Things You'll Need
Mildew removing cleaner
Trisodium phosphate (TSP)
A humid or musty smell in your home is due to excess moisture and possibly mold. Before you can get rid of an ongoing humidity odor in your home, you must find the source and fix it, or hire a professional to do the job. Otherwise, the smell will return. Water, for example, may be seeping into your basement or perhaps your bathroom has poor ventilation. After the problem is fixed, or if it was a one-time problem that caused the humidity smell, such as an overflowing toilet, several methods can be used to rid your home of the musty odors once and for all.
Air out your home by opening the windows and doors, and turning on fans. Run a room dehumidifier also, emptying the water reservoir as necessary. Air conditioners can help remove the moisture in a home, too. You can place bowls of water-absorbing silicon gels, available in home improvement stores, in the areas where humidity is an issue.
Sprinkle chlorinated lime over the floor in your basement if that is the source of the humidity smell. According to the University of Georgia, leave it there until the smell disappears, then sweep it up.
Clean the bathroom or kitchen tiles and grout if there is mold that is causing the humidity smells. Use a household cleaner that contains bleach or make your own using about 1/2-cup bleach for every gallon of water. Allow the cleaner or bleach to sit for a few hours before rinsing and wiping the area dry. This also works for concrete surfaces. Note that if you can't clean the mold off the grout, you may have to remove and replace it.
Clean painted walls with a special mildew-removing cleaner, which is available where paint is sold, if that is the source of the musty smell. If the drywall is moldy on the inside or the insulation is moldy, it must be replaced. Wood floors can also be cleaned with trisodium phosphate (TSP) to help get rid of mold and musty smells. Always use cleaning products as stated on the label.
Adopt some good habits so the humidity smells or mold do not return. For example, turn on an exhaust fan or crack a window open when taking a shower, boiling water and cooking, and when running the washing machine.
If the odors persist even after you thought you removed the smell and fixed the problem, you may have a severe mold issue that needs to be removed before you can get rid of the humidity smell.