How to Cool Down a Room

Warm days are pure joy, full of frolicking outside, barbeques, and drinking cold beers with friends. But the downside of a hot day is not being able to escape the heat. If you’re lucky, your house has central air or air conditioning in each room that allows you to quickly and easily cool down the ambient house temperature. If, however, you’re relegated to just fans, you’ve likely realized that, though they can be enough at night, when the outside temperature is cooler during the hottest part of the day — usually mid-afternoon — all they do is push around hot air, and little else. 

Luckily, there are some tips and tricks for keeping your rooms cool that allow you to totally hack your house temperature. It’s even possible to make your own homemade air conditioner with just a few simple tools, and minimal expenditure! Read on to learn how to cool down the rooms in your house, followed by a step-by-step guide to building your own homemade air conditioner.

History of Cooling

Mankind has been trying to hack the temperature around them since the beginning of time. Prehistoric humans dug burrows into the ground, or set up shop in caves, which sheltered them from the heat above ground. 

Hand-held fans were the original air conditioner, and are still used to this day — all over the world.

The earliest-known evidence of hand-held fans — which were the first known tools for keeping cool — dates back to ancient China, where they were used for 3,000 years. In the 2nd century, a Chinese inventor built the first known rotary fan. It had seven 9-foot-long wheels and was powered by hand. 

In ancient Rome, the famed Roman aqueduct system allowed the rich to disperse cool water throughout the walls of their homes. The technology was, however, too expensive for anyone else to afford. By the 3rd century, Emperor Elagabalus took things an indulgent step further: he imported mountain snow by donkey train and had his own snow mountain built right next to his villa. 

Can you imagine building your own snow mountain by your house just to keep it cool? It’s not fiction — a Greek emperor did just that!

In ancient Egypt, crafty citizens hung wet reeds in their windows. As the breeze from the hot Nile River valley blew past the reeds, the water inside the reeds would cool the air, thereby cooling the room with it. 

For the Victorians, with their high ceilings, large recessed windows, and covered porches, air flow was key to keeping cool in the heat. High ceilings, they discovered, allowed the warm air to move into the space above a room (since hot air rises), while covered porches and windows created shade, which cooled the air before it circulated into and through the house. 

Early compression technology was employed by a Florida doctor in 1982. John Gorrie invented an ice-making machine, which he hoped to use to regulate the temperature of his hospital building. While it wasn’t a great success, it did offer his patients some relief from the hot Florida air. 

A few decades later in 1902, Willis Carrier invented the first electric air conditioner by accident. What the inventor was actually trying to do was to control the humidity in a printing plant, to protect the paper and ink. To do so, he reversed the steam heating process by having air pass through cold coils, rather than hot. This caused the air to cool and the water to condense — and it turned out to not only control humidity as he’d hoped, but it also cooled down the entire building. A few years later, textile mill engineer Stuart Cramer coined the term “air conditioning”. 

But it would be a while before these systems would make their way into homes — it was 1914 when the first-ever residential air conditioning system was installed, measuring 7 feet high and 6 feet wide, and an incredible 20 feet long. Not surprisingly, only the rich could afford the air conditioners, not to mention the fact that they were the only ones with homes big enough to house them. At this time, air conditioners cost between $10,000 to $50,000 USD, which is today’s equivalent of $120,000 to $600,000. 

In 1931, the first-ever single-room air conditioner was invented by H. H. Schultz and J. Q. Sherman, designed to be perched on a window ledge. It was, however, prohibitively expensive: while most people were making around $0.64 per hour, air conditioners cost over $400. This would have meant having to work an incredible 650 hours to be able to purchase such a unit.

As such, the public generally had their first experience of artificially cooled air at the movie theater. Refrigerated air was, indeed, frequently advertised as a perk of going to the theater.

Movie tickets were extra valuable back in the day, since they were also a ticket to cooler temperatures inside the theater!

We have lack of air conditioning to thank for school summer vacation, which was brought about because school buildings usually heated up to unbearable temperatures in the summertime. Government offices also shut in summer for the same reason. 

Once residential air conditioning became the norm, it led to the growth of the US population, due to the fact that it made the hottest states — Arizona, Nevada, Texas and Florida to name a few — much more appealing. After WWII, air conditioning became a status symbol. Over a million air conditioning units were sold in 1953. 

Most Common Ways To Keep Cool

With some simple tips, you can stay cooler in hot weather than ever before.

There are many different room-cooling solutions that you can take advantage of to escape the heat. The most obvious place to start is window coverings, which include roller blinds, roman blinds, and vertical blinds. All of these should be purchased with the thickest fabric available, which will be far more effective at blocking out heat. 

