For those folks wanting to upgrade from a free-standing air purification system to a more sophisticated method of removing pollutants from your indoor air, an electronic air cleaner may be a logical step.
Electronic air cleaners can be free-standing but most units are mounted to your furnace.
In either type of air cleaner the method of operation is usually the same.
Air is drawn in through a pre-filter of some type, most commonly an aluminum mesh filter.
This filters out the big stuff like animal hair and other pollutants that are easily seen by the naked eye.
Smaller particles pass through the pre-filter and are ionized by receiving an electrical charge.
These charged particles continue until they reach grounded collector plates at which point they are trapped on these plates.
The treated air, free of particles, is then distributed to all the rooms in the house through the ductwork.
At regular intervals these collector plates are then washed with soap and water and re-installed to catch the next batch of junk in your air.
In most cases an electronic air cleaner can trap up to 98% of the pollutants in the air passing through your heating and cooling system.
This effectively treats most of the air in your home and does a much better job than a portable air cleaner that uses only a filter.
But keep in mind that this type of unit only treats the air that actually goes through the duct system and misses many of the "dead air" spots you may have in your home.
While this type of system works fairly well, one of the drawbacks is the initial cost.
Most furnace-mounted electronic air cleaners can cost $1500-$2000 installed.
In addition, these types of systems work best when the system is operated in the "fan on" or continuous mode.
This means the fan is always blowing whether or not there is a need for cooling or heating.
Offsetting this cost somewhat is the fact that there is no need to buy replacement filters, as the filter is built-in to the unit.