
Cooling a house without air conditioning - lots2learn
http://www.bbc.com/future/story/20190822-are-there-alternatives-to-air-conditioning
======
simonsarris
A lot of the need for AC (and having lights on) is just really, really bad
modern house design. I recently finished building a house (my first one) and
everyone acted like I was crazy for not building in central air conditioning.
(This is in New Hampshire)

I built in an older style, with windows on every side, with a mind towards
ventilation and light. Inexplicably most houses in the area, even $500k+
houses do not have these two things. My mom's condo has central air but the
system is so feeble and the venting upstairs so poor that two bedrooms in the
house remain stuffy anyways. It seems like light and natural ventilation are
not even afterthoughts, but non-thoughts, and the designs all rely on electric
light and forced air. Its amazing being in an expensive home where you need a
light on in the kitchen at 8am. How do they decide what to build?

I built 9 foot ceilings on the first floor and 8.5 on the second. Then I
placed the attic (3rd story) door centrally in the upstairs hallway. The
result of the design is that airflow moves on the first floor in all
directions, and upward, and on the second floor can move _at least_ east-west
(bathroom and hallway windows), and also north-south if bedroom doors are
open. Finally, air flows upwards to the attic, which has windows north-south.
So winds should suck air higher, and out.

If I close windows in the morning and open around 7pm, the result is that the
house stays very cool, about(? only tested with temp gun a few times) 74
downstairs and 76 upstairs during these 90 degree days, and then gets cooler
at night as I open windows again. So far, I've only bought one fan, though
things might work better with more. Note I'm not an expert or an architect, I
just included some design features that should be obvious to anyone who's
lived in an old house for a summer.

This takes some manual control, but there are far fewer parts to maintain
(this was a general design goal beyond AC), and summer electric bills are
$50-60/month. With this design, there have been 3 icky-hot days so far this
year, when there was no wind and the night did not get very cool.

~~~
Shivetya
there are two common mistakes in many modern implementations of central air.

the first is the hardest to get done as most hvac companies resist, having the
exhaust not be at the exact end of the the pipe. the pipe should end just
beyond it.

the second is not having a return or sufficient returns in each room. if you
are stuck with a central return then make sure doors are open if the room has
no pass through vent to the hall with the central return; at most the master
bedroom will have pass through vents to a hall so the door can remain closed.

the only omission from my current home is an attic fan but building codes
precluded it at the time but I hear I can do it now if I want.

still I find even with central air a lot of comfort can be found by having a
dehumidifier. down in the south it is not uncommon to wake to humidity higher
than the temperature which makes it feel sticky and uncomfortable.

with regards to cooling needs and such, we simply have changed what we want
and want we are willing to tolerate. its not a bad thing, we just have to find
efficient ways to have it.

~~~
skellington
Building very tight house with good insulation is the key. Then of course you
need an ERV to keep the air good and a separate dehumidifier is also great.

~~~
kaybe
If you have cool nights and your heatwaves don't last too long large thermal
mass is also very good and can be enough.

------
lxe
Major function of AC is humidity control. If you have humid summers, AC will
help your house to stay dryer and prevent mold and other damage. There are
climates in which AC is essential and even the most advanced thermal and
airflow design can not replace conditioning.

~~~
ZeroFries
I was told many times to go with a slightly undersized AC, precisely for this
reason - they're better dehumidifiers because they run for longer periods of
time.

~~~
hellofunk
Why would an undersized air conditioner be more effective? What’s the size got
to do with the efficacy?

~~~
showdead
Less effective at cooling, more effective at dehumidifying (it seems there is
a presumption that dehumidification is roughly linear with operating time.)

~~~
toomuchtodo
AC units also last longer if they run continually vs frequent starts and
stops.

~~~
throw_away
Why not just buy a dehumidifier made specifically for this with collection
bucket and all?

~~~
wasdfff
That bucket can fill in a day and click off the machine sometimes.

~~~
Johnny555
Some (all? most?) dehumidifiers can accept a hose connection in place to the
collection bucket, my parents have one on a raised shelf in their basement and
have the hose drain in the laundry sink -- no need to empty the bucket.

------
lhorie
Not everyone has the time and energy to build their entire house, but I found
that one relatively easy thing that helps a lot is attic insulation and a bit
of DYI. It turns out that contractors often do really shoddy work when it
comes to insulation because it's exceptionally easy to skimp on materials to
save money: they buy the cheap fiberglass stuff and they use too little of it.

You can buy 15-20 bags of cellulose insulation and rent the blower machine
from home depot, and you can do the whole attic in a few hours yourself.
Including a rental van, that cost me around $600.

