Unit had been left off so there was no ice on the coil. I found the filter and evaporator coil were clean as well as the condenser coil. Unit has a txv metering device and was operating with 1-2 degrees subcooling and high superheat. I ended up adding 1lb 8oz of r410a refrigerant to achieve 10-12 degrees subcooling, 8 degrees superheat and 20+ degrees delta temperatures across the evaporator coil. Unit operating normal.