Home › Furnace filters › ML193UH
Our script found these filter sizes in the Lennox ML193UH source document's filter table: 16x25x1, 20x25x1, 24x25x1. This page is pending human review, so check the source excerpt on the page to see which size applies to your cabinet and return.
Auto-extracted · review pending Filter sizes auto-extracted from the manufacturer document.
| Sizes found in the source table |
|---|
| 16 x 25 x 1 |
| 20 x 25 x 1 |
| 24 x 25 x 1 |
Extracted by script from the linked document. Read the excerpt to see which size applies to which cabinet or return.
General guidance (not from this manual): check monthly and replace 1-in. filters every 1–3 months, or follow the filter maker's guidance and your owner's manual.
Pull the old filter and read the size printed on its frame. Nominal sizes are rounded up: a 15.5 x 24.5 in. filter is sold as 16 x 25.
Your furnace manual lists the filter's dimensions, not its MERV rating. Higher-MERV filters restrict more air. Manufacturers such as Carrier recommend keeping the clean-filter pressure drop under 0.2 in. w.c. (ideally under 0.1). Lennox warns that an over-restrictive filter can trip the high limit in winter and freeze the coil in summer. If you want MERV 11–13, a 4-in. media cabinet is the usual route. Ask an HVAC tech to check static pressure. Nominal sizes are rounded: a filter labeled 16 x 25 x 1 actually measures about 15.5 x 24.5 x 0.75.
Manufacturer document for Lennox ML193UH
Last checked 2026-10-25. Manufacturers revise documents. If your unit's label disagrees, trust the label.
can Society for Testing and Materials (ANSI/ASTM) stan
TABLE 1 dards. The solvent shall be free flowing and contain no
Furnace Filter Size lumps, undissolved particles or any foreign matter that ad
Cabinet Width Side Return Bottom Return versely affects the joint strength or chemical resistance of
the cement. The cement shall show no gelation, stratifica
17-1/2” 16 X 25 X 1 (1) 16 X 25 X 1 (1)
tion, or separation that cannot be removed by stirring. Re
21” 16 X 25 X 1 (1) 20 X 25 X 1 (1) fer to the table 2 below for approved piping and fitting ma
24-1/2” 16 X 25 X 1 (2) 24 X 25 X 1 (1) terials.
Page 13
CAUTION IMPORTANT
Solvent cements for plastic pipe are flammable liq ML193UH exhaust and intake connections are made
uids and should be kept away from all sources of of PVC. Use PVC primer and solvent cement when
ignition. Do not use excessive amounts of solvent using PVC vent pipe. When using ABS vent pipe, use
cement when making joints. Good ventilation should transitional solvent cement to make connections to
be maintained to reduce fire hazard and to minimize the PVC fittings in the unit.
breathing of solvent vapors. Avoid contact of ce
ment with skin and eyes. Use PVC primer and solvent cement or ABS solvent ce
ment meeting ASTM specifications, refer to Table 2. As an
TABLE 2 alternate, use all purpose cement, to bond ABS, PVC, or
PIPING AND FITTINGS SPECIFICATIONSOur script found these filter sizes in the Lennox ML193UH source document's filter table: 16x25x1, 20x25x1, 24x25x1. This page is pending human review, so check the source excerpt on the page to see which size applies to your cabinet and return. 16 x 25 x 1; 20 x 25 x 1; 24 x 25 x 1.
General guidance (not from this manual): check monthly and replace 1-in. filters every 1–3 months, or follow the filter maker's guidance and your owner's manual.
Filter sizes are nominal (rounded). A filter sold as 16 x 25 x 1 actually measures about 15.5 x 24.5 x 0.75 in. Buy by the nominal size printed on the frame.
Manufacturer document for Lennox ML193UH (https://www.lennox.com/dA/491eea6b1d/Lennox_ML193UH_IOM.pdf), last checked 2026-10-25.