AC Evaporator Replacement
What is an air conditioning evaporator?
To cool the interior of a vehicle, the air conditioning system has to compress and expand refrigerant, changing its temperature. The air conditioner evaporator is what makes the refrigerant cold. This part is typically found underneath the dashboard.
How does an AC evaporator work?
As compressed refrigerant reaches the evaporator, it passes through an expansion valve. This rapidly depressurizes the refrigerant, causing its temperature to drop dramatically. Now a cold gas, the refrigerant passes through the evaporator, causing that part's metallic core to become extremely cold. The cold evaporator is in the airflow path of the blower motor, and it cools down the air that blows into the car's cabin.
What are the symptoms of a bad AC evaporator?
Anytime the AC evaporator goes bad, the air from the vents will be warmer than expected. This is because a clogged or leaking evaporator won't get enough refrigerant to cool the air.
In some vehicles, there may be some type of warning like a blinking AC switch.
Can I drive with a bad AC evaporator?
Vehicles with a bad evaporator can be driven, but they won't be comfortable when it's hot outside. In extremely hot climates such as deserts, not having a working air conditioner could be dangerous for children and seniors.
How often do AC evaporators need replacement?
Most cars will never need a new evaporator, but there are factors that can shorten its life. The evaporator is metallic, and if there's moisture in the air conditioning system, that moisture can cause corrosion. Likewise, a leaking heater core can get coolant on the evaporator, potentially ruining it.
Additionally, the rubber seals for the AC lines connecting to the core may cause the evaporator to leak, in which case the technician may recommend replacement.