Let’s talk about car watching- trying to prevent mold in your seasonal parked car.
Most seasonal homeowners in SW Florida are well aware of the need to have someone, preferably a professional home watch company, monitor their home, but what about your car? (Since this article’s focus is on mold, this article will assume that the cars are on a trickle charger or the battery is disconnected which is standard procedure for a car not being used for several months.)
Leaving a car at your seasonal home is also a big concern because mold in an unused cars can be a real issue. Our weather here is subtropical and humidity here during our rainy season lends to mold growth.
So let’s consider the preferred environment of mold- Damp, dark, and warm.
>Mold prefers temperatures of 60-80 degrees Fahrenheit according to https://epi.dph.ncdhhs.gov/oee/mold/grow.html
>What about humidity levels? “When relative humidity is above roughly 60%, there is a risk of mold growth– with risk really increasing when the RH exceeds 80%.” (https://indoorscience.com/blog/relative-humidity-and-mold)
>Let’s face it- garages and parking garages tend to be dark. So basically most cars parked in garages have three strikes against them.
These are the three key factors we are working against. We have to keep these all in mind. Think like a scientist.
Sadly, there isn’t a perfect clear solution because we can’t control the weather, but let’s be proactive.
1. Reduce microbials. Wiping down your car’s interior with an antimicrobial cleaner (safe for leathers) would be a first step. Our cars can be exposed to man kinds of bacteria and mold spores are always in the air. Let the car thoroughly dry out. Open the car on a nice hot sunny day. Sunlight is an enemy of mold and can also be useful. Mold prefers organic materials. Those surfaces in your car are even more susceptible.
2. Control the humidity. Few people have the opportunity to store their cars in an air conditioned garage. BUT there is a solid option for people who have their own garages- a dehumidifier. Keeping the humidity controlled in a contained space is achievable and a great option. The unit, if the drain is gravity fed, needs to e higher than the exit out of the garage’s wall or vent. a few dehumidifiers come with pumps. I think a larger diameter hose that is gravity fed works fine. We have one client that has a dehumidifier with a pump and the hose is very small like a straw where It can tend to get clogged. Close the windows and vents. If a client has their own garage, we always suggest a dehumidifier!!!
Is running a fan effective in the garage? My opinion? Not really. Is isn’t addressing any of the three key factors. We have to respect the laws of science. Improving ventilation can help but I don’t feel it’s over impact is enough.
What if your car is in a high rise garage? This scenario is a tough one. We have several clients who leave cars over the summer in their high rise condo’s parking garage. Damprid isn’t a solution, but it is better than nothing. It has to be checked and changed to keep it effective. Windows should be up and the air vents closed (set to recirculate). Newer cars have better seals on them. This lets the Damprid remove the moisture from the air inside the car sealing it off from the outside. I did a test one day to see if this setup was being effective. Keep in mind, how tightly sealed the car is makes a difference. One day the outside humidity in this high rise garage was 73%, it was in the 80s that day. I took a humidity reading inside the client’s car and let it adjust for a few minutes. The humidity reading was at 53%. For him it was being effective. How will it do in the peek of rainy season? I plan to follow up with some regular readings this summer and will report back on that.
Every situation is different. Looking at how to best offset the environment that mold thrives in is your best attack.
What are some other options? Taking the car to a sunny spot can be helpful. Think of how hot your car gets when you go into a store and it’s all closed up. Temperatures, high temperatures can help destroy mold spores. A professional home watch company will help monitor your car and may be able to repark the car for a period of time to a sunny spot. Many can do this for a modest fee.
Having your home watch company drive the car for a good 20 minutes, running the AC, can help extract humidity that builds up in the upholstery, carpet, and fabrics. This would be called a car drive service. Make sure your have proper authorization forms in place. The frequency can vary depending on the environment the car has been stored is in. Will just starting the car and letting it run be as effective? Not really, the car’s engine when driving makes the AC system run far more effectively when than sitting idle.
For some home watch companies, a car watch service may be an added charge.
One other thing to add to the list would be to have the car professionally detailed from time to time to keep microbial growth reduced. There are some products on the market that may help to reduce microbial growth. Talk to your detailing service about this.