Once upon a time, a car's HVAC system consisted simply of a heater, an air conditioner, and a few positionable vents. Those features still make up the backbone of an automotive HVAC system, yet technological developments have allowed more sophisticated features to evolve, including such things as heated seats, zoned cooling, and automatic control systems.
The complexity of such systems means that cars require a much larger array of sensors in order to stay on top of cabin conditions. By familiarizing yourself with some of the most common types of sensors, you can arm yourself with vital information should problems develop later on. This article takes a look at three key sensors used in your car's HVAC system.
1. Temperature Sensors
Automobiles being produced today contain a staggering number of temperature sensors. These monitor the temperature of everything, from your engine to your exhaust, with plenty in between. In fact, the majority of a car's temperature sensors don't have much to do with the HVAC system at all.
Nonetheless, your HVAC system depends on the data provided by a key set of temperature sensors. Cabin sensors supply vital information about the temperature inside of your car. Some vehicles use just one cabin temperature sensor, while others may incorporate several, often in conjunction with a zoned HVAC system.
Zoned HVAC systems allow different parts of your car to independently control their temperature. Cars with certain auxiliary heating features - like seat warmers - use additional sensors to monitor and regulate their temperature.
Your HVAC system also utilizes temperature sensors on the outside of the car to determine exterior air temperature. This information plays an important role, allowing your HVAC system to determine how much or little it needs to heat the incoming air in order to meet your desired comfort level.
2. Sun Load Sensors
Unless you drive a car with heavily tinted windows, sunlight plays a huge role in the comfort conditions inside of your cabin. In fact, sunlight entering a car through the windows may account for as much as 60 percent of the heating load being placed on the HVAC system. As you can imagine, sunlight has an especially potent impact during the summer months.
In order to account for the effects of this sunlight, many cars utilize a type of photodiode sensor known as a sun load sensor. The sun load sensor can usually be found mounted on a plate at the top of a car's dash. There, it has one simple goal: to measure the intensity of the sunlight falling on it.
The car's computer actively monitors the information from the sun load sensor. When it detects especially sunny conditions, it makes subtle alterations to the system to improve its cooling. For instance, the computer might send a signal telling the fan that cools the air conditioner compressor to rotate at a higher speed.
3. Humidity Sensors
At one point or another, most people have had to deal with a foggy windshield. This frustrating - and sometimes dangerous - phenomenon happens when the humidity levels inside of your cabin get too high. Many cars currently in production have humidity sensors that allow the HVAC system to prevent problems like window fogging.
Humidity sensors also help to ensure optimal comfort. Passengers can easily become sweaty and uncomfortable when humidity levels rise too far. In addition, humidity sensors help to prevent mold and mildew infestations inside of your car's duct system. Such microorganisms can easily thrive should those cool, dark tunnels grow too moist.
Today's cars rely on a sophisticated group of HVAC sensors in order to maximize your driving comfort. For more information about which such sensors your car contains, please don't hesitate to contact the auto pros at Letcher Bros. Auto Repair.