Stumbled across this on Amazon. Looks to be an all time low. Decent reviews and for $15.00 is a great deal for a smaller space.

Amazon product: PureGuardian H920BL Ultrasonic Cool Mist Humidifier for Bedrooms, Babies Nursery, Quiet, Filter-Free, Up to 10 Hour Run Time, Treated Tank Reduces Mold, Pure Guardian Desktop
Customer Reviews:
I bought my first one of these back in February 2016 and it works perfectly today. I recently added two more for the kids bedrooms after trying and being very disappointed with this other model from the same company – | PureGuardian 3.1L Output per Day Ultrasonic Cool Mist Humidifier, Baby Room, Nursery Humidifier, Portable Humidifier, Travel Humidifier, Small Humidifier, Desk Humidifier, Pure Guardian H925S | I find this model puts more mist out and lasts longer despite being the same price in general. In addition the blue light when you have it on is more relaxing (white LED through blue material, not actually a blue light) than the white light through the gray material on the other model. This model has a flat top (where the mist is directed out through) so you can place it upside down, the other model is curved and you have to take the top off to stand it far more precariously on the edge of the misting chamber. | It’s very quiet and it has no problem getting my room handily above 30% RH when in the middle of winter – I don’t have central humidifer on my furnace (I do, but it’s busted) so it can get down to 10% RH in January, which really sucks for asthma and coughs and just breathing in general. I blast the kids rooms on high for an hour before they go to bed, then refill and turn to low – lasts until the morning no problem and the individual hygrometers in the other rooms usually read 35-43%. At 43% flu viruses can’t survive, so ideally I’d be able to keep it at 45-55% but hey for a little $30~$40 humidifer being able to acheive 35-40 or so is a big health benefit and I’ll take it until I can afford to completely redo my furnace. | Cleans easily with the included brush, power cable is about 6′ long, would transport easily too if you need to go on the road to a hotel and are worried it will be dry. | For a single room unit, this works great. My rooms are around 11’x16′ on average. I expect if your room is 20’x30′ or quite large, you may need to opt for a bigger model.