Philips Air Purifier a good product

I just started to use my air purifier Philips since may of days I thought would be useful to me because I have respiratory problems from allergies standing but I had a big doubt, but I have to go to Clearly I start see a significant difference in the air quality and even the smells of my house when I made the kitchen frying eg. the unpleasant smell disappears very quickly. Philips thank you for this quality product little less pleasant point is the price of the filter because you are forced to change from time to time I find a high but can if not everything is perfect ..... very nice plus it designates is perfect for silent night