Air Conditioning after the SHTF

Our modern society lets us maintain our homes and workplaces at comfortable temperatures at all times. There are adults living today, who’ve never had to live without air conditioning for longer than a few hours. We take this modern marvel for granted now, but what if civilization were to collapse?

Humans have lived in harsh climates since the dawn of time, so there’s a good chance you’ll learn to adjust and survive too. But that doesn’t mean you have to sweat and wallow in misery. This article will provide some pointers and ideas on how to heat and cool a home with no air-conditioning or electricity.

Cooling the Home

There are a lot of things you can do to cool your home after the SHTF, but I’d like to make a couple observations first.

  • Some of these ideas may not be practical in some oppressively hot and humid climates (like mine).
  • Some of these ideas aren’t possible if you live in a multi-family structure.

Open the windows and close the curtains. Open windows and doors to allow a breeze to blow through your home. Closing the curtains will help to deflect solar heat back out of the home.

If you have white or light-colored curtains, consider dampening them. The home will cool even more as the water evaporates out of the curtains. But, don’t dampen them if you aren’t going to open the windows, because that’ll only cause mold and mildew to develop on the curtains and in the home. 

Consider using double curtains. For double-layering curtains, some people think it’s best to use a white/light external curtain and a dark one facing the interior. Light-colored external curtains will reflect light back out of the home and the dark interior curtains will absorb all remaining solar energy to help ensure the room stays cool.

Double-layering should help cool the home regardless of the windows being opened or closed.

Let the night air in. Opening windows and interior doors at night helps cool the home, even in oppressively hot and humid climates. It may not seem like it to our spoiled senses, but the night air in such humid regions lower by an average of 10-15 degrees below the day’s peak temperature. This is especially helpful in dry or arid climates, which the temperatures at night can drop 30-40 degrees below the daytime temperatures.

The key is trapping and preserving this cold air for as long as possible throughout the day, by using other methods to keep the house cool.

Live on the 1st floor. Hot air rises and if there isn’t a way to vent the heat, it may become necessary to avoid the second floor of the home. Yes, the upper floors of a building usually benefit from stronger breezes than the first floor, but that may not be enough to keep it cool for comfortable habitation. If this happens, your family may have to learn how to live on the first floor (and/or basement) and only use the upper levels during colder months.

Keep in mind the upper floors of your home still have benefits in this situation. The extra storage is an obvious benefit, but less obvious is the additional insulating properties vacant floors provide to lower levels.

Have you ever walked past a large parking garage in a major city and felt nice and cool air exiting the structure? The owners aren’t air-conditioning the garage, but the building is benefitting from a sort of natural air-conditioner. Each floor is shaded and cooling air. As the cool air flows down, it gets cooler and cooler to the point it feels like a crisp 70 degrees at ground level. Don’t expect that sort of cooling ability from a 2 or 3-story home, but the general principle is the same when it comes to insulation and keeping lower floors cool.

Close off hot rooms. Some rooms of a home get more direct sunlight than others, or there may be something else making it hotter than the rest of the home. It may be necessary to sacrifice these rooms by closing them off to the rest of the house. Simply close the interior door during the day and commit to use the room only at night. If the room in question was an office before the SHTF, maybe you should turn it into a bedroom so it’s only in use when it’s cooler.

Adjust the ceiling fan. This will only work if you have access to electricity or a solar/wind/other generator. We tend to forget about it but, most ceiling fans have a small switch on the side of the unit that changes the direction the blades spin. If the fan is rotating in a counterclockwise direction, it’ll push air down and create a cool breeze. Alternately, a clockwise direction is best for winter to bring the hot air back down.

Use a rechargeable fan. This will only work if you have some way of charging the battery, but a battery-operated fan will help you feel cooler. I have a few of these and they’re great while camping. They can last about 4-6 hours on a single charge if used at the lowest setting.

Paint the roof. If you have white or light-colored paint, painting the roof can help reduce the amount of solar heat the home absorbs. That means the house can stay cooler longer throughout the day.

Add awnings. Adding awnings to your windows and doors will help keep direct sunlight out, while still allowing a breeze to come in. Awnings help keep the rain out as well, so you don’t have to close the windows during a heavy shower.

