Filter Dimensions Outside Dimensions Rough Opening (min.-max.) Free Air
10x10 10'' 10'' 14.5'' 14.5'' 10.25'' - 12.75'' 10.25'' - 12.75'' Side - reversible 0.428 61.6%
10x16 10'' 16'' 14.5'' 20.5'' 10.25'' - 12.75'' 16.25'' - 18.75'' Side - reversible 0.725 65.2%
10x20 10'' 20'' 14.5'' 24.5'' 10.25'' - 12.75'' 20.25'' - 22.75'' Side - reversible 0.923 66.4%
10x24 10'' 24'' 14.5'' 28.5'' 10.25'' - 12.75'' 24.25'' - 26.75' Side - reversible 1.121 67.2%
10x25 10'' 25'' 14.5'' 29.5'' 10.25'' - 12.75'' 25.25'' - 27.75'' Side - reversible 1.170 67.4%
10x30 10'' 30'' 14.5'' 34.5'' 10.25'' - 12.75'' 30.25'' - 32.75'' Side - reversible 1.418 68.0%
12x12 12'' 12'' 16.5'' 16.5'' 12.25'' - 14.75'' 12.25'' - 14.75'' Side - Reversible 0.638 63.8%
12x14 12'' 14'' 16.5'' 18.5'' 12.25'' - 14.75'' 14.25'' - 16.75'' Side - reversible 0.758 65.0%
12x16 12'' 16'' 16.5'' 20.5'' 12.25'' - 14.75'' 16.25'' - 18.75'' Side - reversible 0.878 65.8%
12x18 12'' 18'' 16.5'' 22.5'' 12.25'' - 14.75'' 18.25'' - 20.75'' Side - reversible 0.997 66.5%
12x20 12'' 20'' 16.5'' 24.5'' 12.25'' - 14.75'' 20.25'' - 22.75'' Side - reversible 1.117 67.0%
12x24 12'' 24'' 16.5'' 28.5'' 12.25'' - 14.75'' 24.25'' - 26.75'' Side - reversible 1.357 67.8%
12x25 12'' 25'' 16.5'' 29.5'' 12.25'' - 14.75'' 25.25'' - 27.75'' Side - reversible 1.417 68.0%
12x27 12'' 27'' 16.5'' 31.5'' 12.25'' - 14.75'' 27.25'' - 29.75'' Side - reversible 1.536 68.3%
12x30 12'' 30'' 16.5'' 34.5'' 12.25'' - 14.75'' 30.25'' - 32.75'' Side - reversible 1.716 68.6%
12x36 12'' 36'' 16.5'' 40.5'' 12.25'' - 14.75'' 36.25'' - 38.75'' Side - reversible 2.076 69.2%
13x18 13'' 18'' 17.5'' 22.5'' 13.25'' - 15.75'' 18.25'' - 20.75'' Side - reversible 1.084 66.7%
13x20 13'' 20'' 17.5'' 24.5'' 13.25'' - 15.75'' 20.25'' - 22.75'' Side - reversible 1.214 67.3%
14x12 14'' 12'' 18.5'' 16.5'' 14.25'' - 16.75'' 12.25'' - 14.75'' Bottom 0.749 64.2%
14x14 14'' 14'' 18.5'' 18.5'' 14.25'' - 16.75'' 14.25'' - 16.75'' Side - reversible 0.890 65.4%
14x18 14'' 18'' 18.5'' 22.5'' 14.25'' - 16.75'' 18.25'' - 20.75'' Side - reversible 1.171 66.9%
14x20 14'' 20'' 18.5'' 24.5'' 14.25'' - 16.75'' 20.25'' - 22.75'' Side - reversible 1.312 67.5%
14x22 14'' 22'' 18.5'' 26.5'' 14.25'' - 16.75'' 22.25'' - 24.75'' Side - reversible 1.452 67.9%
14x24 14'' 24'' 18.5'' 28.5'' 14.25'' - 16.75'' 24.25'' - 26.75'' Side - reversible 1.593 68.3%
14x25 14'' 25'' 18.5'' 29.5'' 14.25'' - 16.75'' 25.25'' - 27.75'' Side - reversible 1.663 68.4%
14x28 14'' 28'' 18.5'' 32.5'' 14.25'' - 16.75'' 28.25'' - 30.75'' Side - reversible 1.874 68.8%
