Upon my arrival I started by installing the pressure switch and sampling probe onto the ovens range hood vent stack. I then installed a transformer inside the furnace cabinet. I went into the ceiling and wired the make up air damper to the transformer and pressure switch. I secured any loose wiring. I then went outside and prepared the vent opening for the louvered vent cap. I installed it and made sure the louveres opened freely. I used white elastomeric caulk to seal all around the cap so no moisture can enter. Customer had a concern about the upstairs unit not cooling adequately. I let the unit operate for 10-15 minutes and put my gauges on and a temperature probe on the high side. Subcooling was only 5 degrees, design of 11. I added 8oz of r410a refrigerant to achieve 11 degrees subcooling. I tightened all valve stems on both units and installed brass caps on the true suction lines and tightened the tamper proof caps. I made sure the unit had 20+ degree delta temperatures across t