Think of it this way. If there is too much subcooling that means liquid refrigerant is stacking up in the condenser. This effectively reduces the surface area that can be used to turn that hot high pressure superheated vapor coming from the compressor back into a liquid. Remember a condensers job is to remove heat from the high pressure vapor, and to a smaller extent subcool the liquid a little to assure a solid column of liquid getting to the metering device. On systems with no receiver a small portion of the condenser is needed to store the extra liquid to assure that solid column reaches the metering device. Too much subcooling would be like removing a portion of the condenser, ie reduced area for condensation.
Originally posted by casturbo
High subcool reading...why would that be bad? Seems to me if the condensor is doing the best job it can, a high subcool reading would indicate that. It could be considered a measure of condensor efficiency, right? I fully understand superheat, but this subcool has got me wondering....anyone lend some help?