14x30 14'' 30'' 18.5'' 34.5'' 14.25'' - 16.75'' 30.25'' - 32.75'' Side - reversible 2.015 69.1%
14x36 14'' 36'' 18.5'' 40.5'' 14.25'' - 16.75'' 36.25'' - 38.75'' Side - reversible 2.437 69.6%
15x20 15'' 20'' 19.5'' 24.5'' 15.25'' - 17.75'' 20.25'' - 22.75'' Side - reversible 1.409 67.6%
15x25 15'' 25'' 19.5'' 29.5'' 15.25'' - 17.75'' 25.25'' - 27.75'' Side - reversible 1.786 68.6%
15x30 15'' 30'' 19.5'' 34.5'' 15.25'' - 17.75'' 30.25'' - 32.75'' Side - reversible 2.164 69.3%
16x10 16'' 10'' 20.5'' 14.5'' 16.25'' - 18.75'' 10.25'' - 12.75'' Bottom 0.699 62.9%
16x12 16'' 12'' 20.5'' 16.5'' 16.25'' - 18.75'' 12.25'' - 14.75'' Bottom 0.860 64.5%
16x16 16'' 16'' 20.5'' 20.5'' 16.25'' - 18.75'' 16.25'' - 18.75'' Side - reversible 1.183 66.6%
16x18 16'' 18'' 20.5'' 22.5'' 16.25'' - 18.75'' 18.25'' - 20.75'' Side - reversible 1.345 67.2%
16x20 16'' 20'' 20.5'' 24.5'' 16.25'' - 18.75'' 20.25'' - 22.75'' Side - reversible 1.506 67.8%
16x24 16'' 24'' 20.5'' 28.5'' 16.25'' - 18.75'' 24.25'' - 26.75'' Side - reversible 1.829 68.6%
16x25 16'' 25'' 20.5'' 29.5'' 16.25'' - 18.75'' 25.25'' - 27.75'' Side - reversible 1.910 68.8%
16x30 16'' 30'' 20.5'' 34.5'' 16.25'' - 18.75'' 30.25'' - 32.75'' Side - reversible 2.313 69.4%
16x32 16'' 32'' 20.5'' 36.5'' 16.25'' - 18.75'' 32.25'' - 34.75'' Side - reversible 2.475 69.6%
16x36 16'' 36'' 20.5'' 40.5'' 16.25'' - 18.75'' 36.25'' - 38.75'' Side - reversible 2.798 69.9%
17x17 17'' 17'' 21.5'' 21.5'' 17.25'' - 19.75'' 17.25'' - 19.75'' Side - reversible 1.345 67.0%
17x29 17'' 29'' 21.5'' 33.5'' 17.25'' - 19.75'' 29.25'' - 31.75'' Side - reversible 2.377 69.4%
17x30 17'' 30'' 21.5'' 34.5'' 17.25'' - 19.75'' 30.25'' - 32.75'' Side - reversible 2.463 69.5%
18x12 18'' 12'' 22.5'' 16.5'' 18.25'' - 20.75'' 12.25'' - 14.75'' Bottom 0.971 64.8%
18x13 18'' 13'' 22.5'' 17.5'' 18.25'' - 20.75'' 13.25'' - 15.75'' Bottom 1.063 65.4%
18x14 18'' 14'' 22.5'' 18.5'' 18.25'' - 20.75'' 14.25'' - 16.75'' Bottom 1.154 65.9%
18x16 18'' 16'' 22.5'' 20.5'' 18.25'' - 20.75'' 16.25'' - 18.75'' Bottom 1.336 66.8%
18x18 18'' 18'' 22.5'' 22.5'' 18.25'' - 20.75'' 18.25'' - 20.75'' Side - reversible 1.518 67.5%
18x20 18'' 20'' 22.5'' 24.5'' 18.25'' - 20.75'' 20.25'' - 22.75'' Side - reversible 1.701 68.0%
18x24 18'' 24'' 22.5'' 28.5'' 18.25'' - 20.75'' 24.25'' - 26.75'' Side - reversible 2.065 68.8%
18x25 18'' 25'' 22.5'' 29.5'' 18.25'' - 20.75'' 25.25'' - 27.75'' Side - reversible 2.156 69.0%
18x30 18'' 30'' 22.5'' 34.5'' 18.25'' - 20.75'' 30.25'' - 32.75'' Side - reversible 2.612 69.7%
18x36 18'' 36'' 22.5'' 40.5'' 18.25'' - 20.75'' 36.25'' - 38.75'' Side - reversible 3.159 70.2%