This alone made a noticeable difference in my house in Toronto (where it can
easily get to 32°C/90°F in sun in the summer)

~~~
throwaway6734
This is next up on my todo list.

Any particular advice/pain points for re-insulating an attic with cellulose?

~~~
lhorie
It's actually surprisingly simple to do.

If you've never done it or seen it done before, my only real advice is break
up the cellulose into fluff _before_ you put it into the blower machine, and
put little bits gradually and slowly rather than stuffing it to the top. My
wife thought she could shove a whole bag inside and have the mixing blade
break it up, but it clogged the machine instead, and I had to waste a couple
of hours unclogging the tube.

In terms of applying the insulation, you just want it to be thick, fluffy and
somewhat even.

Other than that, just captain obvious stuff:

\- you need two people (one in the attic and one feeding the blower machine)

\- start from the edges towards the manhole

\- use a respirator mask

\- stay hydrated and take breaks if you need to (the attic is surprisingly
hot)

~~~
zonidjan
The worst mistake I've ever made in an attic was doing cable runs (TV to the
bedrooms) on a summer day in Texas. Sure, we started when it was cool at
7am... but we finished around noon.

So, to add to that: do it on a nice day in spring or fall.

------
bradlys
This article isn't so much "cooling a house without air conditioning" \- it's
more "here's some designs for houses that can be cooled without air
conditioning".

This has very little to no help for existing homes unless you have a large
budget to demo your existing home/yard/surrounding-infrastructure. For a
perpetual renter such as myself (bay area lifestyle), this is useless
information.

Where I live in the bay area - we live in a greenhouse of an in-law unit. Only
solution to cool it without AC would be to tear it down and build something
different. I can't even keep the top room below 80F on quite a few days with a
window unit I installed. That unit is rated to do over 2x the size of the room
too but it can't keep up. On days we know it'll be 95+, we leave the AC on all
day. Otherwise, the heat soaks into the walls so much that we can't cool the
house down after we get home and it'll still be 85+ in our bedroom past
midnight. Opening windows has no effect since we can't get an effective cross-
breeze.

I feel bad about it but I don't have much of an option if I want to be
somewhat content. I get quite unbearable to be around if I am suffering in the
heat.

~~~
Johnny555
As a renter you can look for a more energy efficient space.

If your in-law unit was built without permits (which seems likely since it's
apparently below-standard for insulation), you can probably get out of your
lease early if you wanted to.

Putting in more insulation doesn't require a full teardown, but it's not cheap
if you had to, say, build false walls to add insulation.

~~~
bradlys
More energy efficient space -> remodeled recently -> $$$$$.

I'm not able to afford such a thing. Most apartments/in-laws in my price range
(<$2500/month) were remodeled no later than 1970.

Putting in insulation means you have to take down the dry wall (if it is even
drywall - might not be). That's pretty extensive for most people.

~~~
kyriakos
In most European countries building energy efficiency is required by law and
anything under a certain rating cannot be rented forcing owners to renovate
with energy efficiency in mind

------
nostromo
The funny thing about solar panels is that just having panels above your
ceiling cool your house a ton.

It makes me wonder if people in hot climates that can't afford solar shouldn't
just put white glossy panels a foot above their roof.

There are a lot of other obvious, non-exotic things we can do, like require a
certain amount of tree coverage and reduce the spread of concrete surfaces. We
could also use shade sails a ton more than we do (which are nice because they
can be removed in the winter).

~~~
Loughla
Honestly, when we re-roof our home when the shingles go, we're putting on a
white roof. I'm sure it will tank the resale value because it will be the only
white roofed home in my county or even region, but the cost savings on cooling
has to make up for that, to me.

~~~
pkaye
You can get light grey shingles. Might look fine if it works with the paint
color of the walls.

~~~
kaybe
I'm thinking about the non-visible wavelength ranges. Changing the IR
properties might be very helpful as well.

~~~
pkaye
Is there a particular brand you are considering? I'm planning to change our
own roof in a year or so.

------
mabbo
I was in Phoenix last summer in what (to my poor Canadian body) was the
hottest day ever, anywhere. I think it was like 111F / 44C. While my friends
and I were over at an outdoor mall looking for dinner, we entered a spot that
was more than 10C lower than the ambient temperature. Just instantly colder. I
honestly stopped in my tracks.

Above us, a mister was spraying water. None of the water was coming within 10
feet of the ground as it all instantly evaporated- Phoenix is a desert- but in
doing so, the air was chilled. The cold air dropped, cooling this small area.

