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return fan
05-10-2007, 09:51 PM
im fairly new to refrigeration, 6 years exp with comfortcooling and heating. slowly ive been working on more and more med temp refrigeration. im having difficultly with a warehouse evaporator blowing water. there are 6 evaporators in this particular building, 2 evaporators per condensing unit. access is difficult, the evaps are 18 feet up.the system with the problem, only one of the evaporators is blowing water, i checked what seemed to be the obvious, cleaned the coils, checked the condesate drain for proper drainage. system is fully charged, 30 superheat at the compressor, 5 degrees subcooling out of the receiver. when i go back i plan on taking a hard look at the txv, superheat leaving the evaporator at issue, sublcooling at the txv, even refrigerant distribution from the txv, temp drops accross the coil. none of the other 5 evaps are doing this, the other evap on the same circuit is not "raining". im asking for any other insite on what to look for before i tackle this. thanks. would my pschometric chart explain why this is happening?

yotaman16
05-10-2007, 10:05 PM
Seems strange that only one is doing it but is the drain line traped?

AirComfortMecha
05-11-2007, 08:35 AM
Make sure your getting the right amount of cfm over the coils. Check fan blades to make sure there not bent or something and also motor rpms.

icemeister
05-11-2007, 09:17 AM
Some additional info would be helpful.

What is the manufacturer, model numbers, etc.?

What are the design conditions, actual operating conditions, room temp, room RH, stored product type, etc.?

When you say "raining", is the water being blown off the evaporator coil? Are the evaps draw-through or blow-through? The blow through units tend to have more water carryover. Is this a new problem? What's the history here? Is the water problem only occurring during defrost or all the time?

hvaccop
05-12-2007, 10:09 PM
Make sure motors are going right direction and correct rotation on blades. Look at the coil internally real well to make sure evap coil is clean