This ionizer works great year round to keep the air in my house fresh and crisp. It is sort of like an air duct cleaning blowing through the house. I use it all year long because we are smokers. Since I have been using it, allergies have been reduced an I know that me and my family are all breathing much better. It really helps a lot. It is big enough to work inside of my living room but can also be used in a bedroom or other room in the house. Although it is powerful, it is compact in size so you don't need a lot of room to sit the machine. It has an awesome cool which really adds style to my house. And, it is really quite in operation, so sometimes I do not even realize that it is on. Best of all, it is energy efficient so it does not cause my bills to increase.