House Smells Musty - But No mold? 7 Main Reasons (Explained) -

Having a musty smell in the house can be a cause for concern. When the house smells musty, it usually means that mold and mildew are growing inside the house.

But what if there is no visible mold anywhere in the house? Could a house still smell musty even if there is no mold?

In this article, we’re taking a closer look at the different reasons why a house smells musty:

Table of Contents

1. Excess Moisture Around The House

One of the most common causes of musty smells in the house is excess moisture, which means there’s water in some areas where it shouldn’t be.

Excess moisture or water can come from leaky pipes. It can also come from humid parts of the house without enough ventilation to dry out the moisture.

It can even come from piles of wet clothes, towels, and other items made from fabric.

Excess moisture can give your house that unpleasant musty smell even if no mold grows.

Then it’s only a matter of time until mold starts growing in areas of the house with excess moisture or water.

As you know, mold can cause several health-related problems for you and other household members.

Mold exposure can cause wheezing, stuffy nose, and allergic reactions such as red or itchy eyes or skin.

2. Poor Air Circulation Inside The House

Inadequate airflow is another common reason a house smells musty, even without mold.

When there is stagnant air inside your home, bacteria and other contaminants can get trapped indoors, which results in that old musty smell.

This is why having good air circulation indoors is very important. And you can improve the air circulation inside your house in just a few simple ways.

Small things like opening the windows or turning on the fans can greatly impact ensuring that air circulates properly indoors.

Of course, it can get tricky come winter and summer when it’s too cold or hot outside to open the windows.

It helps to install an air exchanger. Air exchangers typically have a fan and ventilation system to remove stale air from the inside and bring in fresh air from the outside.

A good-quality air exchanger may be a bit pricey, depending on the brand, but it can be a good investment to ensure that your house consistently has good air circulation indoors.

3. Household Members Smoking Indoors

If you or another household member smokes indoors, even if it’s only occasionally, then you may have found the culprit behind that old, musty smell inside the house.

Walls and other surfaces in your house can absorb the smell of cigarettes and nicotine over time, which can cause your house to smell musty.

If no household member smokes and you just recently moved into your house, and it already has that musty smell, then the previous homeowner could be a smoker, and they might have smoked indoors.

The smell of smoke can stick to the carpets, furniture, walls, and other surfaces inside the house.

To prevent this, you must avoid smoking indoors and tell your household members to do the same. And if you really must smoke, make sure that there is proper air circulation inside your house.

4. Dirt & Spills that Haven’t Been Properly Cleaned

Dirt, spills, and messes are quite common, and even unavoidable, when you have little kids or pets in the household.

Any dirt and spills not cleaned up properly can cause your house to have that unpleasant musty smell.

If your kid accidentally spills their drink on the carpet or if your dog urinates on it or walks all over it with its muddy paws, that carpet has to be cleaned thoroughly.

If you don’t, dirt and bacteria will build up, and your carpet will emit that old musty smell.

The same goes for any surface that can easily absorb liquids, such as pads and subfloors, and more so if you have wooden floors.

The key is to spot-clean any dirt or spill as soon as they happen.

Don’t let these messes settle on the surface because if you don’t clean them right away, they might become stubborn, and you may need a professional cleaner’s help in the future.

5. Dirt Trapped in the HVAC System

If you have an HVAC system, any dirt trapped in it could give your house that old musty smell.

HVAC stands for heating, ventilation, and air conditioning, and HVAC systems control the humidity, temperature, and purity of the air in your house.

This is why cleaning them regularly, including the ducts and heating and cooling appliances, is so important.

If they’re dirty, grimy, and dusty, they could emit poor-quality dirty air with a bad odor.

6. Dirty Curtains, Carpets, and Rugs

A musty smell can also come from dirty curtains, carpets, and rugs, which is why it’s so important to wash them regularly.

Curtains should be washed every 3 to 6 months.

On the other hand, carpeted floors and rugs have to be vacuumed at least twice a week. In addition, rugs also have to be thoroughly cleaned every 12 to 18 months, depending on the material and how absorbent they are.

Rugs made from polyester and other synthetic materials can be machine washed safely, so you can do it at home. Rugs made from wool and other heavy materials may require the help of a professional rug cleaner.

7. Unpleasant Smell Coming from the Vents

This applies if you live in an apartment or shared residence, as these places often have shared air ventilation.

One challenge with living in apartments, condominiums, or shared residences is that they’re often hard to ventilate properly.

These places have an air ventilation system with air inlets that allow fresh air into the building. Then the air goes through air ducts into a supply fan, which then enhances the pressure of the air and supplies it to the rest of the building.

This system also has exhaust fans to eliminate stale air from the building.

While air ventilation systems work well to ensure that air is being circulated properly, it also causes some problems. For example, musty smells from another apartment can enter your unit through the vent.

If the air ventilation system in the building is dirty and not being maintained regularly, it could also give your apartment a musty smell.

8. How to Prevent Your House from Smelling Musty

Now that you know the common reasons why a house smells musty, even if there’s no mold, you know how to prevent this from happening.

Here are some tips to prevent your house from smelling musty:

Regulate the moisture inside your house by getting a dehumidifier and placing it in areas with poor ventilation.
Avoid piling on wet clothes or towels, and wash them straight away instead of putting them in your laundry basket.
Regularly check your house for leaky pipes, unwanted moisture, or water sources.
Ensure all house areas are properly ventilated by opening the windows to let fresh air in.
Place fans in rooms with no windows.
Avoid smoking indoors.
Spot clean dirt and spills as soon as they happen.
Regularly clean your curtains, carpets, and rugs.
Regularly clean your HVAC system, vents, and cooling and heating equipment.

Keep in mind that a musty smell is an indication of a dirty house or poor ventilation.

The key is to always keep your house clean and well-ventilated.