Tough Questions about Air Purifier Efficiency

How can the DC1100 be used to improve my home air quality?

The Dylos DC1100 is a tool which gives you information about your indoor air quality. It is a Laser Particle Counter which counts and sizes the invisible particles polluting your home air. With this knowledge you can take intelligent steps to improve your indoor environment. Since the DC1100 gives you an actual count of particles you can adjust those steps to achieve the amount of cleanliness you desire. Quality air purifiers and air cleaners are expensive, but without a way of measuring the cleanliness of your air you cannot know how well they are working in your house.

My air purifier has a built in air quality monitor. Isn’t that good enough?

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.

How is the DC1100 better than my built in air quality sensor?

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. With this ability the DC1100 cannot only count the particles, but it can also size them based on the amount of light they scatter. For convenience sake, the DC1100 displays two particle counts – small and large. The large particle count includes pollens, dust mite debris, insect feces, coarse dust, etc. The small particle count includes most bacteria, mold, fine dust, etc. The small particle count can range from many thousands down to zero so the home owner can measure his air quality with vastly greater resolution than is possible with 5 green LEDs.

Can the DC1100 tell me if my air purifier is working effectively?

Yes. With the DC1100 you will know the actual number of particles suspended in the air within the unit’s 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.

If the manufacturer says the air cleaner will clean 1,000 square feet should I believe this?

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.

Do high particle counts on the DC1100 mean that I am at increased risk for an asthma attack or other respiratory problem?

While a growing body of research has shown a direct link between increased levels of particulates and increases in asthma attacks, respiratory problems, and even acute cardiovascular events (see our Studies and Reports page) you should consult your physician with any concerns. The DC1100 is not a medical device and is not intended to be used in the treatment or mitigation of any disease.

How much reduction in particulate pollution is possible in the average home?

This is a tough question. We think 90% is easily obtainable with high quality air purifiers, air cleaners, filters, and good practice. This may not be enough and you may want to push the limit. Average counts in the 10 to 20 range on the DC1100 are possible. The air quality throughout the home will vary significantly, but we believe average readings in the 10 to 20 range are possible which, if the outdoor ambient is 500, results in a 96 to 98% reduction in particles within the detection range.