Hi there, time to share ways to keep your home cool during hot times
So ok, usual ways I use:
- open everything during night
- close everything during day
- external sheets on windows without shutters
- some curtains to prevent heat from going upstairs
I was also wondering if plants could also help inside, any ideas ?
Share your advices !
From a Deep South transplant who went through plenty of hurricanes with no electricity, a frozen gel pack between your thighs. You’re welcome
another on back of the neck, and for the ladies, small ones under the boobs
I wish I had enough boob to know about that last one lmao
Ah but if you did, you’d have more insulation and the effects would negate
Plus big ones reduce your cornering speed at full sprint
There kind of… isn’t. I’ve been battling heat with extreme prejudice my entire life. MAYBE the closest thing to a solution is to drink lots of ice water and then hopefully you’re not one of those people who can’t sleep if its hot (i am).
Try to “store” as much “cold” as possible. i.e. if you have a half working a/c unit, run it at 100% at night and once the temperatures get as low as they’re going to get, close all the windows, cover the windows, unplug fridge or whatever is producing heat you can afford to shut down and maybe if you’re lucky it will be around 1 or 2 pm before it heats up to utter bullshit temperatures.
If you have a way to get unlimited free ice (IMPORTANT: and NOT from the fridge in the living space you are trying to cool), you can use that to cool things down in the evening when everything is the hottest. If you have to buy the ice, just buy a ac unit because it will pay for itself in no time. And if you’re doing this because you can’t afford the electricity, maybe see about wiring up a solar panel and battery which, again, will pay for itself if you could’ve afforded to literally buy bags of ice every day. And if you’re doing this to protect the environment, get a ac unit that doesn’t contain ozone-layer destroying coolant (i.e. most of them). Buying ice for cooling is incredibly inefficient.
You can also take the ice-based cooling strategy further. Get a bucket. A fan. A big radiator (you need quantity(sq area) not quality, get a shitty heater core one and not a pc watercooling one). A pc watercooling pump. Some tubing, along with whatever barb fittings and pipe clamps you need. Make it so that the radiator is sitting in front of a fan while having water from the bucket being pumped through it. Add your ice to the bucket. This system will dump the “cold” from the ice into the room as quickly as possible, MUCH quicker than just setting the ice in front of a fan to melt by itself. If you actually have a truly unlimited source of ice this will provide nearly the same amount of cooling (while the ice is fresh at least) as an actual window ac unit. I do this irl sometimes and usually keep one mostly set up and ready to go just in case my a/c stops working.
It’s going to take time to find a cheap or free radiator if you’re living like this for financial reasons but bending some copper tubing around the fan also works decently. If you buy it at the hardware store its likely going to come coiled up in a box and already in the perfect shape for this.
At a certain point, obtaining the amount of ice you need to maintain this becomes a problem. If you REALLY don’t want to buy an ac unit at this point as maybe some kind of personal challenge or whatever, its time to science the shit out of it. Get a refrigerator. Put it outside, as leaving it inside will dump heat into the room defeating the purpose. Mod a bucket into the fridge and run 2 tubes out of it: an input and an output. Run this tubing into your living space somehow and into the radiator and the fan. You could alternatively put the fridge inside and find a way to attach a duct to the back of it to vent air outside which is may be more convenient depending on your living situation. Congratulations. You’ve built an a/c unit without technically actually building an a/c unit. Maybe in some countries this helps for tax purposes. I’ve never tried going this far with it before saying fuck it and getting an a/c unit so post pics if you do.
Get a box fan and a coil of copper pipe, run the coil all around the front of the box fan like a snake going back and forth, on the top end of the pipe attach a box for icewater, and a bucket to catch the outflow.
Put an adjustable valve at the end going into the drain bucket and let it dribble a bit. You’ll have to adjust it to get the longest cold air time/least having to get up to empty the valve
It’s not super efficient but it’s cheap and can be made with parts in the garage
You’ll need a lot of ice tho
If you own the place or can get permission, a mini-split air conditioner is very easy to install with minimal tools, and they’re pretty affordable online.
For under 500 buck including drill and bits you could have AC in a few days. It’s not free, but it’s a huge quality of life improvement.
I’ve been getting by just fine with a couple standing fans. I’ve had to turn the ACS on a couple times for my kids when I was around 110F
Before going full blast AC in all the rooms I’ll turn on the big Window unit in the living room and set up fans so it blows the cold air through the whole house (our house isn’t big) and I find its a good middle ground. It cools down the rooms pretty well.