Roller blinds

Roller blinds are extremely effective at keeping out the light, particularly when lined with blackout fabric.

The most commonly used type of blackout blinds, roller blinds wrap around a roll that sits at the top of the window and are let down using a pulley device. They can be made to measure and ordered with thick, blackout fabric, in the color and style of your preference. If you would like to open yourself to a wider array of styles and fabrics, choose a thinner material and have it lined with blackout material thereafter. 

Roman blinds

Roman blinds are not only effective window coverings, but stylish too.

Roman blinds are a unique form of window covering that stack up evenly while being closed, hanging at the top of the window, and open up to a smooth, flat sheet when opened, to completely cover the window. They’re typically operated with a cord mechanism that gives the operator control over how much of the window they want to be covered. Roman shades come in two forms: classic and looped. The latter, which is also known as hobbled shades, carry folds that cascade down the shade face. Classic Roman shades are available in both seamless and pleated styles. Both forms are easily lined with blackout material, making them ideal room cooling tools.

It’s not uncommon to find matching fabric and accessorize your Roman blind to make your room extra beautiful.

Vertical blinds

Vertical blinds are excellent at keeping out the light, but not so great at blocking out noise.

Vertical blinds are generally made from PVC material, which tends to be very good at blocking out sunlight. This style of window covering is far more effective at blocking out light than Venetian blinds, since with vertical blinds, the slats overlap one another in a more efficient way, ensuring there are no gaps in between. The PVC material is water resistant and easy to clean (simply wipe with a wet cloth), making them ideal for a kid’s room. However, it should be noted that they are less effective at blocking out noise or providing thermal insulation than other types of window coverings. 

Creating a cross-breeze

Beyond blinds and window coverings, creating a cross-breeze is another way to cool down a room. Here are some facts and tips for creating a nice, airy cross-breeze.

Create an effective cross-breeze, and you’ll be well on your way to cooling down your favorite space, even on the hottest days.

A cross-breeze happens when cold air displaces warm air in a room or area, via either natural or planned methods. Creating an effective cross-breeze translates to cost savings on utilities, while also filling a room with clean air. The bonus? The breeze is free!

Cross-breeze works like this: heat seeps out of an area and tries to raise the temperature of the cooler areas that surround it. This means the area it’s left will be cooler. That’s it! So, if the temperature outside is lower than the temperature inside your home, you’ll be able to cross-ventilate with relative ease, either using your windows or a fan, or potentially both. 

How to Cross Ventilate Naturally With Windows

The first step towards a good cross-breeze is to open the windows in your home, ideally ones that are opposite one another. If, however, the layout of your home doesn’t allow for this, that’s fine — simply be sure to open windows and doors located at different sides of your home. 

Ideally, the breeze enters one window and exits the one opposite it. However, air is pretty mobile, so even if the “opposing window” is situated elsewhere than directly opposite the entry window, the air will find its exit point.

💡Tip: The size of your open windows or doorways will determine the amount of air that moves into and through your room or space. 

Using fans to help with cross ventilation

Fans can either help create a cross-breeze, or help a natural cross-breeze along. They’re essential for hot days in a house without air conditioning.

If that cool breeze the cross-breeze requires just isn’t happening in your area, get yourself some fans to help the process along. Believe it or not, the most effective way to set up your fan is facing out of the window, rather than in. What this does is draw in cooler air through the inlet opening, while creating a vacuum to suck out the warmer air. 

💡Tip: If you have a ceiling fan with a switch that reverses its direction, use it occasionally to mix up the air in your room, rather than allowing the hot air to sit near your roof, where it will inevitably fall back down and heat the room up once again.

Clever tips to keep cool

Here are some more ways you can beat the heat.

  • Open your windows at night to create a cross-breeze. Position a fan to aid the process along.
  • Keep your curtains or blinds closed throughout the day to block out a good portion of the daytime heat. 
  • Plant shady trees and foliage in front of light-facing windows. 
  • Consider investing in insulated window film to keep the heat at bay.
  • Close your doors to stop heat from traveling through your doorways. Screens don’t really stop the heat, so you’ll need to fully close your door to make this tip work. 
  • Light = heat — so anywhere you see light, it’s creating heat. Act accordingly.
  • Fill a bowl with ice cubes and place it in front of a fan that’s pointing at you. This will have the effect of blowing cool air your way as the cool vapors from the ice hit the fan. For a more effective homemade air conditioning unit, read our step-by-step guide later on in this article.

Ice cubes have more uses than keeping your drink cool. A bowl of ice is another super useful tool on a hot day.

