Summer is here, and it’s time to start thinking about your car’s AC system! Nobody likes driving around in a hot, stuffy car, and a car with an AC system which only works marginally is somehow almost even worse than one which doesn’t work at all. Let’s go through a few tips which can help you keep your ride a little more comfortable this summer…
Remember a cars AC system is really a heat exchanger which moves hot air out of your vehicle, then replaces it with cold air. One thing you can do to help improve its efficiency is to leave your windows down an inch or two (if possible) when you park the car, helping to prevent excess heat buildup. When you start the car and begin to drive off, lower all the windows for the first minute or two to help move hot air out of the car more quickly, giving the AC system a chance to refill the car with cold air faster. And of course, as you probably already knew, parking in the shade when possible can be a big help too!
The conventional wisdom used to be, “AC systems are a drag on your car’s engine and fuel efficiency — drive with the windows down if possible to enhance gas mileage.” While that may have been true in your dad’s day with his 60s- or 70s-era cars, it’s no longer correct. Modern AC systems are much more efficient, and cars are more aerodynamic — on today’s cars, driving with the windows down at highway speed actually creates enough aerodynamic turbulence and drag to drop gas mileage. Leaving your windows up and the AC on is the way to go…unless, of course, it’s a pretty day and you just feel like having the breeze in your face for a while!
When you first enter the car and start driving, turn the AC to its highest setting (MAX or REC), with the fan turned all the way up as well. This will help move a greater volume air, cycling hot air out of the car and replacing it with cold air. As soon as you’re comfortable, go ahead and lower the AC settings again to stabilize the temperature. On cars with climate control or automated temperature control, just lower the temperature setting to the lowest mark, then raise it again once you’re comfortable.
Are you noticing a musty or “dirty socks” smell from the AC vents? Try running the AC system on the Defrost setting for a while, or toggle back and forth between the MAX setting (which recirculates cabin air) and the NORMAL setting (which introduces fresh air). If the smell persists, it could be an indication of a cabin air filter which needs to be changed, or possibly a system which is low on refrigerant. Don’t just put up with that smell — it means there are bacteria and mildew circulating through the system, which can be a real problem for allergy or asthma sufferers.
Run your AC system once a week or so, even in cooler temperatures. Lubrication is essential to the proper operation of any AC system, and running the AC for a few minutes helps circulate refrigerant and lubricant through the system and keeps the components, valves, lines and seals conditioned.
When a cars AC system isn’t blowing air that’s cold enough, nine out of ten times it’s due to being low on refrigerant. This is pretty routine, really — any car which is more than a few years old will lose a small amount of refrigerant over time. Older cars (before 1994) used R12 Freon refrigerant, which was found to be harmful to the ozone layer. Since 1994, R134a has been the standard refrigerant; it’s relatively simple to retrofit older cars to use R134a rather than the hard-to-come-by R12. If your car’s AC vents aren’t blowing sufficiently cold, it’s important to not use the AC, as low refrigerant can damage the compressor and result in some expensive repairs. Most refrigerant formulations also include a lubricant for the system and a fluorescent dye that can indicate leaks around seals, O-rings, lines or components once the system is pressurized again.
With summer here, you’ve surely got plans for road trips, vacations and other summertime fun. Don’t let a sweltering-hot car get in the way of those plans! If you suspect there may be issues with your car’s AC this summer, bring it on by MB Mercedes BMW Mini and let our techs have a look. We’ll inspect all the components, check the refrigerant level and recharge if necessary, clean bugs and debris from the condenser, check the serpentine belt that drives the compressor and check the cabin air filter so you can keep your cool this summer.