Why does a desert cooler cool better on a hot dry day?

Answer 

A desert cooler works due to evaporation .

The water falling on the sides of the desert cooler is evaporated by the hot air. Hence, the water takes up the latent heat from the air and the air becomes cool and is spread in the room with the help of the fan. 

 

The rate of evaporation depends upon the temperature and the humidity(amount of water vapour present in air) .

Evaporation takes place faster when

  • Temperature is high 
  • Humidity is less

 

During a hot and dry day , the temperature is high and the humidity is less.  Both the conditions are favourable for evaporation to take place faster. 

Hence, a desert cooler cools better on a hot dry day, as compared to on a humid day.

Desert cooler cools better on a hot dry day-Teachoo-01-01.jpg

  1. Class 9
  2. Chapter 1 Class 9 - Matter In Our Surroundings (Deleted)

About the Author

CA Maninder Singh's photo - Founder at Teachoo
CA Maninder Singh
CA Maninder Singh is a Chartered Accountant for the past 11 years and a teacher from the past 11 years. He teaches Science, Accounts and English at Teachoo