Does your vehicle air conditioner smell sort of like mold, especially right when you first turn it on? If so, you’re not alone – it’s a very common problem. Here in Phoenix, this can be an especially annoying problem because so many of us use the air conditioner every day.

The cause of this problem is just what it smells like – mold and bacteria. Inside your vehicle’s air conditioning system, you have a part called an evaporator. This part is designed to remove both the heat from your vehicle’s interior (when the A/C is turned on, anyways) as well as remove any moisture from the air that’s being cooled. While most of the air around here is pretty dry, there’s still enough moisture in the air to condense upon your vehicle’s evaporator.

An evaporator from a vehicle air conditioner, removed from it's housing

When moisture condenses on the evaporator, it’s supposed to drip drain away. However, very often the drain will become clogged and/or it won’t drain quickly enough. If water can stagnate inside the evaporator unit, this water grows mold and bacteria that causes your vehicle’s air conditioning system to smell — especially immediately after the system is first turned on.

There are three ways to solve this problem:

Each year, the Asthma and Allergy Foundation of America starts the summer by declaring a National Asthma and Allergy Awareness Month, the idea being that it helps allergy sufferers remember that the end of Spring and beginning of the Summer is a “peak” season for asthma attacks and allergies.

Raising awareness about allergies and asthma is important because:

1. Asthma is particularly hard on children. According to the Clean Air Council, about 5 million children in the U.S. have asthma. Because they’re so active – and because they spend so much time outside – they’re more at risk this time of year.

2. Allergies and asthma can be hard on adults too. People with compromised immune systems – be they elderly or suffering from a chronic illness – experience undue stress due to allergies, which are easy to mistake for a cold or the flu. Not to mention that everyone who suffers from allergies suffers. It’s no fun.

3. There are a lot of things you can do to reduce allergy and asthma triggers. Cleaning and/or replacing the filter in your air conditioner or swamp cooler is a great way to reduce risk…but did you know your car may have a similar filter?