  • Keep a small fan and spray bottle by your bedside to stay cool from the night heat. 
  • Be sure to use your ceiling fans if you have them. These units keep air circulating throughout your house, rather than allowing it to get stagnant. 

💡Tip: You want your ceiling fan rotating counterclockwise for the most effective circulation of cooler air.

  • Try not to use your stove or oven on hot days, as these both massively heat up your house. Hot days are a good time for nice, cool salads anyways! It’s a great excuse to get outside for a picnic or even better — a barbeque.
  • Make good use of your stove’s exhaust fan, which sucks up the hot air and spits it outside.
  • For that matter, use your bathroom fans too — these also suck the heat and steam out of the space.
  • Drink cold beverages and wrap a cool, damp cloth around the back of your neck.
  • Freeze two 2-liter water bottles and then put a sock around them. Place them beneath your feet to cool you right down. 
  • Turn off as many electronics as you can do without. Electronics give off tons of heat when operating. Particular culprits are computer cooling fans (which cool down the computer but emit hot air into the room).

If you’ve ever placed your hand on your laptop or tablet when they’ve been on for a while, you’ll know just how much heat these devices can generate!

  • Buy energy-efficient light bulbs over regular ones, which radiate much more heat. Incandescent light bulbs get crazy hot, so toss them and replace them with energy-efficient ones to not only save on your electric bill, but instantly lower the ambient temperature of your house.
  • Freeze a hot water bottle and place it behind your lower back when seated, or at your feet when lying down in bed. The material the bottle is made with prevents it from sweating and getting all over you and the fabric on your sofa or your bedding.
  • Alternatively, fill a sock with rice, and put it in the freezer for an hour. The rice will absorb the cold and stay that way for quite some time, which makes it ideal to wrap around your neck.
  • Sleep in the downstairs bedroom or, if there are no bedrooms downstairs, on the sofa. Since heat rises, the lowest floor will be the coolest. 
  • Stuff your pillows with buckwheat, or buy buckwheat-stuff pillows, which doesn’t absorb heat like other pillows.

Believe it or not, you can actually use a hot water bottle to cool you down, too!

  • Dampen your bed sheet with cold water, and place it overtop of you at night while you sleep. Consider placing a towel beneath you to protect your bedding and mattress from getting wet. Alternatively, place the wet sheet in front of your window, which can help cool down the air as it passes through it. This is also known as the “Egyptian method”.
  • Avoid anything polyester (from clothing to bedsheets), which doesn’t breathe well and makes you extra sweaty. Instead, opt for loose clothing that’s 100 percent cotton, and remember — less clothing means you’ll be cooler.
  • If it’s an option for you, sleep on your own. Bodies are hot, and any extra bodies create a significant amount of extra heat. Time to kick your husband to the couch!
  • Open up your windows and doors to let in the cool evening air. Remember to close them all before the morning heat seeps in.
  • Drink lots of water, to help your body effectively produce sweat, which then cools your body right down.

A cold glass of water on a hot day will not only help you feel instantly cool, but will also help your body create sweat, which is mother nature’s air conditioning for humans.

  • Hop in the shower, and turn off the heater. This cools you right down, but proceed with caution. Going from really hot to really cold can shock your system, and could put people with heart problems at risk for a heart attack. 
  • Consider investing in a whole house fan, which consists of a hallway vent that sucks all of the hot air out of your home.
  • Put your pyjamas and bed sheets in the freezer. Make sure they’re dry, of course — you don’t want them to freeze solid, but popping them in the freezer for a few hours before bed time will ensure you’re nice and cool when you slip them on or slip into them.
  • Sleep on a bamboo mat, which may not be as comfortable as your big, thick mattress, but it encourages air flow and doesn’t hold heat the way a traditional mattress does.
  • Close off unused rooms to keep the cold air limited to the spaces you actually use. Why bother to cool down a room that no one uses?

💡Tip: Try this window hack. Open the top set of your windows that sit on your house’s downwind side. Next, open the bottom set of windows on the house’s upwind side. Face a box fan out one window, which serves to push out the hot air from your house. Hang a damp sheet or dampen a set of curtains, which will cool down the breeze as it passes through your house. 

  • Keep a bowl of cool water by your bedside, and use it to dip your feet into should you find yourself overheating in the middle of the night.

Air conditioning is, of course, the ideal way to cool down a room, if you have access to it.

💡Tip: If you do decide to buy an air conditioning unit, you’ll need to know the square footage of the room you wish to cool. To get this measurement, work out the length and the width of your room, and multiply those numbers together — this will give you the square footage of your room.

