Water can be used to cool a room when you don't have air conditioning or want to save electricity. Evaporation is the best method and these methods are often referred to as a "swamp cooler".
Method 1: Face cloth or small towel[edit | edit source]
- Use a usual room fan, such as a box fan or window fan, with a grill on the front.
- Dip a facecloth or a small towel into cold water. If possible, use water in a bowl filled with ice cubes to make it as cool as possible.
- Wring the cloth out so that it's damp, not dripping wet.
- Lay the cloth over the fan. As it blows the air out, it'll circulate through the cloth and the air will feel cooler. Make sure that the cloth cannot get caught on the fan in any way at all––if this is a possibility, don't use this method.
- Replace the cloth frequently, as they dry out.
- On a larger scale, soaked blankets or sheets can be hung in front of a window or porch screen and the night breeze can go through the wet fabric and cool the room.
Method 2: Ice bowl in front of fan[edit | edit source]
Another approach is to place a bowl of ice water in front of a fan. Keep refilling with ice as it melts. Mind that freezers generate heat on the outside as they cool down the internal space. If your freezer is in the same room that you want to cool down, it will create more heat in the long run and consume more energy.
Method 3: Styrofoam cooler combined with a fan[edit | edit source]
A step up from the ice bowl is a styrofoam ice cooler that provides continuous cool air for hours due to its larger capacity and styrofoam insulation. Note that while this method does cool a room for longer and with less maintenance effort, the cooling effect is still enough for only one medium or small-sized room.
- Acquire a styrofoam cooler and a desk fan. Remove the front grill of the fan if possible.
- Cut a hole to the cooler's lid that is wide enough for the fan to efficiently blow air through but small enough that the fan won't fall in through when placed on top of it.
- Cut one to three smaller holes for the air to exit through. If your fan isn't very strong you may want to add only one hole. You may want to add the exit holes to the lid (if there is enough space) or to the sides of the cooler.
- Optional: Fit some PVC plastic tubes or metal vent tubes to the holes to direct the airflow where you want it.
- Fill the styrofoam cooler with frozen water bottles, place the fan on top of the intake hole, and turn it on.
Method 4: Pots of water[edit | edit source]
- Find a few round bowls such as fishbowls. They should be medium to large in size.
- Lay down some soil in the base of each bowl. Add water plants.
- Fill with water.
- Place the bowls under a window. Every time the window is open, the breeze will flow over the bowls of water and help to cool the air in the room.
- This method can also be used in large containers outdoors provided you don't live where mosquitoes are a health problem.
Note: To avoid the mosquito threat, have one or two small aquarium fish such as Guppy (alias Gambusia Affinis) in the tank.
Method 5: Swamp cooler[edit | edit source]
When I'm at Burning Man, I typically stay up until after sunrise. Then, knowing that I'll be doing the same all week, I want to get a good sleep. During the day, sleeping in a tent is like sleeping in a sauna, even with a shade structure. This little solar swamp cooler chills the space enough for me to get a good rest.
Swamp coolers or Evaporative coolers only work well in hot, dry environments. Perfect for Black Rock City (BRC). Here's a rudimentary explanation of evaporative coolers (but follow the link for more):
We all know water boils (evaporates very quickly) when we heat it up enough. Well there's a direct correlation between how much energy is added to water and its rate of evaporation. Looking at it another way, if water evaporates, it must have gotten the energy to do so from somewhere. When we blow hot, dry air over water, the water evaporates and takes the heat energy from the air to do so. As a result, the air gets cooler. And, the air gets more humid, which at Burning Man gives a nice break from all the dry dustiness.
Method 6: Deep water source cooling[edit | edit source]
Deep water source cooling (DWCS) or deep water air cooling is a form of air cooling for process and comfort space cooling which uses a renewable, large body of naturally cold water as a heat sink. It uses water at a constant 277 to 283 kelvins (4 to 10 degrees Celsius) or less which it withdraws from deep areas within lakes, oceans, aquifers and rivers and is pumped through the primary side of a heat exchanger. On the secondary side of the heat exchanger, cooled water is produced.
Other methods[edit | edit source]
Please help us by expanding on some of these methods if you have experience with them.
- Keep doors shut and drapes drawn to help cool a room space. Covering the outside of the window helps, opening the window a little bit and having cold water on the window sill to catch the breeze coming in.
- Keep your hair wet; this can help to keep you cool when it's really hot.
- Spray water mist on your skin frequently from a spray bottle.
- Have a bath in cold water or a cold water foot bath (ice optional).
- You can buy an evaporative cooler that uses water to cool; this needs frequent refilling and needs to be run on electricity.