Electrostatic Air Cleaner

An electrostatic air cleaner uses static electricity to charge the particles in the air. These machines can remove particles from flowing air. It can remove dust, pollen, smoke and other allergens.

They have been around for a while. In fact, the first patent was applied for in 1907.

How They Work

An electrostatic air cleaner must have a fan to push or pull air through the purifier. If the air isn't moving, it cannot be cleaned.

Inside there is a row of thin vertical wires. As the air passes over them, they are subjected to a high voltage discharge. This gives the particles in the air a charge (usually negative). This is commonly called ionization. Ionic air purifiers use technology similar to this.

Next, the air passes through a stack of large metal plates. These are called collector plates. In household air purifiers they are spaced about 1 cm apart. The plates have the opposite charge (usually positive).

The particles in the air are attracted to the plates. They stick to the plates and are removed from the air. As long as the plates maintain their charge, the particles remain on them.

Although they both produce negative ions to charge the particles in the air, this is not a negative ion generator.

Problems

There are two things we don't like about electrostatic air cleaners.

1. They are messy to clean.

   • In most home air purifiers the collector plates are spaced closely together, about 1 cm apart. They cannot be separated so it is very difficult to clean the whole plate. There are two solutions to this problem. Some collector plates can be washed in the dishwasher. Others have a special solution to soak the plates in overnight.

   • The dust, pollen, and other particles from the air are collected on the metal plates. This means the plates can become very dirty. The particles can bond, like glue, to the plates. This makes it even more difficult to clean the plates. Now this can be avoided by regularly cleaning the plates.

2. Electrostatic air cleaners can produce ozone and nitrous oxides. Both of these can be harmful to our health. If the charging station is before the collector station, then there should be minimum ozone released. Check to be sure that no ozone is produced by the machine.

Advantages

The biggest advantage of these air purifiers is there are no filters to replace. They are really permanent filters. You only have to wash off the collector plates and put them back in the air purifier. You will never have to buy another replacement filter. This can potentially save you hundreds of dollars a year.

What We Think

We think electrostatic air cleaners are very effective. They can do a great job of cleaning the air. In theory. In practice, however, we see a wide variety of effectiveness.

You like the permanent filters. Spending no money on replacement filters sounds great, doesn't it?

There are a few things to look out for when you are shopping for an electrostatic air cleaner.

1. The air purifier must have a fan. These air cleaners cannot work if the air doesn't move through them. Some manufacturers have produced air purifiers that use electrostatic filters but they don't have fans. They don't work! We can't stress this enough: If there is NO fan, it will NOT work.

2. Make sure it produces NO ozone or other by-products. Any reputable manufacturer will state how much ozone is produced. It should be under the 50 ppb (parts per billion) recommended by the FDA. If the package doesn't say this you should contact the manufacturer. You can also email us and we will do our best to help you.

3. Be sure to check how often the plates should be cleaned. This will also vary depending on how dirty the environment is. The dirty the air is the more often you will have to clean the plates. The biggest reason why these kind of air purifiers stop working well is because the plates are not cleaned. As long as you keep the collector plates clean, it should keep working.

   There is a trade off you make with permanent filters. You may have to clean the plates once a week. With a normal HEPA filter you put them in and forgot about them for months.

If you really want to use an electrostatic air cleaner, we recommend you get a combination air purifier. Find an air purifier that uses an ionizer together with a HEPA filter. BlueAir makes air purifiers like this. They combine a ionizer with a HEPA filter. They are highly effective at cleaning the air. They release no ozone or other by-products. We recommend you take a look at these air purifiers.