iSingo Humidifier Wicking HFT600 Filter T for Honeywell Hev615 Hev620 Humidifier, Compatible with Honeywell HFT600 Humidifier Filter T Compare to Part HFT600T HFT600PDQ,

What I tested

I ran the iSingo HFT600 wicking filters in two Honeywell evaporative humidifiers (HEV620B in a medium bedroom and HEV615W in a small home office) over several weeks at the tail end of heating season. I swapped between these filters and the OEM equivalents, kept notes on fit, startup wicking time, moisture output, and how quickly the media stiffened from mineral buildup. I also followed the recommended care routine: flipping the filter daily, rinsing the filter and tank base roughly weekly, and using distilled water in one unit and moderately hard tap water in the other to see how lifespan diverged.

Compatibility and fit

These are marketed as “Filter T” replacements for the HFT600 series, and they are indeed sized for Honeywell’s HEV615/HEV620 families. In the HEV620, the fit was snug but straightforward; I had to make sure the diamond grid was fully seated into the filter basket, but it clicked in without fuss. In the HEV615, I noticed a slightly tighter insertion on one of the four filters in the pack, though with a bit of coaxing along the edges it dropped in and held shape fine. Once installed, there was no buckling or slouching that would impede airflow.

If your humidifier’s filter basket has any warp from age or heat, expect the snugness to vary filter to filter. I didn’t need to trim or modify anything, but careful seating made a difference in how quietly the fan ran at start-up.

Build and design

The media uses a honeycomb pad embedded in a diamond-shaped plastic grid. It’s clearly lighter than the OEM filter—both in hand and in the rigidity of the paper. The upside is that it wets quickly and doesn’t overly burden the fan; the downside is you’ll notice the media softens and then stiffens faster as minerals accumulate. The grid holds the shape well enough that the filter doesn’t collapse when saturated, and it doesn’t whistle or buzz in the basket when properly seated.

There’s no adhesive smell out of the bag, and the packaging is minimal. Each filter was clean-cut along the edges—no loose paper strands that could shed into the tank or airflow path.

Setup and startup

After a quick rinse under cool water, the iSingo filters wicked readily. From a dry start, I saw water climbing through the media within a few minutes and moisture output stabilizing at the outlet in 15–30 minutes. Pre-wetting helps the first cycle, especially if your fan starts on high. In both humidifiers, noise level and airflow were indistinguishable from the OEM filter once the media was fully saturated.

Moisture output

In a 180–200 sq ft bedroom, with the HEV620 set to medium, I typically see an 8–12% bump in relative humidity over a two-hour window with a fresh OEM filter under winter conditions. With the iSingo filter, output felt comparable during the first two weeks—steady, even moisture without cool mist “spitting,” which you’d expect from a proper wick-based design. As the filter accumulated minerals (more on that below), output tapered sooner than with the OEM media when I used tap water, but stayed on par across the same period when I used distilled.

A nice behavior I appreciated: flipping the filter daily (as suggested) did restore a bit of vigor on day 3–10 of a run, which tracks with how evaporative wicks tend to load unevenly from the bottom.

Longevity and maintenance

This is the trade-off to know. With distilled water in the bedroom unit, each iSingo filter comfortably ran 4–6 weeks before I noticed meaningful stiffening and a drop in wicking height. Weekly rinses to remove surface film helped. In the office with moderately hard tap water, the same filter paper reached that “crunchy” stage closer to 3–4 weeks, at which point the bottom inch was heavily mineralized and wicking slowed. That’s within the 1–2 month guidance, but realistically, if you’re using hard water and running the machine daily, plan on the short end of that range.

Daily flipping is not mandatory, but it does even out saturation and slightly prolong useful life. If you prefer set-and-forget, expect earlier performance taper. Rinsing the tray and the filter under cool water every week kept odor-free operation and reduced mineral crust; avoid scrubbing hard, which can tear the paper.

Performance consistency

Across the four-pack, consistency was good. All four filters wet quickly and held their shape. One had a slightly looser edge seam that softened earlier than the others, but it didn’t collapse or cause airflow noise. None shed fibers into the tank. There was no discoloration beyond the normal yellowing that comes from mineral loading in tap water use.

Value

The most compelling reason to choose these is cost per month. In my math, the iSingo four-pack brings the running expense down enough that replacing a bit earlier becomes reasonable, especially in hard water areas. OEM filters last longer for me when used with tap water, but the premium is steep enough that I’m comfortable trading a few weeks of lifespan for lower recurring cost, particularly in a household with multiple units.

If you exclusively use distilled water, the value widens: output stays strong across a larger fraction of the filter’s life, keeping performance close to OEM while still saving money.

What could be better

• The paper media is a touch flimsy compared to the OEM, and it telegraphs water hardness more quickly. A slightly denser paper blend could push lifespan closer to two months in average tap water use.
• Tolerance variability across humidifier baskets means some users may experience a snugger fit. It would be welcome to have clearer guidance on seating or a micro-bevel at the edges to ease insertion.

Tips for best results

• Use distilled or demineralized water when possible. It’s the single biggest factor in how long any wick lasts.
• Flip the filter daily. It’s a small habit that slows uneven mineral loading.
• Rinse the filter and bottom tray every 1–2 weeks. Don’t use hot water or detergents; just a gentle cool rinse.
• Replace when the media gets stiff or output drops, even if it’s earlier than your last cycle. Running a spent filter strains the fan and doesn’t add humidity.
• Seat the filter carefully in the basket. Make sure the grid edges are fully engaged to avoid vibration or gaps.

Who it’s for

• Budget-conscious owners of Honeywell HEV615/HEV620-series units who run their humidifiers daily and don’t mind a light maintenance routine.
• Households using distilled water that want performance on par with OEM without the premium price.
• People who prefer to replace filters a bit more often to keep output at its peak.

Who should consider OEM instead? If you want the longest possible lifespan on tap water with minimal attention, the thicker OEM media still has an edge in how slowly it mineralizes.

Pros and cons

Pros
- Solid moisture output comparable to OEM when fresh
- Quick wicking and stable airflow with minimal noise
- Cost-effective four-pack reduces ongoing expense
- Clean fit in HEV615/HEV620 baskets once seated
- No odors or shedding in my testing

Cons
- Paper is thinner and tends to stiffen sooner in hard water
- A bit snug to insert in one of my baskets; careful seating needed
- Daily flip recommendation adds a small maintenance task

Bottom line

The iSingo HFT600 wicking filters delivered reliable humidification in both of my Honeywell units, with easy installation, good initial output, and predictable behavior as the media aged. They don’t quite match the OEM filters for lifespan when using hard tap water, but they come close with distilled water and are substantially more affordable. If you’re willing to adopt the simple maintenance routine—flip daily, rinse weekly, replace monthly to bimonthly—these filters are an easy recommendation.

Recommendation: I recommend the iSingo Filter T for Honeywell HEV615/HEV620 owners who want solid performance at a lower ongoing cost and don’t mind light maintenance. If maximum longevity on tap water with minimal attention is your top priority, stick with the OEM; otherwise, this 4-pack is a smart, economical choice that keeps humidity where you want it.