203372 Residential Grade Prefilter

• Residential Grade

Genuine Honeywell residential grade prefilters are available for only $39 while supplies last. 

The residential grade prefilters should be handled with care, since they have a weaker frame that can be damaged. Additionally, the mesh can be pulled out of the aluminum frame that holds the mesh like a spring clamp.

Honeywell Commercial Prefilter

Our prefilter is a Honeywell commercial grade prefilter. The commercial prefilter has more layers of expanded aluminum, starting with a noticeably heavier gauge, course grid. The commercial prefilter weighs 33% more, you can not see clear through this prefilter like the residential version.

The commercial prefilter has an exclusive vinyl bonding process so the frame securely grips the mesh. Also the corners of the frame overlap adding more strength. The flimsy residential prefilter twists and flops when handled, the commercial version is ridged.

We purchase these prefilters from the Honeywell Commercial Air Products division. These prefilters are made in Madison Wisconsin. Honeywell residential prefilters are stamped Product of Mexico.

Prefilter Efficiency Improvement

• Filter Coat Adhesive

Aprilaire 412 Super Filter Coat increases efficiency and dust holding capacity of prefilters used in electronic air cleaners.

The Super Coat adhesive have a unique viscosity oil in a gel-like straucture. This viscosity oil constantly absorbs dirt particles. As particles are trapped, they recede into the interior of the adhesive, and throught the circulation of the low viscosity oil a renewed impurity absorbing surface is established. This action provides a continuous impurity absorbing surface layer.

The aluminum mesh prefilters will maintain their initial efficiency with periodic applications of RP Super Filter Coat after cleaning. After a period of use of the prefilter, dirt, lint and the original water soluble adhesive coating are easily removed by simply flushing the filter in a stream of water. A new, easily-applied coating of RP Super Filter Coat can restores the filter's superior performance qualities.

• Material Safety Data Sheet
• Aprilaire 412 Product Data

Prefilter Washing

• Fiberglass Wash Tub
• CalClean Detergent

When cleaning the prefilter be careful not to flatten down the woven foil. The aluminum weave can be easily flattened with water pressure or when cleaning with a brush. Soaking the prefilters in a tub is recommended.

See your owner's manual for washing instructions.

• Honeywell Instructions
• White-Rodgers Instructions
• Cell Washing Frequency

F50E F50A vs F50F F300 Difference

Choosing a prefilter depends on the model and size. The F50F and F300 use the same prefilters and are available in 4 sizes. The F50A and F50E use a slightly shorter prefilter and are available in 3 sizes.

To determine your model, the photos show the difference is in the power box. The newer F50F-F300 have a full length power box because the contacts for the cells are built in to the power box.

The top-left photo shows the F50A and F50E. The F50A and F50E are identical except the F50E had been enhanced with an air flow sensor built in to the power box.

The lower-left photo shows the F300 and F50F model. Note the F50F and F300 are identical except for paint color.

The F300E was manufactured with a plastic access door from 2000 through 2005. This door and alll parts are interchangeable with all F50F and F300. The plastic door was the same as used in the F200E without RF (airwatch indicator).

F50A/F50E Series Difference from F50F/F300E

Photo shows an F50F series frame with both an F50F prefilter and an F50A prefilter. The F50A prefilter is shorter than the F50F prefilter. To reduce the need for residential distributors to stock a prefilter for both models, Honeywell made the F50A prefilter universal. The F50A prefilter has extender clips that allow it to also fit the F50F series. The photo shows the fit is loose. We stock both prefilters and do NOT recommend using the universal F50A prefilter in the F50F.

This information is provided because you may have noticed your F50F manual lists the 203373 prefilter as the replacement. The nice fitting prefilter that came with your F50F was the 203370. The 203373 would fit the F50F loosely.

If you have the F50A or F50E, then the 203373 is a good fit.

F 50A-E Prefilters are Shorter than F50F F300

The F50A and F50E have a shorter prefilter height because the prefilter slot is a separate channel mounted inside the chassis with phillips screws. The chassis height is either 16" or 20" on all F50-F300 models, but the prefilter height is shorter on the F50A F50E models so to clear the screws. The F50A and F50E prefilters are either 15¾" or 19¾" high.

The prefilter slot on the F50F and F300 is formed in to the chassis. There are no screws that the prefilter needs to clear. The cells are 16" or 20" high and the prefilters are also 16" or 20" high.

To the left is a close up view of the F50a F50E prefilter channel. Bumps are formed in to the channel to help the prefilter ride over the screw heads.

F50 F300 Cell & Filter Reference

Air Cleaner Size	20 x 12½	16 x 20	16 x 25	20 x 20	20 x 25
Model Number	F300A2012 F300B2012 F50F1040 F50F1057 F50E1349 F50E1331 F50E1075 F50E1067 F50A1116 F50A1108	F300E1001 F300A1620 F50F1149	F300E1019 F300A1625 F50F1073 F50E1307 F50E1281 F50E1174 F50E1158 F50E1034 F50A1033 F50E1018 F50A1017 F58E1002 F58A1001	F300E1027 F300A2020 F50F1032 F50E1323 F50E1315 F50E1190 F50E1182 F50A1165 F50A1124 F50E1091 F50E1083	F300E1035 F300A2025 F58F1000 F50F1065 F50E1299 F50E1273 F50E1166 F50E1141 F50E1026 F50A1025 F50A1009 F50E1000
F50 F300 Requires	1 Cell 1 Prefilter	2 Cells 2 Prefilters	2 Cells 2 Prefilters	2 Cells 2 Prefilters	2 Cells 2 Prefilters
Cell Dimention	20 x 12½	16 x 10	16 x 12½	20 x 10	20 x 12½
Cell Part Number	FC37A1064	FC37A1114	FC37A1130	FC37A1049	FC37A1064
F50F-F300E Prefilter	You are Here 203369	209989	203368	203370	You are Here 203369
F50A-F50E Prefilter	203372	209989	203371	203373	203372
Post Filter Part Number	50000293-004	50000293-001	50000293-002	50000293-003	50000293-004