A/C tips for light trucks

Further south, Raleigh, NC, witnessed a 12 day stretch of 95-plus weather, while out west, Kingman, AZ, tied a record number for most 100-degree-plus days in a row.

Needless to say, when it gets that hot out, air conditioning (A/C) systems get a workout, for homes, office buildings, malls, and – of course – vehicles.

Yet where light vehicles are concerned, A/C systems are changing to make them operate more efficiently – and Larry Karas, climate control supervisor at Ford Motor Co. recently offered some insight into how those changes aim to improve the comfort of vehicle operators and passengers.

“Vehicle air conditioning systems are powerful,” he explained. “Most drivers expect their vehicle’s interior to reach a reasonably comfortable temperature within 15 minutes. But on a sunny 95-degree day, that interior may be upward of 140 degrees. So in order to cool a vehicle down to a comfortable level, the cooling capacity of most vehicle air conditioning systems must equal that of a small home.”

Karas noted Ford uses what is called a “limited reheat strategy” to create the most comfortable interior environment. “Previous systems cooled all of the processed air to just above freezing, then ‘reheated’ the air to the desired temperature,” he pointed out. “The newer systems of today cools the air down to just below the desired temperature, then reheats it slightly. This reduces the amount of energy required to operate the system and results in better fuel efficiency.”

Ford also “smartened” its A/C system with a sensor that identifies where the sun is shining strongest on a vehicle car, adjusting output temperature accordingly.

“If the sun is shining on the front passenger-side window, cool air output is stronger on that side of the vehicle than on the driver’s side to offset the added heat and keep a consistent level of comfort,” Karas noted.

He also offered a few more tips to obtain better cooling performance from vehicle A/C systems:

• When you first enter a hot vehicle, lower the windows completely for a few minutes to push out hot air.
• Use the max A/C button to quickly cool down the vehicle.  
• If you get too cold, don’t switch the unit on and off; adjust the temperature or fan speed to help keep the temperature consistent.
• If it’s too cold in the front, but still not cool enough in the back seat, don’t shut A/C vents in the front; redirect them to the ceiling or sides of the vehicle to keep air flowing to the rear.
• If it isn’t too hot, when driving around town turn off the A/C and roll down your windows instead.
• Parking in the shade whenever possible or using a reflective windshield shade can dramatically reduce heat buildup in your parked vehicle. Cabin temperature at startup will be much lower, and temperature comfort will be achieved much sooner on your drive.
• If your vehicle is equipped with a moon-roof or large panoramic roof, always close the roof shade to reduce heat buildup in your parked vehicle.
• If your vehicle is equipped with a remote start system, be sure to set the climate control system up for automatic operation so you can start the cool-down process before entering the vehicle.
• If you live in a predominately hot weather state, choosing a lighter exterior color and/or a lighter interior color will reduce heat buildup in your parked vehicle.

Proper maintenance, of course, is critical to keeping the A/C in tip-top operating shape. For example, when the cabin air filter gets dirty, Karas said it should be replaced rather than cleaned.  

He also noted that after several years, some refrigerant may escape from the A/C system. Yet the only way to restore the system back to peak operating condition is to have the remaining refrigerant removed and the proper quantity of refrigerant added.

“That will ensure the vehicle’s air conditioning is running efficiently and keeping everyone inside comfortable,” Karas said.