I cannot believe just how effective this means was. Now, granted, to do this
they had to waste clean fresh water in the middle of a desert, which isn't
great. But it does go to show the potential of some of these tricks. May not
work in 99% humidity, mind you, but there are other tricks up the sleeve of
the clever engineer.

~~~
ebiester
It's called evaporative cooling, and until recently the principle was the way
the vast majority of Arizonans cooled their houses. (They are called swamp
coolers down there.)

It only works in dry climates, but it makes such a difference.

~~~
cr0sh
Also - it only works for part of the summer; we're in our so-called "monsoon
season" right now, and humidity is highly variable, but is generally above
what most evap coolers will help with.

However, if there is some evaporation that can takes place (that is, the evap
gradient is large enough to let it happen, but directly using that cooler air
would make it uncomfortably humid), you can instead do what is called
"evaporative chilling" (or something like that), where you run the water over
a radiator, and the water evaporates, cooling the radiator (actually, removing
the heat), and inside the radiator, you run coolant/water mix - that's your
outdoor side. Inside you have another radiator, with a fan circulating air
over it. It's something like an A/C system, with water/coolant as the "working
fluid" and no compressor, just a pump. Think of it like a "dry evaporative
cooler".

This kind of system does work - it's actually used for industrial A/C systems
as some kind of "pre-chiller" or something, but it isn't something you can buy
for a home that I know of - but you can build it. But like all evap systems,
once the humidity gets too high, it stops working.

Another kind of system that can be used here in Arizona, but few do because it
is ugly, big, and works only so well - are something called "solar chimneys".

The simplest is just a large 2-3 story structure painted mostly white at the
bottom and mostly black toward the top; the idea is that the sun warms it,
sucking air thru it and out the top - the bottom end is connected to the
house, to make a "forced draft" through the house.

The better way is to make a similar "chimney" on the opposite side of the
house and add cooling pads and a fan at the top (basically a large diy swamp
cooler). Misting can also be used. So you evap cool the air, which falls,
enters the house, then is sucked up and out the other side by the "hot"
chimney.

Another "hot climate" design for cooling is something that used to be found
all over the middle east:

[https://en.wikipedia.org/wiki/Windcatcher](https://en.wikipedia.org/wiki/Windcatcher)

Sometimes used in combination with:

[https://en.wikipedia.org/wiki/Qanat](https://en.wikipedia.org/wiki/Qanat)

As you can see, this is basically the ancient form of "solar chimneys" \- if
we instead used these in Arizona, coupled with either monolithic dome
construction and/or rammed earth, and below-grade construction (to take
advantage of earth insulation and cooling) - it'd be so much better for energy
use here in Arizona.

~~~
ebiester
Oh, this irritated me so much growing up in Tucson. I would read about
something like passive water heating, or all of the ways we could reduce our
need for AC (even back growing up where climate change was more theoretical)
and saw that people didn't care.

------
elicash
I only use air conditioning once or twice a year (in DC). This article was
very interesting, but if you can't rebuild your home you have fewer options.
Here's how I deal with it to make it not miserable.

1\. You don't need to cool "a house" \- just the room you're in. If I _do_ run
the air conditioning for 20 minutes before bed, I'll block under my door to
keep that cold air in.

2\. If there's no reason for you to be in a hot house, then don't be. If I'm
teleworking, I end up not just being cooler, but also happier, if I find a
nice quiet spot somewhere else. I'm lucky enough that I have a free museum not
far from me that has an indoor courtyard I can work at.

3\. Air circulation and window fans that expel heat from the room can do a
lot. Fan quality and fan placement is tremendously important for circulation.

4\. At least the last two minutes of your shower should be cold.

5\. Blinds should be closed during the day.

6\. Drink lots of water, of course.

I think there's more I can probably do. For example, I've been meaning to
research reflective blinds to see if they do more than normal blinds at
keeping out heat. (Shutters aren't an option for my building.) Dehumidifiers
are also something I want to look into.

I haven't personally found that bed sheets make much of a difference, outside
the way too obvious things like I don't use my winter (flannel) sheets. But
this might reflect that I only buy nice ones.

~~~
wil421
Come to Atlanta and try it. My upstairs will get 80 degrees in the morning
easily. My wife and my offices are upstairs. Luckily I have 2 units so I can
balance it. Even if I didn’t use AC I would have mold problems due to
humidity. Dehumidifiers also warm up the room they are in. The only plus is I
have lots of tree cover in the afternoon.

~~~
horsawlarway
I'm in Atlanta. We live in a house built in the 20s just south of I-20. Thick
brick walls on all sides, windows laid out so you can create a relatively
strong breeze by opening the front and the back windows.

Most days we can leave the AC off. Temps will climb to about 75-76 by mid-
afternoon, but rarely get too far above that.

The only part of the house that absolutely needs the AC is the upstairs
converted attic. It was renovated in the 80s with no thought to air flow, and
no way to get a cross breeze from the windows. So we have a mini-split we can
run for that floor.

The house is going to feel warm if you're used to running AC 24/7, but 2 weeks
in and 76 with a breeze feels fine.

I understand where you're coming from, the last place we lived was a more
modern ranch house near Morningside, with bad layout for airflow and it was
MISERABLE in the summer (routinely 90+ by 11am if the AC was off).

I'm just saying design matters a lot here, and makes a big difference. There's
nothing special about Atlanta that makes that any less true.

