R1 Fundamentals of Refrigeration R1 Fundamentals of Refrigeration - Subject 3 Recovery, Evacuation, Charging v1.1 11/20/2018 R1 Fundamentals of Refrigeration #3 Recovery, Evacuation, Charging © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Manifold Gauge Set High and Low side gauges Close valves on gauges R1 Fundamentals of Refrigeration - Subject 3 Recovery, Evacuation, Charging v1.1 11/20/2018 Manifold Gauge Set High and Low side gauges Close valves on gauges Read system pressure with valves closed © 2004 Refrigeration Training Services - R1 Subject 3 Recovery, Evacuation, Charging v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

How a Manifold Gauge Set Works Gauge Manifold Close left handle Close right handle To Low Side To High Side Low Pressure High Pressure Center port for evacuation and charging © 2004 Refrigeration Training Services - R1 Subject 3 Recovery, Evacuation, Charging v1.2

Hook up gauges to service valves Discharge service valve High pressure gauge (red) Suction service valve Low pressure gauge (blue) © 2004 Refrigeration Training Services - R1 Subject 3 Recovery, Evacuation, Charging v1.2

Installing Gauges Hook up gauges Gauge Manifold Hook up gauges Crack service valves to read system pressures Path of refrigerant CONDENSER Compressor EVAPORATOR Receiver TEV Sight Glass Filter-Drier © 2004 Refrigeration Training Services - R1 Subject 3 Recovery, Evacuation, Charging v1.2

Recovering Refrigerant Recovery machine is just a compressor Pumps vapor only Inlet is the suction side of compressor Outlet goes to recovery tank Recovery tank acts as a condenser © 2004 Refrigeration Training Services - R1 Subject 3 Recovery, Evacuation, Charging v1.2

Refrigerant now in tank Vapor Recovery Start recovery Gauge Manifold IN OUT Recovery Unit Recovery Cylinder Open valve Now open high side gauge valve Scales CONDENSER Compressor EVAPORATOR Refrigerant now in tank TEV Sight Glass Filter-Drier Receiver © 2004 Refrigeration Training Services - R1 Subject 3 Recovery, Evacuation, Charging v1.2

Recovery Completed Gauge Manifold All refrigerant is recovered when unit pulls a vacuum. IN OUT Recovery Unit Recovery Cylinder System now ready for removal, repair, etc. Scales CONDENSER Compressor EVAPORATOR Receiver TEV Sight Glass Filter-Drier © 2004 Refrigeration Training Services - R1 Subject 3 Recovery, Evacuation, Charging v1.2

“Push-Pull” Liquid Recovery Large units have a lot of refrigerant Vapor recovery takes too long Recovery unit can push liquid into tank Then pull out remaining vapor © 2004 Refrigeration Training Services - R1 Subject 3 Recovery, Evacuation, Charging v1.2

Liquid Refrigerant Recovery - "Push-Pull" Method Gauge Manifold Open high side gauge valve, IN OUT Both recovery tank valves, Recovery Cylinder And the King valve Turn on Recovery Unit, push liquid out of Condenser and Receiver, into recovery tank Scales Most of the liquid has been removed. Begin vapor removal. CONDENSER Compressor EVAPORATOR Receiver TEV Sight Glass Filter-Drier © 2004 Refrigeration Training Services - R1 Subject 3 Recovery, Evacuation, Charging v1.2

Evacuated Tank Liquid Recovery Pull a vacuum on a recovery tank Connect to receiver The tank will suck out liquid Note: a cold tank will speed the transfer © 2004 Refrigeration Training Services - R1 Subject 3 Recovery, Evacuation, Charging v1.2

Liquid Recovery: Evacuated Tank Gauge Manifold Recovery tank in a Vacuum Liquid refrigerant can be removed without a recovery machine Vacuum in tank removes most of the liquid Use recovery unit to complete vapor removal Scales CONDENSER Liquid is sucked out Compressor EVAPORATOR Open King Valve on Receiver Receiver TEV Sight Glass Filter-Drier © 2004 Refrigeration Training Services - R1 Subject 3 Recovery, Evacuation, Charging v1.2

Single Evacuation What is evacuation? Why? How long do you evacuate? Pulling a vacuum on a system Why? To remove air and moisture How long do you evacuate? To 500 microns © 2004 Refrigeration Training Services - R1 Subject 3 Recovery, Evacuation, Charging v1.2

System Ready for Charging Single Evacuation Shut off pump valve Start Pump and open valves on Gauge Manifold Gauge Manifold 500 Continue Vacuum to 500 microns Vacuum Pump Wait 5 min. to see if proper vacuum remains Turn off pump System Ready for Charging CONDENSER Compressor EVAPORATOR Receiver TEV Sight Glass Filter-Drier © 2004 Refrigeration Training Services - R1 Subject 3 Recovery, Evacuation, Charging v1.2

