Subject: Can lowering the partial pressure of water in the air create evaporation?

I understand that there is a gross evaporation and a net evaporation.  I know energy (heat and air 
movement) creates gross evaporation. I have been told that condensation is always occurring and 
reducing that will increase the net evaporation.  I am confused, will lowering the partial pressure of 
water in the air create a vapor pressure differential and will that create a gross evaporation?  Is the 
only way to create gross evaporation by heat/energy or is there such a thing as vapor pressure 
differential that creates gross evaporation?  I am thinking it only increases net evaporation. 
Thanks in advance, I just learned that air doesn't actually hold water and has got me thinking. 

Re: Can lowering the partial pressure of water in the air create evaporation?