Author Options:

How do I effectively (and cheaply) cool a rom in a warm day? Answered

Of course I cannot afford an air conditioner, and a simple vent is not enough. Is there any way to cool my room?


I have to throw in a bit of shameless and blatant spam here...

Two easier options, but ones that will add humidity:
  • The simplest is to simply place ice in front of a fan. Freeze a half-gallon milk jug of water, and sit it in front of a fan. The air is cooled as it passes over the old jug.
  • The slightly more complex option is to build a swamp cooler. A bit of Googleing will give you more detailed instructions, but the simple one I can think of is to just put a wet sponge in front of a fan.

Thanks a lot! I have more (second-degree) questions. Do I have to close the windows? I mean, is this more effective in a shut-air room? I'll try it freezing the wet sponge, to give it an extra effectiveness. According to wikipedia a swamp cooler work better in a dry environment, and here it's lower than 30%, then science by my side.

Yep. In a humid environment the swamp cooler turns into a pretty inefficient dehumidifier.

Closing the windows would probably be best, because otherwise you'll just have warm air coming in. For a little bit less cooling, you could still get better air quality/ventilation by running an outside air intake directly through the cooler, and letting air back out from near the ceiling,where it is warmest.

Remember that this is similar in principle to having a fridge with the door open- you can't cool a space using a fridge inside it, thermodynamics won't let you. If you are cooling your bedroom and the freezer is in the kitchen, then it's fine- you are just moving heat from your room to the kitchen.

Not quite, at least for the swamp cooler. When you run a refrigerator, the heat is removed from the inside and dispersed through coils. With the swamp cooler, the energy is absorbed by the water during the phase change from liquid to gas. This energy does not heat anything up, it is simply energy stored in the water molecules.