Home Central Air Conditioner

Refrigerant

There are 2 different types of air conditioning refrigerant currently used in residential cooling systems. R-22, commonly referred to a Freon and R410A, a blend considered to be more environmentally friendly, sometimes called Puron.

R-22

R-22 also known as Freon has been used for decades as the refrigerant in central air conditioning systems. However it has been linked to Ozone depletion and has therefore been banned from being manufactured after the year 2010.

Pump Down Procedure

You will need a set of refrigeration gauges and a means of closing whatever types of service valves are on your unit. You will also need to know what order in which to close those valves and what the readings on the gauges are telling you. The pump down procedure only takes a couple of minutes.

There are two valves at the condenser, one valve for the suction line and one valve for the liquid line. Close the liquid line valve and turn the air conditioning on. The compressor pumps all the refrigerant into the condenser coils. Watch the gauges carefully and when the pressure gets to zero on the gauges quickly close the suction line valve to trap the refrigerant in the condenser. Now quickly turn the compressor off. This saves using refrigerant unnecessarily because the same refrigerant in the system can be reused for the new evaporator coil or air handler.

After the new evaporator coil or air handler is installed you need to evacuate the new part of the system. When evacuation is completed open the valves to allow the refrigerant into the new part of the system. To make sure the charge is correct use the gauges and the superheat method or subcooling to ensure the proper amount of refrigerant is in the system.

Troubleshooting

Blowing Warm Air & A-Coil Not Frozen

Low on coolant. Refrigerant doesn't require periodical charging. It is not a consumable item within an air conditioning unit, unless, there is a leak within the system. Given that it worked previously, and now it is not working, it is likely there is a leak in the system.

Blowing Warm Air & A-Coil Iced Over

The A-Coil can freeze up, building up ice and lowering efficiency. When completely frozen over it will not function. One cause if this happening is lack of circulation, due to the fan malfunctioning or insignificant fan speed, or and undersized blower. Increasing air circulation though the system can prevent the A-Coil from freezing over.

If the air conditioner is not properly charged, such as too much or little coolant (pressure) then the system may operate in an inefficient way and also cause the A-Coil to freeze up.

Turn off the unit and allow the A-Coil to thaw completely. Make sure the tray below the A-Coil is not pooling with water. It should be able to drain out a hose.