What is Humidity?

‘Temperature is 80 degrees, and humidity is 75”.Perhapsyou has been puzzled by a statement of this sort. What is meant by humidity?

First of all, we must remember that the air is not composed of a simple uniform substance; it is made up of a number of different gases. Most popular is oxygen, Nitrogen is another, carbon dioxide is third. But the most important is water vapor, or evaporated water.

There is always a certain amount of this vapor in the air. The amount of this vapor that the air can hold at any one time is determined by the temperature; the higher the temperature, the more water vapor the air can contain. When it can take up no more water, we say that it has reached at a saturation point. If any more vapor is added, condensation takes place: that is, the vapor is observed in the form of dew, mist, rain, hail or snow.

Now by humidity we simply mean the amount of water vapor in the air. Absolute humidity is the weight of the water vapor per cubic foot of air. Generally when we refer to humidity, we mean relative humidity. This is the percentage of water vapor in the air with respect to the total amount of vapor that the air can hold at any one time at the given temperature. When we say that the temperature is 80 degrees and that the humidity is75, we mean that the air has 75 % or ¾ of water vapor that it can contain at a temperature of 80 degrees.

When the temperature is high [that is, when the air can hold a good deal of water vapor] and the humidity is also high, we find ourselves exceedingly uncomfortable.

On the other hand, our bodies need some water vapor; and in parts of the earth when the air is hot and very dry, human beings cannot maintain health for long. We are most comfortable when the humidity is neither too high nor too low. We can do nothing about it outdoors, but it can be regulated by air conditioning in offices and homes.

In America a unique way is adopted that to dig small/big deep earth to hold water for a long time, so even on high temperatures, the temperature do not go much dry.


Thanks to: "Brahma Mehrotra" brahma9151939@yahoo.com