~~~
wil421
Ranch has better cooling but I actually pay less in my new house compared to
the ranch I was in. The ranch I was renting had roof issues. My new place is a
2 story house with half basement and garage underneath. 3 sided brick. Bought
a place in Roswell to be closer to work and family.

My wife is almost 9 months pregnant and AC is mandatory!

------
lukifer
If you live in a dry climate (I'm in Colorado), consider a swamp cooler. It's
an amazingly simple and efficient machine: just a water pump and a fan, and
peanuts in electrical costs compared to a full air conditioner. As long as you
can establish airflow throughout the home, it feels just like A/C on days
below 95F; you won't feel chilly on 95F+ days, but it's still quite livable.

~~~
bhhaskin
I have a swamp cooler in Reno NV, and on 95+ days if I leave it on all day on
max the house will be 60-70 degrees. It works so well I rarely run it on max
settings as it just gets too cold. Of course there are some draw backs like
swelling due to the humidity, and if there is smoke in the air I can't run it.

~~~
ulkram
curious why can't you run it if there's smoke?

~~~
bhhaskin
It pulls in air from outside. So if their is smoke in the air from a wild fire
then it will just fill your whole house with smoke. So you can run it, just
highly ill advised.

~~~
adrianmonk
What about dust storms? Seems like some areas in the American Southwest (AZ,
NM, West Texas) are dry enough for swamp coolers, but they also can have these
insane dust storms that are so intense you can't see to drive on the highway.

------
JCoder58
The Earthship[1] were designed to solve this problem (among others).

[https://en.wikipedia.org/wiki/Earthship](https://en.wikipedia.org/wiki/Earthship)

~~~
icebraining
Fun factoid: Joey Hess (Debian developer & creator of git-annex) lives/lived
in one:
[https://joeyh.name/blog/entry/hackerholler/](https://joeyh.name/blog/entry/hackerholler/)

His blog has occasional experiments with off-grid and low-power living.

------
saiya-jin
Persians know for millenia how to store _ice_ in scorching desert [1] and have
in places like Yazd 'windcatchers' [2]

I've seen through Islamic world and India buildings at least 500 years old
that were constructed around constant air flow through buildings, having
patterned stone mesh windows. It can be done with low tech approach.

[1]
[https://en.wikipedia.org/wiki/Yakhch%C4%81l](https://en.wikipedia.org/wiki/Yakhch%C4%81l)
[2]
[https://en.wikipedia.org/wiki/Windcatcher](https://en.wikipedia.org/wiki/Windcatcher)

------
non-entity
My question: Is it healthy or safe to live in a house or apartment that has no
working AC in areas like the southeastern US. I know AC is a modern luxury and
that people survived for years without it, but I wonder if the design and
construction of later houses or apartments affects anything. My AC
ritualistically dies every summer and while I wait for maintenance to drag its
feet, I often find myself waking up in pools of sweat

~~~
kalleboo
When really bad heat waves hit Europe where home AC is rare, they can kill
thousands (mostly elderly).

The 2003 heatwave killed upwards of 70,000 people (in France, 8 consecutive
days of 40°C [104 °F], in the Netherlands it reached 37.8°C)
[https://en.wikipedia.org/wiki/2003_European_heat_wave](https://en.wikipedia.org/wiki/2003_European_heat_wave)

~~~
neaden
This is what really scares me about cities like Phoenix, that can get so hot,
have a high elderly population, and are increasingly vulnerable to blackouts.
What is going to happen if the city loses power on a 110 degree day?

~~~
TheOtherHobbes
Some of them will die.

It's that brutal. It's also something people used to do a lot of, especially
if they were working outdoors.

I've seen house designs for the South which have an open central corridor. It
catches and channels any wind and helps cools the rooms on either side.

I'm sure there are other tricks, but builders don't seem to know them any
more, and architects build more with a view to looks than practicality.

Modern architecture - whether it's McMansion design, concrete box design,
glass tower design, or suburban vernacular design - can be almost criminally
stupid about environmental issues.

There are exceptions, especially in the occasional environmentally controlled
low-energy office block.

