Home >> Science & Nature >> Science

Evaporation and How to Extract Heat

Evaporation is a vaporization process that can provide cool air in a hot climate. Water that reaches its boiling point of 212 degrees Fahrenheit is rapidly converted from a liquid to a gas. At normal temperatures, the same process is often underway, though at a much more gradual pace. As water molecules in their liquid state change into a gas, heat and energy are pulled from the surrounding air. Evaporation therefore adds moisture to the air while simultaneously extracting heat.

Things You'll Need

Fan
Mesh pad

Instructions

- 1
  Soak a mesh pad or similar material in water. The pad should both retain water and allow air to pass through easily. Cotton bedsheets also work well for this purpose.
- 2
  Hang the mesh pad on the outside of an open window. Fold or trim the pad such that it completely covers the open window but isn't larger than the window.
- 3
  Place an ordinary box fan just inside the window, pointing toward the interior of the house. A larger fan will create better airflow. Make sure water doesn't get on the fan blades.
- 4
  Open a window on the farther side of the house. This allows indoor air to be pushed out as the fan blades force the cooled outside air in.
- 5
  Switch the fan on. The fan will pull hot outside air through the wet mesh. The heat forces the water to evaporate, cooling the air in the process.
- 6
  As the mesh dries, add fresh water to the top until the pad is again saturated. Monitor the temperature and humidity in the house. Too much warmth may require you to lower the venting window partially. Too much humidity indicates that not enough air is venting, and you may need to open another window partially.

Science