Multiple Evacuation For systems with lots of moisture: Pull a vacuum to 1000 microns Break vacuum with nitrogen Pull a second vacuum to 1000 microns Pull a third vacuum to 1000 microns If system holds vacuum start charging © 2004 Refrigeration Training Services - R1 Subject 3 Recovery, Evacuation, Charging v1.2

Multiple Evacuations: Step 1 Start pump and open valves on gauge Evacuate to 1000 microns Shut off valve at pump 1000 Vacuum Pump CONDENSER Compressor EVAPORATOR TEV Sight Glass Receiver Filter-Drier © 2004 Refrigeration Training Services - R1 Subject 3 Recovery, Evacuation, Charging v1.2

Multiple Evacuations : Step 1 Break vacuum to about 2 psig NITROGEN Close valve to pump, open valve to nitrogen Nitrogen removes moisture Vacuum Pump 1000 CONDENSER Compressor EVAPORATOR TEV Sight Glass Receiver Filter-Drier © 2004 Refrigeration Training Services - R1 Subject 3 Recovery, Evacuation, Charging v1.2

Multiple Evacuations: Step 2 Close valves to nitrogen tank Run compressor 5 seconds Open valve to pump Pull 2nd vacuum to 1000 microns Vacuum Pump 1000 NITROGEN NEVER start a compressor in a vacuum CONDENSER Compressor EVAPORATOR TEV Sight Glass Receiver Filter-Drier © 2004 Refrigeration Training Services - R1 Subject 3 Recovery, Evacuation, Charging v1.2

Multiple Evacuations: Step 2 Break vacuum with nitrogen Vacuum Pump 1000 NITROGEN CONDENSER Compressor EVAPORATOR TEV Sight Glass Receiver Filter-Drier © 2004 Refrigeration Training Services - R1 Subject 3 Recovery, Evacuation, Charging v1.2

Multiple Evacuations: Last Step Pull 3rd vacuum to 1000 microns Vacuum Pump 1000 NITROGEN CONDENSER Compressor EVAPORATOR System Ready for Charging TEV Sight Glass Receiver Filter-Drier © 2004 Refrigeration Training Services - R1 Subject 3 Recovery, Evacuation, Charging v1.2

Disposable Refrigerant Drums Look for direction on drum: Upright position, charge with vapor Upside down, charge with liquid Some manufacturers tried dip tubes It is confusing, most stopped © 2004 Refrigeration Training Services - R1 Subject 3 Recovery, Evacuation, Charging v1.2

Freon tanks R22 404A 404A Turn over for liquid R22 tank cut-a-way view Originally R404A tanks had dip tubes Now R404A tanks have NO dip tubes © 2004 Refrigeration Training Services - R1 Subject 3 Recovery, Evacuation, Charging v1.2

Charging the System Assumptions for the following slides: Procedure: System is clean and in a vacuum Compressor is off Procedure: Charge by liquid through high side Shut off discharge valve when pressures equalize Start compressor Finish charging through low side All blended refrigerants must be charged by liquid © 2004 Refrigeration Training Services - R1 Subject 3 Recovery, Evacuation, Charging v1.2

Charge liquid through high side Charge System Open tank valve Refrigerant tank Charge liquid through high side Compressor is OFF 404A Purge hose Use refrigerant scale Scales CONDENSER Compressor EVAPORATOR TEV Sight Glass Receiver Filter-Drier © 2004 Refrigeration Training Services - R1 Subject 3 Recovery, Evacuation, Charging v1.2

Charge System 404A Start compressor Close off high side valve Open low side valve and charge by liquid Monitor compressor amps while charging liquid Monitor head pressure Scales System now charged to “present conditions” on TEV system CONDENSER Compressor Note: Refer to manufacturer’s manual for proper charging of critically charged systems and units with flooded condensers EVAPORATOR Check sight glass TEV Sight Glass Receiver Filter-Drier © 2004 Refrigeration Training Services - R1 Subject 3 Recovery, Evacuation, Charging v1.2

Removing Gauges While the unit is running, return as much refrigerant to the system as possible: Bleed the high pressure in the hoses To the low pressure side of the unit © 2004 Refrigeration Training Services - R1 Subject 3 Recovery, Evacuation, Charging v1.2

Remove Gauges Properly Shut off tank while unit is running 404A Purge high side vapor into low side Open high side valve Now, remove gauges Scales Back seat suction valve Back seat discharge valve CONDENSER Compressor EVAPORATOR TEV Sight Glass Receiver Filter-Drier © 2004 Refrigeration Training Services - R1 Subject 3 Recovery, Evacuation, Charging v1.2

End of Recovery, Evacuation, Charging © 2004 Refrigeration Training Services - R1 Subject 3 Recovery, Evacuation, Charging v1.2