The reality is that it's possible to manage heating and cooling far more
intelligently and effectively in most kinds of buildings. But it's considered
a fringe eco-hippy interest and not something most of the population needs to
care about.

~~~
cr0sh
> But it's considered a fringe eco-hippy interest and not something most of
> the population needs to care about.

Here in Arizona, if we built things for cooling more like in the middle east
(windcatchers/solar chimneys/qanats + thick walled rammed earth and/or
monolithic domes), it would probably be more energy efficient.

But I can't imagine that style would go over well with our current (overall)
political climate here...

------
haunter
Thick stone walls (well brick). I live in Hungary EU, lot of old houses (early
XXth/late XIXth century or earlier) has really thick stone walls. In the
summer it keeps the house cool (as long as you close the windows and shades)
and in the winter it keeps the warm inside. Even if the temp outside is +35c
the inside is between 23-25c (or even less)

~~~
scott_s
As I understand it, the difficulty with this approach is that it depends on
the night being significantly cooler than the day. Heat from the day can
radiate away during the cooler night, preventing cumulative heat buildup in
the stone, which acts as an insulator. But one of the effects we're seeing
from climate change, even in Europe, is that nights are warmer as well.

(This was discussed recently on an HN thread, but I can't find it.)

~~~
noir_lord
Just got back from Rhodes in Greece and their architecture is interesting
(given that day time temps where 32-35C and night time temps 27-29C) -
everything was built thick and massive with overhangs on any windows that get
sun, shutters on every window during the day (and AC but often off) and
everything was painted white (or very pale shades of blue, yellow or pink).

It was interesting to see how they've built to adapt to their environment.

We had a north face hotel room and with the massively thick walls and double
glazing (plus no direct sun) the room was just about bearable at night even
without the AC (which was actually outputting much less cold air than the AC I
had in a hotel in Manchester this year).

~~~
cr0sh
My wife and I a couple of decades ago took a camping road trip down the middle
of New Mexico, starting near the top of the state. One of our first stops was
to visit the Acoma community, which is a pueblo built on top of a mesa; very
few people still live up there. The various "apartments" are passed down
matrilineally, which was an interesting thing to learn.

It was August, and very hot outside - well over 100F. Inside one of the
apartments on the tour, someone was selling snowcones - a welcome relief. We
went inside (had to duck under the doorway, as it was only 4-5 feet tall) and
it was easily 20-30 cooler than the outside. The only thing we could figure
was that being on top of the mesa, plus night temperatures, and the thick
adobe construction, all acted as a thermal-mass barrier system or something.
It was really amazing to experience. I honestly wish that kind of construction
was more common here in the southwest.

~~~
noir_lord
Partially the curse of cheap energy - throw up a cheap shitbox and then use
vast amounts of power keeping it cool.

Be interesting to see if that changes in a warming world, I hope so.

------
grandinj
I have found (in mild but sometimes warm South Africa) that the best bet is to
prevent the sun from getting through the windows.

Curtains/blinds are not nearly as effective as external shutters or some kind
of external blind.

I make my own frames with light coloured textile stretched across it that I
attach over the sun-facing windows, which has a dramatic effect without
completely blocking out light.

~~~
cr0sh
One thing my wife and I have done to our house, which is a regular "ranch
style" 1970s home - here in Phoenix, Arizona - is to add on our back porch
"house curtains".

Our porch faces toward the west. We have a huge mesquite tree back there that
shades the house during latter part of the day (plus our patio is covered),
but in the later afternoon, sun will shine in as the sun sets, and heat the
house up. So we strung aircraft cable with small turnbuckles and hung up
colorful polyester fabric shower curtains (this was a recent change,
originally we had used canvas dropcloths, which worked well too - but were
difficult to keep clean). We can slide the curtains "closed" to block out the
sun in the evening.

Between that, plus having double-glazed windows installed, extra insulation in
the attic, roof ventilators, and the fact that our house is of concrete block
construction (not stick frame) - while we still have to use AC, we find that
we can keep it set higher most of the time, and during the early summer/spring
and late summer/fall times - not at all (opening the windows at night and
using fans to bring in cooler air - then closing things up in the morning
before it gets too hot). It's noticeably reduced our bills, considering how
old our house is (and we have two heat pump AC units on the roof - that has
it's own interesting story, but not relevant here).

------
hilbertseries
Yes, a building in San Francisco doesn’t need air conditioning in the summer,
what a surprise. Make the same design work in Phoenix Arizona and we’ll have
something.

~~~
ceejayoz
This is a weird critique.

Even in Phoenix, the need for air conditioning can be _reduced_ by designing
houses well. As the article notes:

> Even in exposed, hot and arid climates, cooler temperatures are never too
> far away. In Jaipur, the capital of Rajasthan state in northern India,
> daytime temperatures regularly reach upwards of 40C in the summer months.
> But just a few metres below ground, the temperature of the earth in the
> region remains a much gentler 25C, even through the fiercest summer heat.

