Hello, Top Gear Philippines! I am not really knowledgeable about cars and would like to ask about air-conditioning and air fresheners. Are air fresheners really bad for the A/C system in the car? What should I buy to keep away the bad odor inside the car and maintain a refreshing smell every time I ride? Looking forward to your reply!
Hi, Lei. Any perfume or car freshener that, over time, leaves a sticky or somewhat greasy residue on surfaces should be avoided. It's not that they're bad for your heating, ventilation, and air-conditioning (HVAC) system, but because dust and other minute contaminants tend to be attracted to said sticky surfaces, making your car even dirtier. This isn't as much of an issue on surfaces that you can regularly clean, such as your dashboard and door sidings.
In the case of hard-to-reach or -clean areas, like your HVAC's cooling coil (that needs to be as clean as possible to operate efficiently and be cold), it will be more of an issue. The built-up contaminants will reduce the A/C's ability to cool the car's interior and may possibly (but not usually) be the cause of foul odors. On more modern vehicles that have a cabin filter, this may not be as much of an issue, but you may possibly need to replace your cabin filter more often.
If you generally keep your car's interior clean and devoid of stinky footwear, gym clothes, or other foul-smelling objects (significant others may or may not be included) there's probably not a lot of need for car fresheners.
To keep my car smelling and feeling fresh, I regularly clean the interior, as well as keep a few packs of silica gel and some activated carbon (when available) securely under the front passenger seat. I also occasionally air out the interior every now and then by parking in the noon time sun with the windows open. However, this may not be something you want to do if you don't have access to secure parking.