💡Tip: Did you know that, counterintuitively, drinking a hot drink on a hot day can actually cool you down? It’s been found that doing so actually increases how much you sweat disproportionately. This means that the sweat your body produces will cool you down to a cooler temperature than you were before the hot drink, so long as the sweat is allowed to evaporate.

Material for making your own homemade air conditioning unit

A cooler, some ice, some tubes and a fan are the basic tools you’ll need to build your homemade air conditioning unit.

You don’t need to be an engineer, or have engineers’ tools, to create your own homemade air conditioner. Here are all the materials you need, which can all be easily sourced either around your house, from a friend, or on Amazon or your favourite DIY store. 

https://www.amazon.com/dp/B001R1RXUG/?tag=happydiyhome00-20

Optional 

Step by step guide to making your own homemade air conditioner

If your home doesn’t have its own air conditioning, you can build your own with the simple tools listed above in the materials section. It’s pretty easy, and, it turns out, quite effective too!

1. Mark your fan around the rim. 

Trace around your fan in the center of your cooler’s lid.

Use a something with a sharp edge. If you use a marker fan, you’ll mark your fan.

2. Remove the face of the fan. 

Be careful when you remove the face of your fan — even if its blade is plastic, it can hurt or cut you when it’s on if you accidentally touch it.

Normally, the face of your fan will just be held in by clips but sometimes there are screws that you’ll need a screwdriver to remove.

3. Cut out the circle you traced. 

Using an exacto knife, saw a circle through your cooler lid, using the tracing as a guide.

Cut a circle about one centimeter inside your line.

4. Mark around each pipe placed equally on each side. 

Now it’s time to prep your cooler lid to install your pipe, which will direct the cool air right at you, wherever you’re sitting in the room.

It’s fine to use a marker to draw these circles, as you’ll not likely use the pipe for any other purposes.

5. Cut around your circles. 

Use an exacto knife for best results. 

Cut on the inside of the line to make sure that your pipe fits snugly.

6. Fit your pipe inside of the holes that you just cut.

If you cut to the inside of your holes, your pipe will fit them snuggly. 

These pieces of pipe will direct the airflow in your direction, once the fan is operational.

7. Measure and cut your pipe. 

Use a hacksaw to cut your pipe for best results, though any saw will do. Be careful with this step as the cylinder plastic can be tricky to cut.

Keep your pipe about an inch off the bottom of your cooler. this will prevent your pipes from being submerged in water when your eye starts to melt. The length of your pipe will depend on the size of your cooler which will vary individually.

8. Attach your pipe to your elbows.  

Your straight pipe should slot in perfectly into the 90-degree bent pipe, also known as elbows.

For this step, you’ll just push your pipe ends together. This conjoined unit will provide an exit point for the air, once it’s circulated through the ice. 

9. Empty your ice into your cooler. 

Be sure to put the ice in loose, if you can. Bags of ice placed inside the cooler will work, but won’t be as effective as the air will not circulate through the individual ice cubes, which cools it down much more.

Spread it out evenly around the bottom of the cooler. We used three bags of ice for this. Don’t overdo it with the ice because if you do when it melts it’ll block the tubes.

💡Tip: If you want to be economical, you can use big bottles of frozen water, but for best results use ice cubes.

11. Place your open fan 

Position your fan downwards, so it will blow on the ice, which will circulate and then exit through the pipes. 

Put it face down on the whole you cut out of the top of the cooler.

12. Close all the curtains or blinds in your room.

If you have blackout curtains, they’ll be perfect for this room-cooling experiment.

Preventing light from entering your room will keep out a good amount of heat. 

13. Close all openings to the room including doors and windows.

The more you can seal up your room, the cooler it will become with your homemade air conditioning unit on full-blast.

Our homes get around ⅓ of their heat from their open or uncovered windows and doors. Seal off entrances, and close and cover windows. 

14. Cover up all remaining light or open areas

The thicker the material of your towel, sarong or cloth, the more effective it will be at blocking out light and heat. 

Hang sarongs and towels around any windows that aren’t covered or openings that can’t be closed by a door. 

15. Turn on some fans around the room

Invest in good ceiling and floor fans if your home doesn’t have air conditioning. 

You can use both floor fans and/or ceiling fans. This will help the cool air circulate around the room, and prevent the hot air from simply rising to the ceiling, only to settle down later and heat the room back up to the temperature it was previously.

16. Turn off all electronics.

Unplug your devices or switch off all your plugs. A charging station is ideal for this purpose.

As previously mentioned, electronics are a massive source of heat. Switching them off will help cool your room down quickly.