Proper Auto A/C Vent Temperature: How Cold Or Hot Should It Blow?

auto ac vent Proper Auto A/C Vent Temperature: How Cold Or Hot Should It Blow?

Traditionally, vehicle manufacturers relied on the car’s engine to power the air conditioning unit. Today they are being fitted with electrically powered air conditioners. But whichever air conditioning system is installed in your car or truck, the A/C unit is an essential feature to cool you down when the outside air temperature gets hot.

As a rule of thumb, when the air temperature is 70° Fahrenheit (21° C), the A/C outlet air temperature should be in the 27° to 38°Fahrenheit (-3° to 3° C) range. When the ambient air temperature hits 80° or 90° Fahrenheit (27° to 32° C), the outlet air temperature should be in the 33° to 48° Fahrenheit (3° to 9° C) range. 

Due to the varying ranges, it’s essential to check your manufacturer/vehicle information manual to see the exact A/C temperature during specific temperature conditions.

How To Check If The Vehicle A/C Is Cold Enough

You’ll need a thermometer with a long probe that can go into the center air vent on your car’s dashboard. They are readily available at most auto parts stores and cost just a few dollars.

  1. Park your vehicle in an outside area away from direct sunlight.
  2. Measure the temperature outside the vehicle. This will help determine if the air conditioning is working efficiently.
  3. Close all the vehicle windows and the air vents apart from the center air vent on the dashboard.
  4. Start the engine and turn the air conditioner to the coldest setting possible, and with the fan at its slowest speed.
  5. Allow a little time for the A/C to work.
  6. Place the probe thermometer into the only open-air vent and check the reading after a few moments.
  7. With an outside temperature of about 90F (32C), you would expect a thermometer reading of between 40F-50F(5C-10C) in the air conditioning duct.

Anything above this would require servicing by a qualified auto air conditioning mechanic. Each particular vehicle manufacturer has its own specifications for its air conditioning systems. It would be worthwhile checking its website for information about your specific model.

A/C & Heater Temperature Chart

These values are from Honda and can be taken as a generalization for most vehicle air conditioners.

Why Is My Vehicle Temperature Too High?

There can be several reasons why your air conditioning system has lost its cool.

  • There has been a loss of refrigerant. This is most often caused by the failure of a seal or a hose. The gas used in A/C units contains oil to lubricate seals within the system. If it is not used for some time, these seals can dry out, letting refrigerant escape.
  • The expansion tube or refrigerant charging hose may be clogged.
  • The compressor clutch or the compressor itself may have failed.
  • The motor on the blower may have failed.
  • Less likely is that the condenser or evaporated may have a problem.
  • There could also be vacuum leaks within the system or failed fuses, which can be easily replaced.
  • Catching early for a leak in the system is imperative. If moisture is allowed to get into the system, it could damage vital and expensive parts.

How To Check If Vehicle Heater Is Warm Enough

If you think your car’s heather is not performing as it should, the first step is to do a test drive check.

Take your car out for a drive, and wait until the engine temperature is in the normal zone on the dial. Once everything is warmed up, turn the heater up to hot, and select the blower to a medium/high speed, directing the blowers to your feet or floor. Then place a probe thermometer into the lower air vents on both the driver and passenger sides.

Any reading around 115F-120F (46C-49C) is acceptable. Some vehicle manufacturers boast their heaters will do 135F-155F (57C-68C), which would make things very toasty indeed. Suppose the temperature is OK, and the vehicle’s cabin is still not getting warm. In this case, it might be a problem with the fan blower or the ductwork under the dashboard.