Bests & Worsts Reviews from Amazon

Why I bought the Alen BreatheSmart: I recently found out I am quite allergic to dust. I live in Hong Kong where pollution can be dangerously high. I started researching air purifiers and ended up choosing the Alen BreatheSmart because 1) They have great reviews. 2) They offer a reasonably priced unit (in the premium range) that could cover a large space (1000 sqft). 3) They offer a Life-Time Guarantee and seem to have good customer support. I ended up buying two units (one for home and one for office) with the upgraded silver filters. I was very excited and eager to try them. What happened: When I first turned on the unit (in the office), we were taken back and surprised by the noise it made. It was extremely loud even at the lowest setting. We brushed it off and thought it was putting overtime in and doing its job since it was new. Maybe the noise will improve we thought. After a few days, it did not improve and we decided to turn it off during the day when we were working and turn it on during the night when we leave. I was suspicious about the noise (being a product designer myself), something didn't sound right. Sounded like there was a problem with the fan. One day I came into the office and the unit did not even turn on. It broke in less than 1 week of use. The EXACT same thing happened to the other unit I was using at home. The video uploaded is the noise it made at the lowest setting. Pretty ridiculous. I could only upload one video per review so I cannot upload the new replacement they sent, which is ALOT quieter and does not make the 'broken' noise. So at least now I know for sure that the two units were 100% faulty. UPDATE: So the replacement unit started all good but now it's making another type of noise and it's very annoying again. The unit has only been on for less than 1 hr! What is going on here Alen? Asking for the replacement units: It was very straight forward and easy to get the replacement units through Amazon, but they only cover 50 USD for the entire order. That means I have to now send back 3 units from Hong Kong and I will have to pay over 400 USD in delivery. I paid 475USD for two units deliver to Hong Kong. Ridiculous. TIP: If you have thrown away the packaging, wait until the new one arrive so you can use that packaging to send it back. Otherwise, you'll have to spend and repack everything yourself. Overall experience / theory / conclusion: What are the chances that now 3 units are all faulty?!!! I have never in my life experienced this type of faulty products 3 times in a row. I have two theories: 1) The units were damaged during the delivery stage- I see there are dents and marks on the packaging itself, meaning the boxes were probably being thrown around. The build quality is very poor as well. 2) I HIGHLY SUSPECT they reuse the parts and refurbish the faulty units and send them out as new, which leads to a bunch of obvious problems down the product's life cycle. After 3 faulty units in a row, I have lost all confidence in this brand. Maybe a freak coincidence? I do not believe so. After spending over $2000 USD on this purchase (with a bunch of upgraded filters), in my own humble experience with this product- I HIGHLY DO NOT recommend this. STAY AWAY AT ALL COST!