1)The cooling in a desert room cooler is caused by the process of evaporation.It cools better on a hot dry day because the higher temperature of the atmosphere increases the rate of evaporation which gives better cooling effect.
2)Cotton clothes are good absorber of water and they have larger size of pores . On hot summer day the cotton clothes absorbe more perspiration from the body and help in faster evaporation giving better cooling effect as compared to the polyester clothes.
3)The earthen pots has a large no. of minute pores in its walls, which help in continuation of the process of evaporation. The latent heat taken for this process from inside water, makes the water kept in pot cool.
1.Hot and dry air passes through the wet pads of wood shearing. Water takes heat from the hot air and evaporates resulting in the cooling of the pads and circulating water.As a result , incoming air also gets cooled down.
2.In summer, we perspire more due to body mechanism to keep us cool.Cotton is a good absorber of water due to pores in it.So it absorbs the sweat from our body and exposes it to the air for evaporation resulting in the cooling of our body.
3.An earthen pot has small pores.Water comes through these pores and evaporates by absorbing heat from the inner water.As a result , the water inside the earthen pot gets cooled.