19x21 19'' 21'' 23.5'' 25.5'' 19.25'' - 21.75'' 21.25'' - 23.75'' Side - reversible 1.894 68.4%
19x22 19'' 22'' 23.5'' 26.5'' 19.25'' - 21.75'' 22.25'' - 24.75'' Side - reversible 1.990 68.6%
19x27 19'' 27'' 23.5'' 31.5'' 19.25'' - 21.75'' 27.25'' - 29.75'' Side - reversible 2.472 69.4%
20x10 20'' 10'' 24.5'' 14.5'' 20.25'' - 22.75'' 10.25'' - 12.75'' Bottom 0.879 63.3%
20x12 20'' 12'' 24.5'' 16.5'' 20.25'' - 22.75'' 12.25'' - 14.75'' Bottom 1.082 64.9%
20x13 20'' 13'' 24.5'' 17.5'' 20.25'' - 22.75'' 13.25'' - 15.75'' Bottom 1.184 65.6%
20x14 20'' 14'' 24.5'' 18.5'' 20.25'' - 22.75'' 14.25'' - 16.75'' Bottom 1.286 66.1%
20x15 20'' 15'' 24.5'' 19.5'' 20.25'' - 22.75'' 15.25'' - 17.75'' Bottom 1.387 66.6%
20x16 20'' 16'' 24.5'' 20.5'' 20.25'' - 22.75'' 16.25'' - 18.75'' Bottom 1.489 67.0%
20x18 20'' 18'' 24.5'' 22.5'' 20.25'' - 22.75'' 18.25'' - 20.75'' Bottom 1.692 67.7%
20x20 20'' 20'' 24.5'' 24.5'' 20.25'' - 22.75'' 20.25'' - 22.75'' Side - reversible 1.895 68.2%
20x21 20'' 21'' 24.5'' 25.5'' 20.25'' - 22.75'' 21.25'' - 23.75'' Side - reversible 1.997 68.5%
20x22 20'' 22'' 24.5'' 26.5'' 20.25'' - 22.75'' 22.25'' - 24.75'' Side - reversible 2.098 68.7%
20x24 20'' 24'' 24.5'' 28.5'' 20.25'' - 22.75'' 24.25'' - 26.75'' Side - reversible 2.301 69.0%
20x25 20'' 25'' 24.5'' 29.5'' 20.25'' - 22.75'' 25.25'' - 27.75'' Side - reversible 2.403 69.2%
20x30 20'' 30'' 24.5'' 34.5'' 20.25'' - 22.75'' 30.25'' - 32.75'' Side - reversible 2.911 69.9%
21x19 21'' 19'' 25.5'' 23.5'' 21.25'' - 23.75'' 19.25'' - 21.75'' Bottom 1.885 68.0%
21x20 21'' 20'' 25.5'' 24.5'' 21.25'' - 23.75'' 20.25'' - 22.75'' Bottom 1.992 68.3%
22x14 22'' 14'' 26.5'' 18.5'' 22.25'' - 24.75'' 14.25'' - 16.75'' Bottom 1.418 66.3%
22x19 22'' 19'' 26.5'' 23.5'' 22.25'' - 24.75'' 19.25'' - 21.75'' Bottom 1.977 68.1%
22x20 22'' 20'' 26.5'' 24.5'' 22.25'' - 24.75'' 20.25'' - 22.75'' Bottom 2.089 68.4%
24x10 24'' 10'' 28.5'' 14.5'' 24.25'' - 26.75'' 10.25'' - 12.75'' Bottom 1.060 63.6%
24x12 24'' 12'' 28.5'' 16.5'' 24.25'' - 26.75'' 12.25'' - 14.75'' Bottom 1.305 65.2%
24x14 24'' 14'' 28.5'' 18.5'' 24.25'' - 26.75'' 14.25'' - 16.75'' Bottom 1.549 66.4%
24x16 24'' 16'' 28.5'' 20.5'' 24.25'' - 26.75'' 16.25'' - 18.75'' Bottom 1.794 67.3%
24x18 24'' 18'' 28.5'' 22.5'' 24.25'' - 26.75'' 18.25'' - 20.75'' Bottom 2.039 68.0%
24x20 24'' 20'' 28.5'' 24.5'' 24.25'' - 26.75'' 20.25'' - 22.75'' Bottom 2.284 68.5%
24x24 24'' 24'' 28.5'' 28.5'' 24.25'' - 26.75'' 24.25'' - 26.75'' Side - reversible 2.773 69.3%
24x30 24'' 30'' 28.5'' 34.5'' 24.25'' - 26.75'' 30.25'' - 32.75'' Side - reversible 3.508 70.2%
