air purifier

Why is "fresh air" fresh?

A big, deep breath of fresh mountain or seashore air. Makes you feel good physically, mentally, and spiritually, doesn't it?

Scientists are attempting to discover just why it is that, say after a thunderstorm, people seem so energized. Or why when a dry hot wind blows off the desert people seem to irritable.

They've learned that one reason for that good feeling is the "balance" of elements (including Ozone and negative ions) in the air we breath. When the air is "balanced" or regenerated by lightning and moving water (waterfalls or ocean waves) our mood is light and spirits lifted. When the air is "unbalanced" by pollutants such as dust, bacteria, chemicals, etc., we're discomforted -- our moods are darker, we don't feel as good as we think we should.

The beauty of negative ions

Actually the preferred method of rating air purifiers is the CADR which is based on how fast the air cleaner or air purifier cleans the air in a sealed room. This is a useful rating for comparing one air cleaner to another. The problem with this concept is that we don't live in sealed rooms. The truth is that you cannot predict how clean the air will be in your house based solely on the CADR. Nobody's home is perfectly sealed, doors open and close, and particles are generated by virtually any activity within the house. So, the number of particles floating in your home air is the result of a constantly shifting balance between particles entering the home, being generated within the home, natural settling, and active removal by air cleaning devices.

The DC1100 works on an entirely different technology than the inexpensive sensor built into your air purifier. The DC1100 is a true Laser Particle Counter that works on the same principles as the $8,000 particle counters used in pharmaceutical and semiconductor clean rooms. Those guys really do need to know how clean their air is and they don't use sensors like the one on your air cleaner. Those cheap sensors usually have an LED and photodiode arranged at an angle so the photodiode will pick up any light scattered back off the particles in the air. This design is inexpensive, but suffers from very poor signal to noise ratio and can only detect light scattered off many particles in a volume of air. In contrast, the DC1100 uses a focused laser which results in a drastically higher signal to noise ratio. This means that air can be flowed through a focused laser beam and the DC1100 is actually sensitive enough to detect individual particles.

We have yet to see a decent quality monitor on either an air purifier or an air cleaner. They typically display air quality as only "good", "clean", 5 green LEDs or some other vague way which gives the user no real information. Our tests have shown that these inexpensive type air quality sensors are inaccurate, with a tendency to drift up and down. Furthermore, they have the major limitation of only measuring the air quality right at the air purifier or air cleaner. Of course that is where the air is going to be cleanest, but unless you have the air purifier strapped around your neck it is not the air you are breathing. Besides, does it make sense to trust your air purifier to tell you it's doing a good job? So, these built in sensors are essentially a gimmick and worthless to anyone serious about improving their air quality.

Yes. With the DC1100 you will know the actual number of particles suspended in the air within the units detection range. The numbers displayed are scaled to correspond to approximately what a 12 year old would inhale with each breath. If the counts drop from 600 to say 60 then you know that you have reduced the detected particulate pollution by 90%. How much a reduction you see corresponds to the effectiveness of your air purifiers and air cleaners.