Ask Lemmy

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.

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

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.

From a Deep South transplant who went through plenty of hurricanes with no electricity, a frozen gel pack between your thighs. You’re welcome

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.

Hot showers at night or when you’re feeling extremely overheated. Trust me, that’s way better than cold showers. First shower warm, then get soapy, and then shower as hot as you feel comfortable. I do this for over 10 years now and it’s amazing. My theory is that it heats up the body and due to the outside being cooler, it actually cools your body down - albeit 35°C. By the way I shower with ~42°C regular lol

OP, do you have an air conditioned library or a cold springs near you? When I was living without AC I found that getting really cold at some point in the day chilled me off for quite a few hours, made the rest of the day feel better. I had a friend who would get in a cool shower then not dry off just lay in the wind from a fan.

If you can afford it, buy a single window AC unit, install it in your bedroom, and then live in there all summer. That's what my parents did when I was little and we lived in a house with no AC. If you can't afford that, a box fan in the window once the sun goes down, then shut it off in the early morning and close/black out the window/draw shades as soon as the sun is up to try and keep the cooler air in that one room for as long as possible.

When its hot, avoid cooking indoors if you can. Especially iff you dont have proper exhaust in your kitchen. Buy some food that require less heat or none. Sandwiches, Fruits, Salads, etc.

Keep your home cool and yourself too.

Passive or Active Ventilation. The idea is to encourage air to pass through the home, which helps with removing heat from inside. Passive Ventilation would be opening windows, using wind catchers, etc. This depends on the design of your home, among other things that you probably don't really have control over. Active ventilation is the same idea, but you use strategically placed fans to induce good airflow. For example, if you have two windows that are opposite to each other, you can place a fan at one window to intake air, and a fan at the other window as exhaust.

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

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.

If your roof is not shaded by trees, a light colored roof makes a huge difference. This can be accomplished a number of ways. Replacing your roofing material with a lighter color is ideal but expensive. Coating it with something like Henry Tropi-cool is durable but the product is also a little pricey. The absolute budget way to do this on an asphalt shingled roof is with a slurry of masonry lime. I've experimented with all of these methods and the results are dramatic. In my case the coating paid for itself within one season and made the house noticeably more comfortable.

Only fans.

Open upstairs windows after 8-9 PM to let cool air in, blackout blinds work really well too

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.

My method is "live in Alaska."

Probably not exactly the answer you're looking for.

If you have access to sun and are tech savvy, hop on Facebook market place or equivalent. You can probably get very cheap used solar panels that still have plenty of output. Rig up a AC unit in one room and cool just it.

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.

Live somewhere it doesn't get hot.