I reversed damper configuration as were instructed when we bought the house now that its getting hotter out. Unfortunately the upstairs is much hotter then the downstairs. More specifically we are having a hard time keeping the nursery cool.

Is there anything that I can try that is not too invasive? Ive already tried opening and closing the returns in each room accordingly but that has not helped.


  • The air handler is downstairs I presume. You say you have returns in each room. Do you mean supply vents? If in fact you have returns in each room that is optimal.
    – Kris
    Apr 12, 2021 at 16:33
  • How does the sun figure into this? Solar load adds 350 BTU per square foot (on axis with the sun). In heating season this is free heat and requires less from the HVAC system. In cooling season this is considerable additional load and requires more from the HVAC system. Of course it moves around throughout the day, and day vs night. Apr 12, 2021 at 20:16

2 Answers 2


Hot air naturally going up. You need to enhance air circulation. Some thermostat has circulation mode. Booster fan in air outlet. Some ceiling fans in area, where no air circulation. All problem because of design of whole system. But change it very complicated.


Assuming you have a single zone system, that cools the whole house at once. First step is an experiment. Ignore balance, see if the system has the capacity to cool the bedrooms at all if it is completely unbalanced.

Step 1: Do an experiment

  • Open the bedroom and nursery vents, close all the other vents in the house. All the downstairs ones closed.
  • Close the bedroom doors .... as long as they are not tightly sealed all around. There should be a crack below the door. If they are tightly sealed, open them a crack but not more.
  • If the thermostat is not in one of the bedrooms set it to its lowest setting.
  • Wait at least a few hours

Now pay attention to the bedrooms for a whole day. Are they cool when you want them to be, especially at night? If you use them during the day are they cool then?

  • Yes they are now comfortable: You have a balancing problem. Go to step 2.
  • No they are not comfortable: Your system cannot cool your upstairs enough even if that is (almost) all it's doing.

Step 2: Balance

If in step 1 you found that the bedrooms CAN be cooled effectively, now you have to balance the whole house. That means carefully tuning the downstairs vents and thermostat until you find the balance.

  • Open all the downstairs vents just a little. Wait a few more hours, then pay attention for another day. Keep doing this until you are happy.
  • Depending on where the thermostat is, you might need it to be at a compromise temperature. For example if it is downstairs somewhere try setting it 5 degrees lower than what you want before you start to slowly open the downstairs vents. And make sure the thermostat is not in a room with a closed door.
  • Some pictures of the upstairs room with the cooling problem would help
    – d.george
    Apr 13, 2021 at 10:54

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