HAC-504 Humidifier Replacement Filter A for Honeywell HCM-350

Product works well. Great price. Changing the filter after it shows wear is beneficial. Hadn’t changed mine in years. Just washed it but didn’t really help. With old one I was filling water reservoir maybe once a week. With new one it’s every 2 days! Much more efficient and humidity balance in room with new filter

It's really nice and it does the job as well nothing in particular I should mention as a drawbacks out of it

After disappointing results with three other brands, I took a chance on these "upgraded blue" filters. Well-made, fit my Honeywell 350, but after using the filter for one week, I found the product "lacking." The big problem: it just doesn't let enough moisture through, and thus seems to never raise the room humidity. But before I trashed the blue-clad filters I tried one desperate move: I carefully took scissors and stripped off most of the blue "wrap." Made a huge difference. Without the "upgrade," the filters do a good job. So - if you want to order these filters, go with the "white" version - you will save a lot of frustration.

These upgraded filters are great. I used to purchase the standard Honeywell HAC-504 Type A filters but they have been hard to find in the stores. The Honeywell usually cost between $7-10 so when I saw these Fette Blue Mesh Type A Filters on Amazon for a package of four for about $16 I thought I would give them a try. I installed the filter in the first week of September and forgot to change it until this week (December) I thought it would be full of mildew and hard water build up but it was still in good shape. You can see the old filter next to a new one in the photo. I should mention that I washed the tank every week and changed the water about every other day. Still the filter looked better than previous standard filters used for about a month. I think the blue mesh helps keep it clean longer. I do suggest that you set a reminder to change the filter every month and at this low cost it is affordable. These are a great alternative when you are unable to find the Honeywell filters. Just a note: These filters are really stiff when new so you can presoak them in a bowl of water before use so they fit in the humidifier a little easier.

Excellent - enough so that it actually motivated my lazy self to write a review here (I'm also ordering another package now so was here anyway) Ive tried a few different types of filters made by other companies and none have been as good as this one. Some, while appearing well made, didnt work well or really at all with my machine. Others were cheaply made - thin and flimsy - and werent worth the money spent for the time gotten out of them. These are thick, sturdy and well constructed. All of which means they last longer than the average replacement designs. If youve previously tried a variety of others, youll notice how substantial these are as soon as you take them out of the package. --- Update --- We run our humidifier 24/7 - probably around 22 hours a day on average, all week long. Its been 5 weeks now and this filter is still working. Not as good as the first few weeks but still good enough to not change yet. I use New York City tap water... not filtered and nothing added to the tank. I flip the filter every time I refill the tank - which is around 3 times a day considering the constant use. If the outer layer of the filter feels dry when refilling, I soak the filter in cold water for a few minutes (this usually starts happening after a few weeks of use). Ive never had more that the tips or portions of the outermost layer get dry. Once a week I soak the filter in a mix of water and vinegar - roughly 1/2 cup of vinegar and 6 cups water - for 15-20 mins. Then rinse gently to flush the vinegar. While soaking the filter I clean the machine tray - a quick scrub with soap and water, then a little bleach rinsed off thoroughly with cold water. The water tank too - soap and water, no bleach (make sure to clean the ring where the cap screws in, and the cap too). The filter gets discolored with time, going from white to a light tan color, with a thin, slightly darker ring near each end - typical result of mineral deposits from what I can tell. I havent seen anything like the dark and black mold issues people post pictures of online. --- Update Two --- Ive seen some people comment about black mold forming on their filter within a week of use. That much, that fast should not happen in a machine that is clean. Assuming the tray and water container are being regularly cleaned... lift the top part of the machine off the water tray, flip it upside down, and take a look inside at the fan casing and motor. Black mold can form inside of the machine, and if this happens it will spread quickly to any filter you use - since it is already present and in close proximity to the filter. Wiping this area down will help prevent this - I used a tooth pick and disinfectant wipe to clean out the little grill at the center under the fan.

I bought these filters for my Honeywell humidifer which I run in 24/7 in order to keep humidity for an 11' x 11' room at about 50%. It worked fine at first but before long it started to dry out at the top and become less and less efficient. In less than 3 weeks I had to throw it out. Other filter brands that I have tried lasted longer. These were pretty low cost -- next time I will spend more on a different, and hopefully better, filter.

These filters are replacements for the 504. I have found these to be the best non-OEM filter for my Honeywell humidifier. In my current environment, they seem to be wicking the best of all the generic filters I have tried. At this time, they are performing as well as the OEM filters. I purchased the Fette brand to try as the OEM filters have been difficult to find in stock at a reasonable price for the past several months. I would rate these a very good product and value at this time.

Filter seems to do the job,what else can I say about a furnace filter ?

not sure that these remain effective as long as the real thing. My softened water is still hard enough to stiffen up most filters. I have to soak them in vinegar every few days. A bit of a pain. I wish I'd bought an ultrasonic unit.

The filters are thinner than others, but they work fine!

I find them better than the original ones from Honeywell. They last longer, and also less smelly

These are the best price and value for the money to replace your Honeywell humidifier filters. They do a great job.