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 !
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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
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.
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.
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.
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.
What part of “without AC” did you fail to ducking understand?
I mean, pretty much any person with central AC would read that as “without central AC.” And the answer would be the same: Fucking install AC. Installing central AC is too big of a project for most, so a window unit is a decent stopgap.
Yup. A $100-200 window unit(personally I prefer “portable” units with the exhaust hose to the window - keeps the main unit out of the sun that causes it to work harder) will be your best bet every single time. But sure, go ahead and check the price of tinting every window(about $20 per window) or getting blackout curtains(~$20 per panel in my experience) or any of the myriad of lesser solutions. Then, when you’ve spent as much or more with worse results and finally cave on getting a small unit, you’ll wonder why you ever did anything else before. Nevermind the fact that OP basically said “so aside from all the normal passive options, what else is left?” AC. That’s what’s left. Unless you want to advise them to replace all the insulation/windows/seals in their house.
Window units are the best bang for the buck. Don’t worry about expensive ones, $100 goes a LONG way to cooling one bedroom. And it’s cheaper than doing the whole house.
We have a big in wall unit in our apartment that can do the whole living space, but we hardly ever run it. We just run the bedroom one, set to like 70-75f, just to take the humidity out and chill it down a bit. A nice place to go cool down if you get hot while doing things around the house. We don’t run it when we’re not home, because even the cheapest Menards special can cool the room down in minutes, and it’s cheaper to not run it when we don’t need it.
Beware of the units with the hose… You’re paying more, and trading the convenience of not lugging a big unit into the window (small ones really aren’t that bad), for the inconvenience of having to dump the water (unless you pay more for one that can pump it out the window).
But by far the worst thing about the hose units, if they only have one exhaust hose, and no return hose? They are less efficient, because they create negative pressure in your house that sucks hot air in through every crack.
For more information see here.
Upvoted for Technology Connections. If you didn’t link that video I was going to. Window units, if you can mount them or get help mounting them, are superior in every way.
But sure, go ahead and check the price of tinting every window(about $20 per window) or getting blackout curtains(~$20 per panel in my experience) or any of the myriad of lesser solutions.
tin foil and painters tape $1.50 per window.
Unless you want to advise them to replace all the insulation/windows/seals in their house.
winter blankets and old shirts.
couple with a window fan and a swamp cooler can reduce internal temps 10-15°.
poor af growing up. that’s what we did. bonus points if you’re in a trailer. you can open both ends and have fans blowing from one end to the other.
The main problem with swamp coolers is they don’t work very well or at all in high humidity climates due to the way in which they cool air. I’m from East Coast US and it gets pretty damn humid in the summer, which is honestly worse than the heat some days. AC is honestly the best solution if dealing with heat and humidity because it combats both issues even if it can’t fully cool a space.
Dryer climates though? Wet towel over a box fan all the way baby!
I mean, sure, if you want to look like you live in a meth lab. Or you could spend a little bit and have something 100x better and actually functional and not be miserable. This is like that whole boot problem: you can only afford $20 boots so you buy them and they wear out in 6 months. Over 5 years you spend $200 when a nice pair that would’ve lasted as long or longer would cost you $100.
You can get an ac for like $60 new, like $20 on Facebook. Walmart has Artic Kings on sale every year for that much. But yeah, spend hours of your time Macgyvering a makeshift solution that maybe drops you 10°. You know what “10° degrees cooler” is where I am? 100°. You’d still be plenty miserable.
yeah sure. the costs stop after you buy it. not like you have to pay to run it or anything.
I think you underestimate how poor some families are.
Energy star sticker on mine says $46 a year to run it. $3.84 a month. If you can’t plan for that then you have bigger issues than AC.
Look, I’ve been poor. What do you think happens when something major like your car breaks down? You figure it out. You don’t really have a choice so you do whatever you can to make it happen. You have to take that same determined energy and go “this is what’s important right now, how do I make this a priority?”. Is it easy, no. But it’s not gonna happen if you just throw your hands up and give up. And sure, if you want to get stuck in that boot paradox of constantly replacing lesser solutions and eventually spending more than the right one in the first place, be my guest.
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.
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.
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.
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
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.
My method is “live in Alaska.”
Open upstairs windows after 8-9 PM to let cool air in, blackout blinds work really well too
This works really well. I also open the downstairs windows. The hot air going up and out creates a draft effect, sucking in cold air from the downstairs windows.
I could never do this, I get swarmed by June bugs at about 850 everyday, it’s like someone kicked a hornets nest outside my windows :(
Years ago I was watching Doomsday Preppers and one fella dug a long trench, 100 foot if I’m not mistaken.
In the trench he laid a large PVC pipe and filled in the trench. At the far end of the pipe there was an air inlet. He ran the pipe into his basement and up inside a wall with an inline fan. Cool air, as well as fresh air.
Didn’t do anything for the humidity, I suspect.
He claimed it worked, I can not confirm.
It does make since as it’s about 4c/39f four feet/1.2m underground.
So DIY ground source heating/cooling, basically.
I suspect that’s not long and deep enough, but if it is, it will produce air at the local year-round average temperature, at all times. (Whatever that happens to be)
Thats basically how earthships are cooled. You can also run the pipe through an evaporative cooler to cool the air even more.
You can also run the pipe through an evaporative cooler to cool the air even more.
At some point there, you’ve just reinvented AC.
Only if you use a better working fluid and add compression and expansion steps, but a long pipe in a ditch filled with water isn’t what I would call AC quite yet.
Aren’t there AC systems that just evapourate water from municipal supplies to the atmosphere?
I mean, yes, I’d agree that blowing air over a standing water body isn’t AC, but we’re getting close.
As another person stated, that’s an evaporative cooler or “swamp” cooler.
AC works by “moving” heat energy from one place to another by way of the refrigeration cycle. This helps you feel comfortable by both cooling the air and also as a byproduct it removes humidity from it. If you want a nice long video on how that works just search “technology connections air conditioning” on YouTube and enjoy. Very informative.
You’re thinking of a swamp cooler. In some places they work great, in other places they’re next to useless.
Air conditioners are called that because they “condition” the air by not just cooling but also by reducing the humidity.
Ah, okay. So not technically an AC unit then.
I think on a purely technical note, Air Conditioning goes beyond just cooling the air and involves reduction of humidity. Personally, I wouldn’t consider it AC because you’d have to keep refilling the evaporator resivor, instead of just powering the device, but that is a nitpicky item that isn’t technically a requirement.
Surprised this hasn’t been mentioned yet, but awnings. Glass is a superb thermal conductor. Not even the best curtain in the world would prevent air getting hot through the window if the sun is hitting it directly. An awning is meant to shade the window glass, preventing heating way more than a curtain alone.
Also, if the home has several levels, open the upper floor windows more than the lower ones. Hot air expands and raises. If it has somewhere to escape it will keep the house cool and the windows will draw in wind. Wind moves faster at higher altitudes. That’s why attic fans are so effective.
I was also wondering if plants could also help inside, any ideas ?
They shouldn’t. Plants can raise humidity, but they have no power to break the the laws of thermodynamics. Once heat is in your house you can only really move it out of your house; there is no destroying it in place. Note this does not apply to plants just on the outside of your home, like on a roof.
Watch your use of appliances carefully. Even a fridge generates heat - it might be better to place it outdoors or semi-outdoors if you’re going to be really hardcore about your approach.
A better insulated house will keep heat out as well as cold, so all usual tips on building or renovating your envelope apply.
