Pros: 5-speed fan adjusts to different room sizes, relatively quiet on lower speeds.
Cons: A bit loud on highest fan setting.
Let me start by saying this is not the first Vornado product I have used. I recently purchased the 610W air circulator, which is a remarkable little fan. (More on the 610W in another review).
The AQS35 is the top of the line Vornado air purifier. It has 5 fan speed settings as opposed to the smaller models which only have 3.
Setup is a breeze (pardon the pun), with the unit all set to plug in and use. There are 2 filters in this unit. The first is a pre-filter for odors and then the air passes through the HEPA (High Efficiency Particulate Arrestor) filter. The HEPA filter is the one that traps all the minute particles of dust, pet dander, pollen, and other allergens. The unit comes with 2 extra pre-filters, but only the HEPA filter that is on the unit. The pre-filters are designed to last 3 to 4 months before needing replacement. Vornado recommends replacing the HEPA filter every 2 years. Interestingly, the effectiveness of a HEPA filter will actually improve over time, trapping more and more particulate matter.
I began shopping for a HEPA air purifier when my 4-yr old daughter developed allergies during what has been one of the wettest, most pollen-filled spring seasons in history.
I needed to get her something that would eliminate as much of the allergens as possible, especially in her bedroom.
I was amazed at the high prices of many of the HEPA filters on the market. Some cost as much as $1300, and these are not even whole-house units! It's true that they are more powerfull than the Vornado unit, but the fact is, the Vornado will clean any size room up to 20x20. It has a nice built in handle feature and it's not very heavy, so it can be moved from room to room without much strain.
A nice feature on the Vornado is the little chart on the top of the unit that tells you what fan speed to set the unit to according to the room size. A small room of 10x12 would have you set the fan to speed 1. A 12x14 to speed 2. In addition, there is the "Quick Clean" speed, actually just the highest speed (5). Vornado recommends using this speed to clean any size room in 30 minutes, and then reset according to room size to maintain the clean air.
There is a "Change Filter" light on the top of the unit that stays green if your filter is fine, and does not need replacement. Once the light goes off, it's time for a new HEPA filter. Which brings us to replacement filters: they aren't cheap, usually priced as high as $50. This is not unique to the Vornado units though, as almost any HEPA filter is expensive.
I like the way this unit blows the filtered air directly up above the unit. This is a good idea for 2 reasons: 1) by blowing directly upward, there isn't a blast of air across the floor, which would further stir up allergens that had settled...2) you are not restricted in placement of the unit, just as long as the top stays clear and the front is not blocked, this unit could be placed right against a wall.
So far, the Vornado has performed wonderfully, and the air is noticeably cleaner. It will actually remove odors as well as allergens, and my daughter is sleeping much better these days.