~~~
marcinzm
I'm skeptical. Jaipur, right now during the day, has 60% humidity at 90F. If
you lower your temperature with transfer into the ground then you're not
lowering humidity but only temperature. That means relative humidity will go
UP. I suspect even 80F at 90+% humidity will feel really unpleasant.

~~~
ceejayoz
> I suspect even 80F at 90+% humidity will feel really unpleasant.

That's hardly likely in _Phoenix_.

~~~
marcinzm
Your quote is about Jaipur and not Phoenix. I am responding to your quote.

~~~
ceejayoz
The article specifically indicates it (and other techniques in concert) works
in Jaipur. It's not going to work 100% of the time in all places, but even in
hot, humid areas _improvements_ can be made.

> This allows air conditioning to be used very modestly, when it is necessary
> at all.

I'm not sure why every thread about energy efficiency improvements has people
come in and do the "it's not a _perfect_ solution for these edge cases" thing.
Everyone _knows_ that already, and it's totally beside the point.

------
fuball63
I visited Savannah, GA this summer. In the 19th century houses were designed
to have tall ceilings to capture heat, and large doors to verandas to capture
wind. It was actually tolerable inside when touring these old houses.

~~~
fuball63
Also, windcatchers are pretty cool too:
[https://en.wikipedia.org/wiki/Windcatcher](https://en.wikipedia.org/wiki/Windcatcher)

------
elikozi
I thought the obvious solution is solar powered run AC. What am I missing?

~~~
psychrometer
That doesn't solve the problem of the refrigerants.

~~~
post_break
1234yf is the new refrigerant in cars. It has a global warming impact of 1,
R-134a for example has a GWP of 1430. If we move to that it won't be much of a
problem.

------
EGreg
Why not have solar panels on the roof absorb all the sunlight and keep the
house cooler via an air gap?

Furthermore, I would love to have water heating this way. Solar panels heating
a water container in the winter, that is mixed into showers and even small
pools on demand.

Any observant Jews here who don’t want to use water heating on Shabbat? This
may be a great idea.

PS: Heating a house is the only application of Proof of Work Mining that I
approve of. But even then, I would rather it be useful work like SETI or
protein folding:

[http://www.cleantechconcepts.com/2018/06/home-heating-
with-c...](http://www.cleantechconcepts.com/2018/06/home-heating-with-crypto-
mining/)

------
mariojv
There are also air conditioners that don't use refrigerated air. The
principles of it are similar to the evaporative cooling mentioned in the
article but with a fan and water pump. If your climate is dry enough to use
it, it can be a great option and much cheaper than refrigerated air. You'll
see one on the roof of almost every home driving through certain neighborhoods
of El Paso.

[https://en.wikipedia.org/wiki/Evaporative_cooler](https://en.wikipedia.org/wiki/Evaporative_cooler)

------
iforgotmypass
This reminded me of zero electricity air-con made of plastic bottles:
[https://www.straitstimes.com/world/zero-electricity-air-
con-...](https://www.straitstimes.com/world/zero-electricity-air-con-made-of-
plastic-bottles)

The hot air flowing from outside through your windows could be compressed
making it cool.

I wonder if there are existing, not so ugly commercial products providing
that. This could be a green alternative for air-conditioning.

~~~
Filligree
> The hot air flowing from outside through your windows could be compressed
> making it cool.

Compressing air actually makes it hotter, but that's not what's happening.
Forcing air through a smaller space makes it flow faster, which ironically
makes it less dense -- and hence colder.

It's the same effect that people claim holds airplanes up. (But doesn't.
That's mostly the angle of attack.)

~~~
DoctorOetker
I don't understand this heat engine yet, one it exits the bottles it contracts
again, heating up? it cools the window but heats up the air?

------
bungie4
Granted, I live 'up north' but it still gets hot in my new house. I mounted
some exhaust fans in the ceiling to pull the hot air from where it naturally
rises too. Combined with the forced air furnace fan to circulate cool air
(pulled from floor level). Finds the inside of my house 9C cooler on the
hottest days of the year.

This is especially important as the brick gets heat soaked and releases its
heat well into the night.

------
koonsolo
Maybe one of you smart people can solve this "mystery": The old farmhouses
here in the region (Flanders) were all built with their length axis on the
north-south line, no matter where the road was.

An old farmer here claims that such a house is cold in summer and warm in
winter. I once saw an architect on TV claim the same thing. But I was not able
to find any explanation for this anywhere.

