Naturally occurring stale air is typically the cause of a dank basement smell. Basements are usually dark, damp and humid and have very little to no air circulation. This can be the perfect breeding ground for mold and mildew, which will add to the dank aroma. This nose-wrinkling odor can drift up from the basement and into the rest of your home. Fortunately, there are various ways you can remove the odors and freshen your basement.
Remove mold and mildew growing in your basement. Fill a bucket with 1 gallon of water and add 1 cup of oxygen bleach. Mix the contents together until blended. Dampen a clean sponge in the mixture and wash the mold and mildew off surfaces in your basement.
Remove odors trapped in basement dirt floors by saturating them with white vinegar. Fill a pump sprayer with undiluted white vinegar and saturate the dirt thoroughly. Let the dirt floors dry. Alternatively, sprinkle a liberal amount of baking soda on the dirt floors.
Open the doors and windows in the basement. This will help air out the basement and allow for proper air circulation and ventilation. Run fans in the basement for several hours to help circulate the stale air.
Scatter handfuls of charcoal briquettes in the basement. You can find charcoal briquettes near the grills at department stores. The active ingredient in many fish tank filters, charcoal will elevate the odors without dangerous chemicals.
Place several bowls filled with undiluted white vinegar in the basement and let them sit for 24 hours. The vinegar will absorb the offensive odors in the basement.
Set several plates with onions cut in half in the basement and leave overnight. The onions have a pungent odor, but when the odor dissipates, it will remove the dank smell from the basement odors.
Scatter yard and concrete deodorizer granules in the basement. The deodorizer granules are reusable, recyclable and non-toxic. You can find them at garden and lawn centers and home improvement stores.