Arrived to remedy a system that seems to not be cooling properly. Checked over settings on the zoning control board and found that the system was set for a 40 degree discharge air temperature limit. This would shut down the system anytime the discharge air temperature dropped below 40 degrees. Adjusted this setting as low as it can go to help ensure the system can continue to operate for a longer cooling cycle. Continued assessing the system and found that the insulation for the sensing bulb for the txv had come undone and wouldn’t allow the txv to adjust the flow of refrigerant according to the load in the house properly. Insulated the metering orifice to ensure correct operation of the system. Found that the vent pipe for combustion air was not properly sealed to the protrusion through the wall. Made the correct adjustments to allow the system to draw combustion air from outside only. Tested system operations to ensure the zones are opening and closing accordingly. Air conditioning s