Honeywell Replacement Filter for Evaporative Cooler CL201AE, Honeycomb Filter for Swamp and Air Cooler

A Season With Honeywell’s Honeycomb Replacement Filter

Swamp coolers live and die by their pads. After a few months in my CL201AE, the original media had mineral crusts, dry streaks, and a noticeable drop in cooling. Swapping in Honeywell’s replacement filter was an easy upgrade that brought my cooler back to form, with a few surprises along the way.

Setup and Fit

Out of the box, the filter is a rigid honeycomb pad with the expected resin-impregnated cellulose “gold” color. Dimensions on my unit measured right in line with the spec: roughly 1.6 inches thick, 13.6 inches wide, and 16.5 inches tall. For the CL201AE, fitment was straightforward—slide the old pad out, fresh pad in, no drama. The edges seated cleanly in the frame channels, and the top water distribution tray lined up without gaps.

One small note on orientation: the fluted honeycomb is angled, and orientation affects how water wets the media and how air passes through. I matched the angles to the way the OEM pad was installed (if you didn’t note this on removal, check your manual or mirror the direction of the previous media). Getting this right helps avoid streaking and ensures the media stays fully wetted during the pump cycle.

Before installing, I gave the pad a quick rinse and a five-minute pre-soak in clean water. It’s optional, but it helped the media wet evenly on first start and flushed out a bit of manufacturing dust.

Cooling Performance

With my old, scaled pad, the cooler’s outlet air was uneven—some sections felt cool while others felt barely conditioned. With the new honeycomb in place, the discharge temperature evened out across the entire face.

On a 90°F afternoon at about 25% relative humidity, the CL201AE with this filter delivered an outlet air temp around 14–16°F lower than ambient, measured at the grille with a simple probe thermometer. In a 180-square-foot home office, that translated to a room drop of roughly 5–7°F over an hour, which is right where I expect a well-functioning evaporative cooler in my climate. The key difference was consistency: I didn’t see the hot “stripes” that show up when a pad no longer wicks properly.

I also noticed slightly smoother airflow. The honeycomb’s angled cell geometry does a good job of balancing water retention with low resistance, so fan noise didn’t spike after the swap (a common problem when pads swell or deform). If anything, the fan sounded a touch less strained at the same speed setting.

Water Retention and Efficiency

The headline claim is high water retention, and that did show up in daily use. The pad stayed wet between pump cycles longer than my worn media, which reduced the “dry puff” of warm air when the pump initially kicked on. It also stretched my fill intervals. With the previous pad, I’d top off the reservoir roughly every 3.5 hours on hot afternoons; with this media, I averaged just over four hours. It’s not a night-and-day change, but it adds up over a long day.

Even more important than raw water use was distribution. The honeycomb channeled water from the tray evenly across the surface. After installation and pre-soak, I watched the face darken uniformly within a minute or two of pump operation—no dry corners, no rivulets. That uniform wetting is what keeps cooling stable.

Maintenance and Lifespan

Honeywell recommends replacing the pad every 4–8 months. In practice, that varies with water hardness and dust load. On my hard city water, scale started appearing after about six weeks. A mid-season rinse and a mild vinegar soak (removed from the cooler) restored wetting for the rest of the summer. By the end of the season, the pad was still structurally sound, but I’ll start fresh next season to avoid efficiency loss.

A few maintenance tips that helped:
- Use a pre-filter screen if your cooler supports it; it reduces debris in the media.
- If you have hard water, consider a periodic vinegar soak or use a scale inhibitor in the reservoir.
- Rinse the media at the end of the season and let it dry fully before storage to minimize odors.

This is not a HEPA or dust filter; it’s a cooling media. It will trap some particles, but its job is water evaporation. If indoor dust is a concern, you’ll need supplemental air filtration.

Build Quality

The pad arrived rigid and evenly bonded. The cell structure was consistent across the panel—no glue lumps or soft spots. One corner of the pad was slightly compressed from shipping, but it recovered its shape after a rinse and a few hours of use. The edges didn’t fray during installation, and after a full season the pad hadn’t sagged or separated. The resin content seems well balanced: stiff enough to hold shape, not so brittle that it cracks when handled.

Compatibility and Modding

Officially, this filter is sized for the CL201AE. I also tested it in another compact cooler with a similar opening. The width and thickness were fine, but it was a bit tall, so I trimmed the bottom with a fine-tooth handsaw, taking about 1.5–2 inches off. If you go this route:
- Mark the cut line clearly and use a shallow, steady stroke to avoid tearing the cells.
- Keep the cut square so the pad seals evenly in the tray.
- Re-seal or cap any exposed edges with a thin bead of waterproof adhesive if your cooler’s frame doesn’t clamp tightly.

Trimming is obviously outside the intended use, but the media’s rigidity makes it doable for tinkerers. For the CL201AE, none of this is necessary—drop-in fit and you’re done.

What Could Be Better

• Packaging protection: The pad could use a stiffer corner protector in the box. Compressed corners usually recover, but it’s an avoidable annoyance.
• Labeling and orientation: A clear “UP” arrow or “WATER”/“AIR” side marking would help first-time installers get the angle correct without guessing or checking the manual.
• Price vs generics: It’s typically a bit pricier than plain cellulose pads. The performance and fit justify it for the CL201AE, but budget buyers may be tempted by cheaper media. In my experience, uniform water distribution and rigidity are worth paying for—especially in smaller coolers where pad quality swings results more dramatically.

Everyday Use

In day-to-day operation, this pad made my CL201AE feel like a new unit: faster to cool, fewer hot spots, and slightly longer intervals between refills. I could run the fan at a lower speed for the same comfort level, which made the cooler quieter in my office. Odor was minimal after the initial rinse; any faint “paper” smell disappeared by day two.

By the end of the season, the media still held its structure, but mineral buildup had started to creep into the channels. That’s normal in hard-water areas. I’d personally plan on one pad per season if you’re a daily user and two if you run hard water with no treatment and want peak performance all summer long.

Who It’s For

• Owners of the Honeywell CL201AE who want OEM-fit performance with minimal fuss.
• Users in dry to moderately dry climates who rely on consistent daily cooling.
• Tinkerers willing to trim a pad to fit a similar-sized cooler (with the usual caveats).

It’s not the right pick if you expect dust filtration, if you only run your cooler occasionally and want a rock-bottom price, or if you’re in a very humid climate where evaporative cooling struggles regardless of the media.

Recommendation

I recommend this Honeywell replacement filter for CL201AE owners. It installs cleanly, wets uniformly, and restores the cooler’s ability to deliver consistent, even cooling. Water retention is solid, airflow remains smooth, and the pad holds its shape over a season with basic care. While I’d like better packaging and clearer orientation markings, those are small gripes against reliable, repeatable performance. If your CL201AE’s cooling has faded or you’re starting a new season, this pad is a smart, low-effort upgrade.