An Oreck 5 stage air purifier uses 5 different filters to clean the air. What are these filters and how do they work?
5 Stage System
It is actually advertised as a 6 stage filtration, but we only counted 5 stages. We'll show you the reason for this difference in a minute.
This is a picture from Oreck's website. It shows the stages of filtration inside their air purifiers. All Oreck Purifiers have the same filtration methods. They all follow the same five stages. Let's look at each stage.
Starting at the bottom with stage 1. This is a pre-filter. It is designed to trap the larger particles of dust and allergens that are in the air. Most air purifiers include these. They do a good job of removing the larger particles. This is desirable for 2 reasons.
The pre-filter is a permanent filter. It can be cleaned and used again and again.
This is the electrostatic filter. The heart of the Oreck 5 stage air purifier, the Truman Cell. The filter has two parts to it. Oreck considers this to be stage 2 and 3. In the picture it is labeled 2 and 3. We put them together, because you can't have one without the other.
The first part is the charging station. Here air is subjected to a high voltage electric charge. Hence the name electrostatic air filter. This is where the particles in the air receive an electric charge.
The second part are the collector plates. The plates have the opposite charge. When the particles pass through, they are attracted to the plates. They remain on the plates until you wash them off.
Keeping the plates clean is very important. Over time the layer of particles gets thicker and thicker. This cause the air purifier to be less effective at cleaning the air.
A more detailed explanation of electrostatic air cleaners can be found here.
This is the odor absorption stage. Odor absorption happens when the air comes into contact with activated carbon. The carbon reacts to the chemicals in the air. To put it simply the chemicals become trapped by the carbon and can't get back into the air.
We think that there is not enough carbon in this filter to effectively filter out odors. It might do a little good and it is better than nothing. If odor removal is your primary concern, this will not do a good enough job for you.
This is what Oreck calls a Oxygenator. It is a metal based filter that supposedly converts the harmful ozone into oxygen. The early Oreck 5 stage air purifiers were missing this filter. As a result they were criticized for releasing ozone in the air.
We hope that this really works well. Ozone is a by product of electrostatic air cleaners. If this can remove the ozone, then we are all for it.
The final stage is the Air revitalizer. This is a small negative ion generator. It releases negative ions into the room.
Negative ions will freshen the air and help remove dust from the air. They have also been reported to improve people's moods.
This is optional and can be turned on or off.
This produces negative ions and as a byproduct it will produce ozone. Since it is after the 'oxygenator," the ozone will be released into the room. Oreck says the emissions of ozone meet the FDA guidelines of less that 50 ppb (parts per billion.)