• chonglibloodsport@lemmy.world
      link
      fedilink
      arrow-up
      19
      arrow-down
      1
      ·
      3 days ago

      I have a heat pump as well as a furnace (for auxiliary heating). The thermostat frustrates the hell out of me! For one thing it loses its date and time (yes it has a full calendar date and time as well as time zone) if there’s even a single second power outage. How hard would it have been to put a CR2032 battery and a diode in there just to run the clock when the power fails?

      For another thing, the thermostat itself runs extremely hot. Just putting my hand on it, it feels super warm to the touch. The LCD touchscreen on the other hand has molasses-slow response time. It’s almost impossible to set the temperature on the first try without overshooting by 2 degrees.

      Lastly, it is designed to be able to run both the heat pump and the furnace when heating load exceeds the capacity of the heat pump. The thermostat also has a sophisticated time of day temperature set point schedule system (with separate schedules for every day of the week). However, the damn thing does not correctly reconcile these two facts!

      I have the system set for cooler temperatures at night and warmer temperatures in the day. When the morning arrives and the schedule hits the higher day time set point, the thermostat suddenly sees a multiple degree deficit vs the set point and then calls for emergency furnace heating because it thinks the heat pump is failing to meet heating demand!

      This is so maddening and stupid! Why can’t I have the temperature set point just continuously and cyclically vary throughout the day and night like a sine wave? No, the dumb thing runs the heating and cooling schedule as a square wave and therefore runs the furnace every single morning in order to slam the temperature up by a few degrees to the day time set point instead of gradually ramping it up over several hours with the heat pump…

      • AA5B@lemmy.world
        link
        fedilink
        arrow-up
        2
        ·
        edit-2
        3 days ago

        Program it in increments?

        My house has a lot of thermal mass. In the morning when the temperature comes up, it tends to overshoot and make the air temperature too hot after working hard to heat all that thermal mass. However I found it much more comfortable to add an increment: half an hour at a degree colder than I want. Now it can heat all that thermal mass while overheating the air is just playing into my hands

            • chonglibloodsport@lemmy.world
              link
              fedilink
              arrow-up
              1
              ·
              3 days ago

              I think they might be computing the derivative of the temperature at time t in real time. When the schedule shifts to a higher set point the derivative goes to positive infinity and the system panics and calls for emergency maximum heat output.

              They really ought to compute the temperature set point schedule for the whole day at once and then apply a low pass filter to that.

    • XpeeN@sopuli.xyz
      link
      fedilink
      arrow-up
      7
      ·
      3 days ago

      If we’re on this subject, do you happen to know any active esp Lemmy communities?

      thanks and merry christmas

    • phughes@lemmy.ca
      link
      fedilink
      English
      arrow-up
      4
      ·
      3 days ago

      If my choices are a z-wave/zigbee thermostat that connects to my HomeAssistant instance and a Raspberry Pi that I have to maintain, I’ll pick the z-wave one (and I did, 10 years ago. It’s been rock solid.)

      For my smart devices I prefer devices that can’t send information over the internet no matter what. I don’t want to worry about my thermostat mining bitcoin for some dude in China.

    • qqq@lemmy.world
      link
      fedilink
      arrow-up
      2
      ·
      edit-2
      3 days ago

      A smart thermostat is the only “smart device” I have in my home (ecobee). I figure it actually is better than something I could design in a week so it seemed worth it. Do you know of an actually competitive open hardware/open source solution?