My wife and I purchased the Allen BreatheSmart HEPA Air Purifier in January of 2014 and the results were amazing. We noticed there was no dust on our TV stand or on the top of our appliances. We both suffer from allergies and within two weeks our allergies significantly decreased. We were able to breathe easier and with less red puffy eyes. We placed the air cleaner near the intake of our air conditioner and when I went to replace the filter 60 days later, it had very little dust on it. We liked the Breathesmart so much that we just purchased the Alen BreatheSmart FIT50 HEPA Air Purifier as well. The Air cleaners are both quit when on high and I did notice any change in my electric bill.