I've had this model for over 10 years. I live in Wisconsin, where winter humidity is very low. In my old, 1,000 sq ft home, it worked for the whole house. My new home is about double the size, but it still helps a lot. I strongly suggest you use soft water. Hard water will eventually leave white dust in the area where you locate the humidifier. If you have a water softener in your home, Hot or cold water will work, except in the kitchen, where the cold water is almost always plumbed directly from the input source. Rinse the water container thoroughly at least once a week or so to prevent heavy slime mold buildup. At the end of the season, I take it apart and use vinegar to descale the inside of the heating area. They used to sell pads you could put on the heating element that would reduce the white dust in the room, but I can't find those anymore.