Having lots of trees around the house will keep it cool but cause lots of other problems. Solar panels and AC is the way to go.
I am fortunate to have moved to a climate where the heat is less severe and when it is hot it tends to be dry-ish. My house does not have AC so we put a big exhaust fan on the top floor and crack a window downstairs. Works so far, but we have some small portable AC units for the bedrooms just in case we need them.
Only fans.
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Only fans.
Most importantly: Make sure no direct sunlight enters the house. Insulate your roof. Plants in the house can have a modest cooling effect. Close doors to rooms that get hot faster. Lower floors (especially cellars) are cooler, with a small ventilator this cooler air can be transported upwards. At night, use small ventilators to “pump” cool night air through all the floors.
Lose weight. I’m totally serious. Thin people have much higher natural tolerance for heat.
It’s no coincidence that so many developed countries have become addicted to AC. The fact is that most people there are now overweight and in many (USA most obviously) over 40% are literally obese. Conversely, AC is much less common in places like France and Japan, and it’s not just because they’re too cheap.
If you want to stay cool in a heatwave, it helps not to be wearing a blubber overcoat that you can’t remove.
Conversely, AC is much less common in places like France and Japan, and it’s not just because they’re too cheap.
This is completely wrong. Like 95% of all households in Japan have ACs. Even on the countryside. I was living in Japan for a year and the only time I visited a house without an AC was on an island with 1000 inhabitants.
in places like France and Japan
This is completely wrong.
You talk exclusively about Japan, so even if your anecdata is representative, then my point is not “completely” wrong. Let’s begin by using language correctly.
If youre making a point and part of it is a lie, it is completely wrong.
Lets begin by growing a pair of balls and owning up to your mistakes instead of hiding behind condescension.
Conversely, AC is much less common in places like France and Japan, and it’s not just because they’re too cheap.
I assure you that practically every household in Japan has an air conditioner these days. Maybe not some decades ago but things have changed, including the climate. And companies are legally required to keep offices at no higher than 28°C, too.
Offices in all countries have AC, the question is about homes. I doubt “practically every household” in Hokkaido has AC. Here in northern Europe, very few do.
Every home I have visited in Japan over the past two decades has had A/C units. You may be right that in regions where it is very cold an A/C unit may not be necessary. However, as heat pumps are one of if not the most energy efficient ways to not only cool but also heat a home, I wouldn’t be surprised to find them even in colder regions.
Add on the fact that houses in Japan are generally considered a depreciating asset, so until recently demolitions and new construction were favored over renovations, I stand by my first statement.
Additionally, every place I have ever rented has come with at least one A/C unit, and additional holes are predrilled in other rooms so that split systems can be installed.
Fair enough. Most of Japan is hotter in summer than northern Europe. Here it has been 35C for much of the last week and domestic AC penetration remains extremely low. There are also quite few fat people, and the two things are probably at least a little bit connected.
I don’t disagree that people who are overweight will feel hotter. The rainy season makes it feel hotter than just the temperature here, too. Buildings here are probably more poorly insulated, too.
My office in Southern Germany doesn’t have AC, even though it should. It’s the hottest part of Germany.
Give it a couple of years and a few more heatwaves! This is the insidious problem with heatwaves, as I see it. Tolerance for heat and cold is in large part cultural - go to Portugal in winter to see how tolerant people can be of cold indoor temperatures. But with every new 3-day heatwave, Europeans are going to rush out to buy AC units to escape the immediate misery. Next thing we know the continent will be like the US, where it’s just unacceptable for indoor temperature to be outside the 19-23C range. And mass AC is just a climate disaster. That’s my worry.
This may explain why I’m wearing a hoodie in the office in late June while most everybody else is comfortable or still hot.
But, I also do lots of outdoors stuff and acclimate to heat up to a point.
AC is much less common in places like France
It’s everywhere around me (in France) because it’s becoming too hot, whether people are fat or not.
I gain weight this winter. I have such a trouble cooling down the part of my body that gain the weight. It is hard…
How is losing weight going to help right now? They can hardly lose enough weight in time for the next heatwave.
Or maybe they’re in the menopause.
Or maybe it’s 50C out.
Or maybe they’re on one of the plethora of medications that causes heat intolerance.
Or maybe they’re elderly.
