Hi all. I have a 2 storey, ~1200 sq ft home in a hot climate. I have a single HVAC unit…central air and ductwork, electric AC/heat. There is no zoning to the system. The thermostat is downstairs.

Everything is great in the winter months. But in the summer months, the upstairs is absolutely stifling. I don’t have a thermostat upstairs, but it feels like it stays at least 10 degrees hotter than downstairs. I get that hot air rises, but considering the bedrooms are upstairs, it makes things unbearable.

My HVAC air handler and condenser are from 2008, so they are rather old and I’m likely to have to replace them soon. When I do so, I want to figure out how to keep the upstairs more comfortable.

Before I start asking companies for quotes, I want to figure out what I’m doing first. Some things I’ve come across…

  1. Install something like a Nest system with a remote temperature sensor. Place the temperature sensor upstairs and have the Nest use that to figure out when to cycle the AC on instead of the downstairs thermostat. I could install something like this myself instead of needing an HVAC company, though it isn’t necessary very efficient.

  2. Consult with an HVAC company about having dampers/a zoning system installed. From what I’ve read online, it seems like people are saying this isn’t really financially worth it. But if I’m at the point where I want a new system anyway, would it make sense?

  3. Window AC units are an obvious “solution”, but I can’t have them due to the HOA.

  4. I have read of suggestions of people saying to close the vents downstairs in the summer, but it seems like this is bad advice, as supposedly it will stress your HVAC and cause it to fail prematurely.

Edit: Just found a new one…setting the fan on the thermostat to “on” instead of “auto”. Although some people seem to warn of mold growth.

Would love to hear any and all suggestions. Thanks!

    • dingus@lemmy.worldOPEnglish
      31·
      6 months ago

      Haha well true. I just presume that if you have dampers built into the system by an HVAC company that steps would be taken to ensure it doesn’t mess up your system.

      • linuxguy@lemmy.gregw.usEnglish
        2·
        6 months ago

        I’ve never seen manual dampers that smart. 🤷 Give closing up downstairs a shot and if your evaporator turns into a block of ice, well, then you let it thaw and know your need more air flow.

        • dingus@lemmy.worldOPEnglish
          2·
          6 months ago

          Haha. Well I don’t mean the dampers themselves are smart. I mean that the HVAC companies will do pressure checks make sure things are flowing and vented properly if they are adding in dampers in particular areas.

    • SchmidtGenetics@lemmy.world
      51·
      6 months ago

      If you close a register all pipes and joints between the furnace and the register will be under more pressure than designed and can force the joints to cause leaks, this can push humid air into joist spaces as well.

      Theres lots of potential issues, putting a damper as near to the source as possible prevents this issue.