Jackie it does evaporate quickly but that is because it is working--and the air is dry--keep the distilled water in it---there is a product by the name of AYR--you put just a bit inside your nose--keeps that dry--bad feeling at bay.

Me to but mostly when I have sinus problems

You are drying out. Get a humidifier to attach to your oxygen.....That will stop those nose bleeds.....

Yes the other gentleman is correct a humidifier for the concentrator is likely going to benifit you IMO, they only cost $3 or $4 please be sure to use distilled water in the humidifier , it won't use a lot of water.

My pulmonary told me to use saline solution couple times a day to keep my nose from drying out and preventing any nosebleeds. It's worked fine.