One thing you can try is cupping your hands around electrical outlets on exterior walls and sniffing in them. You might be able to pin down the general location of the odor. You can also sniff near the corners of the window trim to try to locate the odor source.
Check for Moisture: Look for any signs of water damage or leaks in bathrooms, kitchens, or around windows. Damp areas can lead to musty odors. Inspect Air Vents and Filters: Dirty air filters or mold in ductwork can contribute to musty smells.
Locate the Source of the Musty Smell
Begin your search in areas that are often warm and moist, like a bathroom. Check for mildew growth in the shower, on the shower curtain, and leaks around sinks, tubs, and toilets. In the kitchen, look for leaks around the sink and dishwasher.
If it is outdoors, or if the windows are open, then the smell is stronger near the source. Moving your nose from place to place is a way to determine the gradient of concentration of smelly molecules. Follow the direction of the gradient to locate the source.
An electronic nose is a device composed of an array of odour sensors with sensitivity to a wide range of chemical compounds.
A musty smell is almost always an indicator of unmanaged moisture. This moisture could either be liquid water or vapor. Unmanaged moisture often presents as mold or mildew. If unmanaged moisture reaches the point of smelling musty, it has likely reached the stage of mold or mildew.
Musty odors can be caused by hidden sources of moisture such as leaking pipes, condensation or poorly ventilated areas.
Baking soda and vinegar are often regarded as some of the best natural cleaning ingredients given their inherent deodorizing properties. When using these ingredients to remove the smell of must, simply place a bowl of either baking soda or vinegar in the affected room overnight to absorb the musty odors.
The top causes of musty odors in bathrooms are from fungal growth. Mold and mildew are types of fungus found in damp spaces, like bathrooms. The constant presence of moisture in bathrooms creates an environment where fungus can thrive.
Moldy and mystery smells are almost always in moist places. Kitchens, bathrooms, and utility rooms are common culprits. Wet clothes, damp bags, and soiled carpets can also cause a musty smell.
Poor air circulation: Even if you don't have an issue with humidity, poor air circulation can cause the air in your home to become stagnant which can give it an unpleasant odor. Open the windows to let in some fresh air from time to time – it may also help to set up fans in the windows to facilitate air exchange.
Moisture that cannot be ventilated will settle in areas around your home such as walls, window sills, ceilings and showers. Check under sinks and taps for a build up of water or leaks that may have caused mould growth. Check for damp patches or any signs of water damage.
Most often, a mold problem will be readily identified by a musty smell that becomes obvious in damp environments. Mold also likes to play hide and seek, so if you suspect there is a problem, then check under carpets, behind drywall, inside ductwork, in between bathroom tiles and in other moisture-prone areas.
Around windows where condensation could gather. Behind or under any storage areas that do not get a lot of traffic. Other places you should check for mildew, mold, or moisture are in your air conditioning and heating ducts, inside and around your washer and dryer, and in the walls and ceiling around your home.
Having an air purifier running in places that smell musty can not only remove the smell but can also improve the health of the air in the space. It's important to have an air purifier with an activated carbon filter in order to remove odors from the air circulating in your home.
A moldy odor suggests that mold is growing in the building and should be investigated. The health effects of inhaling mVOCs are largely unknown, although exposure to mVOCs has been linked to symptoms such as headaches, nasal irritation, dizziness, fatigue, and nausea.
Empty and clean the drain pan
If you have a mouldy smell coming from your air conditioner, the first thing to do is check your drain pan. If it's full, empty the water out, and it's also advisable to give it a quick clean with soap and water to remove any possible build-up of mould inside.
An air purifier and specific filters effectively eliminate harmful gases and unwanted odors from your indoor environment. A standard particle filter is not designed to remove gases and odors. For gas and odor removal, the air purifier should be equipped with a filter that includes activated carbon.
Spray Febreze Air for a quick burst of freshness and to eliminate lingering odors. Or consider purchasing an essential oil diffuser, some scented candles, or fresh flowers to replace that musty smell with something positively lovely.
Smell Annotator app is an AI-based software program which is used to view, annotate and analyze smell measurements taken with the Smell Inspector and to recognize annotated smells in real time. The Smell Annotator app is a part of the Smell Inspector Developer Kit.