of sight, as long as the TV can see what
your remote is shining on. I know my remotes work from behind obstacles if I
just aim them up at the ceiling.

There are also inexpensive IR repeaters, intended to let you have your AV
equipment stuffed in a closet and still be able to use all the remotes.

~~~
dvcrn
Oh nice! I know virtually nothing about IR so this is good information,
thanks!

------
roel_v
Should've bought Daikin A/C's - their network bridges speak HTTP with a simple
REST service. Highly recommend, it was very easy to integrate them into my
home automation setup.

~~~
Nextgrid
A lot of consumer-grade ACs use IR-based remotes which can easily be connected
into whatever automation solution you have with something like a Broadlink
bridge.

~~~
roel_v
You can't query those for the current room temp, current settings etc. So then
if you mix the OEM app & your home automation app, things get messed up. IR
bridges are a hack in home automation, when buying new stuff avoid them.

~~~
squeaky-clean
Just my personal opinion, but the thermometer on an A/C unit is kind of
worthless unless you sit within a foot of the unit. I prefer being able to
read a sensor on the opposite side of the room, or even several sensors
throughout the house, rather than one on the A/C unit. I don't use any OEM app
at all, just my own. The OEM ones never do exactly what I want, so I have to
hack something additional onto their features anyways. Home automation systems
are really personal anyways though. I'm sure anyone here who's implemented
their own has their own unique opinions about what's best ;)

~~~
fomine3
Now premium A/C unit in Japan like from Mitsubishi Electric features high
precision temp sensor to detect room temperature. Even middle model has good
sensor rather than simple temp sensor.

[https://www.mitsubishielectric.co.jp/home/kirigamine/product...](https://www.mitsubishielectric.co.jp/home/kirigamine/product/z/feature/convenient.html)
[https://www.mitsubishielectric.co.jp/home/kirigamine/product...](https://www.mitsubishielectric.co.jp/home/kirigamine/product/z/img/feature/convenient/img_05.png)

------
djanogo
Where are the refrigerant lines, how did they run them from compressor to
evaporator?, I thought the biggest issue with AC self install is filling the
refrigerant and sealing those lines.

~~~
pwg
> Where are the refrigerant lines, how did they run them from compressor to
> evaporator?

Look at this image from the blog post showing the post install view:

[https://www.techprowd.com/content/images/2020/09/image-24.pn...](https://www.techprowd.com/content/images/2020/09/image-24.png)

Notice on the left edge there is a large white "pipe" running from the
evaporator unit down to a hole in the wall (the hole was already present and
visible in other photos). The refrigerant lines are running inside that white
cover and through that hole to the outside unit.

> I thought the biggest issue with AC self install is filling the refrigerant
> and sealing those lines.

As for the refrigerant fill, yes, that is the part of the work that most DIY
folks will not have the equipment to perform. The evaporator and compressor
units for most of these mini-split units come prefilled with refrigerant plus
enough extra for X length of tubing (I forget the length X at this time). The
install basically involves installing the lines, evacuating them
(refrigeration grade vacuum pump needed here) and then opening the shutoff
valves in the two units to release the already present refrigerant.

Since most DIY's will not have a refrigeration grade vacuum pump, and are
unlikely to be able to justify the several hundred dollars for one for a one-
off install, this is the point where the DIY'er would need to call a
professional for the final completion of the install.

~~~
Scoundreller
> refrigeration grade vacuum pump needed here

My understanding is that some of the DIY units had a built-in vacuum pump for
this step.

Edit: never mind, I think I’m making stuff up in my head. But I could see it
being a feature in the future.

What makes a vacuum unit “refrigeration grade”? Other than recovering what
you’re vacuuming if you’re doing maintenance instead of a first install?

~~~
pwg
Generally what makes it 'refrigeration grade' is the level of vacuum down to
which it can pull.

Here are some examples of refrigeration vacuum pumps:

[https://www.grainger.com/search/hvac-and-
refrigeration/air-c...](https://www.grainger.com/search/hvac-and-
refrigeration/air-conditioners-accessories/air-conditioning-chemicals-tools-
and-accessories/air-conditioning-and-refrigeration-tools/refrigerant-
evacuation-pumps?ts_optout=true)

------
lxe
I just did a DIY install of a mini split AC, including running electrical and
the refrigerant lines, having never done so before. There was a whole "hidden
side of the iceberg" to learn besides just the controller parts of how it
works. The unit cost was ~600 while the install would have been ~1500, so I
was betting that if I mess up catastrophically I could replace the whole thing
once or even twice.

~~~
OnACoffeeBreak
Did you have to get your work inspected? Where I live in the United States,
the electrical lines would have to be inspected for compliance with building
code, and I am not sure about the HVAC lines.

~~~
lxe
Electrical needs a permit, but AC is not a necessity apparently.

------
phantom784
I wish those holes for refrigerant lines in apartments were standard in the
US. My apartment in the bay area has no AC and furthermore doesn't allow
window units, so I'm stuck with inefficient portable units. I'd love to be
able to just put some mini-splits in (and I'd probably still come out ahead
over renting a place that comes with central AC).

------
boxed
Just by luck before the pandemic hit I installed ground heat exchange with
cooling for my house. This is so efficient the cooling is _free_. How do you
ask is that even thermodynamically possible? Well all the heat from the
cooling is used to heat the hole, which you get back in cheaper heating of the
house from the same hole in winter. It's amazing!

------
esaym
I find it odd that for heat he only mentions units external from the a/c. The
'cu-229cf' unit he bought seems to be capable of heatpump mode[0].
Nonetheless, I really hate mini-splits. They always have really thin intake
air filters that really don't filter anything. Thus the insides of the indoor
unit are always caked in layers of dust and mold.

[0]:
[https://panasonic.jp/aircon/housing/products/19f.html](https://panasonic.jp/aircon/housing/products/19f.html)

