Cool Mist Humidifier by KOIOS, [2019 Upgraded] Advanced Top Filling Desgin Ultrasonic Air Humidifier, 4L Large Capacity, 3 Mist Modes and 15-20 Hours Timing Function, Real-Time Humidity Display

The product worked for a short while before shutting off. Now, none of the lights come on, and nothing happens when the unit is plugged in.I contacted the seller, who responded the next day with a request to send a video of the problem. I did so very quickly, but was still forced to wait another day to receive a reply that the video link was blocked by Amazon's messaging system. After emailing the video to another support email address, the company responded a day later saying they would look for the email.While the unit was working, I noticed a couple serious design issues:1) The LEDs are very bright white, which is a very poor design choice for a product that may be placed in a bedroom or other room where people sleep. The "Sleep Mode" dims the LEDs, but it also modifies all the other settings. There is no way to dim or turn off the LEDs separately. Adding a red film in front of the LED display, or changing the LEDs to red ones, would cut down on the excessive brightness significantly.2) The output aperture is very small, making it possible for condensation droplets to block the opening as they inevitably build up—particularly at the lowest mist settings. If this happens, the unit can no longer function as intended, because little or no mist is emitted from the opening.3) The water level is not regulated very well because of a carbon filter that blocks the feeder port. If the water level is not maintained within a certain level, then the ultrasonic atomizer cannot function effectively. The product does utilize a sensor to detect whether the water level is too low, in which case an error message is displayed, and the unit will not function until the water is replenished. However, if the water level is too high, there is no warning, and the atomizer simply produces very little vapor.Since the seller increased the price by about 45% while misleadingly advertising the higher price as a special "Black Friday" sale price, I cannot simply buy a replacement unit from Amazon at the same price to exchange the non-working one I received. Since I don't expect the seller or manufacturer to help, I will be returning the item for a refund and will consider purchasing an alternative product.--Edit: The seller replaced the defective product. But the replacement I received, which was shipped by Amazon, appeared to have been already opened and used. The poly bag containing the main unit was already torn, and water was inside the reservoir. The replacement appears to work, but only time will tell how long it will last.

I was hoping that this would be a good way to increase the humidity in our master bedroom. We have gas heat and when the furnace runs a lot on cold days the humidity get down to 24 to 29%. I set this on a TV tray and filled the water reservoir in the sink. It worked fine for awhile but then after refilling it a few times I noticed that the carpet was wet. somehow it let too much water down into the misting chamber and started to run out of the water level slit on the outer case. From that point on I only refilled it by leaving the water reservoir in the case and used a pitcher to refill it. That helped with the overflow issue but not completely. The humidistat is usually 5 to 10% off. so I have to set it higher than what it says in the display. When you get the 'HH' in the display that usually means that too much water has been let into the misting chamber and you have to empty the water reservoir and then dump the water out of the misting chamber and dry it out. It is difficult to clean the sediment out of the misting chamber under the water reservoir. I just use a paper towel and get inside all the nooks and cranny's down there.So in conclusion when this product works it works well. it will raise the humidity in our bedroom from 26% to 35% if I keep it running and have the ceiling fan on winter mode. but when the misting chamber gets full of water it is a pain to get it dried out and then filled up again. When I turn it back on the humidity on the unit reads 71% or higher. I learned to take a hair dryer and blow it around the base of the unit and I will get the humidity display back down to 25% or less then I turn the unit back on and off it goes.....till the next time it decides to let too much water down into the misting chamber underneath the water reservoir.

We had difficulty getting the humidifier to run for more than 5 minutes before giving an HH error and shutting off. I saw a video online about a problem with the small, plastic float in the bottom when used at higher elevations. We live at 4,200 feet and the person who posted the video lives at 6,700 feet. When the humidifier is shipped to a higher elevation, the bottom of the float expands out and it becomes slightly convex. I pierced a pin point hole in the side of the float, squeezed out some air to make the bottom very slightly concave, and sealed it. Now it works perfectly. If the bottom is convex, it does not allow the float to move within the plastic holding so the water will not flow into the bottom of the base for the mist to be produced. Maybe if a firmer plastic is used to make the float or some other material, it would work at higher elevations without going through this headache. If you Google search "Koios humidifier" you will see a link to the YouTube video that shows how to fix this problem. He uses a soldering iron to seal the small hole made in the float. I used a small square of Gorilla Tape and it works fine.