It's difficult to diagnose an overcharged system, but common signs are a lack of cool air, changes in noise, and higher energy bills after refrigerant changes.
Hot air from the vents: It might sound counterintuitive, but too much refrigerant can cause hot air. Hot air coming from your vents results from the unit producing excess heat during its operations. The extra power associated with an overcharged system can cause this overheating.
The first sign that there is too much refrigerant fluid in the system, is when there are abnormally high-pressure readings on the pressure gauges of the system.
Most ACs nowadays come shipped from the manufacturer with the exact amount of refrigerant that it will need for the duration of its life. So, unlike a car, your AC won't ever need to “fill up” on refrigerant unless something goes wrong with the system.
First, check your filters and coils for dirt and debris that may be impeding airflow. Once you've cleaned the filters and coils, run the air conditioner with just the fan so that the ice accumulation can melt off. If the AC still doesn't blow cold air, it could be that refrigerant levels are too low.
Generally speaking, a properly maintained air conditioner can expect its refrigerant to last around 10-15 years or longer—depending on usage frequency and environmental wear and tear. To ensure your refrigerant lasts as long as possible, regular maintenance is key.
It's important to remember that, while refrigerant shouldn't run out, it can. The only reason your air conditioner's refrigerant levels might change is if there is a leak in the copper coils or at connection points. This is a serious problem that will keep the AC system from working properly.
Consequences of Having an Overcharged Air Conditioning Unit
Its cooling power will significantly drop, which can be frustrating during the hot months. It will also be harder for the system to convert the refrigerant from gas to liquid and liquid to gas.
Another sign of an overcharged AC is weak cooling. If your air conditioner isn't reaching the target temperature or the air coming out of the vents feels warmer, too much refrigerant might be the problem. Excess refrigerant stops the AC from working correctly and efficiently.
If you put the newer freon in right away, your unit will rupture due to the force. However, you can convert your AC unit to handle R410A. You'll need to replace the compressor, condenser, evaporator, and likely the refrigerant tubing. If you replace all of this, your old unit will work fine with the new freon.
As mentioned earlier, Freon costs about $125 – $150 per pound. Most homeowners will pay in the range of $200 to $400 for a refill, depending on the type and size of their HVAC unit.
First, on your unit's condenser coil, locate a rubber cap. It should be covering a copper tube on top of the condenser coil. From here, you can easily see whether there is enough Freon in your AC unit or not.
Most cars hold between 28 and 32 ounces of refrigerant (or about 2—3 12oz cans), however larger vehicles and those with rear A/C will likely hold more. Check your vehicle manual for the system capacity for your specific vehicle.
An AC leak will lead to warmer air from your vents over time. In most cases this can be fixed with a proven stop leak additive to seal up any leaks. When it's time for an AC recharge, turn to AutoZone.
Loud Air Condition Compressor Noises
However, if there's a sudden onset of unusual noises, like a loud squealing, it clearly indicates something is amiss. These unexpected sounds can often be attributed to the system struggling to manage excessive high-pressure liquid refrigerant.
While the refrigerant in your vehicle can escape even without a leak, it's often not enough to cause significant issues unless you've failed to top up the refrigerant for years. When the lack of refrigerant becomes significant though, it can cause a number of problems, including an overheating driver in the summer sun.