Hello Everybody
Can you people help me to understand the following questons in simple ways?
1). What is humidity how does it effects.
2).what is humidification and de hmidification?
3).In refregeration what is the meaning of
a)cooling and dehumidification
b)heating and humidification(please explane in simple language).
4).what is relative humidity? How does it changes with wheather?
Waiting for your kind replies.

Hello mdahmed

What have these questions to do with mechanical engineering?
Looks me to be more homework questions...
Just let me know and I will help you afterwards.

Hello mdahmed

Just to give you a hint to find your own answers to these questions :

Go to www.google.com (http://www.google.com) and use the search word humidity
Do the same - one by one - for your other search words as per your question.

Humidity has to do with the amount of water vapor in the air.
All your questions have to do with that.

1) One has lots of answers. The primary one being "creature comfort". Do a search on "Comfort curve".
2. Way too simple of a question.
3a) Cooling naturally dehumidifies the air
3b) Heating may also remove water. Water may need to be added to air.
4) again, way too simple of question.
4b) ex: If it rains outside RH increases sometimes to 100%.

These answers are not complete.

Humidity is moisure in the air. Relative Humidity is the amount of moisture in the air as a percentage of what the air at that temperature and pressure can hold as maximum amount of moisture.

Humidification is addition of humidity to the air, Such as when we use steam humidifier.

De-humidification is the removal of humidity from the air. Such what a cooling coil will do and you see it as a water dripping from indoor air conditioning unit.

Cooling and dehumidification: basically a coil that is used to cool the air and by cooling the air low enough it will remove moisture from the air this "low enough temperature" is called dew point temperature.

Heating and humidification: heating is simply heating the air. Humidification is adding moisture to the air. Heating and humidification goes together because heating of the air causes drying of the air thus we need to add moisure to the air.

Relative humidity cajnges with the temperature and pressure of air.


Hope this help