I just received our Alen 45i and 75i air purifier less than a month ago. I was impressed right from the start. They are both nice looking, easy to operate and so very quiet I sometimes have to look to see if they are on. I ordered the Fresh True HEPA Filter since I have a ventless gas fireplace. They state that it protects against toxins like volatile organic compounds (VOCs), pollution and smoke. I have noticed a difference already. It is more than I wanted to spend, but air quality is so important to life.
The 45i arrived on time and very well packaged. It works as advertised. Very quiet, even on turbo. I got readings of 35, 37, 45, and 49 decibels on each of the speeds with a background of 34. On auto it stays mostly on speed 1 or 2. When I cook or open the windows it ramps up. I went with the Heavy Smoke filter as fire season is approaching. I also have a T300 and a T500, all in a 600 sq. ft. apt. Not sure why they quit making the T300. It is superior to the T500, in my opinion and has more filter surface. The 45i has more surface than both T units combined. It really rounds out my air purification stable. Worth it.
Even the packageing was exceptionally well thought out. I have never bought an appliance that is so totally well throughout and manufactured. It works extremely well. The functions panels simple and easy to use. I have 3 of these outstanding air purifiers. They are so quiet, and what I can hear of the fan is a lovely, soft sound, The fact that they have wheels on them like a piece of airplane luggage is also ingenious along with the perfectly place handle on the top. Moving it around is so easy. I bought the filters that are designed to deal with wildfire smoke, which we get so much of here in Bend, Oregon
The unit is very quiet and there is really nothing to the setup. I have developed a dry throat problem, both at night and during the day, which seems to be related to allergies. The doctor recommended an air purifier in the bedroom, and it does seem to be helping quite a bit.