This purifier is not very efficient. Medium speed was not working from day 1. It is better to go for air conditioner. Although it can detect pollution. This water profits does not clean it as expected. You can still see dust particles in sunlight’s beam. Kent customer care service is very bad. Service guys who have come so far probably saw this product for the 1st time in their life, did some time pass and left ABMs never turned up. Please don’t buy this product because it doesn’t have a good support.