The U.S. Environmental Protection Agency estimates that the air inside your home may be up to five times more polluted than outdoor air. Trane, a manufacturer of heating and cooling equipment, is offering up a solution to the mold, mildew, pet dander, pollen, cooking grease, etcetera that is trapped indoors by today’s energy-efficient homebuilding techniques.

The company’s new CleanEffects filter system claims a 99.98 efficiency rate in filtering airborne particles down to a size of .3 microns. How big is .3 microns? About 1/300th of the diameter of an average human hair.

The filter is installed in the return duct of a home’s forced-air system. As the existing fan pushes air through the HVAC ducts it passes through the filter’s multiple stage system. A typical one-inch filter is the first line of defense against pet hair and other easy-to-grab particles. Next, the airborne particles pass through an electrified grid that adds a charge to the tiny particles. Finally, the namesake CleanEffects filter traps the charged particles before the air is heated or cooled and sent back to the living room. The filters are washable.

I watched a simple test (using a not-so-simple machine called a laser particle anaylyzer) that demonstrated the results. An air sample from a room was taken and showed a reading of about 30,000 to 40,000 particles per cubic centimeter of air (think: size of a sugar cube). The same machine was then used to test air that had passed through the Trane filter system. The reading dropped to 5,000 to 7,000 particles per cubic centimeter.

Trane estimates the installed cost of the unit (including contractor’s fees) to be around $1400. It can be retrofitted to work with existing forced-air heating and cooling systems. The unit itself uses very little electricity; however in order for it to work, the fan that circulates hot and cold air in your home has to be running.