AC is horrifically expensive (energy bills) and terrible for the environment, by the way. People aren’t cheap, they can’t afford it.
I found it good advice. We don’t know every detail about OP life. Of course, some example won’t apply but that’s fine.
I mostly agree since it’s healthy either way, but back when I was half my weight when I studied in a 4 seasons country, coming back to the year round hot and humid home country still makes me immediately sweat the moment I step out of the plane. Constantly felt like I always have a blanket on me. Anecdotal for sure, but I just want to say my piece.
Not disagreeing but none of my kids are at all fat and one is so hot-natured, it’s not always just insulation. One of their cousins, too, she was just never cold and always hot.
I did always joke with my ex that I was built spare because I am from the hot part of the world, and he was padded because he was from Michigan.
Interesting anecdotes! There’s actually a bit of truth in the last one, I believe. Bodily fat is more evenly distributed in Inuits and even Europeans than it is in, say, west Africans.
If you live in a humid area, AC will become more and more valuable. Wet bulb temperature. At some point your sweat will no longer evaporate and you’ll die. Climate change cometh.
Thanks, I went down a rabbit hole reading about wet bulb temperature.
Yeah, this recent heat is expected to cause deaths. Not only because of the heat itself, but because of the humidity. Humans can tolerate extremely high +100°F temps when it’s dry… But when you start cranking up the humidity, that tolerable temperature quickly begins to drop. At 100% humidity, that tolerable temperature is only in the mid 80’s. Above that point, even the best fans won’t help cool you. Because fans only work by evaporating sweat, and in high humidity that sweat doesn’t evaporate.
Look at old hot climates.
notice the afternoon siesta. Sleep in the shade in the hot of the day and work (play) later into the night.
notice large covered porches around the house. Spend more time outside in the breeze and shade.
notice the large windows and doors. When you are inside get plenty of ventilation-
notice the ceiling fan (often slave pulled). Be glad we now have electric fans.
notice the folding hand fans. Portable fans exist, though most of the time the hand fan is better - get one.
People in hot climates do not sit outside. They also do not open their windows. Because they’re not insane.
In hot and dry climates, a breeze in a shady place works well, actually. In humid places it’s harder.
That actually has results counterintuitive to temperate people when it comes to clothing. Arabs don’t just cover up for modesty.
Huh? I sit outside, with a fan on, in up to 35/95F in the shade. And it’s humid here. Outside hot does not feel as bad as inside hot, and you do learn to be still and cool enough. It is not weather to go running, but sitting, in the shade, with a fan? No problem.
they do open windows. They also close them. When they do that depends on the situation.
livewise they sit outside at times. They also sit insides.
There are many different hot climates with different situations. You cannot make a blanket statement. And you cannot look at what they do today when ac is common to figrue it out (where at is common)
Apparently window awnings make a considerable difference.
I was searching to see if someone had posted this already because that was exactly what I wanted to contribute. Excellent work!
I have a large room with clear story windows and the entire south wall is windows, in the desert. The roof extends out far enough to block the sun in the summer, but not in winter. In winter during the day it’s 90F when it’s below freezing outside. The amount of heat trapped from the sun coming in through windows is no joke.
As someone from the equator with hot and humid air, this thing is common, it allow hot air in the attic to escape so the hot attic won’t radiate into your house, while sucking fresh air into your house. Plant surrounding your home exterior also will help with the cooling as well, especially when it stop light from hitting your wall. I usually just open everything during day, but open everything during night will also help circulate the hot air heated by the heat-trapping concrete wall. As of now i can’t open during night because my cat will escape, so i just use ac for half hour or so.
as someone from a similar place, mosquitoes make opening windows at night a health hazard, unless you install netting.
I should be getting to do that…
Yeah the mozzy mesh is a life saver, for both mosquitoes and flying termite/ant swarm after rain, but do keep in mind that meshes will restrict some air flow. Still, it’s better than nothing, and combine with that rooftop onion you might get better result.
I never knew what that rooftop onion does. But now that I know, that’s another thing to fix.
Pretty good (but long) answer with historic solutions here : https://solar.lowtechmagazine.com/2025/06/dressing-and-undressing-the-home/
My short answer : do not let the sunshine in (stores, awnings, shutters), let it flow let it go (air), I like big walls and I cannot lie
Came here to point to this.
Also, if outside noise is preventing one from keeping the windows open over night, get custom-fitted silicone earplugs.
