Honeywell Air Filter High-Efficiency TRN2121R1/E, 21x21.5x5 - Merv 10

The Honeywell TRN2121R1/E High Efficiency Air Cleaner Filter is designed for Trane or American Standard Perfect Fit. Featuring an impressive MERV 10 rating, these filters are 20 times more efficient than typical 5 inch pleated filters. The filters are also excellent candidates for capturing a very high percentage of invisible household airborne particles. These filters last up to six months and no longer require an HVAC representative to service and replace your unit's filter. Establish an unrivaled breathing experience for you and your loved ones with Honeywell and their second to none series of Filters.

MERV = 'Minimum Efficiency Reporting Value' this is used to rate the overall effectiveness of an Air Filter. Below you will find a table that measures the MERV strength and tells you the Application of each unit's effectiveness. In general an Air Filter with a higher MERV Rating is more effective and has a broader application, but most residential homes will find the best use from an air filter between the 5-12 MERV rating.

MERV RATING	MIN. PARTICLE SIZE	TYPICAL CONTROLLED CONTAMINANT	TYPICAL APPLICATIONS
1 - 4	> 10.0 Micrometers	Pollen, dust mites, cockroach debris, sanding dust, spray paint dust, textile fibers, carpet fibers	Residential window AC units
5 - 8	10.0 - 3.0 Micrometers	Mold, spores, dust mite debris, cat and dog dander, hair spray, fabric protector, dusting aids, pudding mix	Better residential, general commercial, industrial workspaces
9 - 12	3.0 - 1.0 Micrometers	Legionella, Humidifier dust, Lead dust, Milled flour, Auto emission particulates, Nebulizer droplets	Superior residential, better commercial, hospital laboratories
13 - 16	1.0 - 0.3 Micrometers	Bacteria, droplet nuclei (sneeze), cooking oil, most smoke and insecticide dust, most face powder, most paint pigments	Hospital & general surgery
17 - 20	< 0.3 Micrometers	Virus, carbon dust, sea salt, smoke	Electronics & pharmaceutical manufacturing cleanroom