An awning doesn’t have to be a rigid structure. You can make a simple one by using a towel, pillow case, or sheet (preferably something you don’t care about). Simply nail one end over the top of the window, and use a rope or string to tie the other end to a tree, pole, or another building. It doesn’t have to look pretty if it works.

Shade the home. I just thought of this. If you have a small house, it may be possible to build a shade to cover part or all of your home. Theoretically, this can reduce the amount of solar radiation the home is exposed to, and could potentially keep it about 10-15 degrees cooler than it would be in direct sunlight. The primary problems with this idea involve finding enough material to build the shade, and then tying the shade to something taller than your home (like a tree).

When I first thought of this, I envisioned camouflage netting as the perfect material for shading a home. Camo netting comes in huge sizes and is porous, making it less likely to blow and flap in high winds (which means it’s more stable when tied off to trees). Camo netting also makes your home harder to find from areal searches. But your home needs to be small enough to benefit from this cover.

Build a primitive AC. You can try making a primitive air-conditioner, like the Water Bottle AC I encountered (description below).

Water Bottle AC

I saw a weird contraption that uses large water bottles and a piece of thin plywood to keep a home cool[1]. Here some basic instructions on how to build one using 32 oz water bottles: 

  1. Measure a window and cut a thin rectangular cardboard so it fits snugly into the part of the window that opens. For a 24×36” window, that’s maybe 22×16 inches.
  2. Measure and create a grid on the plywood of about 3×3 inch squares. Depending on the size of the window, you can fit 30-35 bottles onto the board.
  3. Drill holes large enough for the bottles to fit snugly. Uncap a bottle and eyeball the drill bit to be slightly larger than the bottle opening. 
  4. Cut the bottles in half. 
  5. Unscrew the bottlecaps and cut off the top of each cap. Don’t worry about cutting too much off, because you probably won’t be able to tighten them all the way (during step 6).
  6. Slip bottles into each hole and use the caps to fasten or adhere the bottles to the plywood.
  7. Place the plywood-bottle AC unit over a window and cool air should start flowing into the room.
  8. Optional: If you live in a region plagued with mosquitos, staple screen mesh over the semi-flat side of the plywood.

Dehumidify a Room or Home

If you live in an area with high humidity, it may be in your best interest to, at least try, keeping the humidity out and prevent mold from developing inside your home. This will have an added benefit of making you feel a little cooler too. Unfortunately, there’s only so much you can do without electricity, but the following methods may help.

Ventilate the room/home. Open doors and windows to allow a cross-breeze to move the moist air out of the house.

Hang dry clothes inside the home. Hanging dry towels and sheets inside a damp room or house will absorb moisture out of the air. The caveat, is that you must remember to take them outside to air-dry afterward. To do this, use a set of towels one day, then switch them with a fresh set the next day while they dry. 

Use calcium chloride (CaCl). I’m reluctant to mention this because I can’t think of how you’ll find it, but a container of calcium chloride should dehumidify a home as well. If you can find some, pour the calcium chloride into a sock and tie it shut, and then hang it in the room with excess moisture. You’ll probably need multiple socks.

Use salt. Similar to CaCl, salt can help dehumidify a room. Pour a large amount of granular salt onto a plate and place it in a damp room, stir the salt to prevent clumping and expose more surface area to the humid air. This will require several plates to have any noticeable effect, but it may work in a closet.

Another reason why I don’t like this dehumidifying method is because you’re potentially wasting something that can be used with food. The only thing I can think of to alleviate the waste is to try consuming the salt used for dehumidifying, before using containerized salt in food preparation.

Also, don’t tell anyone what you did or you’ll gross them out.

Limit “wet” activities. Don’t do anything in the home which may cause additional humidity, such as: 

  1. Shower without a vent or open window.
  2. Cook soups or recipes requiring boiling liquids. Baking, however, may dehydrate a room… but will make the house hotter than hell. 
  3. Don’t moisten your curtains or dry anything inside the home. Contrary to the advice I previously gave about cooling your home, if you’re facing oppressive humidity or mold, moistening your curtains may be the last thing you want to do.

Heating the Home

Thanks to global warming, or the natural heat cycle of the planet, or whatever you believe… we don’t have to worry about heating our homes as much as we did over a hundred years ago. Hell, here in Southeast Texas, we only experience a few days of real winter.

All joking aside, regardless of how few days of “winter” an area experiences, not being able to keep warm during extremely cold weather can be just as deadly as heat exhaustion. This was most apparent when the winter storm of February 2021 caught us off guard. So, how do you keep warm?

