High Efficiency & Electronic Air Cleaner's

Gate City Sheet Metal Home

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High Efficiency & Electronic Air Cleaners

Is Your Home Too Dusty ?

Electronic Air Cleaners (EAC's) and High Efficiency Air Filters (HEAF) help clean the air in your home and provide respiratory relief by removing dust, dirt and even pollen. They are designed to trap even microscopic particles, so cleaner air is circulated back into your home.

Removing air born dust and dirt benefits the people breathing the air and the machinery moving the air. Dirt accumulates on bearings and motor windings and gradually restricts air flow through a heating or cooling coil and settles in ductwork.

Collecting the dust from before it passes through the furnace or air helps to protect the machinery, and the filter should always be installed in the return air duct.

Mechanical or adhesive filters are the least expensive but the least efficient. Constructed of spun fibers shaped to form a mat, they are framed with cardboard to specific sizes. As air is moved across the fibers, dust is attracted and sticks to an oil film or glue sprayed on the fibers. This type of filter collects between 6% and 8% of the dust passing through when new. Efficiency will increase as the filter gets dirtier, but air flow will be restricted as well. Available at many hardware and retail stores, they are inexpensive, and should be replaced monthly if the system is in constant use.

Some manufacturers include a new filter with the equipment that is rubber coated and washable. Coarse fibers are rubberized to bind them together and make them sticky. As air passes through, dust collects on the fibers. A blast from the sink sprayer or garden hose will rinse the dirt away and ready the filter for re-use.

A better mechanical filter has been developed, called a media filter, that begins it’s life removing more dust (about 75%) and gets more efficient with use. It approaches 99% eventually, but also becomes too restrictive for proper air flow. This filter is made of paper or synthetic fabric, woven just loose enough to allow air to pass, but tight enough to trap particles as small as pollen.

Anywhere from one to five inches thick, the media is pleated to allow as much surface area exposure as possible. A cardboard frame keeps the filter in the proper shape and gives it enough rigidity to prevent collapse from air pressure.

The one inch thick pleated filters need to be replaced as often as the spun filters, but the three to five inch thick pleated filters can last 6 months to a year. Dirt build up is visually noticeable; frequent inspection will help determine life expectancy. Replacement media filters can be found at HVAC and some plumbing supply stores. The one inch thick pleated filters are designed to replace the spun filters, and are available at retail and hardware stores.

The simplest filters are made of fiberglass and are disposable. Others are washable screens.

High performance media filters use pleated paper or spun materials to collect microscopic dust particles as the air passes through.

Electronic air cleaners put an electric charge on the dust particles as they enter the grids and collect the dust on plates that are also charged. In the process of putting an electric charge on the dust, ozone is created, which helps kill bacteria and odors.

Electrostatic filters use the motion of air across a weave of synthetic threads to create a static charge on the dust and collect it.

Electronic air cleaners lose efficiency as they get dirty, and should be washed monthly when in constant use. Loud snapping noises that continue through the entire heating or cooling cycle are signs that the grids need cleaning.

Non-electric filters will increase in efficiency as they get dirty, but also decrease in airflow. The balance between cleaning efficiency and proper airflow is difficult to define. Experience and familiarity with the system’s performance is the best guideline.

Full air flow is critical to the performance of a central air conditioning system; clean filters are a must. The wet cooling coil will collect a great amount of dust particles as the air passes through.

...........Electronic Air Cleaners

The most efficient air filter for improving air quality is the electronic air cleaner. Air returning to the furnace or air handler passes through a screen to trap any large dust particles or objects. Using line voltage to power circuitry, a positive electrical charge of high voltage (upwards of 12,000 volts) is sent through fine wires stretched across the air stream immediately behind the screen. The dust particles pick up a positive charge, then pass through plates or grids that are negatively charged. Opposites attract, and the dust particles collect on the plates. Smoke is microscopic particles, and is trapped as well. Ozone is created from the charged air, which helps kill bacteria and odors.

Electronic air cleaners will usually operate at 95% efficiency, allowing little or no dust to pass through. The dirtier they get, the lower the effectiveness, so clean grids are a must. Before removing the screens and grids for cleaning, it is imperative to shut the power off and wait a few seconds to allow the grids to lose the static charge. They are dishwasher safe as long as they fit inside. If not, sloshing around in a tub of hot soapy water will loosen dirt that can be blasted off with a garden hose.

Extreme caution must be taken when handling to protect the grids and the person handling them. The plates are very sharp, and can cut like razor blades. The fine wires stretched across the grids are delicate and crucial to proper function. Proper spacing between the grids is important. Do not bend or distort them.

If the grids are not completely dry when installing them, do not turn the power back on; damage to the power pack can occur as the water will short the grids out. If in doubt about the dryness, leave the power switch off for a day or two; the air flow will take care of any residual water. Arrows one the grids will display the correct direction for air flow. Improper installation will render them useless. If the air cleaner was installed correctly in the return air duct by the original HVAC mechanic, air flow will be going from the duct toward the appliance. The arrows should do the same.

Troubleshooting falls into two categories: Grid failure or power failure. Excess dirt or a large object stuck in the grids will cause an electrical short. A loud snapping noise will sometimes indicate this problem. If cleaning does not stop the snapping and the grids are bone dry, inspect the fine wires stretched across the terminals. If they are white from oxidation, gently run an old soft toothbrush up and down them once, then rinse and dry again.

Most electronic air cleaners have a light to show operating power. If the light is not on when the system is running and the switch is on, there are two possibilities. The power pack has burned out, the power to it has been disconnected, or the unit has a pressure switch to sense air flow and charge the grids and it has failed. Either repair means opening up the power pack, exposing dangerously high voltage. This task should be left to a qualified technician.