------
fredley
Ceiling fans are ridiculously effective. I'd seriously consider installing one
in the bedroom after the past few years of heatwaves.

~~~
ghaff
You do need ceilings of a certain height. I live in an old farmhouse and the
ceilings are just too low.

I agree that they're great if ceiling height supports them.

~~~
amalcon
Even if you have 8-9 foot ceilings, consider a low profile ceiling fan rather
than the sort that hangs down a foot or more.

Sincerely,

The fingers of the next tall person to stretch his or her arms near your fan

~~~
ghaff
My bedroom's just over 7 feet. Old New England farmhouse :-) So a ceiling fan
doesn't really work even above the bed because I'm the tall person who will
get nicked by it.

------
mythrwy
This guy grows oranges in Nebraska using very little electricity. He mentions
in the video the same principals can be used for cooling.

[https://www.youtube.com/watch?v=ZD_3_gsgsnk](https://www.youtube.com/watch?v=ZD_3_gsgsnk)

------
codingdave
I live in the southwestern USA, and have no air conditioning. I do have a
solid brick house that is an awesome insulator. So we open up all windows and
doors at night, and close the house up tight when the sun rises, putting heavy
curtains over the windows. It still gets warm - up to 85 degrees inside on a
100+ degree day, but you get used to it.

It wouldn't work on all the suburban homes around us. The walls aren't
insulated enough, there are so many windows that you'd never get them all
covered.

~~~
jjoonathan
> you get used to [85 degrees inside]

I sincerely hope that my future places of work and residence will not
regularly subject me to 85 degree interior temperatures on the assumption that
I will "get used to it" \-- which I strongly suspect actually means "live with
it."

~~~
codingdave
> actually means "live with it."

No, it means the human body acclimates to its environment. You really do get
used it.

~~~
jjoonathan
I spent a summer at those interior temperatures without AC. I stopped
"noticing" it, but my subjective ability to focus and objective running &
flash-card-app performance did not recover until the temperatures did. How
long does it take to "get used to it?"

~~~
codingdave
A couple weeks, according to folk wisdom, which matches my anecdotal
experience.

I'm curious if you went home to cooler temperatures, or if your whole summer
was spent in warmth? I definitely have experienced harder times going back and
forth vs. always being in the warm environments.

~~~
jjoonathan
I spent the whole summer in warmth, days and nights. A couple weeks is what it
took me not to notice it anymore, except insofar as it affected my
performance. That's what I meant by "live with it."

------
bryanrasmussen
we've been living in our current house for 11 years. it is a little over a km
from the beach in Denmark, it has big doors that open onto the front porch and
in a direct line with those doors are the windows in the bathroom, in the
summer if we had both open we never experienced the house getting hot. That
has actually stopped this year - now we sweat inside. But until this year we
had a pretty good way to keep the house cool.

------
api_or_ipa
Interesting that this article is posted on the eve of Burning Man. This year
should be especially hot. Every year I bring a simple swamp cooler, this year
I'm going a step farther and bringing 2, plus an active ventilation fan and
ducting. My total power consumption is about 18w, not too shabby to bring down
the temps about 15f in ~1000ft^3 space and well within my modest solar panel
setup.

------
jonnycomputer
The article focuses on strategies effective in arid climates. In California,
evaporative coolers worked really well for us except on the hottest days. No
way they'd work for us here on the US East Coast.

OTOH, I'm pretty enthusiastic about the exchange systems that circulate fluids
to exchange heat with soil beneath home. That's a really reasonable approach.

~~~
wasdfff
The best part about southern california is even if its 100 during the day, it
will be a brisk and breezy 70 once the sun sets.

------
mmcnl
Funny that this article doesn't talk about keeping warmth out. Whatever you
can keep out you don't need to cool. So invest in:

\- Insulated glazing

\- Sunscreens in front of windows

\- Wall and roof isolation

The nice thing about this is that these measures also keep you warm in the
winter (lower energy bill), it's a double-edged sword.

------
b0rsuk
Obligatory reading: The Revenge of the Circulating Fan
[https://www.lowtechmagazine.com/2014/09/circulating-fans-
air...](https://www.lowtechmagazine.com/2014/09/circulating-fans-air-
conditioning.html)

------
aatharuv
UV reflective film on the windows seems to be helping one room in my house
which was consistently 10 degrees fahrenheit warmer than the others.
Alternately, but a little uglier, taping white kitchen paper towels to the
window solved the problem as a temporary solution.

------
zonidjan
I really wish I could have a well-designed (for electricity use) house.
Unfortunately, they don't seem to exist unless you build it yourself, and I
can't even dream of doing that (although to be fair I can hardly dream of
buying a house at all).

------
jhallenworld
My house has an attic, and an attic fan or vent helps a lot.

I have cheap asphalt roof shingles (even so, $10K to replace them)- I did look
into reflective shingles, but they were much more expensive, plus I had to
consider resale value..

