Whatever the reason for the evacuation, it is important to evacuate the system correctly. Extracting the refrigerant from the unit is possible without having much experience in heating and air conditioning work, but any knowledge can be helpful. The evacuation process takes at least two hours to complete.
First turn off the air conditioning system. Find the service valves located on the system’s pump. The valves are typically marked. The vapor line service valve is high on the air conditioning pump, and the liquid line service valve is on the lower section of the system.
Screw on the plain pressure gauge hose to the fitting on the liquid line service valve. The gauges are usually labeled. Connect the compound pressure gauge hose to the fitting on the vapor line service valve. Secure the center manifold of the gauge set to the fitting on an air conditioning vacuum pump. Inspect the manifold gauges and ensure the regulators are completely closed and the connections are tight.
Locate the regulator from the compound hose on the manifold gauge and completely open it. Turn on the vacuum pump and closely watch the compound hose’s gauge. This process will evacuate the refrigerant from the AC unit. Switch off the vacuum pump after the pressure gauge reads 0 psi. Hold the pressure for a few hours or half a day. Shut the compound hose regulator. If the pressure does not maintain, there could be a leak in the hose.
Look for the pressure rising slowly on the gauge. If the pressure is slowly increasing, then there may be moisture or refrigerant still remaining in the unit.
Remove the manifold hoses from the system’s service valves.
Tips
The refrigerant you are removing from the AC system has to be stored in a container that is approved by the Environmental Protection Agency (EPA).