What should be expected from an air conditioner with two zones, and how do we get it to work most efficiently?

Question

My home, which is a year old, has an air conditioner with two zones. We keep the temperature upstairs warmer (80) because we never go up there. In addition, we keep the bedroom doors upstairs closed-yes, there are return vents. However, it seems the thermostat tends to read the actual temperature we have set for downstairs (75-77). One of the rooms upstairs is actually the coldest room in the house, but the other bedrooms do stay warmer than the rest of the house! Is this normal, or is there something wrong? Do we need to do something to help the A/C work more efficiently? It seems counterintuitive as hot air should rise and we live in a HOT, humid climate. We also do not have one of those huge fancy foyers, which certainly cause cooling difficulties! Ultimately, we want to conserve energy-to be green and keep our bills lower. How can we get the A/C working most efficiently, and what can we set each thermostat to without damaging the house or growing mold?

Answer 1

are there return vents in the downstairs?

what would happen if you opened the bedroom doors upstairs?

Sounds like you'll really need to watch the system for a while and feel where the cold air is coming out, maybe get an HVAC person over to assess it.

Without knowing your exact layout, it's hard to imagine what could be going on. Seems like it should work unless the A/C is undersized or the zones aren't set right.