I am also not sure about this but, as I could understand the 2000 series is newer a bit but smaller and can filter the air in a bit smaller rooms than the 3000 series. Also the 2000 can be controlled over your phone.

I was not happy with this product for me from the beginning on showed me that the air in my house it absolutely clean even with open windows during the highest pollen alert period. After a week of working really did not feel any difference when my windows were closed.

At the end the devices showed me an error and I could never turn it on anymore , so I took it back to the shop.