Classic Toyota’s Automotive Terminology Decoder: Decoding Your Vehicle’s Climate Control/Ventilation System

Apr 21, 2023

Summer is Coming! And it’s time to talk about the importance of cleaning and servicing your car’s AC and ventilation system before the heat wave hits.

We’re here to break down some of the important terminology and terms with our next installment of Classic’s Automotive Terminology Decoder!

Here are some of the terms you may hear when speaking with your mechanic or service professional about your AC and Climate Control system:

A/C compressor

An engine-driven pump in the air conditioning system that increases the pressure of the refrigerant.

A/C drain hose

A hose used to drain condensation from the air conditioner evaporator.

Air conditioner refrigerant

The liquid used in air conditioning systems, which has the property of boiling at ambient air temperatures.

Air conditioning

The cooling and dehumidification of a vehicle’s cabin air.

Air conditioning filter

A device that removes contaminants from external air entering the ventilation system.

Air filter

A device that filters incoming air fed to the engine.

Climate control

The computer-controlled regulation of heating and air conditioning systems to accommodate a user-specified temperature setting.

HVAC

Heating, ventilation and air conditioning.

Radiator core & AC condenser

The part of a vehicle’s radiator and air conditioning systems made up of small-diameter tubes with a series of thin, heat-conducting fins in between.

Rear HVAC

The climate-control system used to regulate heating and air conditioning for the area of a vehicle behind the front row seating.

How does it all work?

Your car’s climate control system is a complex combination of components that include the compressor, condenser, receiver/dryer or an accumulator, a thermal expansion valve or orifice tube, and an evaporator. The compressor helps pressurize refrigerant to cool the air, and can sense the temperatures both inside and outside the vehicle, moves air to the condenser, etc. The condenser helps reduce the temperature and the pressure of any hot gasses emitted from the refrigeration system, and moves cold liquid refrigerant to your receiver/dryer or the accumulator. The most common parts to need service are the compressor and the condenser Additionally, low refrigerant (can be caused by leaks), a worn or broken v-belt or serpentine belt (helps the compressor function), or a busted compressor switch may also be the culprit.

How do you diagnose an issue with your vehicle’s AC/Heating system?

If you notice any of these warning signs, it’s an indication that your car’s AC system is in need of help from a pro:

The air from the vents is not actually cold. This may be due to debris clogging the AC unit, low or no refrigerant, damaged cooling fans, or more.
You hear strange noises coming from the vent such as banging, rattling, squealing. This might be a simple fix such as removing debris, or it may be a broken component inside.
Your nose twinges due to foul smelling, musty, stale, or strange smells coming from the AC vents. This may indicate that you need a new air filter or clear debris, but it may also indicate that you have mold growth inside the unit. If you notice a chemical smell, that may indicate a leak in the AC or the radiator.
There are water stains inside your vehicle instead of underneath it. Your AC system drains water out from underneath your vehicle, and it’s a perfectly normal, healthy sign. However, if you run the unit and notice any puddling or dampness inside on your floormats or under the dash, it may indicate that there’s a clog.
There may be a leak in the AC system, which a professional will diagnose with special dyes to help identify and indicate the location and source of the leak.

If you spot any of the above issues, it’s time to schedule a call with our service department for an AC system check. Our professional technicians will thoroughly inspect your climate control system and its components to diagnose if the problem is mechanical or electrical.

What can I do to help maintain my car’s ventilation and air conditioning system?

Check under the hood and remove any leaves, trash, or other debris from inside the engine bay (when the car is cooled!)
Check the cabin air filter and clean it or replace it.
Clean your vehicle’s air vent system with a microfiber cloth, small brush, and air sanitizer.