Firstly, get a recovery tank and the related accessories such as manifold, hoses, 1/4″ fitting, and vacuum pump. Connect the hoses and manage the valves. Drain the Freon only after evacuating the tank and hoses with the help of valves.
How to Recover Freon With Vacuum Pump
Recovering freon from a system requires condensing it out. This section will discuss the systematic way of doing so with a vacuum pump.
Step 1: Get a Recovery Tank
Find yourself a refrigerant recovery tank with 1/4″ fittings. You could make use of a propane tank by emptying all the gas inside. You can try venting the rest into the atmosphere. Remove the original valves and wash the tank with water. Then screw in adapters, a valve, and a 1/4″ fitting. Freon pressures are typically lower than a propane tank’s rated pressure. So, there should be no overloading issue as long as the tank does not get too hot.
Step 2: Gather the Attachments
Get an automotive HVAC manifold that has high/low/vacuum valves. Also, get the hoses and the high/low side Freon couplers. Now get an automotive two-stage vacuum pump to start the main task.
Step 3: Connect the attachments
The next step for you is to connect the three hoses. Connect the low side of the blue hose and coupler to the manifold. Similarly, tie the yellow hose to the recovery tank. Finally, the black vacuum hose connects to the pump.
Step 4: Manage the Valves
Open the tank valve, vacuum valve, and LOW valve. Then close the low Freon coupler.
Step 5: Evacuate the System
Now you have to evacuate the recovery tank and the three hoses. When you are done, close the vacuum valve. Then disconnect the pump and black hose from the gauge. In the meantime, the tank, the manifold, yellow, and blue hoses will be evacuated.
Step 6: Freeze the Tank
Find yourself a chest freezer to freeze the tank. Put the tank inside the freezer and let it freeze all-night. Also, make sure that the system you are working on has cooled down overnight.
Step 7: Start draining Freon
Now close the low valve and attach the low-side coupler to the system. The next thing to do is to open the coupler. Then steadily open the low valve so that the pressure does not exceed the refrigerant’s rated pressure at ambient temperature. This will drain the Freon into the tank through the low-side valve. In the tank, you will see the refrigerant condensing.
Step 8: Block off the Sublimation
Finally, fill a plastic bucket with ice and put the tank in it. Then take it back into the freezer. This will slow down the sublimation. Don’t forget to close all the valves, including tank valves. That’s how you will be done removing Freon from the system.
How Do You Get Freon Out of a Car with a Vacuum Pump?
Getting Freon out of a car air conditioner is similar to the process of removing refringent from a system. First, get a recovery tank with the necessary adapters, valves, fittings. Also get the HVAC manifold, hoses, and couplers. Connect the manifold, vacuum pump, and tank to the respective hoses. Evacuate the tank and hoses and freeze the tank in a chest freezer.
Make sure you do not turn the car on and cool it down as well. Then attach the low side coupler to the car and slowly open the low valve. The pressure must not exceed the refrigerant’s expected pressure in ambient temperature. Just like that, the Freon will be stored in the tank condensing.
Furthermore, you can put the tank into the freezer to slow down the sublimation. That’s how you can remove the refrigerant from your car’s air conditioner.
Can You Recover R134a with a Vacuum Pump?
You can certainly recover R134a with a vacuum pump. R134a is easily recoverable through condensation. The refringent has a pressure of ~150psi at 100F. So, get a recovery tank with a pressure rating of over 300psi. This is to avoid overloading. Just make sure the tank does not get too hot. Gather the manifold, hoses, valves, and vacuum pump.
Connect the hoses to their respective systems. Evacuate the systems and freeze the recovery tank overnight. Manipulate the low side valve to draw out R134a. The expected R134a pressure at ambient temperature is 150psi at most. Slowly open the low valve as you don’t want to exceed that. At the typical freezing temperature, the remaining pressure should be around 6psi.
Frequently Asked Questions
Q: How much does it appropriately cost to recover Freon?
Ans: Without including the taxes and fees, the average cost for refrigerant recovery is between $35 to $44 approximately. The cost may vary with location and other factors.
Q; Does vacuuming air conditioner take out oil?
Ans: Vacuuming air conditioner does not remove oil. Unless you replace the compressor or accumulator, you won’t need to add oil either.
Vacuum pump is a multipurpose tool that allows you to do many works like bleeding a clutch with a vacuum pump, vacuuming the AC system etc. Recovering Freon with a vacuum pump is not an easy task. If you are a shade tree mechanic, you need to maintain even more strictness. The processes mentioned are precise and they need to be executed properly. If you are not confident enough, getting help from a professional would be best.