Where I’m at, the temps flip-flop day to day, even hour to hour. In the morning it’s 35° outside, and by evening it’s 79°. I gave up keeping up with the temps and shut my unit off for the time being.

My question is why can’t HVAC units be programmed to say that if the outside temp reaches n° and the inside temp reaches m° cold, turn on the heat; conversely, if the outside temp rises to n° and the inside temp reaches m°, then turn on the AC?

My thermostat already knows the outside and inside temp, but I still have to manually switch it back and forth. I want a system that I can just set it and forget it all year round.

  • Cousin Mose
    14·
    3 days ago

    I do exactly what you’re wanting with a smart thermostat integrated with Home Assistant. Because my old, horrible apartment is poorly insulated I have everything automated based on indoor/outdoor temps.

      • snooggums@lemmy.worldEnglish
        132·
        3 days ago

        If the outside temp is hotter there is no need to heat and if it is cooler there is no need to cool, because the house will even out with the temp.

        It is slightly more complicated because of sunlight heating the building, but there is no need to spend energy changing the temp a few degrees when it will happen due to changes in temps outside. Like there isn’t a need to run the AC in the evening shortly before dark if it is only a couple degrees too warm inside because it will cool off on uts own pretty quickly.

        • Blue_Morpho@lemmy.world
          71·
          3 days ago

          But that’s why thermostats have a range and turn on/off cool/heat as needed?

          If you were gone for a day with everything off then it would make sense to not overshoot. But when you are home it’s not like it goes from 30-60F instantly outside. As the outside gradually changes, so does the amount of heat or cooling on the inside.

          • kikutwo@lemmy.world
            101·
            3 days ago

            Yes, this entire post is in search of a thermostat and it’s hilarious. Bizzaro.

          • tankplanker@lemmy.world
            31·
            2 days ago

            With a thermostat, smart or dumb, you set a target temperature and a time. With a dumb thermostat it waits till that time and then activates. With a smart thermostat it should learn how long it takes to heat or cool to that target temperature in certain conditions and then aims to hit the target at that point.

            So if you got up at 8am and wanted it 20c with a dumb thermostat you got to work out when it needs to go on in order to hit that as no heating system is instant on something the size of a house, with a smart thermostat with learning you do not need to do that at all, just set it for 8am.

            As no system is working in a vacuum how hot or cool it is outside, even how sunny it is, has a big impact on how quickly your system heats or cools. Being able to measure and compensate for the outside temperature means the actual start time can be adjusted for you. This can save significant amount of cash.

            As an example, lets say the outside temperature was going to be -10c 6am till 8am and you wanted it 20c by 8am. Doing it with a dumb thermostat you would either have to live with an under or overshoot on temperature. Say next day its 2C, now you need to adjust your overshoot again. With a smart thermostat I do not need to do that at all.

            Sure, you can just live with the under/overshoot, but its better for your bills and better for the environment not to.

      • Cousin Mose
        2·
        2 days ago

        For the reason I explained:

        Because my old, horrible apartment is poorly insulated I have everything automated based on indoor/outdoor temps.