When the problem with your car's air conditioning has to do with weak air flow, charging it with more refrigerant is not going to solve it. It is important that you fix the problem before it causes more damage to the whole system and you need to have it replaced. Here are a few of the things that might be causing the AC in your car to not blow strong enough and how to fix them.
Mold or Mildew
The moisture that collects on the coils and evaporator of the AC unit creates a breeding ground for mold and mildew. Reaching the unit is not a simple task as it is inside the dashboard. However, you may be able to access it by removing the instrument panel. Once you see the evaporator, clean the coils by spraying it off with a hose. Once all the mold and mildew have been removed, spray it with an antimicrobial agent.
A blower motor pushes the cool air through the system. If the hose connecting the blower to the evaporator is loose or damaged, the amount of air flowing through the system will be reduced. Check the hose connections, and if necessary, tighten them. If they are tight, make sure there are no holes or other damage. If damaged replace it. You can also remove the hose and make sure it is not blocked. Sometimes small birds or animals can get inside a hose and make a nest or die.
Every connection on the AC system has a seal. If any seal is cracked or damaged in any way, the vacuum is compromised and the airflow is reduced. With the system running, spray a bit of water at each seal and look for bubbles. Any seal that is not intact needs to be replaced. Be sure to clean the area where the seal sits completely. A tiny bit of dirt can keep it from sealing properly.
If no air is coming through the system, but the hose and all seals are good, it could be the blower motor. This will require you have the motor replaced. A professional mechanic can verify this is the trouble and install a new one.
There is no reason to suffer in a hot car when the air conditioner is not blowing enough air. Once you do a bit of troubleshooting, you may discover you can fix the problem yourself. If the problem is beyond your mechanical abilities, contact a mechanic or auto AC service like Modern Auto Air, explain what you have done and the results, and then have him or her fix the problem.