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frank14
15-08-2009, 04:26 AM
I will be going to repair a unit ( cracked discharge piping due to broken compressor mount ) I have been told that the ambient airflow to the condenser is somewhat restricted and that because of an I beam about 2.5m in font of the condenser the air leaving the coil shortcyles back onto itself.

After the repairs to mounting and pipe, leak check, drier core change and vacuum. I need to charge the unit. If I charge to a subcooling of between 4 & 7 deg C, I am expecting that I will have slightly higher than normal HP and a still flashing sightglass.

Any help or thoughts on the matter will be appreciated.

frank14

Gary
15-08-2009, 04:36 AM
Move the condenser. Recirculating the air will increase the operating cost and shorten the lifespan of the system.

frank14
15-08-2009, 09:47 AM
Gary

That is the first thing I suggested.

Its on a drilling rig.

1. there really is not anywhere else
2. the on board guys would battle to justfy the time and cost to move it if there was a more suitable place, but would have no problem to replace the unit every couple of years.

Looking forward to your wisdom as to charging the unit

Thanks

Frank14

Gary
15-08-2009, 10:59 AM
In that case, the system is better off with minimum subcooling. If there is enough refrigerant to feed the coil (proper superheat), then it doesn't matter if the sightglass flashes and the HP won't run quite as high. A slight undercharge is the lesser of evils.

frank14
16-08-2009, 04:13 AM
Gary

Thanks again for the wisdom

frank14

Peter_1
16-08-2009, 07:39 AM
I should monitor both (SH especially and SC) : if SH drops while filling to 7 /10 K and SC is then only 1 or 2K, then I should leave it this way.
Can't you install some sort of deflector before the beam so that the air is more guided?