Air Box Jr Pre-Filter Refill | 12 x 12 x 2 in Replacement

Why the Air Box Jr Pre-Filter Is the Part to Change Often Every filter stack has one part that should be treated as disposable, and this is it. The Junior pre-filter measures 12 x 12 x 2 in and sits in front of whichever main cartridge the housing carries, carbon or MERV 13 HEPA. Its job is the coarse load. Lint, hair, leaf debris and visible dust would otherwise blind a pleated element or pack the face of a carbon cartridge. Change it around every 6 months, sooner or later depending on how dusty the space is. It costs a fraction of the cartridge behind it and directly decides how long that cartridge lasts. How Often a Pre Filter Replacement Actually Pays For Itself A pre filter replacement is the highest-return maintenance item in a filtration stack, and the arithmetic behind that is simple. A low cost element changed twice a year protects a far pricier cartridge that would otherwise be changed twice as often. Hold the old one up to a light before deciding. If you cannot see through it, the main cartridge has been doing work it was never meant to do. In a room with pets, carpet or an unsealed floor, six months is optimistic and quarterly is more honest. Keep two on the shelf, since the change takes under a minute and there is no reason to defer it. Key Features 12 x 12 x 2 in element: The pre-filter size for the Air Box Junior housing, carbon or HEPA. Catches the coarse load: Lint, hair, leaf debris and visible dust, before they reach the main cartridge. About six month intervals: A starting point, shorter in a dusty or carpeted space. Low cost, high return: The least costly item in the stack, protecting the most costly one. Protects the pricier part: Directly determines how long the carbon or HEPA cartridge behind it lasts. One minute change: Comes out of the front of the housing with the unit still hung and ducted. Technical Specifications Specification Value Brand Air Box Product Junior Pre-Filter Refill Part Number 4501-P Fits Air Box Junior housing, carbon or HEPA Size 12 x 12 x 2 in Function Coarse pre-filtration ahead of the main cartridge Suggested Interval About every 6 months, shorter in dusty spaces Installation Front loading, no unhanging required