There are many portable humidifiers on the market today which may be acceptable to some people. Because of my allergies and not wanting to bother with cleaning and disinfecting a portable humidifer to prevent the growth of microbial organisms in standing water,I opted for an Aprilaire 600 Whole House Humdifier. This humdifier is installed directly to your heating and cooling system. Water vapor is emitted into the air which prevents the inhalation of minerals into your lungs. The Aprilaire 600 Humidifier continually monitors humidity levels in your home so you neither have too much or too little humidity. Too little humidity can cause dry sinuses, itchy skin, and static shock. Some doctors claim that adding humidity to your home during the winter months can reduce upper respiratory problems and speeds recovery from the common cold. Before I had the Aprilaire 600 Humidifier installed in my home, I suffered nosebleeds frequently and my throat was always dry upon awakening. Humidifying my home at the proper levels has alleviated these problems. The only maintenance on the Aprilaire 600 Humidifier is replacing the filter on an annual basis. The filters can be purchased at any home improvement store and are very easy to replace. My Aprilaire 600 Humidifier makes me feel warmer at a lower thermostat setting. According to the EPA, it is possible to save up to 4% on heating bills for every degree the thermostat is lowered. My cats love my Aprilaire 600 Humidifier, too. Now, they don't get shocked when I stroke them! Thank you for reading my review.