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9 Reasons Your Car AC Takes a While to Get Cold

Car AC Takes a While to Get Cold

The last thing you want during the middle of a heat wave is a car AC that takes a while to get cold. If the air-conditioning system in your car isn’t cooling you off within a reasonable amount of time, you’ll need an AC checkup.

The A/C can stop blowing cool air for any number of reasons. But a trained mechanic will likely have the tools necessary to run the right diagnostics for pinpointing the exact issue and get you back to enjoying frigid air. Here are just nine reasons why your car’s AC takes so long to get cold.

1. Low-Capacity A/C System

One of the reasons why your car AC takes a while to get cold is because many cars today are manufactured with a low-capacity air conditioning system. My Ford Fiesta is equipped with one of these.

When temperatures exceed the 100 degrees Fahrenheit range, it takes forever to get the interior feeling cool, if at all. The air conditioning system in your car is like the AC system in your house. If it’s very hot outside and the ac unit is too small, there won’t be enough power to keep your space cool.

2. Low Refrigerant

Low refrigerant could be the reason why your car AC takes a while to get cold.

But a more likely reason why a car’s AC takes a while to get cold is because of low refrigerant. An air conditioner works by converting liquid refrigerant into cool, dry air. In modern cars, refrigerant is in the form of R-34a and soon R-1234yf. If the refrigerant is too low (or too high), the engine may not allow the compressor clutch to engage. The AC compressor clutch connects and disconnects the AC compressor from the engine.

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3. Weak AC Compressor

A weak AC compressor could be the reason why your car AC takes a while to get cold.

A weak AC compressor will take time to build up pressure. This means that the air conditioning system can only produce cold air once the engine is at a high RPM. An AC compressor is a vital part of any air conditioning system.

It’s responsible for turning power into energy and circulating the refrigerant necessary for the heat exchange process. When I finally took my Fiesta to a professional to get looked at, a weak AC compressor turned out to be the issue. At the cost of $1,000, this is an expensive part to replace.

4. Refrigerant Leak in the AC Unit

Another reason why a car AC takes a while to get cold could be because it’s leaking refrigerant. Damage or corrosion to AC system components; wear and tear on AC components; improper installation of the AC system and environmental factors can all lead to a refrigerant leak. Besides the environmental impact of a leak in your AC system, it can also cause you health problems, such as dizziness, headaches and nausea when inhaled.

5. Bad AC Expansion Valve

Remember that an air conditioning system converts liquid refrigerant into cool, dry air. Also known as a thermal expansion valve or thermostatic expansion valve, this component removes pressure from the liquid refrigerant allowing expansion (change of state from liquid to vapor) in the evaporator.

Essentially, it steadies the amount of refrigerant flowing out of the evaporator for more consistent airflow. A faulty expansion valve leads to a fluctuation in an AC system’s ability to control the flow of refrigerant. This results in inconsistent airflow through the vents, which is why it takes a while for the AC to get cold in your car.

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6. Faulty Climate Control System

A fault climate control system could be the reason why your car AC takes a while to get cold.

There are numerous reasons why the climate control system keeps your car from cooling and can even stop working. But most are electrical. And some of those electrical issues could be due to a refrigerant leak. Refrigerant gets transported throughout the AC system by a network of hoses and tubes. But if one of those hoses or tubes gets damaged because of leaking refrigerant, it could affect the climate control system’s settings due to condensation.

7. Clogged Air Filter

A clogged air filter could be the reason why your car AC takes a while to get cold.

Dirt, leaves and bugs can clog up an air filter preventing your AC from reaching its maximum cooling potential. Simply replacing a dirty air filter may be all that’s separating you from cooler air.

Sometimes the air conditioning unit is blowing cold air, but you just can’t feel it. This can also be the result of a faulty blower fan, which requires a fix that’s a lot more complicated.

You’ll have to remove the dashboard to get to where the fans are to diagnose and/or replace them. And especially in modern cars, this is not a task you’ll be able to complete in one weekend without some serious know-how and tools.

8. Open Recirculation Door

When the air conditioning is at its max setting, the recirculation door should close. The recirculation door controls the intake of air into the air conditioning system. It can either bring in air from outside or recirculate air that’s inside the cabin of your car.

But if the recirculation door won’t close, then hot exterior air compromises the work of the A/C system causing your car’s AC to take a while to get cold. If the AC unit is at the maximum setting and the recirculation door is even partially open. It can slow down cooling by redirecting some of the cool airflow through the heater.

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9. Issues with the Radiator Fan

The reason why your car AC takes a while to get cold could be that the fan clutch or electric fan is engaging late. This reduces airflow, which in turn reduces the air conditioner’s ability to blow cold air, especially if you’re not driving that fast like in stop and go traffic.

A viscous fan clutch acts as a heat exchanger for the air conditioning unit. The engine fan keeps the condenser cool helping the AC system run smoothly. But a bad radiator fan can not only cause the AC to take a while to get cold. But it could damage the entire air conditioning system.