Start a fire[2]. Use the fireplace if your home has one. Grab fallen wood from a nearby woods or scavenge wood from around the neighborhood. You’ll be amazed at what you can find. Most pallets can be burned safely because the wood isn’t normally treated. If you can’t find any wood, you may be forced to burn whatever non-toxic trash you can find to survive the cold.

But what if your home doesn’t have a fireplace?

Absorb solar heat. Keep the windows closed and open the curtains to absorb as much solar radiation as possible during the day. Then close the curtains at night to trap that heat and insulate the window. If direct sunlight shines into a room, consider laying a dark blanket there to absorb even more heat.

Bundle up. Wearing warm clothes and jackets at all times will help keep you warm. You can even use a blanket as a make-shift cape for additional heat retention[3]. Below are a couple examples of the best blankets for staying warm:

  1. Wool blanket: Wool is the best natural cloth for heat retention and will keep you warm even when it’s wet.
  2. Thermal blanket: One of the best synthetic blankets available is a “Space Blanket”[4]. These blankets are made of thin, heat-reflective, plastic sheeting, and helps to retain heat when wet or dry[5].

Move to the second floor. All heat generated from cooking or absorbed from the sun will rise into the upper part of your home. You should use that trapped heat to stay warm by living in the second floor. If your home doesn’t have an upper level, and you don’t have enough materials to keep a fire going, you should consider using the attic, even if it’s just for sleeping.

Build a terracotta heater. Currently, the most popular alternative source of heating is the “terracotta heater”. This ingenious device only requires: a candle, a quarter, and an upside-down clay pot.

The theory behind terracotta heaters depends on the candle’s heat being trapped by the upside-down clay pot, which absorbs and radiates the heat into a room. Most videos call for you to cover the hole at the “bottom” of the pot with a quarter, or some non-flammable object.

Most of the instructions I’ve seen claim these heaters can warm an entire room. However, I’ve tested it and learned this type of heater doesn’t work as well as these videos would lead us to believe. Here’s why:

  1. Some instructions position the candles fully inside the pot, which doesn’t allow enough oxygen to reach them and the flame is suffocated.
  2. Even if the design allows for air to enter from below the flames, blocking the hole at the “top” also suffocates the candles and they burn out.
  3. Just one of these heaters will not noticeably heat an average-sized room.

I don’t mean to bash the concept, but I must ensure you don’t expect a miracle from these emergency terracotta heaters. I’ve built a functional clay-pot heater and used it in a well-insulated, 91-square-foot tiny house. The clay pot got extremely warm and became too hot to handle, but I had to sit right next to it for any warmth to be felt.

But in a survival situation, a terracotta heater is better than nothing.

***

These primitive air conditioning methods should help make life more comfortable after the SHTF. They can be used individually, but a wise survivalist will use a combination of these ideas to maximize your ability to remain comfortable.


[1] Water Bottle AC Source: I don’t have permission to provide an exact source for the first Water Bottle AC I encountered, but I found the below source. The article calls it a “Bangladeshi air cooler”, and it’s close enough to be used for a visual reference.

DiStasio, C. (2016, August 01). This amazing Bangladeshi air cooler is made from plastic bottles and uses no electricity. Retrieved from Inhabitat: https://inhabitat.com/this-amazing-bangladeshi-air-cooler-is-made-from-plastic-bottles-and-uses-no-electricity/

[2] Fire Safety: Fire is a serious tool and should be handled responsibly. Never leave a fire unattended, even if it’s contained in a seeming innocuous vessel (candle, lamp, etc.). Always take precautions when using any form of fire, or when handling or storing any type of flammable substance. Always have fire extinguishing equipment or substances available in case a fire gets out of control.

This disclaimer provides a few general fire safety guidelines, which do not encompass all safety precautions related to using fire.

[3] Necked Cape: I’ve used various blankets as capes and they’ve helped keep me warm… while walking around a cold house in my underwear.

[4] Space Blanket: These may be called by different names, such as: emergency blankets, “foil” blankets, reflective blankets, first aid blankets etc.

[5] Wikipedia. (n.d.). Space blanket. Retrieved from Wikipedia The Free Encyclopedia: https://en.wikipedia.org/wiki/Space_blanket