I've had my air filter in the bed room ( a larger than usual size room) because I always got congested when I slept.  I live in San Antonio which is famous for its allergens so I wasn't sure it would make a difference.  I noticed how much better I slept on the first night!  I've had my Blueair for about a year and I wouldn't give it up.  Ordering replacement filters is easy.  I'm very pleased with this product.