Clearing the air
By James Dulley from April 2013 Issue
You do not technically improve the efficiency of your heating and cooling system by installing a high-quality central air cleaner or filter in the furnace/air-conditioner and cooling system. But it will keep the units running at their highest original efficiency. Most air cleaners use little or no electricity.
With a lower-quality air cleaner, such as the standard 1-inch-thick fiberglass filter, dust and dirt can build up on the heat exchanger and cooling coil surfaces. This dust creates a layer of insulation so that heat is not transferred as effectively, reducing overall efficiency.
If you don't change the filter often enough, dirt can clog the filter and reduce airflow. This further reduces efficiency because the heating and cooling coils and heat exchangers are designed for a specific airflow rate.
Manufacturers have begun producing new, super-efficient central air cleaners that trap almost all of the tiniest particles. They can even catch flu viruses and bacteria.
Keeping it clean
Standard electronic air cleaners use wires to give air particles a negative charge. A collection cell has plates with a positive charge so the negatively charged particles stick to it. When the collection cell is dirty, you can wash it in the dishwasher or bathtub.
It's important to regularly clean the collection cell of the standard electronic air cleaner to keep it operating at maximum performance and reduce the amount of ozone generated. When the cell gets dirty, the charge can arc from the wires to the collection plate. This may produce excessive ozone gas, to which some people are sensitive.
Another option is a pleated media air cleaner. This type of unit is less expensive and relies on many square feet of folded material to catch particles as the air passes through it. Effectiveness can be compared by the MERV (minimum efficiency reporting value) rating.
If you don't want to have the ducts modified to install a new air cleaner, consider a self-charging electrostatic model. This slips into the existing furnace filter slot and is many times more effective than a fiberglass filter
Stronger air filter comes with its own motor
A bypass HEPA (high efficiency particle air) cleaner has its own air circulation motor. A HEPA is a dense media filter, which makes it very effective, but it may create too much resistance for the furnace blower to force adequate airflow through it. The bypass design has its own blower so the airflow through the coils or heat exchanger is not impeded.