Electronic Air Cleaners, The Basics

Electronic air cleaners are designed to remove pollutants from indoor air. Most of the units operate using the principle of electrostatic precipitation. Most of us have played with a couple of magnets before. We have seen how the two magnets are attracted to each other if they are turned the proper way. That is what electrostatic filters are based on. The pollutants are given a charge and then they are attracted to a material with the opposite charge. This attraction results in the removal of the pollutant from the air which is know as precipitation. An electronic air cleaner (eac) can be a portable unit or it can be attached to your central hvac system. Some of the units are the same size as a standard filter and can be installed in the existing filter opening in a forced air duct system. They are more commonly referred to as electrostatic air filters and use a much smaller electrical charge. Other units require modification of the duct system. These units work by establishing an electrical field. Then, the hvac system blower pulls air into the unit. First, the air passes through metal filters called pre-filters. Here, the larger particles are trapped and the smaller particles pass through to the ionizer section. Here they receive an electrical charge and pass into the collector section. There are thin metal plates in here with the opposite electrical charge. The particles are attracted to the plates and collected there. Finally, the air exits the eac to be conditioned in the hvac system.

Electronic Air Cleaners, Pros & Cons

An eac can remove small particles but cannot remove gases or odors. They can remove these very fine particles without significantly reducing the air flow through the hvac system. For example, they will remove the small particles in tobacco smoke but the smell and gases will remain in the air. Also, these units require monthly maintenance. This includes removing the pre-filters and cells and washing them. Most of them can simply be put in a dishwasher to be cleaned.

**HOT TIP** Do not run them through the dry cycle in the dishwasher as this can cause possible damage. It is better to let them simply air dry.

Keep in mind that, if the blower on the hvac system is not running, these units do nothing. Therefore, to get the full benefit, the blower must run continuously. This will raise your electric bill. This increase can be minimized with a variable speed fan motor. They also make a popping noise when particles are trapped. Lastly, they are pretty expensive (~$500) to install.