~~~
randcraw
Attic fans are great for cooling at night, but I've found they make a
difference only at cooler latitudes like Michigan where night temps fall 15 or
20 degrees below daytime highs of ~85F, reducing the house to 65 or 70 after
sunset.

In the mid-Atlantic where I live now, night temps don't drop more than maybe
10 degrees below daytime highs of ~90F. So bringing in the evening air via an
attic fan puts the house at no less than a toasty 80 (with 70% humidity) --
still uncomfortable.

~~~
artimaeis
Attic fans are great anytime the air temperature difference between the attic
and the outside is great. In the hotter regions (such as the southeast US)
they're great for venting hot air out rather than pulling cool air in. Attics
will often get 20 degrees hotter than the outside air, so forcing that out
helps to insulate the cooler indoor spaces.

Of course in older, not-well-sealed housing the venting poses the risk of
drawing cooler air from the house to the attic, negating much (or all) of the
benefit. So their efficacy is very situational.

~~~
randcraw
Attic fans aren't for cooling attics. Ridge vents, and passive and powered
roof vents, and turbines mounted in the roof surface can cool attics far more
efficiently than attic fans which consume over 100 watts and must run
continuously on summer days -- a very costly way to air out an attic.

Though old houses often have attic fans, they weren't there to cool attics.
That was the purpose of widowed attic gables or breathing slats under wood
shingled roofs. Attic fans are there to cool the house interior, especially
the hottest rooms on uppermost floors. That's why the intake of an attic fan
is the highest point inside the house and not the lowest point inside the
attic. Even then attic fans aren't intended to run for more than perhaps 30
minutes a day after sundown -- just long enough to replace the hot air inside
the home with cool air from outside.

To vent an attic, the ideal air flow is to intake cool dry outside air from
along the attic soffet, pass it along the underside of the hot roof sheathing,
and have it exit high where attic heat is at its peak. And do this passively
without a powered fan if at all possible.

------
ubermonkey
In Houston? No. Next question.

~~~
gwbas1c
I thought Houston is dry enough that you can use swamp coolers? (They work by
evaporation.)

~~~
pixl97
Houston is beside the ocean and in generally swampy areas. Its average
humidity range is between 60 and 90 percent depending on time of day. Hard to
evaporate in those conditions.

~~~
gwbas1c
Shows how little I know about Texas!

~~~
rstupek
Texas weather isn't uniform because it's a very large place

------
Stronico
Whole house fans are one possible solution to reduce (not eliminate) the need
for air conditioning - I'm using a quiet cool right now which works fairly
well (haven't tried it during the spring or fall yet)

~~~
giarc
My last house didn't have AC but did have a basement (like many homes in
Canada, although less common in the States I understand). I would just run the
furnace fan which circulates the cooler air in the basement throughout the
house.

------
lota-putty
Water, so precious.

[https://en.wikipedia.org/wiki/Pot-in-
pot_refrigerator](https://en.wikipedia.org/wiki/Pot-in-pot_refrigerator)
rocks.

------
ohiovr
You can spray water on your roof with a garden hose and cool your house. Of
course water isn't free either.

~~~
switch007
I might actually try this during our next heat wave. All the other tips and
tricks do absolutely nothing for the upstairs in many UK properties in my
experience (I'm talking indoor temps of 23-29c at midnight, when the outside
has cooled to 20c, from a daytime peak of 35c). It's like the whole house is
turned in to a radiator and there is nothing you can do

~~~
ohiovr
Hello, I tried the experiment a few years ago briefly and it did work. Some
back of the envelope calculations show that it is cheaper and more energy
effiecient. However there is a risk that lichens and or moss will thrive on a
moist roof. So could be more trouble than it is worth.

~~~
switch007
I'm rather confused by your reply and the reply to it. It rains a lot in
England. Why would spraying it with water be any different from night upon
night of heavy rain ?!

~~~
ohiovr
I don't know actually. I had not thought of about places with constant rain.
Anyway does it work? If you spray your roof on a super hot day does it feel
any better indoors?

------
tus88
> installing energy-hungry air conditioners – a major contributor to climate
> change

Is this a fact?

~~~
drak0n1c
It's a bit hyperbolic. Home heating in colder areas uses significantly more
energy and fossil fuels than AC in warmer areas.

------
sizzle
Anyone else browse www.hvac-talk.com from time to time?

------
somesortofsystm
The Earthship people called. They want their cool-hunters back.

[https://www.earthshipglobal.com/](https://www.earthshipglobal.com/)

------
elikozikaro
Solar powered AC