25x10 25'' 10'' 29.5'' 14.5'' 25.25'' - 27.75'' 10.25'' - 12.75'' Bottom 1.105 63.7%
25x12 25'' 12'' 29.5'' 16.5'' 25.25'' - 27.75'' 12.25'' - 14.75'' Bottom 1.360 65.3%
25x14 25'' 14'' 29.5'' 18.5'' 25.25'' - 27.75'' 14.25'' - 16.75'' Bottom 1.615 66.5%
25x15 25'' 15'' 29.5'' 19.5'' 25.25'' - 27.75'' 15.25'' - 17.75'' Bottom 1.743 66.9%
25x16 25'' 16'' 29.5'' 20.5'' 25.25'' - 27.75'' 16.25'' - 18.75'' Bottom 1.871 67.3%
25x18 25'' 18'' 29.5'' 22.5'' 25.25'' - 27.75'' 18.25'' - 20.75'' Bottom 2.126 68.0%
25x20 25'' 20'' 29.5'' 24.5'' 25.25'' - 27.75'' 20.25'' - 22.75'' Bottom 2.381 68.6%
25x25 25'' 25'' 29.5'' 29.5'' 25.25'' - 27.75'' 25.25'' - 27.75'' Side - reversible 3.019 69.6%
27x12 27'' 12'' 31.5'' 16.5'' 27.25'' - 29.75'' 12.25'' - 14.75'' Bottom 1.471 65.4%
27x19 27'' 19'' 31.5'' 23.5'' 27.25'' - 29.75'' 19.25'' - 21.75'' Bottom 2.438 68.4%
28x14 28'' 14'' 32.5'' 18.5'' 28.25'' - 30.75'' 14.25'' - 16.75'' Bottom 1.813 66.6%
29x17 29'' 17'' 33.5'' 21.5'' 29.25'' - 31.75'' 29.25'' - 31.75'' Bottom 2.325 67.9%
30x10 30'' 10'' 34.5'' 14.5'' 30.25'' - 32.75'' 10.25'' - 12.75'' Bottom 1.331 63.9%
30x12 30'' 12'' 34.5'' 16.5'' 30.25'' - 32.75'' 12.25'' - 14.75'' Bottom 1.638 65.5%
30x14 30'' 14'' 34.5'' 18.5'' 30.25'' - 32.75'' 14.25'' - 16.75'' Bottom 1.945 66.7%
30x15 30'' 15'' 34.5'' 19.5'' 30.25'' - 32.75'' 15.25'' - 17.75'' Bottom 2.099 67.2%
30x16 30'' 16'' 34.5'' 20.5'' 30.25'' - 32.75'' 16.25'' - 18.75'' Bottom 2.253 67.6%
30x17 30'' 17'' 34.5'' 21.5'' 30.25'' - 32.75'' 17.25'' - 19.75'' Bottom 2.406 67.9%
30x18 30'' 18'' 34.5'' 22.5'' 30.25'' - 32.75'' 18.25'' - 20.75'' Bottom 2.560 68.3%
30x20 30'' 20'' 34.5'' 24.5'' 30.25'' - 32.75'' 20.25'' - 22.75'' Bottom 2.867 68.8%
30x24 30'' 24'' 34.5'' 28.5'' 30.25'' - 32.75'' 24.25'' - 26.75'' Bottom 3.482 69.6%
30x30 30'' 30'' 34.5'' 34.5'' 30.25'' - 32.75'' 30.25'' - 32.75'' Side - reversible 4.404 70.5%
32x16 32'' 16'' 36.5'' 20.5'' 32.25'' - 34.75'' 16.25'' - 18.75'' Bottom 2.405 67.7%
32x20 32'' 20'' 36.5'' 24.5'' 32.25'' - 34.75'' 20.25'' - 22.75'' Bottom 3.062 68.9%
34x20 34'' 20'' 38.5'' 24.5'' 34.25'' - 36.75'' 20.25'' - 22.75'' Bottom 3.256 69.0%
36x10 36'' 10'' 40.5'' 14.5'' 36.25'' - 38.75'' 10.25'' - 12.75'' Bottom 1.602 64.1%
36x12 36'' 12'' 40.5'' 16.5'' 36.25'' - 38.75'' 12.25'' - 14.75'' Bottom 1.971 65.7%
36x14 36'' 14'' 40.5'' 18.5'' 36.25'' - 38.75'' 14.25'' - 16.75'' Bottom 2.341 66.9%
36x18 36'' 18'' 40.5'' 22.5'' 36.25'' - 38.75'' 18.25'' - 20.75'' Bottom 3.081 68.5%
36x20 36'' 20'' 40.5'' 24.5'' 36.25'' - 38.75'' 20.25'' - 22.75'' Bottom 3.451 69.0%