relative humidity

Ultrasonic humidifier

Relative humidity – The amount of water vapor in the air at any given time is usually less than that required to saturate the air. The relative humidity is the percent of saturation humidity, generally calculated in relation to saturated vapor density.

It’s a dry heat

People tend to feel most comfortable at a relative humidity of about 45 percent. Humidifiers and dehumidifiers help to keep indoor humidity at a comfortable level.

  • Ask – What is the usual humidity? What change would make this more comfortable?
  • Imagine – There are several ways to add or remove humidity to the air. What is the most appropriate for this particular situation?
  • Plan, Create – How much change is required to get to a comfortable humidity? What is the amount of air that needs to be treated? How can this be accomplished?
  • Improve – Is there a better solution to the humidity problem? What changes are necessary to ensure that the relative humidity is always comfortable?

That’s engineering

  • humidifier – The most common type of humidifier is called an evaporative humidifier. A reservoir holds cold water and dispenses it into a basin. A wicking filter absorbs the water from the basin. A fan then blows air through the moistened filter. As the air passes through the filter, it evaporates some of the water there.
  • evaporation – the process of turning a liquid into a gas or vapor. This happens more quickly if the liquid is heated.
  • saturate – to soak thoroughly or completely; to load, fill or charge to the utmost

Engineering ideas

  • temperature, relative humidity, evaporation, wicking, evaporation, heat

Do It
Challenges for you to work on…

  • make a simple humidifier using ordinary kitchen materials – bowls, towels, fan.

Learn more…