Possible moisture in system

[tonyk]

Hi guys have Trane close control unit in a server room with 2 circuits. Circuit 2 has poor of coil temp and low suction pressure, traced to the filter drier beginning to block up as temperature is lower on outlet side. Also both circuits sight glasses are just beginning to show wet. Plan is to reclaim both circuits, too also confirm issue is not low refrigerant charge then cut out driers and braze new ones in. Question is should the refrigerant also be replaced or reuse existing and see if sight glass shows dry. Refrigerant is r407c and given the high cost trying to save the client some money.

[Goober]

Driers should clean up refrigerant and dry out. But you have to ask where has moisture come from? Also R407C is a blend, so balance of mixture could be out. So in hind sight may be best to replace refrigerant.

[tonyk]

Thanks Goober, we've just taken the maintenance over on this unit so we don't know it's history, if a circuit comes up short when reclaimed then yes we'll replace refrigerant with new, Just wanted others thoughts.

[hyperion]

You could use a further drier inline when recharging the reclaimed gas, as this would help to remove any potential moisture before relying on the circuit driers.

[tonyk]

Yes Hyperion, will probably run it through a drier when reclaiming as well.

[chemi-cool]

You should also replace your moisture indicator. They don't last forever and many times, if there was a lot of moisture, they stay yellow.

[Glenn Moore]

If you can, drain and replace the oil charge as if you have moisture in the system then the oil will also be contaminated with moisture which will compromise it’s lubricating ability and compromise the system vaccing process

[tonyk]

Thanks for the advice guys much appreciated