Watercress is fun and easy to grow at home. Take a look at our article showing you how to use the grocery store watercress to start your own patch of watercress at home. Hydroponic Water Cress. This is an image of commercially hydroponically grown watercress.
Fog is the extreme of humidity. Humidity control systems add or remove water vapor from indoor air to stay within proper humidity ranges. Humidity control is important for three reasons: 1  It is a large factor in people's thermal comfort.2  Excess moisture in a building can lead to mold and mildew, causing problems for indoor air quality.umidity control systems add or remove water vapor from indoor air to stay within proper humidity ranges. Humidity control is important for three reasons: 1  It is a large factor in people's thermal comfort.
In any one stationary parcel of air, the dew point of that air will remain the same as will the amount of moisture in that parcel, regardless of air temperature. But as air temperature increases, so will the capacity of that air to hold more water vapor. The higher the air temperature, the stronger the bond between water and air molecules, and the drier the air seems to be. To determine how dry or wet the air is at any given temperature, we use a unit of measure called relative humidity.