Returned to add refrigerant to the system as per the request of tech support, added 1 lb of refrigerant and was able to increase my Delta t across the coil to 18.4°. I cannot add any more refrigerant as this time as the system will be overcharged and we do not want to run the risk of flooding back and damaging the compressor. We will have to monitor the operation of the system see how it is working, the house was 72° upon my arrival and in a matter of 40 minutes The house was able to get down to 71° and the system is still running and cooling.